Response of CARI-Sonali hens to different nutritional methods of moulting

Two hundred, 78 wk old CARI-Sonali hens (egg production around 20%) were randomly divided into 5 groups of 40 each. Different moulting treatments consisted of complete feed withdrawal, high Zn (20g/kg) in normal layer diet, high Zn (20g/kg) without supplemental Ca and P, high Al (0.4%) in normal layer diet and high Al (0.4%) without supplemental Ca and P. The treatments were continued for eight days and thereafter, the birds under each treatment were divided into two subgroups. Each subgroup received normal layer diet or a diet with low CP (12%) and low Ca (1%) for a period of 21 days and then all the birds were switched on to a standard normal layer diet. Egg production, feed intake and body weight changes were recorded at regular intervals. At the end of 8 days of moulting treatment, 3 birds per group were sacrificed and the samples of intestinal contents were collected immediately and processed for microbiological analysis. Three birds were kept full-fed throughout for microbial analysis. Cessation of egg production in different groups was on 5^th, 5^th, 4^th, 2^nd and 6^th d from the start of moulting treatment in groups I to V, respectively. The body weight decreased in all the treatment groups (11.6–26.7%) and the maximum decline was in complete feed withdrawal (26.7%) group. The microbial counts viz. total viable count, coliforms, Staphylococcus aureus and yeast and mold were significantly were higher in the moulted groups in comparison to full fed layers. Salmonella winneba was positive in all the test groups except for full fed and high Al without supplemental Ca and P. Egg production resumed 26 days post-moulting and for normal feed intake and peak egg production, it took 39 days. The birds moulted with Al and then fed with normal layer diet resumed egg production earlier with significantly higher rate. Body weight slowly improved to positive balance after 2 months. It can be concluded that inclusion of Al (0.4%) in normal layer diet followed by feeding of normal layer diet during rest period was most beneficial for moulting of laying hens.