SATOH J. Fac.Agric., Iwate Univ., Associate, 農学部・獣医学科, 助手 (30250632)
OKADA K. Fac.Agric., Iwate Univ., Associate, 農学部・附属家畜病院, 助手 (60233326)
NAITO Y. Fac.Agric., Iwate Univ., Professor, 農学部・獣医学科, 教授 (40003785)
OSAWA T. Fac.Agric., Iwate Univ., Associate, 農学部・獣医学科, 助手 (90302059)
|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 1998 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1997 : ¥2,700,000 (Direct Cost : ¥2,700,000)
To make program for reproductive improvements in infertile Japanese Black cattle, Japanese Black cows (n=47) in a prolonged non-pregnant condition were used in these studies. Blood was collected 0, 1, 2, 3, 5, 1 3, and 21 weeks after entering the pasture. The serum chemical components, namely TP, Ht, AIb, BUN, NEFA, T-cho, TG, glucose, AST, and ApoB-1 00, were analyzed. Body weight, body height, and the circumference of the chest were also measured at that time. A total of 47 cows were given an initial injection of PGF_<2alpha> at 3 weeks after entering the pasture.
Eleven of 37 cows (29.7%) artificially inseminated at oestrus after the PGF_<2alpha> treatment of were pregnant. The 22 (62.9%) by natural mating in the pasture. All together, thirty-three of the 47 cows (70.2%) used in the experiment became pregnant.
By clinico-biochemical studies, it was concluded that the cows during the pasture were in the condition of negative energy balance during early pasture feeding because of the accelerated energy metabolism, changes in the feeding environment, and the diet. It was also indicated that the ability to lipometabolize in the liver declined because of the mobilization of a lot of triglycerides from body fat at 3 weeks. During pasture feeding, therefore, we believe it would be better to start breeding programs in cows with reproductive failure at 5 weeks after the enterance of the pasture.
The objective of this study was to determine the effect of probiotics and past exposure to the pasture environment on BOS and lipometabolism in the liver in pasturing Japanese Black cows. It was concluded that, in cows that had been previously exposed to the pasture environment, the damage of the liver function on lipometabolism due to pasturing stress during the early pasturing period may be less severe than in naive cows. Moreover, time to the resumption of the liver function in pasturing cows could be shortened by the oral administration of probiotics.