Effects of restricted nursing on milk production and collection, kid growth and plasma prolactin and growth hormone concentrations in dairy goats

Abstract

The milk production of dairy goats under various regimes of mother-young contact from day 4 post partum were studied during the first 2 months of lactation, together with the prolactin (PRL) and growth hormone (GH) responses to udder stimulation. In the control group, 13 goats and their kids were left in permanent contact and did not undergo milking. In two additional groups, goats were machine milked once a day in the morning (at 0800 h) and kids were allowed 10 hours (from 1000 to 2000 h; 10H group, n = 11) or 5 h (from 1000 to 2000 h; 5H group, n = 11) of mother-young interaction per day. In the last group (MO, n = 10), mothers were permanently separated from their kids on day 4 post partum and milked once a day. Milk production during a 24-h period at 37 days post partum performed by controlled nursing and weighing of the kids (groups with kids) or by two machine milking 12 h apart (milking only group) revealed a higher production in the three groups with some mother-young contact than in the MO group. Total milk collected by milking over the 2 months of the study did not differ between the three groups that underwent milking. Kid weights at 2 months were 3.4 to 4.8 kg. lighter in the groups that underwent milking than in the control group. Hormonal profiles were significantly affected by restricted mother-young contact, with highest pre-stimulation concentrations of PRL and GH in the 5H group. Restricting mother-young contact from the first week postpartum can permit an early collection of milk without major effects on kid growth, when compared with one daily milking in goats totally separated from their young.

Milk let‐down in goats can be influenced by the type of stimuli applied or to which goats are exposed during suckling and hand milking

“…In a previous study, we determined that in Alpine goats, allowing some time for mother–offspring contact (5 h/day), starting 1 week after parturition until 60 days of lactation, resulted in an adequate collection of milk during milking. Notably, this milk collection did not differ from goats whose goat kids were removed on Day 4 postpartum (Hernández et al, 2007). Although our study on the presence of the dams' own goat kids was performed over a very short period, these results provide new information about the period after weaning, with regard to the stimuli relating to milking that can affect the milk let‐down and yield.…”

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

“…The presence of the young strongly inhibits the resumption of postpartum sexual activity, and sensory stimulation caused by suckling is a very important component of this process (Ascari et al, 2013). During early lactation prolactin concentration is increased in goats that nurse their kids as well as in those that are machining milked (Hernandez et al, 2007). Prolactin has an inhibitory effect on GnRH, so high levels of prolactin reduce the concentration of follicle stimulating hormone (FSH) and decrease the frequency of pulses of luteinizing hormone (LH), inhibiting ovulation (Ascari et al, 2013).…”

The Course of Machine Milking in Small Ruminants

“…The mother-young bond plays an important role in the modulation of maternal endocrinology also in goats (Hernández et al, 2002). In addition, a prolonged period of maternal nursing may have positive effects on the welfare of the mothers and their young (Hernández et al, 2007). Dairy ewes produce 25% of total milk production in lactation during their first month of lactation.…”