Effects of feeding diets varying in nutrient density to Hy-Line W-36 laying hens on production performance and profitability

laying hens;low density diets;egg production.

dePersio, Suzette A. ; Koelkebeck ; Kenneth W.

关键词: laying hens;    low density diets;    egg production.;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/26084/dePersio_Suzette.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

An experiment was conducted with 480 Hy-Line W-36 laying hens to determine whether feeding diets that varied in nutrient density would affect long-term egg production performance. At 18 wk of age, laying hens were weighed and randomly allocated to 6 replicate groups of 16 hens each (2 adjacent cages containing 8 hens per cage, 60.9 x 58.4 cm) per dietary treatment in a randomized complete block design. Placement within house and initial body weight were used as blocking criteria. The hens were fed 5 treatment diets formulated to contain 85, 90, 95, 100, and 105% of the energy and nutrient recommendations stated in the 2009 Hy-Line W-36 management guide. Production performance was measured for 52 wk from 18 to 70 wk of age. At 31 wk of age, hens fed the 85% Treatment experienced a post-peak decrease in egg production, with an average hen-day egg production of 65%. At 32 wk of age hen-day egg production for hens on the 85% Treatment was below 50%, with an average of 36%. At this time, hens fed the 85% Treatment were switched to the 100% Treatment (control) due to low egg production.Over the course of the trial, a significant linear response to increasing nutrient density was seen for average hen-day egg production (18 to 70 wk of age), with Treatments 90 to 105% being 81.87, 81.28, 85.98, and 84.62%, respectively. From 18 to 70 wk of age, a significant linear response to increasing nutrient density was found for egg weight (g/egg), with Treatments 90 to 105% being 58.38, 59.15, 59.10, and 60.00g, respectively. Similarly, there was a significant linear increase in egg mass in response to increasing nutrient density, with Treatments 90 to 105% being 46.77, 47.35, 47.71, and 48.32 g egg/hen per day, respectively. A significant linear increase in feed intake due to increasing nutrient density occurred early in the production cycle and from 18 to 70 wk of age, an increase in nutrient density showed a significant linear response in improved feed efficiency (g egg/g feed), with Treatments 90 to 105% being 0.47, 0.48, 0.49, and 0.50, respectively. A significant linear response to increasing nutrient density was seen from 18 to 70 wk of age for Jumbo to Large and Medium to Small eggs. The majority of eggs produced throughout the trial (about 90%) were Extra Large, Large, and Medium sized eggs. On average, the 100 and 105% Treatments produced the most Jumbo to Large eggs, while diets of lower nutrient density produced more Medium to Small eggs. A significant linear response to increasing nutrient density was seen for body weight, with the 85% Treatment hens being the lightest and the 105% Treatment hens being the heaviest. At 70 wk of age a significant linear increase in nutrient density produced heavier fat pad weights, but no effect was noted for bone ash or bone breaking strength due to increasing nutrient density. Significant linear responses due to nutrient density were seen for income, feed cost, and return over feed cost. In general, as nutrient density increased, egg income and feed cost per hen increased, while return over feed cost decreased.Overall, these results indicate that feeding Hy-Line W-36 hens diets formulated to contain lower nutrient density specifications (85% of control) than recommended may compromise production performance. Furthermore, increasing nutrient density in the diet of a laying hen will increase egg production, egg weight, and feed efficiency. However, these benefits do not take effect in early production and seem to be most effective in later stages of the production cycle; perhaps ‘priming’ the birds for better future production.