| dc.description.abstract | This study was conducted to evaluate the performance of Hy-line Brown laying hens reared in caged or free-range facilities and fed two different diets: soybean meal (SBM) or soybean meal free (SBMF) with cottonseed meal (CSM) and distillers dried grains with solubles (DDGS). The objectives were to: 1) evaluate laying hen early production performance and egg quality for hens fed both SBM or SBMF diets, using either caged or free-range rearing systems; 2) evaluate overall consumer preference regarding egg flavor, texture, odor, and color based on samples of scrambled and hard cooked eggs from both diets and systems; 3) evaluate the influence of yeast cell wall (YCW) on post peak performance of caged Hy-line Brown layers on egg production, egg quality, and ileum digestibility; and 4) evaluate the influence of YCW based on gene expression profile of metabolic pathways in caged hens.
Results from the first experiment indicated that free-range production (87.97± 2.52%) is more variable than the traditional cage system (92.40 ± 1.63%), and a SBMF diet can be used in both caged and free-range production systems without negative impact other than significantly lower egg weight (SBM 59.85 ± 0.59 versus SBMF 56.48 ± 0.60 g). From the consumers’ perspective, flavor did not differ, but texture preference was higher for scrambled eggs from the SBMF diet versus scrambled eggs from the SBM diet. For hard cooked eggs, the consumer panel preferred the flavor of eggs from the caged rearing system versus eggs from the free-range system, and consumers liked the texture of eggs collected from hens fed SBM (6.91 ± 1.85) versus eggs hens fed SBMF (6.30 ± 2.01).
Data related to the use of YCW in the diet indicated that egg production was greatest for hens fed the SBM diet with 250 ppm YCW (93.6 ± 0.6%), and egg weight was greater for the SBM (63.5 ± 0.3 g) versus SBMF (61.2 ± 0.2 g) diet. Yeast cell wall supplementation improved apparent ileal amino acid digestibility of lysine in the SBM diet (83.9 ± 3.8 versus 71.2 ± 8.9%) but not the SBMF diet. Prebiotic YCW increased the expression of the liver tissue BAK gene for both the SBM and SBMF diets. With respect to splenic tissue, the combination of YCW with the SBMF diet increased the POR gene over 6 log fold. In the presence of YCW, the SBMF diet upregulated (P<0.01) CYP3A4 and MCL1 genes in the liver and BIK and POR genes in the spleen. The CYP1A2 gene was downregulated over 9 log fold in the liver. | en |
