A Comparison of the Effect of Two Force Molting Methods on Performance of Two Commercial Strains of Laying Hens

Abstract

A low-sodium diet (.08% Na) was used to force molt 409 hens. Another 421 hens were force molted by conventional water and feed restrictions. Birds were 68 weeks of age at that time, and two strains were about equally represented in each treatment group. These strains were: A, DeKalb; and B, Hisex. The low-sodium diet and water were provided ad libitum to the first group for the entire period of molt (42 days). The second group received no water for 3 days, and no feed for 4 days, after which incremental amounts of whole oats were provided as the only feed until Day 18. After Day 18, incremental amounts of a regular laying mash and decremental amounts of whole oats were provided through Day 26, when laying mash only was given ad libitum. Both treatment groups were in the same building and received the same lighting program during the force-molt period. This program consisted of: Days 1 to 3, no light; Days 4 to 18, 8 hr/day; Days 19 to 25, 9 hr/day; Day 26, 10 hr; then, light was increased 30 min weekly until 14 hr daily was attained. The low-sodium group ceased laying after 28 to 31 days, lost 8.7% of their premolt body weight, reduced feed consumption by 35%, and decreased egg production from 62.3% (in the 28 days preceding the molt) to 19% in the 42 days of molt; their mortality rate was 3.4%.(ABSTRACT TRUNCATED AT 250 WORDS)

Indução a muda forçada em Galinhas D'Angola (Numida meleagris) através do óxido de zinco

“…Em geral, os resultados de regressão obtidos estão de acordo com Woltford 22 que analisando vários métodos de indução a muda verificou redução de ovário e oviduto, havendo portanto uma relação direta entre a PPC e a redução do aparelho reprodutor. De uma maneira geral, em nosso experimento, foi obtido resultado de regressões superiores aos encontrado por Koelkebeck 12 , onde trabalhando com poedeiras brancas, obteve resultados em que o ovário representava 0,2% do peso corpóreo, já em nosso trabalho todas as aves obtiveram maiores regressões. O mesmo aconteceu com relação ao oviduto em que todas as aves obtiveram seus órgãos representando pesos menores a 0,5% do peso corpóreo.…”

“…Vários são os programas citados na literatura 5,6,7,8,9 , capazes de provocar a muda forçada nas aves, dentre eles estão: os métodos nutricionais, em que são oferecidas às aves rações com níveis nutricionais alterados 10,11,12,13,14,15,16,19 e os métodos clássicos ou de manejo, onde as aves são privadas de alimentos por um período não superior a 10 dias. A maioria dos métodos utilizados no Brasil e em outros países trata-se de métodos agressivos ao bem estar animal, sendo proibidos pela Sociedade Protetora dos Animais.…”

Comparison of the Use of Dietary Aluminum with the Use of Feed Restriction for Force-Molting Laying Hens

“…Mortality was zero during the entire experiment. Said and Sullivan (1984) reported that hens subjected to feed and water restriction stopped egg production after 11 days, lost 17% of their initial body weight, and had a mortality of 5% during the molting trial. McCormick and Cunningham (1987) found similar results when they fasted hens for 10 days.…”

Requirement of Sodium to Molted Laying Hens

“…Different strains may to present different responses on performance after molt, especially on laying hens and semi-heavy hens (Said et al, 1984;Gongruttananun et al, 2017;Hu et al, 2019). There is very limited literature about the performance, egg composition, egg solids, egg quality, and profits of postmolt hens (Wu et al, 2007), especially at long-term, a period near or exceeding to 100 weeks.…”