Chemical and Non-Chemical Molting Methods As Alternatives To Continuous Feed Withdrawal in Laying Hens

An experiment was conducted to evaluate the effectiveness of chemical and nonchemicalmolting methods as compared to conventional feed removal methods withrespect to the physiological response and postmolt performance in hy-line w36 layinghens. one hundred and eight 78-week-old hens were distributed among 27 groups of fourbirds and placed in cages so that the mean body weight of each cage was very similar.three adjacent cages were considered as a replicate and 3 such replicates were assignedto each treatment. there were three treatments (molting procedures). treatment 1 wascontinuous feed removal (cfr) and considered as the control. hens on treatment 2 (t2)were fed finely ground delinted whole cottonseed as the sole feed ingredient and dietaryvitamin and macro and microelement levels were maintained according to hy-line w36guideline specifications. birds on treatment 3 (t3) received a layer diet containing 5,000ppm zn and fed at the rate of 50 g b-1 d-1. the results indicated that hens subjected tocfr, whole cotton seed and zinc supplemented diet went out of production on day 6, day7 and day 14, respectively. continuous fasting and feeding whole cottonseed as moltingprograms resulted in significantly (p< 0.05) lower body weight and serum t3concentrations but higher heterophil to lymphocyte (h:l) ratio and hematocrit,compared to the zinc method when measured on day 7. birds that received molt dietsupplemented with zinc produced heavier eggs postmolt (p< 0.05) in comparison to othertreatments but the egg production, egg mass and egg quality criteria were not differentamong the treatments.