Laying Performance and Egg Quality of Bovans Brown Hens on Brewer’s Spent Yeast-Based Diets

Abstract

This study evaluated the effect of dried brewery spent yeast (BSY) as a protein source on the feed intake, body weight (BW) change, egg production, egg quality, and feeding cost in laying hens. One-hundred fifty Bovans Brown hens, aged 23-weeks, were randomly assigned to five dietary treatments. The control diet (T1) contained 0% BSY and 20% soybean meal (SBM), while diets T2, T3, T4, and T5 contained BSY at 5, 10, 15 and 20%, respectively, replacing SBM at 25, 50, 75 and 100%. The diets were formulated to meet the nutrient requirements of laying hens targeting nearly 2750 kcal/kg DM ME and 16.5% CP. The inclusion of BSY in the diet did not affect feed intake (P>0.05), which ranged from 111 g/hen/day (T5) to 115 g/hen/day (T4). Moreover, egg weight (55-56 g) and feed conversion in dozens of eggs produced were not influenced by the diet (P>0.05). However, higher inclusions of BSY decreased (P<0.05) the total number of eggs laid per hen (90.6 in T1, 81.3 in T5), %lay (92.4 in T1, 83.0 in T5), and feed conversion in egg mass (2.23 in T1, 2.52 in T5. No significant differences were noted in laying performances, feed efficiency, and egg quality parameters between hens fed diets with 10% and 15% BSY. Final BW and BW gains were lowest (P<0.05) in hens on diets with 15% and 20% BSY. Egg quality parameters were not changed with up to 15% BSY inclusion. However, hens fed a 20% BSY diet exhibited a decrease (P<0.05) in egg albumen weight, egg yolk weight, and Roche color fan values, while egg weight remained unchanged. The cost per kg of feed or dozen eggs decreased with increase in the level of BSY. It is concluded that up to 15% dried BSY can be incorporated into the diet of laying hens as a low-cost protein source, partially replacing soybean meal.