Methionine and lysine supplementations either in diets or drinking of one-phase low dietary protein feedind system for laying hens : Effects on laying performance, feed utilization, egg quality and digestibility

Abstract EN

This work was conducted to study the effect of methionine and lysine supplementation to the level of 120 % of requirements either in feed (F) or drinking water (W) for one-phase low protein diet on laying performance, feed utilization, egg quality and digestibility.

A total number of 180 H and N females pullets of 19 weeks of age (previously divided into control (C), F treatment and W treatment during growing period) were classified into 9 experimental groups, 20 pullets for treatment, in 5 replicates, 4 birds each, as C / C, F / C, W / C, C / F, F / F, W / F, C / W, F / W and W / W groups.

Control diet (C) during laying period contained 19, 18, 17 and 16% crude protein (CP) as strain requirements, while experimental diet F and W contained 15% crude protein (CP).

All diets were iso-calorie and iso-nitrogenous.

Results obtained could be summarized as follows : The lowest (P < 0.05) final body weight obtained by F / F group (1.696 kg), while control group (C / C) attained highest (P < 0.05) final body weight (1.889 kg).

Birds in W / F group recorded higher values in total egg number (105.6) and rate of egg production (75.26 %) compared to the other experimental groups, while the heaviest egg mass recorded by control group (6.111 kg / hen) followed by W / F group (5.959 kg / hen).

The lowest egg mass obtained by F / F group (4.844 kg / hen) followed by C / F group (4.852 kg / hen).

The heaviest average egg weight recorded by control and W / C groups (58.0 gm) followed by C / W group (57.5 gm), while the lightest average egg weight recorded by F / F group (55.8 gm) followed by F / W group (56.2 gm).

The largest amount of feed intake recorded by W / F group (111.9 gm / bird / day) followed by C / C group (106.1 gm / bird / day), while the smallest amount recorded by F / F group (93.7 gm / bird / day) followed by C / F group (96.5 gm / bird /day).

The best feed / egg conversion recorded by C / C and F / C groups (2.43), while the worst one recorded by C / F (2.75) followed by F / F group (2.73).

The smallest (P < 0.05) albumen weight, the highest shell thickness and percentage were recorded by W / F group.

However, albumen percentage, yolk weight, yolk percentage, shell weight, Haugh units and yolk index were not affected by treatments through 19-38 weeks old.

Groups of W / F recorded lower feed cost per dozen eggs than the other experimental groups.

The experimental treatments revealed no significant effects on nutrients digestibility, except those of ether extract where it was higher being 82.79 % in W / C group, while the lowest one recorded by W / F group (71.10 %).

Finally, it could be recommended to formulate a layer diet of lower crude protein content (15 %) with lysine and methionine supplementation either in feed or drinking water during laying period.

This will, in turns, alleviate the higher cost of feed and improve some of laying performance.