@article {3672, title = {Comparison of two milk replacer formulations on the growth, health and purchased feed costs of artificially rearing male dairy-sheep lambs using a restricted milk intake feeding system and early weaning}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {7-13}, address = {Online}, issn = {1176-5283}, author = {McCoard SA and Birch D and Hea, S-Y and Maclean P} } @article {3672, title = {Impact of maternal diet during late gestation and pre-weaning milk allowance on heifer growth and first lactation milk yield}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {99-103}, address = {Online}, abstract = {A total of 60 Friesian x Jersey heifer calves were allocated to a 2{\texttimes}2 factorial design to investigate early life nutrition on growth and production. The first factor was the maternal treatments where dams were offered a low crude protein (7.8\% LCP) or moderate crude protein (13.6\% MCP) diet for the last 50 days of gestation. The second factor was the calf milk replacer (CMR) allowance to heifer offspring, which was either restricted (RES) or high allowance (HA) allowance (15 or 25\% of initial live weight, respectively). All calves were given colostrum for 4 days then, warmed CMR (150 g/L) in two equal feeds between days 5 and 39, after which all calves received the same 15\% allowance. Milk intake, liveweight gain and fecal score were recorded for 5 weeks. Calves were weaned off milk at 8 weeks of age. The HA treatment improved weaning weight (88 vs 79{\textpm}1.4 kg; P<0.001) and overall ADG pre-weaning (0.9 vs 0.8{\textpm}0.02 kg/day; P<0.001) compared to RES. There was no effect of maternal diet on pre-weaning growth or fecal score. There was limited statistical evidence of a long-term effect of early life nutrition on milk yield, though maternal nutrition appeared to be more important than pre-weaning nutrition on future milk production.}, issn = {1176-5283}, author = {Moonsan Y and Thomas C and McCoard SA and Hammond KJ and Edwards GR and Bryant RH} } @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 = {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: Impact of maternal plane of nutrition, ewe weight and twinning on fetal mammary gland development in sheep}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {183-185}, address = {Lincoln}, abstract = {This study evaluated the effects of maternal nutrition, weight and gestation rank on fetal mammary gland development. Light (L) and heavy (H) single- and twin-bearing ewes were fed ad libitum (A) or maintenance (M) nutritional regimens from day 21 to day 140 of gestation and euthanised for tissue collection. Plane of maternal nutrition or maternal weight did not affect histomorphometry of fetal mammary glands. Singleton fetuses had 43\% greater total duct area (P<0.05), 62\% greater secretory cell area and 32\% fewer ducts (P<0.05) but similar total lumen area, cell size and total cell number than twins. These results indicate that twinning reduces area of mammary ducts and secretory cell area while maternal weight and plane of nutrition from day 21 have little impact on mammary morphology at day 140 of gestation.}, issn = {1176-5283}, author = {McCoard SA and Adiletta AM and Jenkinson CMC and Peterson SW and Kenyon PR and Blair HT} } @article {3672, title = {Growth performance of crossbred dairy calves fed different milk allowances using an automatic feeding system}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {21-25}, address = {Lincoln}, abstract = {The impact of feeding different levels of milk replacer via automated feeders on intake and growth was assessed in calves. Heifer calves (Holstein {\texttimes} Jersey; n=198; 11{\textpm}4 days old) were randomly allocated to low-allowance (LA; n=67; calves were fed milk replacer at 10\% of initial live weight), high-allowance (HA; n=65; calves were fed milk replacer at 20\% of initial live weight), and ad-libitum (ADLIB; n=66; calves were given ad libitum access to milk replacer). Pelleted calf starter was provided ad libitum and daily individual intake of milk replacer and calf starter was measured via automated feeders. Calves were gradually weaned from 69{\textpm}2 days over 14 days. Average daily weight gain during pre-weaning was the highest (P<0.05) for ADLIB (0.69{\textpm}0.02 kg/ day), followed by HA (0.61{\textpm}0.02 kg/day) and LA (0.54{\textpm}0.02 kg/day) calves. Calf starter intake was the lowest (P<0.05) in ADLIB calves followed by HA and LA calves. The ADLIB calves had the lowest (P<0.05) calf starter intake during the week after milk weaning but it did not affect the live weight of calves. In conclusion, provision of more milk promoted pre-weaning growth, and restricted milk feeding to trigger solid feed intake failed to match that growth advantage.}, issn = {1176-5283}, author = {Groenendijk ME and Lowe K and Schreurs NM and Molenaar AJ and McCoard SA and Luo D and Khan MA} } @article {3672, title = {The impact of different management systems on behaviour and milk production of dairy ewes in different stages of lactation; a case study}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {116-121}, address = {Lincoln}, abstract = {Comparisons of New Zealand dairy sheep farm systems are currently lacking. The aim of this preliminary study was to evaluate the effects of different management systems on the behaviour and milk production of East Friesian cross-bred sheep at different stages of lactation. Two study groups were evaluated. In study group 1, a mob of 479 mixed-age, mid-lactation ewes were housed 24 h/day, and a separate mob of 473 mixed-age, mid-lactation ewes were managed in a hybrid system (housed between morning and afternoon milkings; grazed lucerne overnight). Both received a total mixed ration (TMR) indoors. In study group 2, a mob of 604 mixed-age, late-lactation ewes grazed pasture 24 h/day, and a separate mob of 452 mixed-age late-lactation ewes were in a hybrid system, grazing pasture overnight. For both study groups, individual milk yield, walking distance, lying time, live weight (LW), and body condition score (BCS) were recorded. All sheep gained BCS and LW except fully grazed late-lactation ewes. For study group 1, fully housed ewes in mid-lactation lay down less during the day, but more overnight compared to those in the hybrid system, likely due to the latter grazing overnight. Lying bout times were similar between groups, while milk yield was 29\% less in housed ewes compared to the hybrid ewes. For study group 2, grazing ewes in late-lactation lay down more, had longer lying bouts, and walked further daily than those in the hybrid system, but both late-lactation treatment groups had similar milk yields. In summary, the hybrid management system seems to improve milk yield in mid-lactation compared to the fully housed system, whereas there was no difference between the hybrid and fully grazed systems in late-lactation. Lying behaviour and walking distances (group 2 only) differed among different systems, however, it is unclear what this means in terms of animal welfare, and warrants further investigation.}, issn = {1176-5283}, author = {Bliss AE and Chylinski C and Luo D and Sch{\"u}tz KE and Lowe K and Peterson SW and Stevens D and MacDonald T and McCoard SA} } @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: The effect of arginine supplementation and milk allowance on small intestinal development in pre-weaning calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {88-90}, address = {Rotorua}, abstract = {The gastrointestinal tract is an organ system crucial in feed digestion, nutrient absorption and protection against external pathogens. In this respect, changes in the structure of the small intestine in pre-ruminant calves are particularly important because it is the primary site of digestion and absorption (Blum 2006). Understanding factors that influence intestinal development is essential to inform calf feeding practices to optimise growth performance and health. Increasing milk allowance increases calf growth, but suppresses solid feed intake before weaning and, therefore, delays rumen development (Khan et al. 2011). In comparison to the rumen, development of the small intestine has received little attention in calf nutrition (Steele et al. 2016) and the effect of increased milk intake on small intestine development in calves is largely unknown (Khan et al. 2016)....}, issn = {1176-5283}, author = {van Keulen P and Welboren AC and Kahn MA and Knol FW and Dijkstra J and McCoard SA} } @conference {3672, title = {The effects of early access to meal on the behaviour of artificially reared dairy lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {18-22}, address = {Rotorua}, abstract = {he New Zealand sheep dairy industry is growing (Peterson \& Prichard 2015). Several large commercial sheep dairy farms remove lambs from their dams within the first four days of life. In some systems, lambs have access to milk replacer (MR) ad libitum and a grain-based solid feed (Bimczok et al. 2005). Compared to young ruminants fed a milk-only diet, early access to solid feed stimulates rumen development (Baldwin et al. 2004) and earlier onset of rumination (Khan et al. 2016) to allow early weaning off MR (Bimczok et al. 2005). Earlier rumen development through access to meal may also encourage earlier grazing of pasture and greater rumination, thereby supporting early weaning. The potential to replace meal with early pasture access as the sole solid feed source to support early weaning has not been evaluated...}, issn = {1176-5283}, author = {Nieper BA and Khan MA and Ganesh S and Knol FW and Peterson SW and Stafford KJ and Stevens DR and McCoard SA} } @conference {3672, title = {How does feeding meal affect growth of artificially reared East Friesian-cross dairy lambs?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {13-17}, address = {Rotorua}, abstract = {Artificial rearing is routinely used in large-scale dairy sheep farms. One approach is to offer milk replacer (MR) and meal ad libi-tum to lambs. Our aim was to evaluate growth performance of female lambs in the first 12 weeks of rearing with (M) and without (NM) grain-based meal access (n=30/group) during four feeding periods. In period 1 (wk 0-3) lambs were offered MR and meal ad libitum, and in period 2 (wk 4-5) were transitioned outdoors onto pasture with continued access to MR and meal. Lambs were weaned off MR in period 3 (wk 6-10), and meal in period 4 (wk 10-12). The NM lambs received identical management but meal was excluded. A treatment-by-time interaction was found whereby NM lambs had lower average daily gain (ADG) (P<0.05) in periods 1 (376{\textpm}6 vs. 414{\textpm}8 g/day) and 3 (146{\textpm}7 vs. 241{\textpm}7 g/day), no difference in period 2 (P>0.05), and higher ADG in period 4 (157{\textpm}18 vs. -55{\textpm}18 g/day, P<0.05) than M lambs. There was no difference (P>0.05) in live weight by week 12, and all lambs survived. These results indicate when lambs fed MR ad libitum are offered unrestricted access to good-quality pasture before weaning, meal may not be required to achieve a similar live weight at 12 weeks.}, issn = {1176-5283}, author = {Jensen AC and Khan MA and Knol FW and Peterson SW and Morel PCH and McKenzie C and Stevens DR and McCoard SA} } @conference {3672, title = {Impact of early weaning on rumen fermentation profiles of artificially reared lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {49-54}, address = {Rotorua}, abstract = {This study investigated the impact of weaning age on rumen fermentation profiles in lambs. Mixed-sex lambs (n=32) were ran-domly allocated to one of two weaning groups: early-weaning (4wk) and control (6wk). Milk replacer (24\% CP and 25\% fat, DM basis) was offered at 20\% of initial body weight. Lambs were weaned at either four or six weeks after commencement of the trial using a three-week step-down procedure, initiated at the start of week 2 (early weaned group) or week 4 (control group). Lambs were individually penned indoors and concentrate and chopped meadow hay were offered ad libitum and individual feed intakes recorded until week six. At the end of week six, lambs were moved onto a ryegrass-based pasture and transitioned to an all pasture diet by week ten. Rumen contents were collected at slaughter, half of the lambs from each group at week four and sixteen, to de-termine rumen pH, and short chain fatty acid (SCFA) and ammonia concentrations. Ammonia concentrations were 132\% greater (P<0.05) in early weaned than control lambs at week four, but did not differ at week sixteen. Weaning age did not affect ruminal pH and SCFA total concentrations and proportions at week four or sixteen. The results suggest that ruminal fermentation can be established in lambs weaned off milk by four weeks using a step-down weaning method.}, issn = {1176-5283}, author = {Cristobal-Carballo O and Khan MA and Knol FW and Lewis SJ and Stevens D and McCoard SA} } @conference {3672, title = {BRIEF COMMUNICATION: Does Viagra protect fetal lambs against maternal pregnancy toxaemia?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {172-174}, address = {Adelaide}, abstract = {Poor fetal growth is commonly caused by placental insufficiency. In sheep, multiple fetuses have relatively small placentae with fewer cotyledons than singletons, limiting blood flow to the placenta, especially in late gestation when fetal growth rate is highest. Factors that reduce fetal growth, such as maternal genotype, nutrition, age, parity, fetal number, or environmental temperature, typically reduce placental size and are associated with lower rates of fetal oxygen and nutrient uptakes and placental blood flow (Reynolds \& Redmer 2001). Further, circumstances that influence placental vascular development have a dramatic impact on fetal growth and development, and affect neonatal survival and growth (Borowicz et al. 2007; Satterfield et al, 2010). Sildenafil citrate (SC, trade names Viagra or Avigra) increases vasodilatation of uteroplacental vessels (Wareing et al. 2005) and may represent a novel therapy to improve fetal lamb growth. Sildenafil citrate has successfully increased birth weight in rodent models and singleton bearing ewes (Satterfield et al. 2010; Miller at al. 2009). There is no published information regarding the use of SC in multiple-bearing ewes. The objective of this trial was to determine if SC administration to triplet-bearing ewes in late gestation could increase lamb birth weight. In addition, the influence of SC on the incidence of pregnancy toxaemia is also reported here.}, issn = {1176-5283}, author = {Peterson SW and Pain SJ and McCoard SA and Oliver M and Baker PN and Kenyon PR and Blair HT} } @conference {89277, title = {MRI technology to better understand placental placental function in sheep - A pilot study}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {90-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The placenta is the organ responsible for exchange of nutrients and waste products between the mother and her fetus (Bell \& Ehrhardt 2002). It is therefore the main regulator of fetal growth (Murphy et al. 2006). In sheep, placental exchange of nutrients occurs at sites called placentomes (Ford 2000). Placentomes are comprised of cotyledons on the chorioallantoic membrane which attach to discrete caruncles on the uterine wall (Ford 2000). Ovine placentomes can be classified into four types (A, B, C and D) based on their gross morphological appearance (Vatnick et al. 1991). The distribution of placentome type, and size of individual placentomes can be influenced by many factors.These include nutritional status of the dam, placental blood flow, oxygen availability and altitude (Gardner et al. 2002; Osgerby et al. 2002, 2004; Penninga \& Longo 1998).

}, issn = {1176-5283}, author = {van der Linden DS and Oliver MR and McCoard SA} } @conference {89267, title = {mTOR signalling in lactating bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {48-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The mammalian target of rapamycin (mTOR) is a protein kinase that has a well established role in the regulation of a range of cellular functions in response to hormones, growth factors and amino acids (Wang \& Proud 2011). The role of mTOR signalling in the regulation of milk protein synthesis in the mammary gland of ruminants is not well understood. Understanding this mechanism is an important step towards developing intervention strategies on farm, such as the supply of nutrients, to modulate milk protein output.

}, issn = {1176-5283}, author = {McCoard SA and Wards N and Singh K} } @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 {79022, title = {Is placentome size more important than morphologic type in relation to fetal weight in sheep?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {210-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In sheep, placental exchange of nutrients between the ewe and her fetus occurs at sites called placentomes (Ford 2000). Placentomes are comprised of cotyledons on the chorioallantoic membrane which attach to discrete caruncles on the uterine wall (Ford 2000). Ovine placentomes can be classified into four types on the basis of their gross morphological appearance (Vatnick et al. 1991). The distribution of placentome type and size of individual placentomes can be influenced by many factors such as, nutritional state, placental blood flow and oxygen availability (Gardner et al. 2002; Osgerby et al. 2004). In general, previous work has shown that adverse intrauterine conditions early in pregnancy lead to a shift to more everted placentomes (more C and D types) (Osgerby et al. 2004; Vonnahme et al. 2006).}, issn = {1176-5283}, author = {van der Linden DS and Sciascia Q and Sales F 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 {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 {69488, title = {Effect of twinning and sex on carcass weight and composition in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {133-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Lamb producers are being provided with strong incentives to gain better control over the growth performance of their animals. These incentives are driven by increased demand for lean product of consistent quality, rigid market specifications, and significant penalties when carcasses do not meet the criteria imposed by processors. Feed conversion efficiency is enhanced whenthe ratio of lean to fat deposition is improved (Sillence, 2004). This is an important consideration for producers due to rising costs of generating high quality feed. Hence, increasing the proportion ofcarcasses that meet market specifications can improve the profitability of a lamb-production enterprise.}, issn = {1176-5283}, author = {McCoard SA and Koolaard J and Charteris A and Luo D} } @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 {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 {42018, title = {Regulation of milk protein synthesis in the bovine mammary gland : A proteomic approach}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {407-412}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The molecular mechanisms that regulate milk protein synthesis in the dairy cow are not well understood. We used a proteomic approach to identify potential regulators of milk protein synthesis among the endoplasmic reticulum (ER) proteins. Mammary tissue was collected from mid-lactation dairy cows treated with atropine (Atr; decreased milk production), growthhormone (GH; increased milk production) or vehicle alone. Fractions enriched for ER associated proteins were prepared by differential centrifugation and then resolved by 2-dimensional electrophoresis (2-DE). Proteins were visualised using colloidal coomassie G-250 and the phosphor-protein specific stain, Pro-Q Diamond. We identified 4 significant (P<0.05) and 9 marginally significant (P<0.15) spots that were differentially expressed between treatment groups. Six spots were subjected to LTQ ion trap tandem mass spectrometry and 2 proteins were identified with a high level of confidence: major vault protein (MVP) (27\% of the control level after GH treatment, P<0.05), and heat shock 70Kda protein 8 (HSPA8) (41\% of the control level after Atr treatment, P <0.01). Western blotting showed a 24\% decrease in HSPA8 following Atr treatment (P<0.10) and a 55\% decrease in MVP following GH treatment (P<0.10). These results provide a focus for further investigation of the role of MVP and HSPA8 in influencing milk production.}, issn = {1176-5283}, author = {Smolenski G and Bond JJ and Wheeler TT and Roy NC and McNabb WC and McCoard SA} } @conference {40839, title = {Seasonal effects on fetal growth in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {297-300}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Previous studies have shown that autumn-born lambs are lighter (by 0.4 to 1.0 kg) at birth than spring-born lambs, an effect which is associated with impaired placental development in ewes mated to lamb in the autumn. As previous studies have focused on near-term fetal weights and birth weights, the objective of this study was to determine the pattern of growth throughout gestation in lambs destined to be born in the autumn or spring, and to examine associated changes in placental development. Mature N.Z. Romney ewes were randomly assigned to groups mated in December (n=23) or March (n=28) and managed on pasture in both seasons for similar live- weight profiles from mating to day 140 of gestation. Ewes were slaughtered at day 56, 84, 112 or 140 of gestation, and measures of fetal and placental weight were determined. Fetal weights (kg) of December- versus March- mated ewes were: d56 (0.040 }, issn = {1176-5283}, author = {McCoard SA and Peterson SW and Jenkinson CMC and Campbell JW and McCutcheon SN} }