Sterility in the Rabbit Associated with Soybean Hay Feeding

Abstract

Partial reproductive failure in the New Zealand white rabbit characterized possibly by a failure in implantation or early fetal death, decreased litter size, stillbirths, frequent vascular breakdown, particularly in the uterus, numerous partial fetal resorptions, and some partial paralysis of does has been observed as a consequence of soybean hay feeding. The data for does fed rations which contained roughages other than soybean hay included 34 mated females with 32 known pregnancies resulting and 32 litters born at the time of parturition, totaling 267 young, with an average litter size of 8.3 young per litter. Data from studies where soybean hay was fed included 71 mated females, 48 known pregnancies, 22 cases of vascular brakdown, and 39 litters born at the time of parturition, totaling 226 young, with an average litter size of 5.8 young per litter. In some cases females on the soybean hay diet refused to accept the male when the diet was fed prior to the date of mating; others lost their litters from failure to provide nests and to suckle the young stisfactorily; and still others died during gestation, following severe hemorrhage. Research leading to identification of the specific factor or factors contributing to the impaired reproduction in the New Zealand white rabbit fed soybean hay is indicated.