242. Reproductive performance of Australia Cashmere goats supplemented with lupin grain

Abstract

The productivity of Cashmere goats depends on their reproductive performance, which, in turn, depends on their level of nutrition. Ovulation rate and pregnancy in sheep are both affected by nutrition, but little is known about the response of female goats (does) to supplementary feeding. The lupin group (n = 40) received 250 g lupin per head per day in addition to pasture whereas the control group (n = 40) received no nutritional supplement. Both groups were synchronised for 17 days with intravaginal progestagen pessaries. The supplement was fed for 21 days, commencing 7 days before the bucks were introduced and intravaginal pessaries were removed (Day –2). Does were expected to ovulate 2 days later on Day 0 and the bucks were removed on Day 3. Blood was sampled for progesterone every 3 days from buck removal (Day 3) until Day 18. Ovulation rate was assessed by trans-rectal ultrasonography on Day 13 and pregnancy was diagnosed by trans-abdominal ultrasonography on Day 61 of the experiment. Does supplemented with lupins had a numerically higher ovulation rate than does fed only on pasture, but this difference was not significant (1.76 ± 3.21 v. 1.52 ± 3.79; P > 0.05). Similarly, there was no difference in the numbers of does conceiving to the first service between the lupin and control group (89% v. 94%; P > 0.05). Progesterone concentrations on Day 12 were higher in does supplemented with lupins than does fed only pasture (6.29 ± 0.27 ng/mL v. 5.41 ± 0.27 ng/mL; lupin and control group; P < 0.05). In conclusion, lupin supplementation induced a numerical increase in ovulation rate but this difference failed to reach significance. Does supplemented with lupins had higher concentrations of progesterone during early pregnancy, which is the opposite effect to that previously reported in sheep.