SIRE EFFECTS ON CARCASS TRAITS OF JAPANESE BROWN COW

Abstract

The present research aims to obtain more fundamental knowledge of genetic effect (sire effect) on carcass traits of Japanese Brown cow. This experiment was done at Kumamoto Prefecture Japan. The field data of ultrasonic estimates of carcass traits of 9468 head of Japanese Brown cow, which had born from January 3rd 1988 to December 25th 1993 and representing by 88 head of sires were collected. All data were included of pedigree status. Cows data of ultrasonic estimates of carcass traits were taken at the first registration examination. (???15 months of age or ??? 40 months of age).\ud The carcass traits were estimated by ultrasound of Japanese Brown cow were Musculus longissimus thoracis area (MLTA) between the 6th and 7th ribs on the left side of each animal, Subcutaneous Fat Thickness (SFT), Intermuscular Fat Thickness (IMFT), Rib Thickness (RT) and Marbling Score (MS). The data obtained were statistically analyzed by LSMLMW procedure and Duncan test.\ud The average age of cows in this study was 22.7 months. The mean of MLTA was 32.4 cm2 while the means of SFT, IMFT and RT were 10.5 mm, 18.3 mm and 44.9 mm respectively. The mean of MS was 0.52. Sire effects were significant for all ultrasonic estimates of carcass traits (P<0.01). Cows sired by Mitsushige ET, Mitsutake, Mitsumaru, Dai 5 Harutama, Dai 10 Mitsumaru and Namimaru tended to have large MLTA and tended to have high of MS while tended to have optimum SFT, IMFT and RT compare to another sire. Mitsushige ET has the highest genetic quality and should be considered as breeding sire in selection