scholarly journals Effect of Feed Restriction and I.C.I. 33, 828 on Delaying the Sexual Maturity and Laying Performance of Meat-type Pullets

1970 ◽  
Vol 7 (3) ◽  
pp. 109-117
Author(s):  
Takashi SAKAIDA ◽  
Masayoshi SUGIYAMA ◽  
KURIO ENYA
1969 ◽  
Vol 9 (39) ◽  
pp. 417 ◽  
Author(s):  
RAE Pym ◽  
R Sledge

An experiment was conducted to examine the effect of restricted feeding under two lighting systems during the rearing period on the initial laying performance of broiler type pullets. The rearing treatments were imposed at nine weeks of age, removed at 22 weeks and the trial was discontinued at 36 weeks of age. The feeding treatments (restricted versus ad lib.) were arranged factorially with the lighting treatments (decreasing versus increasing). Birds reared on restricted feeding reached sexual maturity 16 days later than full fed birds, ate 17 per cent less feed to 22 weeks and gained seven per cent less in body weight to 24 weeks of age and ten per cent less to 36 weeks. Birds reared under the decreasing lighting regime reached sexual maturity at the same age as those reared under increasing lighting, ate five per cent more feed during the rearing and laying periods and gained five per cent more in body weight to 24 weeks. The mean weight of eggs laid between 24 and 34 weeks of age from pullets subjected concurrently to decreasing lighting and restricted feeding was approximately two grams heavier than that of the other three treatment combinations. Mean egg weight was one gram greater in the restricted than in the full fed group, although the difference was not statistically significant. Laying mortality was lower in the restricted fed group than in the full fed group.


1971 ◽  
Vol 11 (49) ◽  
pp. 161 ◽  
Author(s):  
JK Connor ◽  
HW Burton

Two experiments examined the effects of protein restriction in the growing period on the production of egg type pullets. The protein levels of diets fed in the growing period were 15, 13, and 11 per cent. The treatments were incorporated in factorial designs with nutritional treatments in the laying period involving diet protein levels of 17, 15, and 13 per cent and, for one of the experiments, with housing densities of either 4 sq. ft. or 2 sq. ft. per bird. Restriction of protein during the growing period retarded growth and delayed sexual maturity, but neither of the levels of restriction examined increased subsequent laying performance. Eggs lost due to delays in the onset of production were not compensated for by increases in subsequent production and egg weight was generally depressed by protein restriction. The pattern of egg production was altered by restriction. A 13 per cent protein layer diet introduced at point of lay also reduced bodyweight gain and delayed age at sexual maturity. Interactions between nutritional and housing treatments in the growing and laying periods were apparent in egg production and egg weight.


Author(s):  
A. AI-Sobayel ◽  
A.A. AI-Mulhem

A total of 320 twenty week-old slow and rapid feathering Saudi Arabian Baladi pullers were used to assess the effect of sex-linked feathering genes on body weight, age at sexual maturity, feed intake and subsequent laying performance. Similar numbers of rapid feathering Leghorns pullets were included in the study for the purpose of comparison. The experimental birds of each genotypic group were randomly divided into four replicates and subjected to standard management practices. Slow feathering Baladi pullers had higher (P<0.05) adult body weight, rate of mortality, and feed intake and a similar age at sexual maturity but showed lower (P< 0.05) hen-day, and hen-housed egg production and feed conversion compared with rapid feathering Baladi pullets. Rapid feathering Leghorns had higher (P<0.05) adult body weight. age at sexual maturity, hen-day egg production, rate of mortality and feed intake and lower feed intake/kg eggs than rapid and slow feathering Baladi. However, rapid feathering Baladi and Leghorns had similar hen-housed egg production and feed intake per dozen eggs and had better (l’<0.05') performance than slow feathering Baladi.


2005 ◽  
Vol 143 (1) ◽  
pp. 97-108 ◽  
Author(s):  
P. D. LEWIS ◽  
D. BACKHOUSE ◽  
R. M. GOUS

An experiment was conducted at the University of KwaZulu–Natal to assess the effect of constant photoperiods on sexual maturity and egg-laying performance in broiler breeders given two levels of control-feeding during the rearing phase. Cobb broiler breeder females were grown to reach 2·1 kg body weight at 17 or 21 weeks, and maintained on 10, 11, 12, 13, 14 or 16-h photoperiods from 2 days to 68 weeks of age. There were no significant interactions between photoperiod and growth rate for any production parameter. The time required reaching 2·1 kg increased proportionally with photoperiod but, because of delayed sexual development, birds on longer photoperiods consumed more feed to, and were heavier at, sexual maturity than shorter daylengths. The longer-photoperiod birds also had inferior rates of lay in the first half of the cycle, but superior in the second, which, together with the photoperiodic effects on maturity, resulted in birds on 11, 13 or 14 h producing most eggs to 68 weeks, and those on 16 h fewest. It is possible that the pattern of egg production was due to some of the birds on [ges ]13-h photoperiods becoming photorefractory, having a mid-cycle pause, and then spontaneously resuming egg production in the latter half of the cycle. However, a hinge-analysis of current and other data to the more usual depletion age of 60 weeks showed that the combined effects of photoperiod on sexual maturity and egg production resulted in constant 10-h birds producing the highest number of eggs, with numbers decreasing by 3·6 eggs/h of photoperiod above the hinge and 7·8 eggs/h of photoperiod below it. Mean egg weight increased by 0·4 g/h of photoperiod, but the proportion of abnormally large and floor eggs and the incidence of mortality were unaffected by daylength. For each photoperiod, accelerated growth resulted in body weights being heavier than controls at sexual maturity, despite the mean age at maturity being 10 days earlier for the faster-growing birds. Body weights for the two growth groups were not significantly different at 68 weeks. Faster-growth birds consumed 1 kg less feed to 2·1 kg body weight, but 1·3 kg more feed to sexual maturity and 2·7 kg more to 68 weeks, and produced 6 more eggs than, but had similar patterns of egg production to, the conventionally managed controls. Mean egg weight, the proportion of floor eggs and the incidence of mortality were similar for both groups. Notwithstanding that the overall production of abnormally large eggs was low (1·1 eggs per bird); the faster-growing birds produced significantly more than the controls. Egg weight was positively influenced by age at sexual maturity, body weight at sexual maturity and photoperiod, but was unaffected by rate of growth to 2·1 kg per se.These findings show that there are differences between broiler breeders and egg-type pullets in their response to constant photoperiods. It is likely that the factors responsible for these differences, particularly in terms of sexual development, are the exhibition of photorefractoriness by, and the retardational effects of controlled feeding on, broiler breeders.


1964 ◽  
Vol 43 (3) ◽  
pp. 786-787 ◽  
Author(s):  
E.P. Singsen ◽  
Jobst Nagel ◽  
S.G. Patrick ◽  
L.D. Matterson

2014 ◽  
Vol 151 (3-4) ◽  
pp. 229-236 ◽  
Author(s):  
Yu-En Pan ◽  
Zu-Chen Liu ◽  
Chai-Ju Chang ◽  
Yu-Feng Huang ◽  
Chien-Yang Lai ◽  
...  

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