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Sugarbeet pulp, citrus pulp, sugarbeet molasses and minerals and vitamins were mixed with different amounts of groundnut expeller, potato protein, peas or dried brewers' grains to give 6 concentrates with protein solubility from 7 to 51%. The concentrates (600 g daily) were given with rye grass (300 g daily) to 2 mature Texel wethers with an infusion tube into the abomasum and cannulae in the cranial duodenum and terminal ileum. Degradation of dietary protein in the rumen and synthesis of microbial protein were estimated from diaminopimelic acid and amino acid profiles. The extent of protein degradation in the rumen was almost independent of dietary protein content but varied with the nature of the diet. Degradability decreased in the order, groundnut expeller and peas, brewers' grains, potato protein. (Abstract retrieved from CAB Abstracts by CABI’s permission)

We measured the effect of duration of feed quality restriction and the consequent compensatory growth on body dimensions in 18 crossbred Swifter (Texel sire x Flemish dam) male lambs born in March 1994 and weaned at approximately 2 mo of age. The lambs were fed grass straw (46 g CP/kg DM) for ad libitum consumption and 35 g CP x kg(-75) x d(-1) mixed concentrates (173 g/kg DM). At approximately 3.5 mo of age and average live weight of approximately 34 kg, the lambs were allotted to six blocks, each block with three lambs of approximately the same live weight. Within each block, the three lambs were then randomly assigned to two restricted treatments (R1 and R2) and a control (C) treatment. In treatments R1 and R2, feed quality was restricted by withholding concentrates for 3 and 4.5 mo, respectively. A growth model was developed to study the effects of restriction and subsequent compensation after realimentation (6.5 and 8 mo for R1 and R2 groups, respectively). During restriction, live weight and growth in body dimensions were suppressed. Bone length measures such as body length and ulna length were less affected than live weight. The response in testes girth to restriction was almost immediate. At the end of the experiment (age of about 14 mo), R1 animals fully compensated. However, the R1 animals had higher testes girth (P < .001), chest girth (P < .01), and chest depth (P < .05). Extending the duration of feed restriction did not have a significant effect on the rate of losses in live weight and body dimensions during restriction. At the end of the experiment, except for withers height and trunk length, the R2 animals did not compensate fully in live weight and other dimensions. However, the parameter estimates suggested that the R2 animals may need a relatively longer period of realimentation to reach to the same size as R1 and C animals.

Sugarbeet pulp, citrus pulp, sugarbeet molasses and minerals and vitamins were mixed with different amounts of groundnut expeller, potato protein, peas or dried brewers' grains to give 6 concentrates with protein solubility from 7 to 51%. The concentrates (600 g daily) were given with rye grass (300 g daily) to 2 Texel wethers weighing about 70 kg with a cannula in the dorsal rumen sac. With increasing degradability of protein, rumen fermentation was less stable, the diurnal variation and content of ammonia in rumen fluid were increased, the ratio of non-glucogenic to glucogenic volatile fatty acids decreased and the dilution rate of rumen fluid increased. (Abstract retrieved from CAB Abstracts by CABI’s permission)