title: The effect of dietary wheat middlings and enzyme supplementation. 1. Late egg production efficiency, egg yields, and egg composition in two strains of Leghorn hens.
abstract: A study was conducted to test the effects of wheat middlings (WM) with and without enzyme (xylanase and protease) supplementation on late egg production (EP), egg yields, and egg composition in two strains of Leghorn hens (DeKalb Delta and Hisex White). Six diets were randomly assigned to 300 birds (150 birds per strain) from 42 to 60 wk of age. Diet 1 was a corn-soybean meal control, Diets 2 and 3 had 8 and 16% WM, respectively, Diet 4 had 8% WM with 0.1% enzyme, and Diets 5 and 6 had 16% WM with 0.1 and 0.2% enzyme, respectively. Each dietary treatment was replicated five times per strain. Egg production, feed consumption (FC), feed efficiency (FE), percentage dirty eggs, specific gravity (SP), egg weight (EW), and egg mass (EM) were measured on a weekly basis. Egg components (EC) were measured biweekly and birds were weighed every 4 wk. Egg production was not significantly affected by diet, with averages of 83.7, 85.7, 84.1, 84.2, 82.3, and 84.0% for Diets, 1, 2, 3, 4, 5, and 6, respectively. Strain had a marked effect on FC, with Hisex having higher FC than DeKalb hens. Feed consumption also showed a significant diet by strain effect, being lower for Hisex hens fed diets with enzyme compared to diets without enzyme. DeKalb hens had better FE than Hisex hens, and addition of enzyme to 16% WM improved it further. Strain and diet had a significant effect on EC with higher percentages of albumen and yolk for diets with enzyme and for DeKalb hens. Percentage shell was lower for DeKalb hens than for Hisex hens but was not affected by diet. There was also a significant increase in EW for Diets 4 (63.1 g), 5 (63.8 g), and 6 (63.2 g) compared to Diets 1 (62.1 g), 2 (62.4 g), and 3 (63.0 g), with DeKalb hens showing an increase with Diet 5 compared to Hisex hens. Egg mass improved with the higher rate of enzyme in 16% WM diet compared to the lower enzyme level. Specific gravity declined with enzyme supplementation in WM diets. Eggs from DeKalb hens had lower SP than those from Hisex hens for all diets. Percentage dirty eggs did not differ significantly among treatments but was higher for the Hisex strain than for the DeKalb strain. There were no differences in BW between the two strains of hens or among diets. Adding protease and xylanase to diets rich in fiber can improve the egg output without affecting production parameters.
authors.affiliation: Animal Science, University of Nebraska, Lincoln 68583-0908, USA.
authors.forename: D
authors.initials: D
authors.lastname: Jaroni
authors.forename: S E
authors.initials: SE
authors.lastname: Scheideler
authors.forename: M
authors.initials: M
authors.lastname: Beck
authors.forename: C
authors.initials: C
authors.lastname: Wyatt
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D002645:Chickens / Q000502:physiology*; D004032:Diet; D004531:Eggs; D010450:Endopeptidases / Q000008:administration & dosage*; D005260:Female; D014908:Triticum; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases / Q000008:administration & dosage*
chemical_list: D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase; D010450:Endopeptidases