Luteal inadequacy as a possible cause of repeat breeding syndrome in dairy cattle

Abstract

Repeat breeder (20) and 6 normal cycling (control) cattle were examined per rectally and blood samples were collected on days 0 (ovulation), 6, 7, 10, 12, 14 and 18 of the estrous cycle to study the cause of repeat breeding. The progesterone concentrations (P4) in control animals were I.593±0.41 on day 6 post ovulation and 2.935±I.26 ng/ml between days 77...12. Out of 20 repeat breeder animals, II (55%) were diagnosed as early (day 6 post ovulation) luteal deficient. Two animals (10%) showed lower progesterone than control during mid luteal phase (days 7-12 post ovulation). One animal (5%) was deficient in progesterone concentration during both early and mid luteal phase. In () animals (30%) the mean progesterone concentration remained 1.154±0.98 ng/ml throughout the luteal phase. rt appears fi'om the present study that the subnormal or delayed rising of plasma progesterone levels during different stages of luteal phase may be the possible cause of repeat breeding syndrome in dairy cattle.