@article {3672, title = {Modelling winter feeding practices with fodder beet in growing and dry dairy cattle}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {39-44}, address = {Online}, abstract = {

The objective of this study was to use the Large Ruminant Nutrition System simulation (LRNS) model to evaluate inclusion of different proportions of fodder beet (FB) with several feed supplements to determine if these dietary combinations meet the nutrient requirements of dry cows and growing one-year-old (R1) heifers over winter. The LRNS simulations demonstrated deficiencies in Ca and P when diets contained 60 and 80\% of FB, especially for dry cows up to 21 days before calving and in R1 heifers. When FB comprised 60-80\% of the diet of R1 heifers, there was insufficient metabolisable protein to support maximum average daily gain and insufficient physically effective neutral detergent fibre (peNDF) in diets containing over 60\% FB. Diets containing more than 40\% FB had a negative rumen degraded protein balance (RDPB) and an excess non-fibre carbohydrate (NFC) concentration. Recommendations based on this modelling are for a maximum of 60\% FB in diets and forage supplements must provide sufficient crude protein (CP) as well as supplementation of Ca for R1 heifers and dry cows up to 21 days before calving and P for both dry cows and R1 heifers.

}, issn = {1176-5283}, author = {Jonker A and Dalley DE and Woods RR and Dynes RA and Pacheco D and Khan MA and Edwards JP and Hammond KJ} } @article {3672, title = {Evaluation of existing equations to rank methane yields of sheep fed a range of fresh forages}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {159-163}, address = {Online}, abstract = {The objective of the current study was to evaluate the performance of published equations to predict CH4 yield (g CH4/kg dry matter intake; DMI) in NZ sheep fed a range of fresh forages. A database with 182 NZ sheep CH4-yield treatment means was used to validate 17 published CH4-yield prediction equations. The CH4-yield predictions were evaluated using the square root of mean-square prediction error (RMSPE) and Lin{\textquoteright}s concordance correlation coefficient (CCC). The three prediction equations with the smallest error (<22\% of RMSPE) and the only ones with moderate CCC with observed CH4 yield were all based on data from animals fed forage only. These three models predicted CH4 yield based on DMI plus dietary neutral detergent fibre, and animal body weight, feed crude protein, or feed organic matter digestibility; and they performed better than the DMI only equations that are commonly used in national greenhouse gas inventory models and on-farm accounting models . Keywords: Meta-analysis; enteric methane; model validation; fodder crops}, issn = {1176-5283}, author = {Jonker A and Eug{\`e}ne M and de Klien C and Pacheco D and Vibart R} } @article {3672, title = {Impact of casein- versus whey-based lamb milk replacers on growth and health of artificially reared lambs}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {22-28}, address = {Online}, abstract = {High cost of milk proteins has driven development of cheaper whey-based milk replacer (WBMR) as an alternative to skim-milk (casein)-based milk-replacer (CBMR) for artificial-rearing of young ruminants. This study compared growth, antibiotic/anti-inflammatory use and mortality in lambs reared on either WBMR (n=138) or CBMR (n=151) in the first three weeks of rearing at commercial scale. There was a diet x rank interaction (P=0.001) whereby CBMR-fed single/twin and triplet/quad lambs had the highest average daily gain (ADG) independent of birth-rank (362 vs. 358 g/d respectively, SED=16.7) compared to WBMR-fed lambs where higher ADG was observed in triplet/quad compared to single/twin lambs (275 vs. 213 g/d respectively, SED=16.7). Males tended to have higher ADG than females (311 vs. 294, SED=9.7 g/d, P=0.064). Overall, there was a tendency for greater mortality (11\% vs. 4\%; P=0.055), and overall incidence rate (N/100 animal weeks) for use of antibiotics (4.43 vs. 1.27; P=0.073) and anti-inflammatories (4.59 vs. 1.59; P=0.099) in WBMR- than CBMR-fed lambs. These results highlight that CBMR under an ad-libitum milk-feeding regime supports greater ADG independent of birth-rank and reduces the incidence of disease in the first three weeks of life compared to WBMR. Furthermore, WBMR under an ad-libitum milk-feeding regime results in lower ADG of single/twin-born lambs compared to their triplet/quad counterparts. Keywords: lambs; artificial rearing; milk replacer; composition; growth; health; mortality}, issn = {1176-5283}, author = {McCoard SA and Ryrie J and MacDonald T and Hea S-Y and Pacheco D and Stevens D} } @article {3672, title = {Volatile fatty acids (VFA) in rumen samples collected pre-feeding had a stronger relationship with methane emissions in lambs fed graded levels of forage rape than VFAs in post-feeding samples}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {168-172}, address = {Online}, abstract = {To investigate the effect of farm system, and cow selection for milk urea nitrogen (MUN), on milk yield and milk composition, a farmlet study was carried out between October 2018 and May 2019 in Lincoln, Canterbury. A farm system with a low stocking rate and low N fertiliser input (LSR, 2.9 cows/ha) sown with a conventional ryegrass clover and plantain diverse pastures was compared with a farm system with a moderate stocking rate and moderate N fertiliser (MSR, 3.9 cows/ha) using conventional ryegrass and white clover pastures and supplementing 3 kg DM/cow/d as crushed barley grain. Each farmlet had total herd size of 40 mixed-age HF x J spring-calving dairy cows which included six cows selected solely for a high MUN or a low MUN. There was no effect of farm system on milk fat, protein or lactose content but MUN was lower in LSR compared with MSR. Milk production was also lower for LSR (466 vs 429{\textpm}12.4 kg MS/cow/ha, P<0.05), owing to poorer quality diet in mid lactation. Cows selected for low MUN tended to produce less milk compared with high MUN cows (4478 vs 3987{\textpm}174 kg/cow, P<0.10) though this was partially offset by increased protein content in milk of low MUN cows. Farm system and animal selection for MUN have a greater impact on milk yield than on milk composition. Keywords: Plantago lanceolata; somatic cell count; multi-species pastures;}, issn = {1176-5283}, author = {Della Rosa MM and Janssen PH and Reid P and Sandoval E and Luo D and Pacheco D and Jonker A} } @article {3672, title = {BRIEF COMMUNICATION: Effect of a fodder beet or lucerne-chaff-based diet on triplet-bearing ewe live weight, body condition score and lamb birth weight}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {168-170}, address = {Palmerston North}, abstract = {The objective was to determine whether a fodder-beet based diet (FB) balanced for crude protein, vitamins and minerals could support similar ewe live weight (LW), body condition score (BCS) and lamb birth weight compared to a lucerne-based diet. Triplet-bearing ewes (60-70 days gestation) were randomly allocated to a lucerne-based (65\% of dry matter [DM] n=12) or FB-based (56\% FB bulb; n=16) diet. Lambs were weighed two hours after birth. Ewe LW (P=0.970) and BCS (P=0.165) did not differ between treatments and there was no diet-by-day gestational age (dGA) interaction. A diet-by-dGA interaction was observed for DM intake (P=0.003) where FB-fed ewes consumed less than control ewes with advancing gestation. A diet-by-sex interaction was evident for lamb birth weight (P=0.026) where female lambs from FB-fed ewes were heavier than female lambs from control-fed ewes, with no difference between males. These results indicate that supplementing a FB-based diet with additional protein, fibre and minerals can maintain triplet-bearing ewe BCS and LW and improve female lamb birth weight compared to those born to control ewes.}, issn = {1176-5283}, author = {Knol FW and Erichsen C and Jonker A and Sandoval E and Pacheco D and Hea SY and McCoard SA} } @article {3672, title = {BRIEF COMMUNICATION: Milk production, feeding behaviour and rumen fermentation of dairy cows supplemented with winter brassica crops}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {125-127}, address = {Lincoln}, abstract = {This study evaluated feeding behaviour, dry matter intake (DMI), rumen fermentation and milk production responses of lactating dairy cows supplemented with kale or swedes. Twelve multiparous early lactation dairy cows were randomly allocated to three dietary treatments in a replicated 3 x 3 Latin square. The control diet comprised 10 kg dry matter (DM) of grass silage, 4 kg DM of grass pasture and 8.8 kg DM of concentrate; 25\% of the diet was replaced with kale or swedes. Cows supplemented with kale showed a lower DMI compared to cows supplemented with swedes and the control diet; whereas swedes supplementation increased eating time. Milk production responses were not affected by winter brassica supplementation. This resulted in a greater feed conversion efficiency of cows supplemented with kale compared to that of the control diet.}, issn = {1176-5283}, author = {Keim JP and Rodriguez JR and Balocchi O and Pulido R and Pacheco D and Muetzel S} } @article {3672, title = {BRIEF COMMUNICATION: Milk production responses and rumen fermentation of dairy cows supplemented with summer brassica crops}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {122-124}, address = {Lincoln}, abstract = {This study evaluated the dry matter intake (DMI), rumen fermentation and milk production responses of lactating dairy cows supplemented summer brassicas. Twelve multiparous lactating dairy cows were randomly allocated to three dietary treatments in a replicated 3 x 3 Latin square design. The control diet was composed of 16.2 kg DM of grass silage and 4.5 kg DM of concentrate; 25\% of the diet was replaced by rape or turnip. Cows supplemented with summer brassicas showed a lower DMI (P<0.001) compared to the control diet, however milk yield was not affected, resulting in a greater feed conversion efficiency (1.35 for turnip and rape v/s 1.27 for the control diet). Rape supplementation significantly increased microbial protein (P=0.002). VFA concentration and the relative proportion of propionate were increased with turnips, whereas rape increased the acetate:propionate ratio. Mid-lactating dairy cows fed with brassicas are able to maintain production despite the reduced intake, probably due to improved rumen fermentation and therefore nutrient utilisation.}, issn = {1176-5283}, author = {Keim JP and Castillo M and Balocchi O and Pulido R and Pacheco D and Muetzel S} } @conference {3672, title = {BRIEF COMMUNICATION: Feeding fodder beet to ewes in mid-to-late gestation: impact on lamb size, rectal temperature, and live weights from birth to weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {34-36}, address = {Rotorua}, abstract = {New Zealand ruminant livestock production is largely pasture-based and aligned to seasonal pasture supply. Despite pasture providing a complete diet for grazing pregnant ewes when fed in sufficient quantities, there is a growing trend for farmers to use supplementary feeds to maintain production in times of feed shortages such as during winter, or to facilitate increased stocking rates (McCoard et al. 2015). Due to its high dry matter (DM) yield, and low cost per unit of feed, compared to other supplementary feeds (Gibbs et al. 2015), fodder beet (FB: Beta vulgaris) is a winter feed option. Fodder beet is characterised by its high sugar (energy rich) and low nitrogen (N) contents and although live weight (LWT) responses in finishing beef cattle fed FB have been measured (Gibbs et al. 2015), there is less knowledge on the nutrient-supply profile and performance of offspring when fed to pregnant animals. Knowledge of potential nutritional deficiencies, and the implications for the pregnant ewe and her offspring are essential in order to develop feeding recommendations for farmers. The objective of this study was to determine the effects of feeding FB vs. ryegrass dominant pasture (RG), to ewes in mid-to-late gestation, on offspring performance through the measurement of lamb size, rectal temperature and pre-weaning growth.}, issn = {1176-5283}, author = {Sandoval E and McCoard SA and Pacheco D and Lloyd-West C and Lees S and Hammond KJ} } @conference {3672, title = {BRIEF COMMUNICATION: Plasma amino acid profiles of lactating dairy cows fed fodder beet and ryegrass diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {62-64}, address = {Adelaide}, abstract = {In pastoral systems, N intake by dairy cows generally exceeds requirements (Kolver 2000). Feeds with low N concentration can {\textquoteleft}dilute{\textquoteright} the amount of N eaten by grazing dairy cattle, and ultimately reduce N pollution of the environment. Use of fodder beet (FB) crop has increased substantially in New Zealand because of its high DM yield potential. Fodder beet also has low N content in the bulb of the plant (0.8 to 1.5\% of DM; Heuz{\'e} et al. 2015) which is useful for diluting dietary N content. However, these low N concentrations could result in deficiencies of specific amino acids (AA), potentially limiting milk production. This paper reports the effect on plasma AA concentrations of partial replacement of ryegrass pasture with FB in the diet of lactating dairy cows. This information will provide insights on how low-N diets could impact nutrient supply to dairy cattle.}, issn = {1176-5283}, author = {Pacheco D and Waghorn G and Dalley DE} } @conference {3672, title = {BRIEF COMMUNICATION: Substitution of perennial ryegrass with forage rape reduces methane emissions from sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {64-66}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Sun XZ and Sandoval E and Pacheco D} } @conference {3672, title = {Presidential Address 2014: The role of the New Zealand Society of Animal Production in the era of digital networks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {1-2}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Pacheco D} } @conference {89254, title = {In vitro ruminal fermentation and methane production from maize silage mixed with high or low quality ryegrass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {202-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Methane is the main greenhouse-gas produced by New Zealand agriculture (Ministry for the Environment 2011). The methane loss from ruminants generally ranges from 4.5\% to 9\% of gross energy intake (Hammond et al. 2009). This indicates there is scope for lowering methane production. Replacing pasture forage with maize silage could decrease methane emission by altering fermentation patterns and by reducing rumen pH or ruminal retention time with the addition of starch to the diet (Beauchemin et al. 2008). However, Waugh et al. (2005) found that methane yield (g/kg DM intake) increased when pasture forage was substituted with up to 35\% maize silage in dairy cows fed at similar intakes. Other literature suggests that methane yield in cattle responds in a quadratic manner when pasture forage is substituted with maize silage or grain (Blaxter \& Wainman 1964; Arndt et al. 2010; Hassanat et al. 2012). This effect is associated with pasture forage quality (Kirkpatrick et al. 1997).

}, issn = {1176-5283}, author = {Jonker A and Pacheco D} } @conference {78995, title = {In vitro fermentation of [15N-] ryegrass and ruminal digesta of sheep grazing a ryegrass-based pasture in the morning or in the afternoon}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {100-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Sheep in many areas of Australia and New Zealand experience periods of variable feed supply. Merino sheep can be bred to be more resilient to this varying feed supply. Resilient sheep lose less live weight when grazing poor quality pasture. However, we do not know if breeding for live weight change genetically affects reproduction. To estimate genetic correlations between live weight change and reproduction we used information from 6,870 fully pedigreed Merino ewes aged two- to four-years-old. Liveweight change was measured during joining (42 days) on low quality pasture and during lactation (130 days) on high quality pasture. Reproduction traits were total weight of lambs born and weaned and binary traits of whether or not a ewe gave birth to, or weaned, a lamb. Genetic correlations between live weight change and reproduction within age were estimated. There were moderate to high genetic correlations between live weight loss during joining and the chance of having and weaning a lamb. All other correlations were low. Therefore, change in live weight during joining affects the chance of having a lamb but not the weight of those lambs.

}, issn = {1176-5283}, author = {Vibart RE and Tavendale MH and Burke JL and Pacheco D} } @conference {78977, title = {Milk somatic cells are not suitable biomarkers of lactating ruminant mammary gland function}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {3-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Understanding the molecular regulation of milk production by the ruminant mammary gland may help farmers meet increasing production milestones. Investigating these mechanisms currently relies upon invasive sampling by post-mortem or biopsy. The objective of this study was to determine if milk somatic cells, shed by the gland during milking, could be used as a non-invasive source of cells to measure these mechanisms. To answer this we employed two widely used molecular techniques, biochemical indices and quantitative polymerase chain reaction (qPCR). Experiment 1: Biochemical indices as measures of cell size, protein production capacity and efficiency were determined in milk somatic cells and mammary tissue harvested from six lactating dairy goats. Results showed protein production capacity (P = 0.03) and cell size (P = 0.03) were higher in mammary tissue compared to somatic cells while protein production efficiency was unaffected (P = 0.55). Experiment 2: Milk protein and ribosomal RNA gene expression were measured using qPCR in milk somatic cells and mammary tissue collected from three lactating dairy cows treated with growth hormone and four treated with saline. Results showed expression of all genes differed between milk somatic cells and mammary tissue. Taken together, these results indicate milk somatic cells are not suitable for measuring biochemical indices or gene expression in the lactating ruminant mammary gland.

}, issn = {1176-5283}, author = {Sciascia Q and Pacheco D and Senna Salerno M and Blair HT and McCoard SA} } @conference {78987, title = {The relationship between milk synthesis and intracellular profiles of amino acids in the bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

There is a growing body of evidence that amino acid (AA) signalling in the mammary gland may play a key role in milk production of ruminants through modulation of translational regulation (Moshel et al. 2006; Toerien \& Cant 2007). It has been postulated that the effect of nutrient signalling on elements of translational control of milk protein synthesis may contribute to the variable responses of milk protein yield observed following nutritional perturbations (Hanigan et al. 1998). Consistent with this hypothesis, we have reported that changes in the mean and variance of intracellular free AA (FAA) in the bovine mammary gland are associated with ... continued

}, issn = {1176-5283}, author = {McCoard SA and Pacheco D and Treloar BP and Wards N and Swanson K and Singh K} } @conference {79023, title = {Relationship between profiles of free amino acids in fetal and maternal plasma with those in skeletal muscle, in twin and single fetuses from ad-libitum fed ewes in late gestation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {213-215}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Skeletal muscle growth depends on amino acid (AA) availability, not only as building components, but also as regulatory signals for protein accretion (Wu 2009). However, their signalling role for muscle growth in ruminants is poorly understood. We have previously reported that lower muscle weight in twin compared to single fetuses in late gestation, is associated with changes in the profile of specific intracellular muscle free AA (FAA), when ewes are fed a maintenance plane of nutrition during gestation (Pacheco et al. 2010a). This suggests that some AA may regulate muscle growth during fetal life.}, issn = {1176-5283}, author = {Sales FA and Treloar BP and Pacheco D and Blair HT and Kenyon PR and Nicholas G and Senna Salerno M} } @conference {78997, title = {Rumen fermentation characteristics are influenced by feeding frequency in sheep fed forage chicory and perennial ryegrass at two feeding levels}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {111-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of this study was to investigate the effects of feeding frequency and level of intake on rumen fermentation parameters of sheep fed chicory or perennial ryegrass. Fresh, vegetative chicory or perennial ryegrass were fed twice daily at 0900 h and 1630 h in the first period, and hourly in the second period to eight rumen-fistulated wethers at 1.3 and 2.2 times their maintenance metabolisable energy requirements. Rumen fluid pH, ammonia and volatile fatty acid (VFA) concentrations at 0900, 1000, 1100, 1200, 1300 and 1500 h were determined. When fed hourly (P < 0.05), but not twice-daily, forage type and feeding level significantly affected rumen pH. Differences in total VFA concentrations between forages and feeding levels were influenced by feeding frequency. Ammonia concentrations were always lower in sheep fed chicory than ryegrass (P = 0.001). Differences in rumen pH, ammonia and total VFA concentrations attributed to either forage species, level of intake or their interactions and were more likely to be detected when sheep were fed hourly, compared to twice-daily, as a result of the reduction in diurnal variation of these parameters. Manipulation of feeding frequency and/or feed intake can modulate the responses of ruminal metabolism to fresh forage diets.}, issn = {1176-5283}, author = {Sun XZ and Pacheco D and Hoskin SO and Luo DW} } @conference {75910, title = {The apparent digestibility of palm kernel expeller (PKE) consumed by pasture-fed sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {223-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {

Palm kernel expeller (PKE) usage in New Zealand has increased despite little being known about its nutritional role as a supplement in pasture based diets. The chemical composition of PKE is often reported in New Zealand, but the digestibility is not. A digestibility study was conducted with twenty four lambs fed one of four different amounts (0, 15, 30 or 45\%) of their dry matter (DM) intake as PKE, plus molasses pellets (PKEM; 90\% PKE and 10\% molasses) with the remainder of the diet being fresh pasture. Sheep were fed at either maintenance or ad libitum during two experimental periods, that differed in pasture quality. Digestibilities were extrapolated linearly to estimate digestible energy concentration and the apparent digestibility of DM, crude protein, neutral detergent fibre and gross energy at any intakes for a diet consisting of 100\% PKEM. Overall, the estimated apparent digestibility of DM, crude protein, neutral detergent fibre and gross energy for PKEM at intakes of 670 and 1,214 gDM/lamb/day were 63.0, 52.0, 67.0 and 64.0\%, respectively. The values estimated for digestible energy concentration (MJ/kgDM) of PKEM ranged between 12.4-12.7, from which values for metabolisable energy concentration of 10.2 and 10.5 MJME/kgDM could be calculated.

}, issn = {1176-5283}, author = {Burke JL and Dias FN and Pacheco D and Lopez-Villalobos N and Holmes CW} } @conference {75912, title = {Ruminal fermentation characteristics from sheep offered a fresh grazing allocation of a ryegrass-based pasture either in the morning or in the afternoon}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {234-239}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Eight rumen-fistulated wethers were used to examine the effects of PM (16:00 h) versus AM (08:00 h) allocation of spring herbage from pasture on aspects of ruminal metabolism that lead to increased utilisation of nutrients. The experimental period consisted of two phases; adaptation to diets and intensive sampling. During the adaptation phase, total volatile fatty acids (VFA) and ammonia concentrations were greater for the PM group, whereas the ratio of non-glucogenic to glucogenic VFA did not differ. These results suggest greater fermentation from forage that had similar concentrations of crude protein, neutral detergent fibre, and water soluble carbohydrates, but greater organic matter digestibility (84.1 vs. 82.3\%). During the intensive sampling phase, the mean total VFA and ammonia concentrations did not differ among groups, but the 24-hour pattern varied considerably for all variables measured. Unseasonal weather conditions during the trial were associated with smaller differences in water soluble carbohydrate accumulation than expected. Based on our results, at least four hours of sunshine were needed to obtain diurnal differences greater than 20 g per kg herbage DM. The implication of these findings on the implementation of nutritional management strategies warrants further investigation.}, issn = {1176-5283}, author = {Vibart RE and Burke JL and Pacheco D} } @conference {69473, title = {The effect of growth hormone on the intracellular amino acid profiles in mammary gland of lactating cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {67-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The dairy industry is a cornerstone of the New Zealand economy, and increasing milk production, especially milk protein, is essential to boost farmer profits and meet global demand for milk products. Increasing the milk protein output per unit of intake also has positive environmental effects, due to more nitrogen being partitioned towards product, rather than excreta (Pacheco \& Waghorn, 2008).}, issn = {1176-5283}, author = {Pacheco D and Treloar BP and McCoard SA} } @conference {69465, title = {Effect of growth hormone on the liver transcriptome profile during established lactation in the dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {33-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Milk production involves a coordinated metabolic response from multiple tissues. Administration of growth hormone (GH) to lactating cows provides an endocrine signal that redirects nutrients towards milk production. Hepatic responses to GH define the nutrient supply to peripheral organs both directly and indirectly, through processes such as gluconeogenesis and endocrine modulation. However, the mechanisms controlling these processes in the liver itself have not been completely elucidated. Our objective was to evaluate the effect of GH on gene expression in the liver of lactating dairy cows. Using a 22,690 expressed sequence tags (EST) bovine cDNA microarrays, we examined differences in liver mRNA transcript profiles between four cows treated with a slow-release formulation of GH and four control cows treated with saline solution. We identified 38 unique transcripts in liver that met the criteria of having expression changes greater than +/- 1.2 fold and false discovery rates <0.05. Of these genes affected by GH, 29 were down-regulated and nine were up-regulated. The pathways most affected by GH were carbohydrate and lipid metabolism, molecule transport and small molecule biochemistry. This preliminary study provides further insights into the molecular changes involved in the effects of GH on liver gene expression in the lactating dairy cow.}, issn = {1176-5283}, author = {Pacheco D and Nones K and Sciascia Q and McCoard SA} } @conference {69466, title = {Effect of growth hormone on the mammary transcriptome profile during established lactation in the dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Gene expression profiling studies have provided insights into the potential mechanisms involved in a range of physiological processes in the ruminant mammary gland. However, despite the well established galactopoietic effect of growth hormone (GH) in lactating ruminants (Bauman, 1999; Akers, 2006), the molecular mechanism(s) that mediate the effects of GH on milk production are not fully understood.}, issn = {1176-5283}, author = {McCoard SA and Hayashi AA and Pacheco D and Sciascia Q and Nones K and Rounce JR and Sinclair BR and McNabb WC and Roy NC} } @conference {69471, title = {The effect of growth hormone on translation initiation and elongation in liver and skeletal muscle tissue in the lactating dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {62-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Administration of bovine growth hormone (GH) has been shown to increase milk production in dairy cows by coordinating the metabolism of various organs and tissues, so that nutrients are repartitioned to the mammary gland to support increased requirements for milk synthesis (Keys et al., 1991). Some of the targets for GH are adipose tissue (Gallo et al., 1990), skeletal muscle, liver (Bush et al., 2003) and the mammary gland (Hayashi et al., 2009). In muscle GH decreases glucose uptake and increases amino acid catabolism efficiency (Vallimont et al., 2001), whilst the liver responds by increasing the rate of basal gluconeogenesis through lypolysis of adipose reserves (Gallo et al., 1990).}, issn = {1176-5283}, author = {Sciascia Q and Pacheco D and McCoard SA} } @conference {69463, title = {Effect of white clover containing high or low concentrations of water-soluble carbohydrate on metabolic indicators of protein degradationin the rumen of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {23-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {White clover has high nutritive value, but contains excess protein relative to energy, leading to the wasteful excretion of nitrogen (N) by animals. Five cycles of divergent selection has resulted in white clover lines having high (HS) or low (LS) concentrations of water-soluble carbohydrate. A grazing trial was carried out to evaluate the effect of this selection on protein utilization, using skatole and indole concentrations in the milkfat as metabolic indicators for nitrogen utilisation in the rumen. Skatole and indole arise in the rumen from the degradation of the amino acid tryptophan, and rapidly accumulate in milkfat of lactating animals fed diets rich in soluble and degradable protein. Skatole and indole concentrations were both significantly (P <0.001) lower in cows fed HS clover (356 and 84 ng/g milkfat for skatole and indole, respectively) compared to those fed the LS white clover diet (800 and 420 ng/g milkfat, respectively) suggesting protein utilisation of the HS clover was improved. Although not statistically significant in this short-term study, the trends to lower concentrations of milk urea-nitrogen and urinary-N, and the nitrogen:creatine ratio for the HS clover were in the direction expected and warrant further investigation under longer-term feeding.}, issn = {1176-5283}, author = {Higgs RJ and Cosgrove GP and Burke JL and Lane GA and Pacheco D and Fraser K and Death AF and Ford JL} } @conference {69500, title = {Effects of restricted fetal nutrition in utero on mTOR signaling in ovine skeletal muscle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {180-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {High prolificacy (twins and triplets) is a desirable trait in sheep under intensive management systems. However, multiple-born lambs have lower birth weights resulting from placental insufficiency (McCoard, 1997), and carryover detrimental effects on lean deposition, feed efficiency, and lifelong performance compared to singletons (Greenwood et al., 1998; De Blasio et al.,2007), suggesting differential nutritional programming in utero.}, issn = {1176-5283}, author = {Sciascia Q and Pacheco D and Bracegirdle J and Berry C and Kenyon PR and Blair HT and Senna Salerno M and Nicholas G and McCoard SA} } @conference {69474, title = {Evaluation of sensors for monitoring rumen pH, temperature and pressure}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {71-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Electronic intra-ruminal sensors and telemetry offer new opportunities for remote monitoring of the rumen environment. Sensors capable of measuring pH, temperature and pressure were subjected to laboratory and intra-ruminal evaluation in rumen-fistulated cows offered baleage indoors or hay with pasture outdoors. Each bolus underwent a testing sequence consisting of i) bench-top calibration against certified devices, ii) testing in the rumen to validate sensor measurement against actual measurement, and iii) monitoring the rumen environment of cows under contrasting feeding conditions for periods up to 72 hours. Bolus efficacy was evaluated from the accuracy of temperature and pressure measurements, stability of pH measurements over several days and the data capture rate being the actual number of data transmissions received as a proportion of the number expected based on transmission frequency setting. Intra-ruminal records show clear relationships of pH with diet and feeding bouts, whilst temperature records indicated drinking. Pressure changes were more difficult to interpret but may indicate satiety. These devices provide non-disruptive monitoring of rumen parameters and would be useful for studies of nutritional manipulation and rumen digestion efficiency, and for monitoring aspects of animal health.}, issn = {1176-5283}, author = {Lin X and Pacheco D and Kemp PD and Waghorn GC and Cosgrove GP} } @conference {69504, title = {Intracellular concentrations of free amino acids are reduced in skeletal muscle of late gestation twin compared to single fetuses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {199-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {A cost-effective way toincrease productivity measured as kg lamb weaned per ewe, from sheep farming is to increase lambing percentage. However, late fetal and early neonatal twin lambs have reduced body weight (McCoard et al., 2000) and ~20\% less skeletal muscle mass than singletons (McCoard et al.,2001) with carryover effects on post-natal growth performance (Afolayan et al.,2007; De Blasio et al.,2007), and thus profits. Increased knowledge of the impact of nutrition and other environmental factors on the mechanisms regulating fetal growth, in particular skeletal muscle growth, is essential in order to develop new strategies to enhance meat production performance.}, issn = {1176-5283}, author = {Pacheco D and Treloar BP and Kenyon PR and Blair HT and McCoard SA} } @conference {60974, title = {Exploring the relationships between plant chemical composition and nitrogen partitioning in lactating dairy cows fed ryegrass-based diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {188-195}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Data from experiments in which cows consumed ryegrass-based diets were used to evaluate the effects of plant constituent concentrations and nutrient ratios on the partitioning of nitrogen (N) secreted into milk and excreted as waste products (urine + faeces). The data set used from 32 publications with 170 treatment means, was derived from studies where freshly-cut or grazed pasture comprised more than 70 \% of the total diet on a dry matter basis. The objectives were to identify suitable predictors of N partitioning, both across and within studies, and to examine the relative weight these predictors have on the partitioning of dietary N. Total excretion of N (g/d) and urinary N (g/d) were best predicted by the single predictor crude protein concentration, but better relationships were obtained by adding water soluble carbohydrate (WSC) and neutral detergent fibre concentrations to the models. Although significant across studies, no single plant constituent variable was selected using the meta-analytical approach. The most reliable predictions of N in waste products and urine required measures of N intake for urinary N excretion, or in combination with total OM intake for total N excretion. }, issn = {1176-5283}, author = {Vibart RE and Koolaard J and Barrett BA and Pacheco D} } @conference {60975, title = {Urinary nitrogen excretion from cows at different stage of lactation grazing different ryegrass cultivars during spring or autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {196-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The effects of season (spring or autumn) and stage of lactation (early or late) on the partitioning of dietary nitrogen (N) between milk and urine were measured in experiments in which cows grazed forages with putative differences in the ratio of water soluble carbohydrates (WSC) to crude protein (CP). Sixty cows (n = 30 for each stage of lactation) grazed one of three forages during spring and autumn. Forage treatments consisted of a {\textquoteright}standard{\textquoteright} perennial ryegrass (STG) and two ryegrasses with high WSC concentrations: a perennial {\textquoteright}high sugar{\textquoteright} ryegrass (HSG), and an annual ryegrass (IRG). In spring, grass type had a significant effect on the estimated urinary N excretion. Both the HSG and STG resulted in greater N excretion compared to the IRG, due to the low CP concentration in this forage in one of the grazing periods. In autumn, cows grazing STG excreted less urinary N than both HSG and IRG. In both seasons, cows in early lactation secreted more N into milk but were not different in N excretion. In early lactation cows, the extra N in milk was only a small proportion of the potential N intake arising from higher CP content in autumn grasses. }, issn = {1176-5283}, author = {Pacheco D and Lowe K and Burke JL and Cosgrove GP} } @conference {41818, title = {Effect of once daily milking on milk flavour chemistry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {162-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Indole and skatole have been associated with the "pastoral" flavour of New Zealand dairy products (Bendall, 2001). They occur at elevated levels in milk from pasture-fed cows in New Zealand, particularly in early to mid spring (Lane et al., 2002). On-farm management approaches to control skatole levels in milk could provide benefits to the industry for particular products and ...Continued }, issn = {1176-5283}, author = {Lane GA and Fraser K and Yu M and Pacheco D and Dalley DE and Hofmann LA} } @conference {42058, title = {The effect of palm kernel expeller as a supplement for grazing dairy cows at the end of lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {111-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Palm kernel expeller (PKE) is a solid byproduct from the palm oil. In New Zealand it is used as a supplementary feed on dairy farms to fill short term pasture deficits and according to MAF (2007), over 350,000 tonnes of PKE was imported into New Zealand during 2007. Despite its growing use as a feedstuff for ruminants in New Zealand, information is scarce about the nutritional value of PKE and ...Continued }, issn = {1176-5283}, author = {Dias FN and Burke JL and Pacheco D and Holmes CW} } @conference {41778, title = {Indole and skatole as markers for nitrogen utilisation in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {23-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Indole and skatole are products of amino acid degradation in the rumen which could be useful to monitor protein utilisation in grazing ruminants. Two groups ("1970s" strain and "current" strain) of mixed age Holstein Friesian cows were housed indoors and fed cut pasture for 21 days. Concentrations of indole and skatole in milk fat and of milk urea nitrogen were determined. No significant differences were observed between strains of cow for indole and skatole concentration in milk fat, but they were different (P<0.01) between sampling dates. Both indole and skatole had moderate positive (r ~0.50) correlation with the rumen degradable protein (RDP) balance, whilst skatole had a weaker (r ~0.30) correlation with crude protein intake, metabolisable protein supply and RDP supply. Indole and skatole concentrations in milk fat were more closely correlated to the estimated RDP balance in the rumen than milk urea. A large proportion of individual animal variation in milk metabolites remains unaccounted for by protein intake, and may relate to individual differences in detoxification and elimination of indole and skatole. }, issn = {1176-5283}, author = {Pacheco D and Lane GA and Fraser K and MacDonald KA and Back PJ} } @conference {41983, title = {A dynamic model incorporating dietary protein for predicting liveweight gain of parasitised grazing lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {220-225}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Internal parasites are one of the major constraints toliveweight gain (LWG) in young grazing ruminants. However, even in parasite-free animals, diets low in crude protein can constrain LWG from values expected on the basis of metabolisable energy intake alone. We investigate the impact of protein supplementation in overcoming reduced growth rates of parasitised animals. This was done via a dynamic model which assumes increased maintenance requirements (immune requirements, increased cell turnover and mucous production) in parasitised animals. A key output from the model is LWG over an extended grazing period. We calibrated and validated the model using published data from an indoor feeding experiment in which trickle-infected lambs were fed for 20 weeks on three diets providing different amounts of metabolisable protein. The mean liveweight and worm burden predicted from the model compared well with experimental data. Such models will prove useful in designing supplementation strategies for grazing lambs where anthelmintic control of parasites is not a management option.}, issn = {1176-5283}, author = {Louie K and Burggraaf VT and Pacheco D} } @conference {41864, title = {Clover-rich diets and production, behaviour and nutrient use by cows in late lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {42-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The nutritional value of legumes for high milk production is seldom captured because grazed dairy pastures in NZ typically contain insufficient legume to satisfy the cows{\textquoteright} requirements. This paper reports interim results from a project investigating novel methods of forage presentation to cows, to enhance the contribution of legume to their diet. Four groups of spring-calving cows (n=5) in late-lactation were allocated to four treatments in a balanced, cross-over design. Two treatments consisted of spatial and temporal arrangements of grass and white clover allocated to cows as follows: i) continuous free access to grass and white clover growing separately as side-by-side monocultures (G/C) and ii) grass-only at {\textquoteleft}night{\textquoteleft} between the afternoon and morning milking and clover-only during the {\textquoteleft}day{\textquoteleft} between morning and afternoon milking (GnCd). These were compared against controls of iii) a typical mixed ryegrass-white clover pasture (Mix; an industry standard) and iv) a ryegrass-only pasture (Grass; a forage standard). Cows grazed each treatment for 8 days before moving to the next treatment in the pre-determined sequence. Measurements included milk production and composition, the time spent grazing during the day and the night (separately for grass and white clover in G/C) and the concentrations in the milk of skatole and indole, as metabolic indicators of nutrient acquisition and utilisation in the contrasting forage treatments. Cows offered G/C or GnCd produced 19.4 and 17.9 kg milk/cow/day, respectively, compared with 15.0 and 14.6 kg/cow/day when offered Mix or Grass, respectively (P=0.01, SEM=0.74). The diurnal distribution of grazing was influenced by pasture treatment (treatment x time interaction P <0.001). Cows on G/C grazed proportionately more at {\textquoteleft}night{\textquoteright} and cows on GnCd proportionately less at {\textquoteleft}night{\textquoteright} compared with Grass or Mix. GnCd constrained the cows to spend less time grazing clover than those offered G/C (245 vs. 408 mins grazing clover during 24 hrs) and more time grazing grass (253 vs. 105 mins in 24 hrs). The apparent {\textquoteleft}restriction{\textquoteleft} in GnCd to grazing clover-only during the day did not significantly reduce milk yield compared with G/C. The spatial and temporal allocations of grass and clover affected the concentrations of indolic compounds in PM and AM milk, suggesting there is scope to improve the efficiency of protein utilisation in the rumen. }, issn = {1176-5283}, author = {Cosgrove GP and Burke JL and Death AF and Lane GA and Fraser K and Pacheco D and Parsons AJ} } @conference {41913, title = {Increased hepatic skatole exposure via rumen infusion increases skatole concentration in peripheral circulation and inter-muscular fat in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {295-299}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Skatole meat taint is unique to pastoral systems where high forage digestibility results in tryptophanderived skatole production at rates that exceed the clearance capacity of the liver. We hypothesise that under conditions of minimal endogenous skatole production (diet low in rumen degradable protein) a continuous rumen infusion of skatole will elevate hepatic exposure and modify tissue skatole metabolism. A 72 hour rumen infusion of skatole (140 mg/h; n = 6) dissolved in propane-1,2-diol (PD) or PD media alone (n = 6) was performed. Samples of rumen fluid and blood were collected at 0, 2, 4, 6, 8, 12, 16, 24, 48 and 72 hours for determination of skatole concentration. Infusion of skatole increased (P < 0.01) levels of skatole in rumen fluid (21 {\textmu}g/g), peripheral plasma (154 ng/ml) and inter-muscular fat (4240 ng/g). A two-compartment model was fitted to the rumen and plasma skatole concentration of treated sheep to estimate the rate of transfer from rumen to peripheral plasma (k = 0.23 {\textpm} 0.03/h) and the rate of elimination from peripheral circulation (k = 2.10 {\textpm} 0.56/h). A negative correlation (P < 0.05) between the rate of elimination and level of skatole deposition in inter-muscular fat was also found. }, issn = {1176-5283}, author = {Deighton MH and Pacheco D and Tavendale MH and Schreurs NM and Peters JS and McNabb WC and Roy NC} } @conference {41898, title = {Systems biology and metabolomics : Experimental and computational challenges}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {213-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {High-throughput technologies in the era of post-genomics provide new opportunities to investigate complex biological systems. Data can be collected for a system of interest at the level of gene expression, protein expression and metabolite concentration changes and then used for the assessment of interactions of molecules. However, the vast amount of information also poses challenges for data management, analysis, and interpretation. This paper aims to outline the technical complexity and the sources of variation in the technologies involved in molecular systems biology and computational strategies for data integration. }, issn = {1176-5283}, author = {Cao M and Koulman A and Pacheco D and Lane GA and Rasmussen S} }