Heterosis, maternal and direct effects for postweaning growth traits and carcass performance in rabbit crosses

Abstract

A crossbreeding experiment was carried out in Egypt using a local breed (Baladi Red, BR) and New Zealand White (NZ) to estimate direct heterosis, maternal additive effects and direct sire effects on some growth and carcass traits in rabbits. Data of body weight (at 5, 6, 8, 10, 12 weeks) and daily gains (at intervals of 5-6, 6-8, 8-10, and 10-12 weeks) on 2153 weaned rabbits were collected. Carcass performance at 12 weeks of age (weight and percentages of carcass, giblets, head, fur, blood and viscera) on 213 male rabbits was evaluated. Estimates of coefficients of variation (CV) for most growth and carcass traits were high and ranged from 10.0 to 40.2%. Sire-breed was of considerable importance in the variation of growth traits and some carcass traits, while dam-breed contributed little. Sire-breed × dam-breed interaction affected (P<0.01 or P<0.001) most body weights and gains studied, while it contributed little to the variation of carcass traits. The purebred NZ resulted in rabbits with heavier weights and carcass and with lighter non-edible carcass (blood and viscera) compared to the BR. Heterosis percentages for most growth traits were significant and ranged from 2.5% to 5.0% for body weights and from 0.7% to 9.5% for daily gains. Insignificant positive direct heterosis was observed for most carcass traits. Crossbred rabbits from NZ sires with BR dams were superior to from the reciprocals. Maternal-breed effects on most weights and gains were insignificant, while sire-breed contrasts for some weights and gains proved significant. Postweaning growth and carcass performances of BR-mothered rabbits generally surpassed the NZ mothered, while NZ-sired rabbits were superior at later ages. High edible carcass was observed for BR-sired rabbits, while more non-edible carcass wastes (blood and viscera) for NZ-sired rabbits. Maternal-breed effects appeared to be less important than paternal-breed effects in influencing most weights, gains and carcass traits studied. ZUSAMMENFASSUNG: Heterosis, maternale und direkte Wirkungen bei Wachstums- und Schlachtkörpermerkmalen in Kaninchenkreuzungen Der Kreuzungsversuch wurde mit lokalen ägyptischen Rassen (BR) und Neuseeland Weißen (NZ) zur Schätzung direkter Heterosis, maternaler additiver Wirkungen, direkter Vater-Wirkung auf einige Wachstums- und Schlachtkörpermerkmale von Kaninchen durchgeführt. Angaben über Körpergewicht (5, 6, 8, 10, 12 Wochen) und Zuwachs (Intervalle 5 bis 6, 6 bis 8, 8 bis 10, 10 bis 12 Wochen) wurden von 2153 abgesetzten Kaninchen gewonnen. Die Schlachtkörperleistungen bei 12 Wochen Alter (Gewicht und Anteil von Schlachtkörper, Kopf, Pelz, Blut und Innereien) stammen von 213 männlichen Kaninchen. Schätzungen der Variationskoeffizenten (CV) für meiste Wachstums- und Schlachtkörpermerkmale waren hoch und bewegten sich zwischen 10 und 40,2%. Vaterrasse hatte erheblichen Einfluß auf Unterschiede in Wachstumsrate und einige Schlachtkörpermerkmale, während die Mutterrasse weniger beigetragen hat. Interaktion zwischen beiden beeinflußte die meisten Körpergew...

Analysis of reproductive performances during the formation of a synthetic rabbit strain

“…Direct heterosis on the female body weight (5.6%) is in agreement with the moderate values observed by BRUN and OUHAYOUN (1989), which were between 1.6% and 6.3% on 79 d-body weight, and AFIFI et al (1994), who reported heterosis ranging between 2.7 to 9.5% for post-weaning body weights and gains, but higher than the ones obtained by KHALIL et al (2005b) (BRUN, 1993, BRUN andSALEIL, 1994), between 5.5% and 12.5% in the cross between New Zealand White and Californian breeds (NOFAL et al, 1996), between 4 and 10% in the cross of line A with lines V and H (BASELGA et al, 2003) and between 2.0 and 8.5% in the cross between V line and Saudi Gabali (KHALIL et al, 2005a).…”

Genetic analysis of slaughter and carcass quality traits in crossbred rabbits coming from a diallel cross of four maternal lines

“…For this trait, the contrast G ' M L V -was not significant but the magnitude of the difference was high. Afifi et al (1994), Piles et al (2004), Ouyed et al (2008) and Al-Saef et al (2009) studied crossbreeding parameter in the same slaughter traits as we are considering, however they did not report any significant effects.…”

“…Similarly, Ouyed et al (2008) obtained significant direct effects for LW63 and DP between Californian (CA) and New-Zealand White (NZ) breeds. Al-Saef et al (2009), using crosses between the V line and the Saudi Gabali found that, in general, the effects of the V line were higher than the effects of the Saudi Gabali. These effects were significant for live weight, HCW, DP, HW and LHW, the fattening period finished at 84 d of age.…”

“…With Californian, American Chinchilla and New-Zealand White breeds, Ouyed et al (2011) generally obtained zero or low heterosis for body conformation and carcass traits. Al-Saef et al (2009), using crosses between the V line and the Saudi Gabali, found that the heterosis estimates were mostly positive but only significant for CSkW, HW and LHW. Significant and negative values of heterosis were found by Zabadilová et al (2008) in different crosses between 2 HYPLUS lines for live weight, carcass weight and hind leg weight.…”

“…Significant and negative values of heterosis were found by Zabadilová et al (2008) in different crosses between 2 HYPLUS lines for live weight, carcass weight and hind leg weight. In Al-Saef et al (2009) andZabadilová et al (2008), the young rabbits were slaughtered at 84 d of age.…”