The effect of using conventional feed restriction (70% of ad libitum consumption) and different dietary levels of aluminium (0.15% and 0.30%) as aluminium sulfate and zinc (0.15% and 0.30%) as zinc oxide were compared to determine the influence of forced moulting on the productive performance of Japanese quail laying hens. A basal layer diet was fed alone or supplemented with aluminium sulfate and zinc oxide for 14 days to quail laying hens. A cessation of egg production was effectively produced by the feed restriction and dietary levels of Al and Zn on 5th day of induction of moulting. During two weeks of moulting period percentage body weight loss was obtained in conventionally feed restriction (22.89%), 0.15% Al (26.30%), 0.30% Al (24.84%), 0.15% Zn (27.49%) and 0.30% Zn (30.46%) respectively.
Feed consumption of quail hens of control group differed significantly (P<0.05) with hens given two different dietary levels of Al and Zn in 2nd wk of pre-moult. There was also a significant difference between control treatment and other moulting treatments in 2 weeks of moult and 2 weeks of pre-lay. In 1st wk of post moult feed intake of control hens tended significant (P<0.05) difference with hens of feed restriction and non-significant difference with other moulting treatments, which in turn differed with 0.15% AI, 0.15% Zn and 0.30% Zn supplementation. 0.30% AI and 0.30% Zn given quail hens were also significantly different in feed consumption with each other. In 9th week of post-moult feed intake of un-supplemented control hens revealed significant difference with 0.30% AI and non-significant difference with 0.15% AI, 0.15% Zn and 0.30% Zn, which were not significant with one another. Quail hens restricted to feed also showed significantly difference with liens fed dietary level of 0.30% AI in term of feed consumption. Dietary level of 0.15% Al differed significantly with dietary levels of Al 0.30%, Zn 0.15% and Zn 0.30%. Results indicated that moulting by dietary levels of 0.30% AI and 0.30% Zn produced maximum egg production with less feed in comparison to other moulting treatments in post moult. It means that dietary levels affected the feed intake with subsequent potential.
There was small short term depression in egg production of quail hens in the moult and pre-lay periods. Although the egg production was greater for the control hens during moult, rest period but not in the post moult compared with the conventionally moulted and inclusion of supplemental aluminium Al and Zn, however, it was consistently lower thereafter. Post moult egg production was 72.74%, 72.04%, 71.59%, 71.31%, 71.24% and 64.90% in 0.15% Zn, 0.30% Zn, feed restriction, 0.30% Al, 0.15% Al and control respectively. After moulting percent hen-day egg production peaked 78.85% in 0.15% Zn, followed by 0.30% Zn fed hens (75.42%) and there was no decline over the subsequent 14 weeks of post moult. In two weeks of moult and two weeks of pre-lay egg production of non-moulted control hens revealed significant (P<0.05) difference with moulted quail hens. There was significant difference between control treatment and all other moulting treatments in 7th, 8th,
11th, 13th, and 14th weeks of post moult. The results demonstrated that all moulting methods produced better egg production than control in post rest performance. During 7th through 20th wk post moult all moulted quail hens outperformed non-moulted control. It is concluded that feed restriction and dietary levels increased egg production.
Average feed efficiency for non-moulted quail laying hens 3.19, feed restriction 2.97. 0.15% Al 3.08, 0.30% AI 3.07. 0.15% Zn 3.00 and 0.30% Zn 2.99 respectively. Feed efficiency over the entire experimental period was superior (2.97) in the conventionally moulted hens, followed by 0.30% Zn (2.99). Feed conversion was best (2.89) in hens given 0.30% Al and poorest (3.22) in control in post moult treatment. A significant (P<0.05) difference was also observed between control and moulting treatments in two weeks of moult.
1st wk of pre-lay, 7th, 9th, 11th, 13th, and 14th. weeks of induced post moult. Feeding of 0.30% of AI and 0.30% An consumed minimum feed with best-forced rest production as compared to other moulting treatments.
During the post moult body weight of quail hens increased similarly across groups, with 22.89% weight loss of hens with feed restriction maintaining a slightly heavier body weight throughout the post rest period. Body weight of quail laying hens of control (non-rested) showed significant (P<0.05) difference with all moulting methods in 2nd wk of moult,
1st wk of pre-lay. 3rd and 4th wk of post treatment. Irrespective of the moulting in post moult methods, all dietary groups lost weight, but at different rate during moult induction. It is concluded that liens that lost 27.49% body weight (Zn 1.5 mg/kg) showed comparable result with other moulting methods in post rest performance.
Egg weight prior to moult induction was not different among quail liens and did not vary among various moulting methods. However, eggs laid by quail hens of feed restriction and 0.30% AI treatments were heavier than other treatments. Egg weight was significantly affected (P<0.05) in all moulting treatments in two weeks of moult. Thereafter, a non-significant effect was obtained among all treatment groups at the
1st wk through 14th wk of post moult treatment. There was no significant increase in egg weight with progression of age for all quail hens. As quail hens aged, increased egg production did not influence egg weight resulting into no difference in egg weight of all treatments. Average egg weight was 10.83g, 11.33g, 11.66g, 11.008, 10.83g and 11.998 for control, feed restriction, 0.15% Al, 0.30% AI, 0.15% Zn and 0.30% Zn in pre-moult respectively. The quail hens averaged control. 11.28g feed restriction. 11.028 0.15% AI, 11.668 0.30% Al, 11.358 0.15% Zn and 11.478 0.30% Zn in post moult respectively. Results indicate that quail hens supplemented with dietary level of 0.15% AI in their diet had gained more egg weight than other treatments. It is concluded that egg weight was affected by the dietary treatments and feed restriction.
Total mortality of Japanese quail hens was 21.11, 16.66, 17.77, 23.33, 20.00 and 21.11 % for control, feed restriction, 0.15% AI, 0.30% Al, 0.15% Zn and 0.30% Zn treatments throughout the duration of experiment respectively. Mortality by moult induction method was low in feed restriction and high in 0.30% AI treatments. Mortality by targeted body weight loss was 5.55. 3.33. 6.66, 5.55, and 11.11 % in quail liens for the 22.89, 26.30. 24.84, 27.49 and 30.46% body weight loss groups respectively. Mortality in post moult treatment was for control (16.66%), feed restriction (10.00%) 0.15% AI (13.33%), 0.30% AI (14.44%), 0.15% Zn (13.33%) and 0.30% Zn (10.00%) respectively. Maximum mortality was in control treatment and it remained minimal and similar in treatments of feed restriction and 0.30% Zn supplementation programs. In 2nd wk of moulting mortality differed significantly (P<0.05) between the quail hens of Zn (0.30%) and hens of control, restricted to feed, 0.15% Al and 0.15% Zn, but was non-significant with dietary level of 0.30% Al. In 14 weeks of post rest mortality revealed non-significantly differences among all treatments when subjected to statistical analysis. However, mortality was higher for control compared to moulting groups induced to moult by different techniques. Moulting treatments may help survival rates compare to non-moulting treatment in post moult period. It is concluded that livability was not affected by the dietary treatments and conventional feed restriction.
The results demonstrate that the subsequent post moult performance of Japanese quail laying hens in the experiments was affected by feed restriction and different dietary levels of aluminium sulfate and zinc oxide. Feed restriction (70% of ad libitum consumption), as an alternative moulting and economically effective conventional technique offers advantages over other moulting techniques. Induction of moulting had greater effects on performance and income results. The results suggest that feed restriction and dietary levels of aluminium and zinc may offer an economic advantage over a continuous ad libitum feeding regimen in poultry industry.