South African indigenous does in rural communal farming systems kid for the first time at approximately 17 to 18 months of age. Does conceive at a relatively low body condition score (BCS ≈ 2.5 to 3) and their average litter…
This study was undertaken to investigate the growth performance of calves born to dams with different calving dates and calving intervals. Early calving dams produced calves with the lowest birth weights, the highest actual weaning weights and the highest pre-breeding…
The aim of this trial was to determine the water intake of Tswana goats and investigate the effects of short term water deprivation in summer or winter (6000 ml water offered either once every 72 h, 48 h, 24 h…
This study provides the first account of genetic relationships between three indigenous cattle breeds from Mozambique. Forty-two blood group factors and six blood proteins revealed genetic variation of 84% (Angone), (Bovine de Tete) and 90% (Landim) at the loci studied…
The aim of this survey was to characterize the economic, social and nutritional importance of goat farming in the Mgwalana district of the Eastern Cape region of South Africa, and to identify critical constraints and opportunities for use in future…
Genetic parameters were estimated for 36-, 42-, 50-, 100- and 150-day weight in the South African Mutton Merino breed. The direct heritability estimates obtained were 0.270, 0.366, 0.278, 0.185 and 0.115 respectively. The maternal heritability estimates for the respective weights…
Estimation of 300-day lactation yields of milk, fat, protein and lactose from combined morning and afternoon milk samples collected at five-weekly intervals is time-consuming, and proportional bulking of morning and evening samples is not always done correctly by farmers. This…
The productive performance of major genes for feather reduction (naked neck and frizzle) and body size reduction (dwarf) in a dual-purpose layer strain was evaluated in the subtropical coastal region of southeast Africa (Maputo, Mozambique). The experimental material consisted of…
The aim of the study was to determine the optimum protein inclusion level in diets containing an ideal amino acid balance for growing pigs. The performance of commercial crossbred grower-pigs was studied in two trials in which the experimental animals…
The aim of this experiment was to determine to what extent changes in the blood concentrations of insulin-like growth factor-1 (IGF-1), IGF binding proteins (IGFBPs), leptin and glucose are associated with compensatory growth and age at puberty in Friesian heifers…
The aim of this experiment was to determine the effect of genetic selection for milk production on nutrient partitioning at a high vs. a low plane of nutrition. Twelve Indigenous goat does and eight Saanen x Indigenous crossbred does were…
Known environmental effects influencing type trait scores in South African Jersey cattle were identified. Variance components and heritabilities were estimated for these traits as well as genetic correlations among them and with production traits. Heritability estimates were generally low to…
Data from 1 698 animals belonging to an experimental Caracu herd were analysed with the objective of calculating the population selection differentials, generation intervals, effective size and inbreeding coefficients, and to estimate the direct and correlated responses for growth traits…
From the literature, it is evident that broiler breeder pullets exhibit photorefractoriness, and while it is assumed that male broiler breeders respond in a similar manner to females, it would be beneficial to determine if that is the case. This…
The aim of this experiment was to characterize the milk yield of the Tswana goat of Botswana. Twenty-one Tswana goat does were allocated to one of three diets formulated to provide energy for maintenance and a milk yield of either…
Day-old Amberlink pullets were fed chicken starter mash for the first seven weeks of age. Group A was choice-fed with pelleted protein concentrate, whole yellow maize and limestone powder from seven to 16 weeks of age. Group B received the…
The aim of this study was to determine whether blood metabolite concentrations in free-ranging indigenous goat are sensitive to expected variations in nutrient supply, and whether they could be used to evaluate different kidding season at two locations subject to…
A total of 497 Merino ewes were allocated to one of four experimental groups for the period 1996 to 1998. The treatments were designed to provide data on the effect of shade during an autumn lambing season and the effect…
Data from purebred and crossbred cattle, consisting of the Afrikaner (A), Simmentaler (S) and Hereford (H) breeds managed in a relatively intensive but high stocking rate environment, were analysed to estimate breed direct effects, individual heterotic effects, breed maternal and…
This study was conducted to determine whether rumen dry matter and crude protein degradability in calves aged 8-10 weeks differs from that in mature cows. Five Holstein bull calves were rumen-fistulated at six weeks of age and were used in…
