Response of domestic chickens to fasting and non-fast moulting programmes in a humid tropical environment
The study evaluates the effect of fasting and non-fasting (Zn supplementation) moulting methods on performance of indigenous (IC) and Shaver brown (SB) hens in the hot humid tropical environment of Nsukka, Southeastern Nigeria. One hundred and twenty indigenous and Shaver brown hens (60/genotype) aged between 75 and 80 weeks were shared into three groups (20/group), T : hens fed layers diet at 125 g/bird/day (control group), T : hens fed 1 2 layers mash supplemented with 20,000ppm Zn as ZnO at 125 g/bird/day for 14 days, and T : 3 hens subjected to feed deprivation (FD) for 14 days. Water was given ad libitum to all birds. Data analyzed were pre-moult and moulting body weight, hen day egg production (HDEP), and egg weight. Moulting method significantly (p<0.05) affected body weight in SB but not in indigenous hens; hen day egg production and day to stoppage of egg production in both genotypes with FD resulting in greater loss in body weight and an early cessation of egg production compared to zinc supplementation. Shaver Brown hens subjected to ZnO and FD lost 15.6 and 26.7 % of their initial body weight, respectively while IC lost 16.2 and 32.6 %, respectively. Hen day egg production was 0.00 ± 0.00 % in the last week of moulting in SB and IC moulted by FD but 8.32 ± 6.47 % for SB and 10.71 ± 3.25 % for IC moulted by ZnO. Egg production stopped on day 10 (D10) and 6 in SB hens submitted to ZnO and FD, respectively and on D13 and 5, respectively for the IC. In conclusion, zinc supplementation at 20,000ppm in the diet of laying chickens as moulting agent is a milder but equally effective moulting method as fasting and is recommended for intensive commercial and rural indigenous poultry production.
Keywords: Induced moulting, body weight loss, egg production, Shaver Brown, local chickens.