Effect of the length of the suckling period and dietary energy intake in lactation on the duration of postpartum anestrus in Creole goats

PAEZ LAMA, S.; GRILLI, D.; EGEA, V.; FUCILI, M.; ALLEGRETTI, L.; GUEVARA, J.C.; JAHN, G.A.

JOURNAL OF SMALL RUMINANT RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 139 p. 1 - 6

0921-4488

The objective of this study was to determine the effect of the length ofthe suckling period and the dietary energy level on the duration of postpartumanestrus in Creole goats. Twenty-eight multiparous pregnant goats (bodyweightBW 39.9 ± 6.4 kg; mean ± SEM) each bearing a single fetus were used in a 2suckling period (30 vs. 60 d) x 2 levels of energy intake (low (L) vs. high(H)) factorial design. Kids were separated from their dams 3 d after birth andthen suckled twice per day until weaned at 30 or 60 d postpartum. Dams weanedat 30 d postpartum were hand milked for the next 30 d. Goats were individuallyfed chopped alfalfa hay + balanced concentrates (45: 55 DM basis) at 3 % of BWin the last month of pregnancy and at the same level to the L goats in thepostpartum period when the H goats were fed at 4 % of BW. Energy balance wasestimated by difference between energy intake and calculated energyrequirements. Duration of postpartum anestrus was estimated by determining theoccurrence of ovulation from changes in blood progesterone concentrations.There were no significant lengths of suckling x energy intake levelinteractions. Goats on all treatments lost weight until 45 d postpartum withmore weight loss on the low than the high energy intake level (L 4.06 ± 0.43vs. H 1.99 ± 0.64 kg; P < 0.05). The daily 4 % FCM production was similarfor all treatments (overall mean 1.10 ± 0.01 kg). The difference between thepostpartum anestrus period between low (129 d) and high (128 d) dietary energylevels was not significant but no goat ovulated while in negative energybalance. The effect of suckling on the resumption of ovarian activity washighly significant (P < 0.001) with goats weaned 30 d postpartum resumingovulation 102 d after parturition compared to 155 d for those weaned 60 dpostpartum. This study illustrates the importance of the bond between the doe and its kid in the prolongation of the anestrus period in goats.