Does feeding time matter in gestation?

Commented article

Hayford M., Lee, S.H., Ren, P., Pangeni, D., Yang, X. and S. K. Baidoo. 2019. Effects of time of feeding during gestation on sow’s performance. J. Anim. Sci. 2019.97:1234–1241, doi: 10.1093/jas/skz006

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In gestation, sows have restricted access to feed through differently shaped feeding curves. In practice, to achieve the same total feed intake in the whole of the gestation period, some farms use a flat or almost flat curve (same amount of feed given daily) while others use a classical curve (high level of feed given during the first weeks, then considerably reduced in the middle period, and increased again in the last month.) The overall amount of feed given and the type of curve used will depend on the genetic line, the growth rate of the young sow or the amount of body reserves to be recovered from the adult sow, as well as the type of gestation facility and the logistics used to make up the sow grouping after the first month of gestation. The literature suggests that under normal conditions the total amount of feed administered throughout the whole period is more important than the actual shape of the curve used. It is also worth noting that in a system where feeding is done once, at the beginning of the day, sows remain calm after eating their morning meal. However, in facilities where feeding is done twice daily, sows are restless from mid-morning on, expecting the other half of their ration every time they see a worker.

The study found a few statistically significant results. The time of feeding did not actually affect the BW of the sows (p>0.8) throughout the trial. However, between days 30 and 109 of gestation, sows fed in the afternoon (15:30 h) gained more BF (3.69 vs 2.12, p<0.04) and lost more BF during lactation (-0.70 vs 0.17, p=0.17) than sows fed in the morning. In addition, those sows fed in the afternoon gave birth to one more piglet born alive (13.00 vs 12.02, p=0.25) and, considering the same number of piglets 24 hours post-farrowing, weaned half a piglet more (10.87 vs 10.33, p=0.09) with the same average weaning weight (5.99 vs 6.00, p=0.90). The authors attribute higher fat reserves (BF) to a higher level of triglycerides circulating in the blood, which has been observed in humans who consume a good portion of their diet during the evening hours. There is no solid explanation offered for the additional 0.5 piglet weaned; it is only suggested that sows starting lactation with higher BF have higher milk and colostrum production.

The results seem to suggest that a management strategy as simple as offering pregnant sows feed in the evening can improve the productive performance of the herd. However, since sows in this trial were kept in individual stalls throughout gestation, results cannot be extrapolated to farms where sows are kept in group housing following the first month of gestation. With group-housed sows, feeding time can potentially be very stressful, especially when feed is restricted. However, with electronic feeding systems, sows can have access to feed virtually all day long. Offering sows the option to eat during the quietest hours of the day gives the most vulnerable animals a chance to access feed when other animals are resting. In practice, however, some farms with machines start the daily feeding cycle in the afternoon.