Inclusion of maize in the grazing diet of goats during the last 12 days of gestation reinforces the expression of maternal behaviour and selectivity during the sensitive period

Abstract

The objectives of this study were to investigate if partial substitution of a grazing diet with maize during the last 12d of gestation in goats bred under semi-arid grazing conditions improves maternal behaviour and reinforces the exclusive mother–kid bond at 3h after birth. For the first objective, 20 pregnant goats and their single kids were randomly assigned to 1 of 2 treatments (10 per group): (1) only grazing (control group); and (2) grazing plus 0.6kg/d of supplemental maize during the last 12±1.0d before parturition (maize group). Frequency of amniotic fluid and amniotic membrane consumption and invitations to suckling were higher in the maize group than in the control group during the first 30min after birth (P≤0.049). Duration of invitations to suckling tended to be higher in the maize group than in the control group (P=0.07). For the second objective, 81 pregnant goats were randomly assigned to the same treatments as above to evaluate the effect of dietary treatment on maternal selectivity. During the maternal selectivity test (5min), frequency of low-pitched bleats and udder acceptances to their own kids was higher in the maize group than in the control group (P≤0.03). The control goats emitted more low-pitched bleats and tended to show more udder acceptances to alien kids than the maize group (P≤0.06); emission frequency of low- and high-pitched bleats towards their own and alien kids did not differ in the control goats (P≥0.22). The number of udder rejections and aggressive behaviours towards their own kids was higher in the control goats than in the maize group goats (P≤0.005). At 3h postpartum, 93% of the goats fed maize were maternal, whereas only 78% of the control goats were maternal (P=0.048). Of the maternal mothers in each group, 88% of the goats in the maize group were selective at 3h postpartum (36/41), whereas only 52% of the goats in the control group were selective (15/29, P=0.001). Finally, at birth, kids born from maize goats were significantly heavier than the kids born from control goats (P=0.003). We concluded that feeding supplemental maize during the last 12 days of gestation to goats maintained under semi-arid grazing conditions improves maternal behaviour at birth and significantly reinforces maternal selectivity at 3h postpartum, which may increase the survival of kids during the first days after birth.