Modeling of growth curve in farm bred broiler rabbits in organized rabbitry

Rabbit rearing across the Indian subcontinent is growing rapidly. Growth traits are important parameters on which rabbits are being evaluated. Mathematical models have been tried to establish a relationship between body weight and time. Data spread over six years on the weekly body weight of Soviet Chinchilla and White Giant rabbits were collected and subjected to analysis for assessment of genetic parameters and factors which influence the weekly body weight. Three nonlinear growth models; Gompertz, Logistic, and Von Bertalanffy were fitted for both the breeds separately as well as collectively. The least squares mean for weekly body weights in rabbits from weaning to maturity showed an increasing trend. White Giant rabbits weigh higher than Soviet Chinchilla. The period and season of kindling had a significant influence on the weekly body weight of rabbits. The value of growth curve parameter k (an indicator of growth performance) was estimated to be higher for White Giant by all three models. All three models performed well with a high coefficient of determination values. However, Von Bertalanffy model fitted well for Soviet Chinchilla and Gompertz model for the White Giant as well as when both the breeds were fitted collectively.

Analysis of Reproductive Traits of Broiler Rabbits Reared in Sub-temperate Climate of Kodai Hills, Tamil Nadu, India

Aim:

The present study was carried out at Institute Rabbit Farm of Southern Regional Research Centre, Mannavanur, Kodaikanal, Tamil Nadu, India having sub-temperate climate with winter temperature during night hours going below 0°C with an objective of finding the influence of different factors such as breed, year, season and parity on different reproductive traits of broiler rabbits in order to come out with the best strategies for improving the productivity.

Materials and Methods:

A total of 1793 records (946 White Giant and 847 Soviet Chinchilla) for weight at mating (WM), weight at kindling (WK), gestation length (GL), litter size at birth (LSB) and litter size at weaning (LSW), litter weight at birth (LWB), and litter weight at weaning (LWW) were collected in the period between 2000 and 2009 and the data was analyzed using general linear model option of SAS 9.2.

Results:

The overall mean GL, WM, WK, LSB, LSW, LWB, and LWW were 31.68±0.04 days, 3.65±0.01 kg, 3.84±0.01 kg, 6.91±0.08, 5.49±0.09, 387.62±4.07 g, and 4.66±0.07 kg, respectively. The breed has significantly influenced GL, WK, LSW, LWB, and LWW. The LSB, LSW, LWB, and LWW were 7.05±0.11, 5.76±0.13, 399.55±5.88 g, and 4.87±0.10 kg, respectively in White Giant and corresponding values for Soviet Chinchilla were 6.78±0.11, 5.22±0.12, 375.91±5.64 g, and 4.46±0.09 kg, respectively. The year of kindling had significantly affected all the reproductive traits under study and is varying over different years. The parity significantly influenced the WM, WK, and LWW. The LWW increased from first (4.16±0.21 kg) to second parity (4.86±0.19 kg) and remained in the same range from third parity onward. WM was significantly higher in spring season (3.72±0.02) than the animals in rainy (3.59±0.02) and winter season (3.65±0.02). Better reproductive performance in terms of higher LSB, LSW, LWB, and LWW as observed in the present study might be due to conducive environmental conditions prevailing in the region.

Conclusion:

The significant effects of the non-genetic factors like year of kindling on all reproductive traits, season, and parity on some of the traits in rabbit breeds are indications that any future production enhancement strategy must take into consideration the environment by providing additional care, feed supplementation and better shelter management to the rabbits, so that the full genetic potential can be realized.

Growth and reproductive performance of two rabbit breeds reared under intensive system in Ghana

A study on the growth and reproductive performance of two rabbit breeds was undertaken. Data on 588 kits and 97 does of California White and 574 kits and 90 does of New Zealand White rabbits reared under hot and humid environment in Ghana were taken. The reproductive performance of the two breeds, in terms of litter size at birth and weaning, litter weight at birth and weaning, kindling interval, age at sexual maturity, and gestation length as influenced by breed, season of kindling (rainy and dry), year of kindling (2005-2012), and parity (first to sixth and over) were determined. The performance of California White in terms of litter size at birth, at weaning, kit weight at birth, and age at first kindling was 5.9 ± 0.2, 4.6 ± 0.1, 54.7 ± 0.4 g, and 159.8 ± 0.2 days, respectively. That of New Zealand White was 5.9 ± 0.1, 5.1 ± 0.1, 55.2 ± 1.0 g, and 159.9 ± 0.2 days, respectively. The results obtained also showed a significant breed effects on kit weight at birth, litter weight at weaning, and mortality; whereas no significant differences (p > 0.05) were observed between the two breeds regarding the other traits measured. Parity had significant effects (p < 0.05) on all the growth and reproductive parameters measured with the exception of age at first kindling. Year of kindling also had significant effect on litter weight at birth, kit weight at birth, and at weaning (p < 0.05) but did not have any significant effect on the age at sexual maturity and mortality. Season also had significant (p < 0.05) effects on kit weight at birth, gestation length, kindling interval, and mortality with better performance experienced during the rainy season.