Genetically Furless Rabbit Project at TAMUK

   

Effects of the recessive naked gene on postweaning fryer performance and thermo-tolerance characters in rabbits
A. D. Rogers* , S. D. Lukefahr; Texas A&M University-Kingsville.

This study investigated the effects of the naked gene on postweaning trait performance and thermo-tolerance characters in rabbit fryers during a 42-d growth phase in the summer of 2002 in subtropical south Texas. In 1999, a rare naked rabbit was born in El Campo, TX. "Fuzz", a Mini Lop rabbit, was mated to commercial New Zealand White does at Texas A&M University at Kingsville, which resulted in 16 F1 litters and 113 offspring, all of which had normal fur coats. To reproduce the recessive naked gene in the homozygous state, F1 x F1 inter se matings were made between half-siblings to create an F2 generation. In the F2 generation, 91 weaned fryers from 18 fraternal litter groups were produced. Based on an expected 3:1 phenotypic ratio (furred to naked classes), 70 rabbits had normal fur coats and 21 rabbits were naked. Most litters produced some naked and furred kits. Fryers were randomly assigned to growing pens containing either two or three non-littermate furred or naked rabbits. Individual fryer traits included initial and final body weights and ADG, as well as respiratory rate, rectal body temperature, and ear length, which were recorded at the end of the study. Pen traits included feed intake as an indicator of feed appetite. Data were blocked for effects of fraternal-litter, random pen (within naked and furred groups), age batch, gender, and initial age of fryer as a linear covariate when analyzing body weight traits. Results consisted of naked fryers being 212 g heavier and having 2.69 g/d more rapid ADG than furred rabbits (P<0.001). Initial ear length was generally associated (P<0.01) with more rapid ADG (linear regression of 0.1650.05 cm per g/d). Naked fryers had lower rectal body temperature (38.9 and 39.7C; P<0.001) and had lower respiratory rate (119.7 and 160.6 bpm; P<0.001) at 1400 h compared to furred rabbits, respectively. In addition, pens of naked fryers had higher daily feed appetites by 28.84.5 g per fryer than pens of furred rabbits (P<0.001). Our results indicate that naked rabbits had better thermo-regulation ability than furred rabbits. Based on these promising results, plans for developing a new breed of naked rabbits is justified, which has the potential to contribute more meat and income for subsistence families in tropical regions.

Keywords: Rabbits, Thermoregulation, Tropical Agriculture

Other articles:

Jackson, R., A.D. Rogers, and S.D. Lukefahr. 2006. Inheritance of the naked gene and associations with postweaning performance and thermotolerance characters in fryer rabbits from an F2 generation. World Rabbit Sci. (Spain) 14(3):147-155.

Rogers, A.D., C.J. Lupton, and S.D. Lukefahr. 2006. Fiber production and properties in genetically furred and furless rabbits. J. Anim. Sci. 84:2566-2574.