@conference {40624,
	title = {The effects of restricted suckling and prepartum nutritional level on reproductive performance of primiparous crossbred beef cows.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {307-310},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Reproductive performance was recorded in a total of 21 two-year-old  
Hereford x Friesian and Simmental x Friesian primiparous cows before and  
after restriction of calf suckling.  Cows were allocated one of two pastures  
allowances from day 112 to 212 of gestation so that the high nutrition (HN)  
group gained 0.75 kg/d, and the low nutrition (LN) group gained 0.17 kg/d  
during mid-gestation.  Suckling was suppressed for 7 days by fitting nose plates  
to 46-day-old calves in the restricted suckling (RS) group, whereas the normal  
suckling (NS) group remained as a control.  Dominant follicles in the ovaries  
occurred in all cows by day 32 <I>post partum</I> and underwent a pattern of growth  
and atresia before first ovulation.  Restricted suckling cows had a shorter  
interval from calving to conception than NS cows (76.0 {\textpm} 5 vs 94.1 {\textpm} 6 days,  
P<0.05, whereas genotype and nutritional treatment had no effect on interval to  
conception.  However, the beneficial effect of suckling restriction on days from  
calving to conception only occurred in cows fed the high herbage allowance in  
mid-gestation.  RS calves spent more time grazing during the period of  
attachment of nose plates and differences in behaviour remained over a further  
5 days after nose plates were removed (62.4 {\textpm} 7 vs 38.6 {\textpm} 7 minutes spent  
grazing; P<0.001), but were lighter at weaning (146.7 {\textpm} 3 vs 162.4 {\textpm} 3 kg;  
P<0.01).  Despite the lower calf liveweight at weaning it is concluded that  
manipulation of suckling through fitting nose plates to calves can be used to  
initiate earlier re-breeding in primiparous cows. },
	issn = {1176-5283},
	author = {De Nava Silva GT and Burnham DL and McDonald MF and Morris ST}
}
