Weaning Percentage Research Articles

Calf production of Droughtmaster cows grazing a Townsville stylo-spear grass pasture

An experiment was conducted to measure the calf production over four annual calvings of 96 Droughtmaster cows grazing a Townsville stylo-spear grass pasture. There were two replicates of twelve treatments, which were factorial combinations of superphosphate (three levels), stocking rate (two levels) and conservation of hay (two levels). The three rates of application of superphosphate were nil = F0, 126 kg/ha/yr = F1, and 377 kg/ha/yr = F3. Superphosphate had no significant effect on calf birth weights but significantly increased the weaning weight of the calves in three of the four years. The mean annual weaning weights at l80 days of age were F3 = 202.5, F1 = 197.9 and F0. = 180.2 kg. Superphosphate was only the treatment which significantly (P<0.01) increased the mean annual weaning percentage (F3 = 82, F1 = 73, and F0 = 64 per cent), and the mean annual calf liveweight weaned per cow mated (F3 = 165, F1, = 144, and F0 = 116 kg). The stocking rate treatment had a significant effect on calf birthweights and weaning weights in two out of four years. Averaged over four years the respective weights were 30.0 kg and 199.3 kg for the low stocking rate and 28.6 and 187.5 kg for the high stocking rate. The fodder conservation treatment had its greatest effect on calf birthweights and weaning weights during the 1965-66 drought. The respective liveweights were 29.3 kg and 194.1 kg for conserved paddocks and 26.2 and 184.9 kg for unconserved paddocks.

Survey observations on the reproductive performance of both romney stud and commercial flocks throughout new zealand

Abstract The results of a survey conducted during 1962–67, which examined the reproductive performance of commercial pure-bred Romney flocks in five geographical areas throughout New Zealand, are given. Within each area, flocks were grouped into one of four property-type classifications: unimproved hill, improved hill, rolling, hill, and intensive flat land. Overall, the reproductive performance of approximately 1 1/2 million ewes was examined. Significant between-area differences were demonstrated in the age structure of flocks, the time and duration of mating, and the percentages of barren ewes, ewes lambing, and ewes which lost all their lambs. Significant linear increases in lamb tailing and weaning percentages were shown from north to south. There were highly significant interactions between areas and property types in the time of mating and the percentages of lambs tailed and weaned. Significant between-year differences were demonstrated in the age structure and mean size of flocks and in lamb tailing and weaning percentages, which increased linearly from 1962–65 inclusive.

Effect of prolonged undernutrition on the recovery and reproductive performance of maiden Merino ewes

Data are presented on the recovery and reproductive performance of 2 1/2-year-old maiden Merino ewes after a prolonged period of undernutrition. The 217 sheep had been hand-fed on a submaintenance ration in pen feeding trials at Glenfield, New South Wales. During the seven months of the trials they had lost 6 kg (28 to 22 kg) body weight. They were transported to Condobolin in south-western New South Wales, divided into two treatment groups and run on good quality pastures. One group was joined immediately (May 1959) and again ten months later, and the other group was mated after six months at Condobolin (in October 1959) and again 12 months later. The ewes recovered rapidly. The mean weight of both groups had reached 30 kg within six weeks and 40 kg within six months. In the first year 73 of the 100 May-mated ewes bore lambs, but only 38 of these lambs were weaned. Ewes bearing lambs had a higher body weight at the start of joining and gained more during joining than the barren ewes. At the other three joinings (October 1959, May 1960, October 1960) lambing percentage was from 86-89 and weaning percentage from 62-69-both normal for the district. The proportion of twin lambs (3-6 per cent) was low. Wool weight in 1959 was not affected by time of mating or by pregnancy.