Maternal undernutrition during pregnancy impairs offspring behaviours and thereby their survival rate indirectly by decreasing lamb birth weight or by deteriorating milk production which in turn limits bonding of the dam with the neonate. This study was aimed to investigate the effect of maternal feed restriction during late pregnancy on performance and behaviours of ewes and their lambs. Twenty-four Ghezel ewes were allocated to the three experimental treatments including ad libitum intake (AL); restricted feed intake by 60 % (FR); and propylene glycol- supplemented restricted diet (FR + PG). AL and FR + PG ewes had higher circulating oestradiol (P < 0.001) but not progesterone (P < 0.0001) than FR ewes during late pregnancy and parturition. Prepartum undernutrition of FR ewes resulted in lower milk yield (P < 0.001) and higher milk fat percentage (P < 0.0001) than AL and FR+PG ewes during the initial three weeks of lactation. In the case of offspring behaviours, lambs born to ewes offered PG+FR treatment were quicker to kneel, stand up, reach to the udder, suck and play within the first 2 h of birth compared with those born to ewes offered FR and AL treatments (P < 0.0001). Lambs from FR+PG ewes had a higher birth weight (P < 0.05), weaning weight (P < 0.0001) and average daily gain (P < 0.0001) than those from the other groups. Concerning maternal behaviours, FR+PG ewes started grooming their lambs faster than ewes in other groups (P < 0.01). Moreover, it took more time for FR ewes to deliver their lambs or deliver their second lamb in multiple deliveries compared with those in the other groups (P < 0.01). The maternal recognition test revealed lambs born to AL and FR+PG ewes preferred to spend more time with their dams than did lambs born to FR ewes at 12 h of age (P < 0.0001). The results also showed that the time taken for the lambs to reach the contact zone or to reach their dam was substantially longer for lambs from FR ewes than those from AL and FR+PG ewes at 12 h and 24 h of age (P < 0.0001). There was a positive correlation between lamb birth weight and average daily gain (r= 0.36), weaning weight (r=0.64), survival rate (r=0.62). It can be concluded that although maternal under nutrition can adversely affect maternal and neonatal behaviours, supplementing glucogenic precursor as a strategy can alleviate the majority of physiological and behavioural abnormalities and might have beneficial outcomes for farmers.
|Publication Title||Applied Animal Behaviour Science|
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