Age at first estrus, ovulation rate, and age at anestrus in puberal Boer xSpanish and Spanish does

Sixty doe kids from Spanish dams and Beer (n=6) or Spanish (n=6) sires were used to evaluate selected reproductive traits. Using plasma progesterone c oncentrations, first estrus was detected at 7.7 and 7.5 months of age in Bo erxSpanish (BS), and SpanishxSpanish (SS) doe kids, respectively. Body weig hts (BW) at first estrus were 45% (BS), and 50% (SS) of BW at 18 months of age. Onset of anestrus occurred at 11.3 and 11.4 months of age for BS and S S does, respectively. BS does had an ovulation rate of 1.24, as compared to 1.27 for SS does. Breed, BW nearest first estrus, and birth date were not significant sources of variation for reproductive traits. Age at first estr us was four months greater in twin-born does relative to single-born does. No significant differences were found between BS and Spanish does for age a t first estrus, ovulation rate, and age at anestrus. The results indicate t hat BS crossbred does are similar to Spanish does for female reproduction. (C) 1999 Elsevier Science B.V. All rights reserved.