@conference {69517,
	title = {Daily water intake by individual cows on a pasture diet during mid lactation},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {70},
	year = {2010},
	month = {Jun},
	pages = {257-260},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {Three small studies were undertaken in the Waikato involving daily measurements of water intake of individual mixed-age Holstein-Friesian and crossbred cows, mid lactation. In Trial 1 at Ruakura, cows were monitored whilst grazing and, in Trials 2 and 3 at DairyNZ, pasture was cut and fed to cows indoors. Mean daily water intakes by Trial were 41.3, 78.2 and 60.1 L/cow, respectively; standard deviations were 4.5, 8.3 and 7.2 L/cow, and between-cow repeatabilities averaged 0.56 {\textpm} 0.08. There were two days of rain in Trial 1; the greater of these rainfalls (26.4 mm) led to a 62\% reduction in water intake. There was no rainfall above 2 mm in Trials 2 or 3. Daily feed intakes (and feed dry-matter percentages) of cows were also available (Trials 2 and 3), and combined daily water intake (calculated from actual-water intakes plus water content of the feed consumed) averaged 104.5 and 110.6 L/cow, respectively. At an average water intake from the trough of 60 L/cow, the 25\% of cows drinking least are expected to drink ~8.4 L (14\%) less than average. This knowledge is useful when planning management practices such as supplementing water with zinc sulphate for facial eczema protection.},
	issn = {1176-5283},
	author = {Morris CA and Hickey SM and Thom ER and Waugh CD}
}
@conference {41851,
	title = {Feeding maize silage to dairy cows : implications for methane emissions},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {356-361},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Maize silage was used on 25\% of New Zealand dairy farms in 2003/2004, with 26\% of these farms feeding 2 t DM/ha as maize silage. The nutritional value and animal responses to maize silage fed with pasture are well defined, but its impact on rumen methane emissions is not. In an 11-day indoor feeding trial, 32 Friesian dairy cows in mid lactation were fed ad libitum pasture with 0, 12, 24 and 36\% of the dry matter (DM) intake supplied by maize silage. Pasture and maize silage intakes, milk production and methane emissions were measured. Half of the cows in each treatment group were given intra-ruminal slow release monensin capsules. Total DM intakes were similar for all feed treatments. As maize silage intake increased, milksolids (MS) production decreased linearly from 1.73 (pasture only) to 1.46 kg/day (P = 0.0043, SED = 0.09) and methane emissions increased from 16.3 to 19.0 g/kg DMI (P = 0.0061, SED = 1.03). Increasing proportions of maize silage in a pasture-based diet increased methane emissions from lactating dairy cows. These effects were alleviated by monensin.
KEYWORDS: dairy cows; methane emissions; milk production; perennial ryegrass; maize silage. },
	issn = {1176-5283},
	author = {Waugh CD and Clark DA and Waghorn GC and Woodward SL}
}
@conference {41228,
	title = {Effect on milk characteristics to supplementing cows on a restricted pasture allowance with different amounts of either turnips or sorghum},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {320-323},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {The effect of supplementary feeding 0, 4 or 8 kg DM/cow/d of turnips or sorghum to cows offered a restricted pasture allowance (25 kg DM/cow/d) on milk characteristics (fat, protein and lactose, N fractions, serum proteins, fatty acids (FAP) and solid fat content (SFC)) was investigated. Thirty identical twinsets were used (10 cows/treatment) in a partial cross-over designed experiment comprising two, 10-day periods. Sorghum was higher in fibre (NDF, 65\% v 23\%), total lipid (3.5\% v 1.5\%) and similar for crude protein (9.6\% v 12.0\%) than turnips. Lipid composition differed between crops; turnips had more lauric (C12:0) and less linolenic (C18:3) fatty acids than sorghum. Differences in the chemical composition of the crop were reflected in different milk compositions. Milkfat content was lower for cows fed turnips than sorghum and the effect was greater (P<0.001) with increasing amount of turnips fed (5.5\%, 5.1\% and 5.0\% for 0, 4, and 8 kg DM/cow/d respectively). Milkfat composition also differed for cows fed turnips compared to sorghum. With an increased amount of turnips fed, short, medium and long-chain fatty acids increased (P<0.001) and total unsaturated fatty acids decreased (P<0.001). As a consequence, SFC (an indication of milkfat hardness) also increased. Conjugated linoleic acid (cis-9- trans-11-C18:2) declined (P<0.001) as the level of supplementation with crop increased. The effect was greater (P<0.001) with turnips than sorghum. Compared with the fat components in milk the treatments had minimal effect on milk protein and nitrogen fractions. Feeding cows turnips compared to sorghum decreased (P<0.001) milk urea levels and increased (P<0.001) casein: whey protein ratio. This ratio declined (P<0.05) with increasing rates of supplementation with sorghum. These results show that different feed types can change milk components that influence the efficiency of milk processing, physical characteristics and nutritive value of the final dairy products. },
	issn = {1176-5283},
	author = {Thomson NA and Clark DA and Waugh CD and van der Poel WC and MacGibbon AKH}
}
@conference {41203,
	title = {Heat challenge of dairy cows in the Waikato: a comparison of spring and summer},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {226-229},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {This experiment was carried out at the Dairying Research Corporation, Hamilton, New Zealand, to evaluate the heat challenge imposed on dairy cows during spring and summer. The diurnal temperature profiles of 18 Friesian cows were recorded over five days in November and five days in January. Temperature-humidity index and black globe temperature were used to assess the potential of the environment to induce heat stress. Cows in January had higher maximum (39.5 versus 38.9 {\textpm} 0.09 {\textdegree}C), minimum (37.9 versus 37.6 {\textpm} 0.09 {\textdegree}C) and mean (38.6 versus 38.4 {\textpm} 0.05 {\textdegree}C) daily body temperatures than in November, corresponding with higher ambient temperatures and solar radiation in January. Temperature-humidity indices were highest in January between 09:30 h in the morning and 19:30 h at night and within the range reported to cause mild heat stress in dairy cows (72 to 78). Respiration rate (47 versus 37 {\textpm} 1.4 breaths/minute) and water intake (51 versus 18 {\textpm} 2.3 l/cow/day) were both higher in January than in November. },
	issn = {1176-5283},
	author = {Bluett SJ and Fisher AD and Waugh CD}
}
@conference {41135,
	title = {Milk production from perennial ryegrass pastures containing different levels of endophyte},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {258-262},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {These experiments aimed to compare milk production in spring and autumn from perennial ryegrass pastures containing either
low (L) (<10\%) or high (H) levels of endophyte infection at two pasture allowances.  In October 1997 milk yield was higher (P<0.05) from L compared with H endophyte (15.1 v 14.4 kg/cow/day), similarly for fat yield (0.95 v 0.9 kg/cow/day), and milksolids (MS) (1.53 v 1.46 kg/cow/day), but not protein yield.  In October 1998 there was no effect of endophyte level on milk, fat, protein and MS yield.  In March 1998 milk yield was higher (P<0.001) from H compared to L endophyte (8.5 v 7.4 kg/cow/day), similarly for fat yield (0.53 v 0.48 kg/cow/day), protein yield (0.35 v 0.34 kg/cow/day) and MS yield (0.89 v 0.81 kg/cow/day).  No carryover effects were recorded on milk yield or composition in any period.},
	issn = {1176-5283},
	author = {Clark DA and Thom ER and Waugh CD and Burggraaf VT}
}
@conference {41006,
	title = {Use of {\textquoteright}Barkant{\textquoteright} turnips and {\textquoteright}Superchow{\textquoteright} sorghum crops to increase summer-autumn milk production},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {58},
	year = {1998},
	month = {Jan},
	pages = {121-124},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {{\textquoteleft}Barkant{\textquoteleft} turnips and {\textquoteleft}Superchow{\textquoteleft} sorghum were compared as summer-autumn crops for lactating cows. Crops were fed at three levels (0, 4 and 8 kg DM/cow/d) to supplement pasture offered at a constant allowance. Sixty twin cows were used in two experimental periods in February and March 1997. Feeding 4 or 8 kg DM/cow/day increased milksolids (MS) yield/cow by 29\% or 36\% for turnips, and 26\% or 32\% for sorghum compared with pasture alone. Turnips gave responses of 58g and 45g MS/kg DM offered, at the lower allowance, in summer and autumn respectively, compared with 45g MS/kg DM in both seasons for sorghum. For both crops, increasing allowance from 4 to 8 kg further increased MS yield. Crop utilisation was lower on sorghum than turnips but substitution rates for turnips were higher than for sorghum at both allowances in both summer and autumn. This means that although both crops have a {\textquoteleft}pasture sparing{\textquoteleft} effect, sorghum contributed more to increased per cow intake. },
	issn = {1176-5283},
	author = {Harris SL and Clark DA and Waugh CD and Copeman PJA and Napper AR}
}
@conference {40838,
	title = {Milk production from pastures and pasture silage with different levels of endophyte infection},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {292-296},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Perennial ryegrass (Lolium perenne L.) pastures in New Zealand  contain the fungal endophyte (Acremonium lolii). This association produces  a range of toxins; some, such as lolitrem B and ergovaline have been  associated with ryegrass staggers, decreased serum prolactin, heat stress and  decreased milk yield. Grazing trials with lactating cows have given  equivocal results in terms of milksolids yield. Two experiments examined the effects on autumn milk production of  supplementing cows grazing pasture with grass and grass/clover silages  containing different endophyte concentrations on autumn milk production.  Forty cows were used in a 2 x 2 factorial experiment with low (L) and high  (H) levels of endophyte in both pasture and silage. In Experiment 1 (28  March - 6 April 1995) cows were grazing clover free pastures and  supplemented with either L or H endophyte grass silage. In Experiment 2  (7-12 April 1995) cows were grazing pastures containing about 17-25\%  white clover and supplemented with either L or H endophyte grass/clover  silage. At the first milk sampling three days after treatments started in Experiment  1, milk yield from cows given L pastures was 6.9\% higher than from those  grazing H endophyte pastures (P=0.006), and 4.1\% more when L rather than  H endophyte silages were given (P=0.10). These effects were additive so  the cows fed L endophyte silage and L endophyte pasture produced 11.3\%  more than those fed H silage and H pasture (P=0.002). The effect of pasture  endophyte on milk yield was still evident after seven and ten days of  treatment, with 10.3\% more milk from L than from H endophyte pastures  (P=0.01). Milk protein yields paralleled milk yields after seven and ten days  but there was an endophyte x silage interaction (P=0.05) for milkfat yield  and protein and fat yields were not effected by treatment. In Experiment 2  when clover was included in the diet there were no significant effects from  either pasture or silage endophyte status on any milk yield components. A  comparison of milksolids yield from Experiment 1 and Experiment 2 shows  that changing to diets containing white clover increased milksolids by 6.4,  13.9 and 21.9\% for the L/L, L/H and H/L pasture/silage combinations,  respectively, but only increased milksolids by 2.7\% for the H/H  pasture/silage combination. We conclude that endophyte in both pasture  and pasture silage can have a transitory effect on milk and protein yield  during the autumn and the nutritional benefits of white clover for increasing  milksolids was much reduced by endophyte in both pasture and silage diets. },
	issn = {1176-5283},
	author = {Clark DA and Thom ER and Waugh CD}
}
