ABSTRACT
Cows in severe negative energy balance after calving have reduced fertility, mediated by metabolic signals influencing the reproductive system. We hypothesised that transition diet could alter metabolic status after calving, and thus influence fertility. Multiparous dairy cows were assigned to four transition groups 6 weeks pre-calving and fed: (a) basal control diet (n = 10); (b) basal diet plus barley (STARCH, n = 10); (c) basal diet plus Soypass (high protein, HiPROT, n = 11); or (d) no transition management (NoTRANS, n = 9). All cows received the same lactational diet. Blood samples, body weights and condition scores (BCS) were collected weekly. Fertility parameters were monitored using milk progesterone profiles and were not affected by transition diet. Data from all cows were then combined and analysed according to the pattern of post-partum ovarian activity. Cows with low progesterone profiles had significantly lower insulin-like growth factor-I (IGF-I) and insulin concentrations accompanied by reduced dry matter intakes (DMIs), BCS and body weight. Cows with prolonged luteal activity (PLA) were older and tended to have lower IGF-I. Analysis based on the calving to conception interval revealed that cows which failed to conceive (9/40) also had reduced IGF-I, BCS and body weight. Fertility was, therefore, decreased in cows which were in poor metabolic status following calving. This was reflected in reduced circulating IGF-I concentrations and compromised both ovarian activity and conception. There was little effect of the transition diets on these parameters.
Subject(s)
Cattle/physiology , Diet , Fertility , Lactation , Animals , Body Composition , Body Weight , Corpus Luteum/physiology , Fatty Acids, Nonesterified/blood , Female , Insulin-Like Growth Factor I/analysis , Milk/chemistry , Ovary/physiology , Parturition , Pregnancy , Progesterone/analysis , Time FactorsABSTRACT
A single extra-amniotic injection of 2 or 4 mg of prostaglandin E2 in Tylose gel was administered to 30 primigravidae between the ages of 14 and 20 years to induce first-trimester abortion. Twenty-three patients (76.7%) aborted, though incompletely, within 9 hours, with a mean induction-abortion interval of 6.3 hours. In the remaining 7 (23.3%) the cervical os was found to be open and no mechanical dilatation was required at the time of vacuum aspiration. The only side effect was vomiting, which occurred in 2 patients. The method was shown to be safe and effective and may be employed in young primigravidae, thus eliminating the cervical complications attending vacuum aspiration.