A total of 94 sows were injected intramuscularly at the root of the ear with 0.05mg of Prostaglandin F2αanalogue at 114 days of pregnancy. Twenty control sows were injected with 2.0mlof solvent alone and allowed to deliver spontaneously. The average time of beginning of parturition was 12: 20 p.m. at 115 days of pregnancy in the treated sows and 2: 45 a. m. at 116 days of pregnancy in the controls. The average time required until the occurrence of parturition was 25.77 and 38.67 hours in the treated and control sows, respectively. There was a significant difference in it between the two groups (p>0.05). The rate of parturition during the working time was 41.5% in the treated group and 30.0% in the controls. The average time required for delivery was 4.18 and 4.39 hours in the treated and control groups, respectively. There was no significant difference in the average number of newborn young, the time required for discharge of the placenta, or the frequency of appearance of abnormality in piglets between the two groups.
Immunoglobulin (Ig) concentrations and maternal antibody titers in serum were investigated in calves 1.5-4.5 hours old which had been fed a different quantity of colostrum. The colostrum had been stored at-20°for about 1 year until this experiment began. Four groups, A, B, C, and D, of 4-5 calves each received 5, 15, 25, and 35 ml/kg of pooled colostrum, respectively. The Ig concentration in serum was 0 or trace in precolostral calves. No viral antibody titer was detected from these calves. The Ig concentration increased significantly in calves fed colostrum for 3 days after birth of all the groups, but A. Maternal antibody titers against adenovirus 7 (ADV7), bovine virus diarrhea virus (BVDV), parainfluenza virus 3, and infectious bovine rhinotracheitis virus increased significantly in these animals. From these results, it seems necessary to nurse with 40ml/kg of colostrum at least for granting effective maternal antibody to neonatal calves. Changes in antibody titers against Corona virus, ADV7, and BVDV in the colostrum which had been supplemented with 0.5%, or 1% propionic acid (P) and the same dose of lactic acid and which had been stored at 5°or 20°were studied. The antibody titer of 0.5% P colostrum at 5°was neary stable for 6 to 10 weeks, but those of all the groups at 20°decreased in the early stage. In conclusion, 0.5% P colostrum kept at 5°might confer lactogenic immunity effectively to neonatal calves.