Evaluation of Beeswax Supplementation on Productive Performance of Growing Assaf Lambs

SIMPLE SUMMARY: Beeswax is a by-product of the bee honey industry obtained from the honeycomb of the honeybee and other bees as the crystalline substance formed from honey sugars. From the harvesting of alfalfa, a large quantity of beeswax is commonly available in Egypt. This study evaluated the effects of the supplementation of beeswax on performance, nutrient digestibility, rumen fermentation, blood metabolites, and sustainability in terms of feed costs in Assaf lambs. Eighteen lambs were allotted to three experimental groups fed with a basal diet supplemented with 0, 2, and 4 g of beeswax/day for 90 days. The results revealed an increased performance in the beeswax-supplemented groups, resulting in a higher efficiency and lower feed cost and thus optimizing farming efficiency and profitability. In addition, beeswax inclusion in the feed formulation enhanced the nutrient digestibility by enhancing rumen fermentation and decreasing the ammonia emissions. In conclusion, the use of 4 g/day of beeswax supplementation in growing Assaf lambs could promote zootechnical performance, nutrient digestibility, rumen fermentation and thus lower the cost of feed formulation and support the sustainability of lamb farming. ABSTRACT: The aim of this work was to assess the effects of beeswax supplementation on growth rate, feed intake, nutrient digestion, rumen fermentation, blood parameters, and economic sustainability in Assaf lambs. Eighteen growing Assaf (5 months old) lambs were separated into three experimental groups (n = 6 lambs/group). The lambs were fed a basal diet without supplementation (G1) or supplemented with 2 and 4 g beeswax/head/day in G2 and G3 groups, respectively. Zootechnical performance was evaluated over a 90 day period. Feed digestibility was assessed in faeces through the acid insoluble-ash method, and rumen liquor was collected to measure ammonia (NH(3)-N) and total volatile fatty acid (TVFA) levels. Blood samples were obtained for the titration serum metabolites by colorimetric tests. The findings showed that G3 had an improved performance compared to the other groups (p < 0.01). The lambs in G3 revealed the highest nutrient digestibility and feed use, followed by G2, and G1. G3 recorded the highest economic efficiency followed by G2 and G1 (p < 0.01). The TVFA, acetate, and propionate concentrations were higher and the pH values, NH(3)-N, and butyrate concentrations were lower in G3 compared to G2 and particularly to G1 (p < 0.01). The concentrations of total protein, globulin, and glucose were significantly higher with 4 g beeswax (p < 0.05). However, albumin, cholesterol, total lipids, urea, creatinine, glutamic oxaloacetic transaminase (GOT), and glutamate pyruvate transaminase (GPT) concentrations as well as the albumin to globulin ratio decreased significantly with both levels of beeswax (p < 0.05). The addition of beeswax at the level of 4 g/head/day for growing Assaf lambs significantly improved the growth performance, digestibility, rumen fermentation, and blood serum parameters in addition to the economic efficiency.