Feed type for induced molting of commercial layer hens

Abstract

-An experiment employing three hundred and twenty 81-week-old Lohmann LSL commercial-breed hens was conducted to compare alternative induced-molting methods with the conventional method (fasting). Induced molting lasted 28 days at most, production and quality being monitored for four periods of 28 days thereafter. A completely randomized experimental design with five treatments, eight replicates of eight birds each per plot was adopted. The following experimental treatments were applied until a loss of 26% of body weight was reached: T1 -fasting, T2 -wheat bran ad libitum, T3 -rice bran ad libitum, T4 -cracked rice ad libitum, T5 -ground alfalfa ad libitum. Birds were then fed production diet ad libitum, except for those on treatment T1 (fasting) which received 30, 60 and 100 g/bird/day and then feed ad libitum. During induced molting the birds were exposed to a natural photoperiod and at day 28 that period was increased by 30 minutes/week until reaching 16 hours of light/day. The characteristics evaluated during induced molting were: feed intake, body weight changes and laying percentage. In the post-molt period, performance (feed intake, laying percentage, egg weight, egg mass, feed conversion ratio per dozen and per egg mass and percentage of broken eggs) and egg quality (specific gravity, eggshell breaking strength, percentages of eggshell, yolk, and albumen, eggshell thickness, yolk color and Haugh unit) were evaluated. Every 28 days one egg was collected from each repetition for three consecutive days for quality assessment. The use of rice bran and wheat bran is viable as molting inducers since the birds given those treatments display performance and egg quality similar to those fasted during the induced molting and also because these ingredients promote easier handling, eliminates the need for grinding and feed-mixing equipment and, being less aggressive, provide greater bird welfare.

Response of domestic chickens to fasting and non-fast moulting programmes in a humid tropical environment

“…The corresponding values for indigenous hens were 1.00 and 1.80 kg and 1.25 and 1.60 kg, respectively. Hens are usually forced to moult towards the end of their first laying cycle due to ageing and poor egg production (Moustafa et al, 2010;Santos et al, 2014). In Nigeria, such flocks are disposed and replaced with new stocks.…”

“…Egg production in laying flocks is limited by age and decreases as hen ages. The aging process and cessation of egg production initiate natural moulting which usually lasts for about 4 months (Santos et al, 2014). Moulting is therefore a major event in the annual life cycle of the domestic chicken and other avian species (Aygun and Olgun, 2010).…”

“…Programmes used to induce moulting in laying hens include feed deprivation, photoperiod reduction, mineral (Ca, Cu, Zn, Al, etc) supplementation and the use of low energy diets (Molino et. al., 2009;Santos et al, 2014). These schemes cause total cessation of egg production, shading of body fat, and renewal (involution) of the reproductive organs (Hussen, 1996;Santos et al, 2014).…”

“…al., 2009;Santos et al, 2014). These schemes cause total cessation of egg production, shading of body fat, and renewal (involution) of the reproductive organs (Hussen, 1996;Santos et al, 2014). Feed deprivation was the primary method of induced moulting in hens (Gast and Ricke, 2003;Aygun and Olgun, 2010).…”

Efficacy of various post-moult feed supplementations in poultry: an empirical review

“…Moulting refers to periodic shedding and feather replacement, coinciding with a decrease in the reproductive efficiency function (Berry, 2003) and body weight loss of about 25% (Mrosovsky and Sherry, 1980). These include high dietary zinc supplementation (Sandhu et al, 2006), low calcium (Breeding et al, 1992) and low sodium diets (Berry and Brake, 1985), wheat middling (Biggs et al, 2003), using barley (Onbasilar and Erol, 2007), cottonseed meals (Davis et al, 2002), jojoba meal (Vermaut et al, 1997), alfalfa (Donalson et al, 2005;Landers et al, 2005;Aygun and Olgun, 2010), oat (Fletcher et al, 1981;Aygun and Yetisir, 2009) and rice bran (Santos et al, 2014) in diets. This practice became the most adopted tool to maintain the production potential of laying hens until the early eighties.…”