Effects of Partial Replacement of Conventional with Alternative Feeds on Nutrient Intake, Digestibility, Milk Yield and Composition of Awassi Ewes and Lambs

Simple Summary Alternative feeds have been used to feed animals for decades by replacing traditional feeds to increase the profit of raising livestock. In this study, alternative feeds (dried distillers grains with solubles, carob pods, olive cake, and bread by-product) were fed to Awassi ewes and ewe lambs at 0, 200, and 400 g/kg. Chemical composition was similar among diets. Feed intake, body weight change, and milk yield did not differ among diets. Cost of milk production decreased in alternative feeds containing diets, with no negative effect on health, welfare, and productivity. Two experiments were done to assess the effects of alternative feeds (AF; dried distillers grains with solubles, carob pods, olive cake, and bread by-product) on lactating performance of ewes and digestibility and nitrogen (N) retention of lambs. Diets were: no AF (CON); 200 g/kg AF (AF200); and 400 g/kg AF (AF400). In Experiment 1, 27 Awassi ewes were randomly distributed into three groups, and each was fed one of the diets described before (9 ewes/diet). Evaluation of milk composition and yield was performed at the beginning of the experiment and on days 18, 36, and 54. In Experiment 2, 18 Awassi lambs were allocated to the same diets (6 ewe lambs/diet) during a 21-day trial (14 days housed individually in shaded pens and 7 days in metabolic cages). In Experiment 1, no differences in body weight (BW) of the ewes and their lambs were detected. With the exception of neutral detergent fiber intake, which was lower in the AF-containing diets compared with CON, dry matter, crude protein, and acid detergent fiber intake were not affected by dietary treatment. Milk yield and composition was comparable among diets, and the cost of milk production was lower in AF compared to CON diet. In Experiment 2, nutrient digestibility and N retention were not affected by the diet. Results showed the possibility of including different AF in ewe and lamb diets to mitigate production cost without negatively affecting intake, milk yield, and composition, digestibility, and animal welfare and health.