Anything that reduces the palatability of the feed will reduce intake.
Peet on Pigs
First of two articles on nutrition during lactation
The nutritional demands on the sow during lactation have increased in recent years because litter size has gone up due to genetic improvement. At the same time, sows have become leaner so they have much less backfat to mobilize if their nutritional needs are not met. Consequently, management of the sow and gilt must ensure that feed intake is maximized in order to achieve a high level of reproductive performance. Some of the main factors that influence feed intake are:
Total gestation feed intake has a major effect on lactation intake. This is especially relevant in the gilt, where overfeeding in gestation is a common cause of reduced lactation intake. Also, sows that are over-conditioned at farrowing are likely to have a higher stillbirth level and more udder problems. Therefore feed levels in gestation should be carefully adjusted so that sows enter the farrowing room in condition score 3.0 -3.5 on a 1-5 scale.
While sow condition is not directly related to backfat, it is a practical method to use on the commercial unit. Backfat depth is a more accurate indicator of body energy reserves and backfat level at farrowing is linked to lactation feed intake. Recent Danish work showed that sows with 25mm of backfat at farrowing lost 5mm during the lactation period, whereas those with 15mm at farrowing lost only 2mm because sows with higher backfat eat less in lactation. However, sows with a lower level of backfat had more shoulder abrasions.
Overfeeding prior to farrowing is one of the most common reasons for reduced lactation feed intake and a range of other problems. It causes too much milk to be produced prior to farrowing causing the udder to shut down milk production. Then, when piglets are born, there is inadequate milk available, leading to starvation and loss of body condition.
Eventually the sow’s milk production recovers but piglets are small for their age and unable to digest the volume of milk consumed, leading to scouring at 7-10 days of age, which results in a lower weaning weight. Sows that are fed too much prior to farrowing will eat less in lactation. Therefore, feed intake should be reduced to 2.0kg/day for sows and 1.8kg/day for gilts at 4-5 days prior to the expected farrowing date.
High lactation feed intakes will not be achieved unless the sow has access to a plentiful supply of fresh, palatable water at all times. The recommended flow rate for bite or nose drinkers in farrowing crates is 2.0 litres/ minute although, where possible, this should be 2.5-3.0 litres/ minute.
Even where flow rate is adequate, provision of additional water will lead to increased feed intake, especially where mash is fed. Sows do not drink sufficient water at around the time of farrowing and may become dehydrated, therefore provision of additional water in the trough at this time will help to maximize milk production immediately after farrowing. Additional water can be provided with a hose or by fitting a water tap or valve to each crate.
Room temperature – the sow’s temperature requirement falls rapidly as feed intake increases and maintaining a high temperature will significantly reduce sow appetite. The ideal temperature at farrowing (assuming no drafts) is 21C and this can be reduced by 1C every 3-4 days to reach 17C by day 14 after farrowing when outside temperatures allow this to be achieved.
Trough hygiene and feed freshness. Anything that reduces the palatability of the feed will reduce intake. Therefore it is essential to remove wet, stale or dirty feed each time the sow is fed. Also, any buildup of uneaten feed should be removed. Variation in sow appetite can make it difficult to avoid uneaten feed, however, good implementation of a lactation feed scale will help to minimize such problems.
A wide range of other factors influence feed intake and may be considered when trying to maximize consumption during lactation. These need to be reviewed on the individual farm if consumption is not at the required level. I have seen situations where slippery slatted floors resulted in sows not wanting to stand up and therefore eating less.
Inadequate lighting can also lead to lower intake. Long day length (16 hours) and a high light intensity have been shown to increase feed intake, although light is rarely considered a relevant factor on most farms.
Excessive disturbance in the room during the first two days after farrowing can disrupt suckling behaviour and reduce feed intake, so it is important to minimize noise and activity during this time. In a problem situation, anything that may adversely affect sow or piglet health or comfort needs to be investigated.
Feeding management during the lactation period has a major impact on reproductive performance of the sow and gilt. Attention to a range of management, environmental and nutritional factors, especially water availability, room temperature and trough hygiene, will help to maximize feed intake. This will result in fewer problems at farrowing, lower stillbirths, reduced pre-wean mortality, good sow health, high weaning weights and a short and consistent weaning to re-breeding interval. In my next article, I will look at how to maximize nutrient intake in lactation, especially in younger females.