In mild climatic regions, open camp systems (dry lots) may be used for dairy cattle. These have a lower capital investment cost than intensive housing systems although the management of open camps is more difficult. The effect of (a) an…
Data consisting of records from 3 040 animals, born of 59 sires and 597 dams, were collected from 1978 to 1991 and analysed to estimate variance components for birth weight, weaning weight, average daily gain (ADG) and Kleiber ratio. Birth…
Data collected on the Carnarvon Merino flock over the period 1962 to 1983 were used for this study. Variance components resulting from direct additive genetic effects, maternal additive genetic effects, maternal permanent environmental effects, as well as the relationship between…
Average growth and body weight data, which comprised 745 400 weaning records and 14 990 Phase C growth records of young bulls of 16 breeds were obtained from the National Beef Cattle Performance and Progeny Testing Scheme and used in…
Ruminant animals acquire their amino acids from the small intestinal digestion of ruminally derived microbial protein and dietary protein which has escaped ruminal degradation. The UK metabolizable protein system provides a framework with which the net absorption of amino acids…
A straw (0.25 ml French) semen freezing method for ram spermato¬zoa using a temperature controlled stainless steel plate is described to possibly replace the conventional static liquid nitrogen vapour freezing method.
In an attempt to quantify the requirement for supplementary phosphorus (P) of grazing beef cattle at Armoedsvlakte (which is notorious for its P deficient pastures), 66 cows received supplementary P per fistulam from 1984 to 1989. Supplementation was provided according…
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 effects of feeding diets containing different levels of raw cowpea on the histomorphometry of the small intestine and faecal composition were investigated in weaned piglets. A total of 100 21-day-old weaners were divided into five equal groups and were…
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…
The usefulness of acid detergent insoluble nitrogen (ADIN) to predict digestibility of rumen undegradable protein (UDP-D) of heat processed and unprocessed plant proteins was investigated. A series of drum roasted protein sources, sunflower, cottonseed and soybean oilcake meals, in addition…
During the period 1984-1993 just over 1600 samples of agricultural commodities, comprising maize, compound animal feeds, oil seeds, soyabean, fishmeal and forage were examined for fungi and over 20 mycotoxins using a multi-screen augmented with individual assay. Aflatoxin had the…
Different protein-energy ratios in feedlot diets may effect several combinations of amounts of amino acids and glucose available for absorption in the small intestine. In this regard, the effect of protein concentration and degradation, and energy content of the diet…
Multivariate prediction models were developed from the results of three divergent trials with multicannulated steers. Diets differed in composition and physical structure. Energy contents varied from 10 to 13 MJ ME/kg DM, starch from 20 to 62%, CP from 102…
Weaning weight records of 24 758 Bonsmara calves produced by 503 sires in 30 herds, from 1980 to 1993, were used to examine the importance of the inclusion of herd-year-season by sire interaction in the estimation of genetic parameters. Three…
Blood samples were withdrawn once weekly from the jugular vein of 10 karakul lambs (ca. 17 kg) for 12 weeks. The lambs were randomly allocated to a treatment and fed either a high-fibre (HF, n = 5) or low-fibre (LF,…
