Author : Tablizo, Rogelio A.

Summary : First hand information on litter size and related reproductive parameters in ewes and does were gathered under field conditions. A series of experiments were conducted to determine the effect of short-term mineral oil treatment on the concentrations of peripheral serum progesterone and liver cytochrome P-450, ovulation rate, and eventually, litter size in indigenous sheep and goat. Litter size, interval between births, gestation, postpartum successful mating, and seasonal mortalities were assessed out of 167 kiddings and 355 lambing records of indigenous ewes and goat herds in commercial size operations. In Study II, three representative does from each group (A = control; B = mineral oil) were treated daily with 10 ml of either plain water (A) or mineral oil (B) initiated on day 11 until the onset of estrus following PGF (subscript 2) alpha treatment given on day 16. Animals were slaughtered during estrus for cytochrome P-450 quantification. In a follow up study, 26 does were randomly assigned to same groupings (A & B). Serum pregosterone concentrations were quantified on samples collected on day 15 or after 5 days of treatment. In Study III, 24 cyclic indigenous does and 12 ewes were randomly assigned by species into two treatments, A and B. Ewes were subjected to change over design with 2 cycles intervening between periods. Oral daily doses (10 ml for goat; 15 ml for ewe) of either treatments were given for 10 days, initiated on day 11 in does and day 7 in ewes. On the 7th day of treatment, PGF (subscript 2) alpha was administered to all animals. Laparotomy was done three days after estrus for determination of ovulation rate related parameters. The last study involved 40 does and 61 ewes randomly distributed into two treatments A and B. Oral daily dose (10 ml/head for goat; 15 ml/head for ewes) of either treatments were given 10 days before breeding. Litter sizes and birthweights after treatments were assessed. Indigenous ewes herd had mean litter size of 1.05 + 0.21 while purebred.