Efficiency of conversion of food to wool at two nutritional levels by three merino strains

Efficiency of conversion of fodder to wool in a fine-wool (F), a medium-wool (B), and a strong-wool (S) strain of Merino was estimated by measuring individual fodder consumption and wool production of nine wethers of each strain in two periods, each of 16 weeks. In the first period lucerne chaff and wheat were fed in a 7.2/1 ratio (dry basis) at a maintenance level. In the second, lucerne chaff and wheat were fed in a 2.8/1 ratio at approximately 1.4 times maintenance level. The efficiencies of the strains in the two periods in terms of pounds of oven-dry wool produced per 100 therms of net energy consumed were: Strain Maintenance Maintenance x 1.4 F 1.76 1.52 B 2.03 1.82 S 2.19 1.90 The overall strain differences F v. B and F v. S were significant (P < 0.001) but the remaining difference was not significant. Interactions of strains and nutritional levels were not significant. Individual sheep within strains tended to remain in a similar order of efficiency from one nutritional level to the other, the within-strain correlation between levels being estimated as 0.89. The results suggest that selection of strains and to a lesser extent of individuals on the basis of efficiency will not be seriously affected by the energy level at which efficiency is measured. In a digestion experiment involving all 27 animals of the efficiency experiments, each fed at its maintenance ration, differences between strains in digestibility of organic matter and of protein were extremely small and were non-significant. It is concluded that strain differences in efficiency depend largely on differences in utilization.

Digestibility of brewers’ grains by swine

The digestion experiment was made with two young pigs. The Cr2O3 ratio technique was used. The diet consisted of 4.4 kg wet brewers' grains and 6 kg skim-milk per day per animal. The components of the latter food were presumed to be completely digestible. For the components of the brewers' grains the following average digestibility percentages were obtained: organic matter 43.3; crude protein 58.9; N-free organic matter 38.9; membrane substances 7.8; valuable N-free substances 59.7. According to different food tables the digestibility of the crude protein of brewers' grains is in ruminants 68—73 %, and the corresponding figure for N-free organic matter 59—69. Comparison of the figures presented gives evidence of the inferiority of swine in making use of brewers’ grains.

Digestibility of soybean oil and rape oil by swine

The digestion experiment was made with two pigs. The Cr2O3 ratio technique was used. The basic ration consisted of 2.6 kg skimmilk and 1.6 kg of a concentrate mixture. The animals received in alternate periods soybean oil and rape oil. The digestibility of the oils was investigated on 3 different levels: 100 g, 200 g, and 300 g per day per animal. No significant difference in the digestibility of the two oils could be detected. The digestibility percentage was about 100. Increasing the oil allowances resulted in a slight decrease in the digestibility. The digestibility of rape oil appeared to be very slightly inferior to that of soybean oil.