EFFECT OF PREBREEDING MAINTENANCE DIET ON SUBSEQUENT REPRODUCTION BY ARTIFICIAL-INSEMINATION IN ALPINE AND SAANEN GOATS

The objective of this study was to investigate the effect of 2 levels of prebreeding nutrition on reproduction in yearling does artificially inseminated (AI) by the intrauterine laparoscopic method. Forty-two d oes (Alpine = 22 and Saanen = 20) were randomly penned in groups of 7 and were fed 1 of 2 diets. The diets contained 3.2 Mcal DE/d (MAINT) o r 3.5 Meal DE/d (HIGH), which was 10 and 20% higher than the National Research Council recommendations for maintenance requirements. The doe s were on the 2 feed treatments for 8 wk, after which the MAINT group was switched to the HIGH group diet. A week later, they were fitted wi th Veramix(R) sponges to synchronize estrus. The sponges were removed from 22, 10 and 10 randomly picked does after 17, 22 and 23 d, respect ively. All the does showed estrus within 48 h of removing the sponges. Previously frozen Alpine or Saanen semen (0.5 ml) was deposited into the uterus of does exhibiting standing estrus after anesthetizing them with zylazine and ketamine. Pure breeding was practiced. All the does lost weight prior to breeding. Seventeen does (41%) conceived and kid ded by AI while the rest returned to estrus about 23 d later. A signif icant difference (P < 0.05) in the kidding percentage was observed bet ween the 2 breeds (Alpine = 64% and Saanen = 16%), while the kidding p ercentage between the 2 diets did not differ (P > 0.05). Of the does t hat kidded, seven (41%) had singletons, eight (47%) had twins, one had triplets and one had quadruplets. Average litter size (kids/doe kiddi ng) by AI was 1.76. Although the does lost weight prior to breeding, t his did not affect their reproduction. (C) 1997 by Elsevier Science In c.