Rusa deer (Cervus timorensis russa) farming in New Caledonia: impact of different feed levels on herd breeding rate and performance of newborn fawns

Objective To measure the impact of undernourishment during the rutting period on the breeding rate of Javan rusa deer and performance of fawns from birth to weaning.
Design A random controlled trial.
Animals Two groups of 37 hinds.
Procedure Group P grazed improved pasture and group M native grassland through the rutting period. Hinds were weighed at the beginning and the end of rutting, at ultrasound scan and prior to fawning. Fawning was monitored.
Results At the end of the rutting period, the mean difference in weight between the two groups was 8.5 kg and the pregnancy rate was 95% for group P and 57% for group M. Fifty births were recorded which equates to a fertility rate at 24 hours of 60% for group P and 30% for group M. Fawn mortality occurring in the first 24 hours affected 26% of all fawns. In 54% of the cases, newborn deaths were subsequent to abandonment by the hind. Average rusa fawn weight at birth was 3.6 + 0.1 kg, regardless of sex or group. Among fawns that weighed less than 3.0 kg, the mortality rate was 55%. The newborn fawn weight was related to the weight of the hind at ultrasound scanning. The weaning rate at 20 weeks was 84% for both groups. Mean weight gains for sucking fawns were 150 g per day for the first 2 months and 108 g per day from 60 to 120 days regardless of sex or group. The mean weight at 60 and 120 days was 12.7 kg and 18.5 kg, respectively. Two regression equations enable the calculation of the weight at 60 and 120 days using the fawn weight at birth and hind weight at the beginning of the rutting period.
Conclusion A 5% weight loss for the hinds resulting from undernourishment during the rutting period causes a 32% reduction in the herd fertility rate, without affecting the weight of newborn fawns, the survival rate nor growth performances in the sucking phase.