The experiment was performed on 60 French lop rabbits raised under extensive conditions and sacrificed at body weight of about 3 kg. It was found that the best indicators of meat weight (g) in rabbit carcasses were body weight, head width and lower thigh length among the traits measured in vivo, and carcass weight, chest girth and thigh circumference among the traits measured post mortem. In vivo prediction of saddle meatiness may be based on body weight, trunk length and thigh length, whereas post-slaughter estimation – on carcass weight, hip circumference and thigh circumference. Total meat weight in the hind half of the carcass may be predicted in vivo on the basis of body weight, head width and lower thigh length, and post mortem – on the basis of carcass weight, chest girth, hip circumference, thigh circumference and pelvic width. Multiple regression equations for meat weight estimation in the whole carcass and its middle and hind part were derived in the study. These equations may be applied in selection work directed towards an improvement in carcass meatiness. They may also be used to evaluate the results of experiments conducted on French lops.  

K. 2009. Effect of body weight on the carcass composition of French Lop rabbits. Can. J. Anim. Sci. 89: 47Á51. The experiment was performed on 60 male French Lop rabbits reared under extensive conditions and sacrificed at body weights of approximately 3 kg at the age of 150 d (30 animals) and approximately 4.5 kg at the age of 210 d (30 animals). Chilled carcasses without heads were divided into the front, middle and hind sections, which were then dissected to separate lean meat (including intramuscular fat), fat and bones.An increase in the body weight of rabbits at slaughter was accompanied by a decrease, of about 0.60%, in the proportion of the head and giblets (kidneys, liver, heart and lungs) in the carcass, and by an increase in the perirenal fat content from 0.66 to 1.69%. The average carcass dressing percentage of rabbits sacrificed at an average body weight of 3054 g reached 49.13%, and it was 2.49% higher than in rabbits slaughtered at a body weight of 4427 g. The percentage content of the front, middle and hind sections of the carcasses of the lighter rabbits was 38.50, 21.76 and 39.74%, respectively. In the carcasses of the heavier rabbits, the proportion of the front section was 2.29% higher, the proportion the hind section was 2.45% lower, while the proportion of the middle section remained at a similar level as in the lighter rabbits. The carcasses of the lighter rabbits, compared with the carcasses of the heavier rabbits, had a higher percentage content of meat (82.60 vs. 81.15%; P50.01) and a lower percentage content of fat (1.78 vs. 4.38%). In addition, rabbits sacrificed at a body weight of approximately 3.0 kg were marked by a higher content of lean meat in the middle and front sections of the carcass (by 1.89 and 3.07%, respectively), and by a slightly lower content of lean meat in the hind section (by 0.85%).Key words: Rabbit, body weight, slaughter quality Michalik, D., Lewczuk, A., Brzozowski, W. et Wawro, K. 2009. Incidence du poids sur la composition de la carcasse des lapins be´liers franc¸ais. Can. J. Anim. Sci. 89: 47Á51. L'expe´rience portait sur 60 lapins be´liers franc¸ais maˆles. Les animaux ont e´te´e´leve´s de manie`re intensive puis sacrifie´s au poids d'environ 3 kg a`l'aˆge de 150 jours (30 sujets) ou d'environ 4,5 kg a`l'aˆge de 210 jours (30 sujets). Les carcasses refroidies, sans la teˆte, ont e´te´de´bite´es en trois sections (avant, milieu, arrie`re) qui ont elles-meˆmes e´te´disse´que´es pour se´parer la viande maigre (graisse intramusculaire incluse), le gras et les os. La hausse du poids corporel s'accompagne d'une diminution d'environ 0,60 % de la teˆte et des abats (reins, foie, caeur, poumons) ainsi que d'une augmentation de la capsule adipeuse du rein, dont la proportion passe de 0,66 a`1,69 %. Le pourcentage de parage de la carcasse moyenne des lapins abattus au poids moyen de 3 054 g s'e´le`ve a`49,13 %, soit 2,49 % de plus que celui des sujets abattus au poids de 4 427 g. Chez les lapins moins lourds, l'avant, le milieu et l'arrie`re de l'animal repre´sentaie...

Abstract. The studies concerned the reproduetive perfonnance of four generations of sows originating from families where the average number of piglets in the first three litters amounted to: 8.1–9.0 (group A), 9.1–10.0 (group B), 10. 1–11.0 (group C) and more than 11.0 (group D). 988 sows and 2964 litters were examined altogether. The average number of piglets reared up to the age of 21 days in the first three litters of sows-family founders has a significant effect on the fertility and feeundity levels of sows in the next generations. The best results are to be expected in the case of sows originating from families where the average number of piglets in three successive litters was higher than 10. Sows coming from families in which the average number of piglets on 21st day was lower do not show promise of equally good reproductive performance, in spite of higher weight gains and better appearance (resulting from better conditions in the periods of pre- and postnatal development). In the private sector there were no sows originating from family founders in the group < 9,0 while 95% of them belonged to groups with average piglet number >10,0.