Energy partitioning at low temperatures in broiler breeders

2019 ◽  
Vol 59 (3) ◽  
pp. 435
Author(s):  
M. K. Nonis ◽  
R. M. Gous

The objective of the present study was to investigate how broiler breeder hens partition dietary metabolisable energy (ME) at low temperatures. Performance of caged broiler breeders fed equal quantities of essential nutrients (other than energy) was measured in six environmental chambers, with the temperature in each chamber being kept constant at 10°C, 12.5°C, 15°C (two chambers), 17.5°C or 20°C for two 6-week periods. Throughout these two trial periods, birds were fed 160 g/day of one of four diets containing 12.9, 11.9, 10.5 or 9.7 MJ apparent ME/kg, so that daily energy allocations ranged from 1552 to 2964 kJ/bird. Irrespective of the environmental temperature to which they were subjected, broiler breeders consumed virtually all of the feed allocated to them each day. Mean rate of lay and egg output in the final 3 weeks of each period of hens on the highest apparent ME feed was unaffected by the decrease in temperature from 19.5°C to 9.9°C, but equally depressed on the three lower energy levels. Both weight gain and egg weight increased marginally, but significantly, as the temperature decreased. As a function of body protein weight (BP, kg), egg output (EO, g/day) and growth (ΔW, g/day), the ME consumed (kJ/day) by broiler breeders over all treatments was partitioned as follows: 2423 (±30.3) BP + 7.04 (±0.41) EO + 13.5 (±1.10) ΔW. An ME intake of 1900 kJ/bird.day would appear to be adequate for broiler breeders over the range of temperatures used in the trial.

2016 ◽  
Vol 56 (7) ◽  
pp. 1091 ◽  
Author(s):  
Nayara T. Ferreira ◽  
Nilva K. Sakomura ◽  
Juliano César de Paula Dorigam ◽  
Edney Pereira da Silva ◽  
Robert M. Gous

There is scant information about the reproductive process in broiler breeders, with which to develop a feeding strategy that will be economically optimal for these birds. This study aimed to model the egg production of a flock of broiler breeder hens, using non-isometric equations. The number of eggs produced by 60 broiler breeder hens aged 24–60 weeks was monitored, as was the weight of these eggs and the weights of the components, yolk, albumen and shell. Oviposition sequences and the number and length of pauses between sequences were analysed. Non-isometric functions were applied to predict the weight of the egg; yolk weight was predicted from the age of the hen, while albumen and shell weights were predicted from yolk weight; and egg weight was obtained by summing the component weights. The incidence of soft-shelled and double-yolk eggs was also determined. Yolk weight (YW, g) can be described as YW = 18.03 × (1 – e–0.015 × (t – 103.4)) × e(0.001 × t), where t is the age of the bird (days). The weights of albumen (AW) and shell (SW) were based on YW predictions as follows: AW = 14.38 × YW0.375 and SW = 0.358 × (YW + AW)0.687. The rate of double-yolk egg (DY) production is described by DY = 2.28 × e(0.209 × TFE), and the rate of soft-shelled egg (SS) production by SS = 1.126 + 0.148/(1 – 0.024 × TFE) – 0.056 × TFE, as a function of time from first egg (TFE). On the basis of the results obtained, the model developed here is an accurate reflection of the changes that occur in the number of eggs produced by broiler breeders, as well as in the egg itself and in its components over the entire laying period. This model can thus be used in predicting the nutrient requirements of individual broiler breeder hens, which, when combined with simulated data from a large number of individuals, will accurately describe the laying performance of a flock of broiler breeders.


Animals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 472 ◽  
Author(s):  
L. Li ◽  
K. F. M. Abouelezz ◽  
Z. Gou ◽  
X. Lin ◽  
Y. Wang ◽  
...  

This study aimed to establish the optimal dietary zinc requirement of Chinese yellow-feathered Lingnan broiler breeders. A total of 576 breeder hens aged 58 weeks were randomly assigned to six treatments, each with 6 replicates of 16 birds (n = 96/treatment). The hens were fed either a basal diet (22.81 mg/kg Zn) or the same basal diet supplemented with additional 24, 48, 72, 96, and 120 mg Zn/kg up to 65 weeks of age. Compared to the results of birds fed the basal diet (22.81 mg Zn/kg), the dietary supplementation with additional Zn (mg/kg) showed higher egg laying rate (at 48–120 mg), EM (at 96 mg/kg), yolk Zn content (at 24–120 mg/kg), fertility (at 48–120 mg/kg), hatchability (at 48–96 mg/kg), tibial breaking strength (at 24–48 mg/kg), tibial ash content (at 48 mg/kg), serum CuZnSOD activity (at 72 mg/kg) and T-AOC (at 48 mg/kg), and ovarian CuZnSOD and GSH-Px activities (at 96–120 mg/kg), and lower FCR (at 96 mg/kg). The regression model showed that the optimal supplemental Zn for maximal egg laying rate, yolk Zn content, fertility, and hatchability of Chinese yellow-feathered broiler breeders aged 58 to 65 weeks were 71.09, 92.34, 94.44 and 98.65 mg/kg diet, respectively.


2016 ◽  
Vol 56 (7) ◽  
pp. 1099 ◽  
Author(s):  
M. K. Nonis ◽  
R. M. Gous

Changes in the feather-free body (water, lipid and protein) of broiler breeder hens was measured at intervals between 15 and 60 weeks of age to provide information that could be used as the basis for predicting their maintenance requirements. The mean weight of feather-free body protein varied between 348 and 379 g at 15–20 weeks, increasing to 648 g by 40 weeks and then remaining relatively constant for the rest of the laying period. Mean body lipid content increased from 160 g at 15 weeks to 711 g at 60 weeks. The initial increase in feather-free body protein weight can be ascribed to increases in ovary and oviduct weights as the birds become sexually mature, and to the variation in ages at which this development takes place. Our conclusion is that changes in bodyweight in broiler breeders after sexual maturity are mainly in body lipid content, this being a consequence of the way in which the birds are fed, and that any gain in body and feather protein occurs only in hens that are out of lay. We suggest that it should not be necessary to assume that protein and lipid growth is obligatory when determining nutrient requirements of broiler breeder hens.


2016 ◽  
Vol 16 (4) ◽  
pp. 1185-1198 ◽  
Author(s):  
Agnieszka Otwinowska-Mindur ◽  
Małgorzata Gumułka ◽  
Joanna Kania-Gierdziewicz

Abstract Broiler breeders hens (meat-type hens) have lower reproductive potential than laying-type hens. Statistical models for predicting potential laying pattern are important for economically optimal breeding strategy of egg production in a poultry flock. The aim of the study was to find the most suitable function for describing the egg-laying rate and egg weight during the broiler breeders’ production period and to characterize laying pattern in groups of hens with different egg production. The following four mathematical models were used: gamma, Narushin-Takma, logistic-curvilinear, and compartmental. The daily recorded egg production data from 100 broiler breeder hens were used. Hen-weekly egg production was described using laying rate during successive weeks after reaching sexual maturity (26 weeks of age) and daily recorded egg weight. On the basis of the total number of eggs laid (NEggs), groups of hens with low (21%), intermediate (52%), and high (27%) egg production were created. The differences between the goodness-of-fit criteria values (AIC, R2 MSE) were small, with all the examined models having the same quality of curve fitting for egg-laying rate and egg weight. The logistic-curvilinear model was able to fit well both egg-laying rate and egg weight of the whole broiler breeder hens’ flock, and also when hens were divided into three egg production groups. This model could be considered in a long-term prediction of the reproductive potential in the commercial management. Moreover, the presented model could be useful in the research on different reproduction parameters of individual hens.


2016 ◽  
Vol 101 (6) ◽  
pp. 1194-1204 ◽  
Author(s):  
J. C. P. Dorigam ◽  
N. K. Sakomura ◽  
M. F. Sarcinelli ◽  
C. A. Gonçalves ◽  
M. B. de Lima ◽  
...  

1984 ◽  
Vol 63 (5) ◽  
pp. 1003-1007 ◽  
Author(s):  
R.H. HARMS ◽  
S.M. BOOTWALLA ◽  
H.R. WILSON

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