@conference {40356,
	title = {Effects of the digestibility of hay on milk production by cows grazing on restricted pasture},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {443-446},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Two groups of 12 cows were fed and managed identically  throughout the whole lactation, except that one group was milked twice  daily, whereas the other group was milked only once daily. The cows  were aged 3 years and older, and included 6 pairs of identical twins.    Yields of milk, fat and protein were: 4320 and 2810 kg milk ; 208 and  144 kg fat; 162 and 110 kg protein for the twice and once daily groups  respectively and the differences were significant. However in three  pairs of twin cows, once daily cows produced more than 90\% of the yield  produced by their twice daily twin mates. Lactose concentrations were  significantly higher for the twice daily group, 5.05 and 4.82\% lactose.  Somatic cell counts were significantly lower for the twice daily group  throughout lactation, even though there appeared to be no difference in  the incidence of infection measured at the end of lactation. The twice  daily group lost weight and body condition during lactation, even though  they appeared to eat slightly more feed than the once daily group which  gained weight and body condition. The twice daily group had lower  plasma concentrations of glucose during early lactation than the once  daily group, but there were no differences in concentrations of  calcium, magnesium or Beta hydroxybutyrate between the groups.   The results show that although once daily milking does cause significant  decreases in yields of milk and its components, some cows were only  slightly affected. Selection of tolerant cows, plus appropriate  management such as longer lactations and high stocking rates, may offer  a useful method of increasing labour productivity and reducing costs of  production.  },
	issn = {1176-5283},
	author = {Sangsritavong S and Holmes CW}
}
