• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1080-1084
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• 1999

Carbon (C) and nitrogen (N) balance technique was used to determine energy balance in Rhode Island Red (RIR) and White Leghorn (WL) laying hens fed maize-and broken rice (BR)- based diets. Carbon and nitrogen intake and outgo were determined for three days on ad libitum fed diets followed by 2/3 of ad libitum intake for next three days. Carbon analysis was done by using four 'U' tubes in which carbon dioxide released during bomb calorimetry was absorbed on drierite in tube 1 and 2 whereas tube 3 and 4 contained sodalime self indicating granule. Carbon in $CO_2$ was determined by an open circuit respiration system. Energy retention (E, kcal) was calculated as E = 12.386 C (g) - 4.631 N (g). By regressing metabolisable energy (ME) intake on energy balance, maintenance ME requirement of RIR was 128 whereas, that of WL hens was $144kcal/kg\;W^{0.75}/d$. Effciency of utilization of ME for maintenance from BR-based diet in RIR hens was equal but in WL hens it was 11% less than maize-based diet.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1085-1089
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• 1999

Energy requirement of Rhode Island Red (RIR) hens was studied by comparative slaughter technique. Seventeen hens above 72 weeks of age were slaughtered in batches. Batch I consisted of 5 hens which were slaughtered initially. Batch II comprised of six hens, which were fed ad libitum broken rice (BR)-based diet for 18 days. Record of feed intake, number of eggs laid and egg weight during the period was kept. These hens were slaughtered and body energy content was determined. Egg energy was consisted as energy deposited. Batch III consisting of six hens which were fed varying quantity of diet for 15 days, were slaughtered similarly as hens of batch II. Regression equation (body weight to body energy) developed on batch I was applied to batch II and developed on batch II was applied to batch III hens, to find out initial body energy content of hens. Egg energy (EE) was calculated according to formula: EE (kcal) = -19.7 + 1.81 egg weight (g). Regressing metabolisable energy (ME) intake on energy balance (body energy change + egg energy), maintenance ME requirement of hens was found to be $119.8kcal/kg\;W^{0.75}/d$. Multiple regression of ME required for production on energy retained as protein and fat (body plus egg energy) indicated that RIR hens synthesize proteins with an efficiency of 85.5 and fat with an efficiency exceeding 100 percent on BR based diet.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.12
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• pp.1674-1678
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• 2017

Objective: The aim of the study was to evaluate genetic correlations between the behavioural profile and performance in laying hens as an indirect answer to the question whether the observed behavioural responses are associated with increased levels of stress in these birds. Methods: The assessment of birds' temperament was carried out using the novel objects test. The behavioural test was conducted in two successive generations comprising 9,483 Rhode Island White (RIW) birds (approx. 4,700 individuals per generation) and 4,326 Rhode Island Red (RIR) birds (approx. 2,100 individuals per generation). Based on the recorded responses, the birds were divided into two groups: a fearful profile (1,418 RIW hens and 580 RIR hens) and a brave/curious profile (8,065 RIW hens and 3,746 RIR hens). The birds were subjected to standard assessment of their performance traits, including SM, age at sexual maturity; ST, shell thickness; SG, egg specific gravity; EW, mean egg weight; IP, initial egg production; and HC, number of hatched chicks. The pedigree was three generations deep (including two behaviourrecorded generations). Estimation of the (co)variance components was performed with the Gibbs sampling method, which accounts for the discrete character of the behavioural profile denotation. Results: The analyses revealed negative correlations between the performance traits of the laying hens and the behavioural profile defined as fearful. In the group of fearful RIW birds, delayed sexual maturation (0.22) as well as a decrease in the initial egg production (-0.30), egg weight (-0.54), egg specific gravity (-0.331), shell thickness (-0.11), and the number of hatched chicks (-0.24) could be expected. These correlations were less pronounced in the RIR breed, in which the fearful birds exhibited a decline in hatchability (-0.37), egg specific gravity (-0.11), and the number of hatched chicks (-0.18). There were no correlations in the case of the other traits or they were positive but exhibited a substantial standard error, as for the egg weight. Conclusion: To sum up the results obtained, it can be noted that behavioural responses indicating fearfulness, i.e. escape, avoidance, and approach-avoidance may reflect negative emotions experienced by birds. The negative correlations with performance in the group of fearful hens may indirectly indicate a high level of stress in these birds, especially in the white-feathered birds, where stronger performance-fearfulness correlations were found. Fearful birds should be eliminated from breeding by inclusion of the behavioural profile in the selection criterion in the case of laying hens.