Restricted maximum likelihood (REML) is widely regarded as the preferred procedure for estimating variance components in animal breeding problems. The size of the coefficient matrix, however, often leads to computational difficulties and many simplified algorithms, including diagonalization, have been proposed…
Ruminal degradation of crude protein from feedstuffs was determined in steers that were fed diets based on either maize (whole, meal or flakes) or on by-products of the milling industry. In addition to the in sacco degradation study, fractional outflow…
Twelve steers fistulated in the rumen and duodenum were allocated to one of three diets and fed 80 g DM/kg W0.75/d. The diets consisted of about 80% maize meal, 11% cottonseed hulls and either 1.44% urea (Treatment A), 0.96% urea…
This experiment was conducted to determine whether selection for fleece weight is accompanied by changes in the efficiency of nitrogen utilization, using Angora and Boer goats as models of animals bred for fleece or meat production respectively. A diet, containing…
Samples of 150 different cowpea cultivars, used in the breeding trials of the Summer Grain Institute at Potchefstroom, were analysed and found to have an average crude protein content of 28.4 ± 1.8% (range 24.5 to 33.9%). From these samples,…
The experiment was carried out to compare fababean with lupin crop residues for summer grazing by young Merino wethers. The crude protein (CP) and dry matter (DM) degradability as well as chemical composition of fababean and lupin seed and stalks…
The aim of the study was to examine the effects of the substitution of lucerne hay by untreated, urea-enriched and urea-ammoniated wheat straw on (i) dry matter intake (DMl), digestibility and nitrogen balance, (ii) in situ degradability, (iii) rate of…
The effect of protein supplementation of a wheat straw diet on the metabolism of lysine, leucine, methionine and urea, and on whole-body protein turnover rate was investigated in lambs. The metabolism of lysine and leucine is reported elsewhere (Cronje et…
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…
Two experiments designated A and B were conducted to evaluate the effect of supplementing napier grass with lucerne on dry matter intake (DMI) and weight gain(ADG) of Friesian and Sahiwal heifers. In experiment A which lasted 92 days, 24 heifers…
Genetic parameters and trends were estimated for 2296 lambs from a SA Mutton Merino nucleus breeding scheme using multiple trait mixed model procedures. Direct heritability estimates obtained for the traits were 0.32 for weaning weight, 0.03 for post-weaning average daily…
The effect of the halothane gene on processed pork characteristics was investigated using the meat from 59 Landrace x Large White pigs of known halothane genotype (NN = 31, Nn = 17, nn = 11). The backs and hams were…
A total of 967 animal records, of subjective trait scores, obtained between 1989 and 1990, from the control flock at the Karakul Research Station near Upington were used to evaluate 20 pelt traits in Karakul sheep, applying linear and threshold…
The essential amino acid (EAA) composition of the carcass and duodenal digesta content of South African Mutton Merino ram lambs, fed a standard total mixed diet high in rumen degradable protein (RDP), was investigated. The standard diet consisted (%) of…
The essential amino acid (EAA) composition of the whole empty body of South African Mutton Merino ram lambs fed a standard diet was investigated. The standard diet consisted (%) of 30 lucerne, 8 wheat straw, 56.25 maize meal, 3.5 molasses…
A study was undertaken to compare the effectiveness of three different selection strategies in increasing weaning weight of a Dorper flock under natural conditions. Data were analysed by mixed model procedures. Direct selection for weaning weight under natural conditions proved…
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…
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…
This study was conducted to determine the status of Salmonella during the processing of ostriches to ostrich meat and products. When a total of 1429 samples, collected from fillet, liver, gizzards, blood meal, skins, heart, faeces, large and small intestines,…
