The influence of prepartum feeding strategy on the initiation of parturition in Jersey cows
Parturition is an integral component of the reproductive history of a dairy cow. Parturition is associated with physiological and physical changes, as well as environmental- and management-related stressors, which can all contribute to complications developing during parturition. Physiological challenges such as a decline in dry matter intake, an increase in nutrient demands, immune-suppression, and resulting systemic stress and inflammation (especially around calving) can be experienced by the periparturient cow. If these challenges are managed incorrectly, endocrine disturbances and metabolic disorders could arise that negatively affect the health status of the cow, milk production in the next lactation, and overall reproductive performance.
Not only is the transition period challenging for the cow, but it is also labour-intensive. Efficient and effective management and experienced personal is crucial to ensure optimal management of a dairy farm and parlour during the periparturient period. Intensive supervision of calving behaviour, monitoring of health status and assistance if needed during birth is crucial. At the end of lactation, cows are moved to a non-lactating (dry) cow group. In the three weeks prior to calving, certain dairy farms will move “far-off” dry cows to a “close-up” cow camp, in contrast, other dairy farms will make use of maternity pens when calving signs are first observed. After birth the calf is separated from the dam into a calf rearing system. In the USA, 28% of the producers practice immediate calf-dam separation, and 50% remove the calf from the dam within 12-24 hours after birth. After separation of a calf from its mother, colostrum intake, feeding protocol, access to solid feed, as well as a calf’s immediate environment, will play a vital role in ensuring a calf’s overall health.
When normal working hours on commercial dairy farms are considered, farm staff are normally present to observe pregnant cows from 06h00 to 17h00, which complicates the timely feeding of colostrum to neonate calves that are born during the night, i.e. after normal working hours when there is normally no supervision and calving assistance. Although certain farms have continuous supervision of cows close to parturition, this management strategy is not economically viable on all farms. By synchronizing cows to give birth during normal daytime working hours, the management of cows and neonatal calves in the periparturient period could be optimised. It is generally accepted that feeding cows in the evening tends to increase daytime calving, which will allow for timely intervention to ensure colostrum intake of neonate calves, and assistance during dystocia. Several studies have reported on the influence of feeding time on the onset of parturition in dairy cows.
Several studies have investigated the effect of the time of feeding and different types of feed on the time of parturition in cattle and sheep, but results seem to be inconsistent. It is known that evening feeding could increase the number of cows calving during the day, however the physiological reason of the relationship between the time of feeding and the onset of parturition has not yet been established. The aim of this trial is therefore to determine the influence of prepartum feeding strategy on the onset of parturition considering the physiological changes, time of feeding and calving behaviour.
The aim of this trial will thus be to determine the potential of a night-time feeding practice on the initiation of parturition in dairy cows to promote calving during a normal working day on dairy farms, and to establish the potential of the associated physiological changes to serve as bio-indicators of the onset of parturition in dairy cows. Linked to the overall aim of the project, the objectives will be:
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To compare the potential of a daytime and a night-time feeding strategy to synchronize onset of parturition to ensure daytime calving.
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To determine the influence of timing of the onset of parturition on calf mortality and morbidity, as influenced by feeding strategy.
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To determine the influence of daytime and night-time feeding on pre-partum behaviour of dairy cows.
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To determine the influence of feeding strategy on maternal blood glucose and progesterone levels in the periparturient period, i.e. specifically from 21 days pre-partum to two days post-partum.