Logistic regression was used to develop models predicting preweaning survival in 334 neonatal swine. Measured risk factors included birth weight, litter size (live born), dam parity, serum IgG concentration, serum ELISA titers recognizing common gram-negative core antigens, and serum concentrations of the third component of complement. Larger birth weights were associated with increased probability of preweaning survival. The highest mortality was observed in litters with more than 12 pigs. Pigs with serum concentration of the third component of complement (C3) in the lowest stratum, < 20% adult pooled C3 standard (APC3), had reduced mortality, compared with high (> 38% APC3) and middle (20 to 38% APC3) groups. Associations between all other variables, including total serum IgG concentration and preweaning survival were not significant. Few pigs had hypogammaglobulinemia, < 3% of the study population had serum IgG concentrations < 1 g/dl. Of all measured variables, only birth weight and dam parity were significant predictors of preweaning gain. Larger pigs and pigs born to third or greater parity dams had more preweaning gain than other pigs.

Studies were undertaken to determine the efficacy of milbemycin oxime against the enteric adult stages of Trichinella spiralis and of albendazole against the muscle stage larvae in experimentally infected dogs and cats. Specific-pathogen-free Beagle pups (n = 6) and domestic shorthair kittens (n = 6) were inoculated with 7,500 first-stage larvae of Trichinella spiralis. Physical examination (including collection of blood and fecal samples) was performed weekly. During the first week after inoculation, all animals had mild gastrointestinal tract disturbances, but stages of T. spiralis were not observed in the feces. Beginning on postinoculation day (PID) 10, 3 pups and 3 kittens were treated with milbemycin oxime (1.25 mg/kg of body weight, PO, q 12 h) for 10 days. Muscle biopsy specimens were taken from dogs and cats on PID 26 and 29, respectively. Mean numbers of larvae per gram of muscle were 30.3 in the control and 37.7 in the treated dogs. Mean numbers of larvae per gram of muscle in the control and treated cats were 318.7 and 89.3, respectively. Two dogs and 2 cats were removed from the study at that time. The remaining animals, 2 each of the control and milbemycin oxime-treated animals, were given albendazole (50 mg/kg, PO, q 12 h) for 7 days starting at PID 31 and 34 in dogs and cats, respectively. Muscle biopsy specimens were again taken at PID 46 and 49, for dogs and cats, respectively; mean numbers of larvae recovered from muscle were 0.6 for dogs and 13.5 for cats.

This study was carried out to determine suitable selection factors for recipients and embryos which could improve pregnancy rates following bovine embryo transfer. The experiment included 52 surgical transfers from February, 1985 through June, 1986 performed on Kyongbuk Breeding Center in southern Korea. The pregnancy rate was highest when recipients were in estrus within 6 hours before the donor to 12 hours after the donor (78.3 % versus 50 % for recipients in estrus earlier or later). Pregnancy rates were acceptable following culture under field conditions for up to 17 hours. More recipients over 15 months of age (76.1 %) remained pregnant than those under 15 months (66.7 %). Embryos transferred during the months from February to July resulted in higher pregnancy rates than those transferred during the remaining 6 months (77.3 % versus 57.1 %). Transferrable embryos were classified A (best) to C (worst); those graded A or B resulted in significantly higher pregnancy rates than those graded C (81.8 % and 73.3 % versus 25.0 %, p0.05). Pregnancy rates among recipients of the Korean native breed tended to be higher than among Holstein recipients (100 % versus 71.1 %). Similarly, when the embryo was transferred to the right uterine horn, pregnancy rates tended to be higher than when it was transferred to the left (81.3 % versus 65 %). Pregnancy rates did not differ according to the stage of development of the embryo; they were for morulae, tight morulae, blastocysts, and advanced blastocysts, respectively : 75.0 %, 66.7 %, 75.0 %, and 77.4 %