The aim of this experiment was to distinguish between the effects of dietary roughage: concentrate ratio and rumen ammonia concentration on rumen in situ degradation in sheep. Three diets with roughage: concentrate ratios of (Eragrostiscurvula hay:maize) 75:25, 50:50 or 25:75…
The nutritive value of Exalta was compared with Midmar in a grazing trial with lambs and in a digestion trial with mature wethers. The study was conducted between 17 August and 8 October 1993. Fifteen lambs per cultivar grazed the…
The selenium (Se) status of lambs grazing kikuyu (Pennisetum clandestinum) or ryegrass (Lolium multiflorum) in the KwaZulu-Natal Midlands was determined during four trials and their growth response to Se supplementation was measured. Two methods of Se supplementation were evaluated using…
The investigation entailed four trials in which selenium (Se) was supplemented to lambs grazing kikuyu (Pennisetum clandestinum) pastures during two summer periods or Italian ryegrass (Lolium multiflorum) pastures during two winter periods. Two methods of supplementing the lambs were tested,…
The performance of two fat-tailed sheep breeds, Chaal and Zandi, and their F1 and R1 crossbred lambsfrom a lean-tailed breed, Zel, was compared. The weaned lambs from the Chaal and Zandi groups were finished over periods of 105 and 90…
Twenty sheep, ranging in body mass from 25 to 62 kg, were slaughtered to compare two methods of estimating the chemical composition of the carcass. One half of each carcass was ground in a carcass grinder equipped with a 6…
Water intake, efficiency and consumption of 30 growing individually fed Blackhead Persian, Dorper and South African Mutton Merino (Mutton Merino) ewe lambs were investigated. Average daily water intakes were 2.2, 4.6 and 5.4 litre for the Blackhead Persian, Dorper and…
Weights and individual feed intake data of 30 Dorper crossbred ewes and their single-born lambs were collected from conception to weaning. The data were used to calculate actual weaning efficiency of the individual ewe-lamb units [AEFF = lamb weaning weight/DDMI…
Nitrogen (N) retention and wool growth rate (WGR) responses to various amino acids and derivatives as well as protein sources were determined with six ruminally and six abomasally fistulated Merino wethers in two balanced cross-over design experiments. The six treatments…
Testes diameter of 110 Merino ram lambs was measured at 100, 260 and 550 days of age. At 80 days of age the LH response to exogenous GnRH was determined in these rams. During the breeding season at 18 months…
The objective was to study the partial digestion by sheep of the 500-mm regrowthof three Pennisetum selections (Bana, Greengold and Pennaris) over three seasons (autumn, spring and summer). There were no differences (p > 0.05) between selections in the quality…
Knowledge of genetic correlations among traits is essential for deriving a selectionstrategy for any breed. In this study, genetic and phenotypic correlations were estimated among weaning weight (WW), nine- (W9) and 18-month body weight (W18), clean fleece weight (CFW), mean…
The objective of this study was to investigate the use of four different mathematical functions (Wood, Inverse Polynomial, Quadratic and Cubic models) for describing the lactation curve of unimproved Awassi ewes. Data were collected from 136 ewes from the same…
The amount of allozyme variation within, and the extent of genetic differentiation between, 19 sheep breeds from Southern Africa were determined by six genetic blood systems commonly used to distinguish between animal breeds. Another eight enzyme-coding loci were analysed for…
One hundred and thirty Merino ewes were used to test the efficiency of different doses of medroxyprogesterone acetate (MAP) progestagen to synchronize oestrus outside the breeding season. Three treatments, consisting of intravaginal progestagen doses (60 mg, 40 mg, and halved…
Stocking rates of 20, 35 and 55 seven-month-old wethers/ha were used to determine the stocking rate/sheep performance relationship on kikuyu under continuous and rotational grazing, considering the stress placed on the animals by decreasing the availability of herbage with higher…
The aim of this research was to study the effect of high-maize diets and pelleting on the accumulation of lutein pigments and appearance of the subcutaneous fat in Dorper and SA Mutton Merino wethers. High and medium energy maize diets…
The essential amino acid composition of carcasses from South African Mutton Merino ram lambs fed a standard diet was investigated. Twenty lambs were randomly allocated to four pre-assigned average slaughter weights (30, 35, 40 and 45 kg live weight). The…
Mutton merino wethers (n = 16) fed either a low nitrogen (LN, with a crude protein [CP] content = 5.4%) or a medium nitrogen (MN, with CP = 10.3%) diet were subjected to two water treatments; either ad libitum or…
