Introduction

Weaning weight is an extremely important component of Weaning Capacity and also has a major influence on growth and feed efficiency from weaning to market. An increase in weaning weight of 0.5kg (1.1lb), which is possible on many farms, can boost Weaning Capacity by up to 35kg (77lb), assuming 70 pigs weaned per sow lifetime.

Genetic influences

Genetics plays a significant role in improving weaning weight and Hypor’s selection index places major emphasis on piglet quality traits such as birth weight, survival to weaning and weaning weight. In addition, rigorous selection for teat number and quality, together with physical robustness, results in females that can support big litters and produce large amounts of milk.

Daily feed intake of sows is an important trait in maternal lines, which is highly heritable and directly linked to growth performance and feed conversion. Feed intake in lactation partly determines traits like milk production and body condition loss during lactation. Hypor’s breeding programme has aimed to increase feed intake capacity, but at the same time there has been pressure for conversion efficiency.

One of the results of this is that the Hypor sow is a very efficient converter of feed into milk. Daily feed intake has been continuously increased over the last decade. This means that under more harsh conditions such as in hot or tropical climates the Hypor sow still maintains its intake at a good level. The simultaneous pressure on weaning capacity, feed efficiency and increased daily feed intake has resulted in a relatively efficient sow. Focusing on litter weight gain from birth to weaning in the breeding programme has helped to improve the total milk production of Hypor sows.

For optimal technical and financial results it is necessary to have your sows produce as much milk as possible because it is the best and cheapest feed for piglets you can get!

Weaning Age

Piglets grow at about 250 to 275g (0.55 to 0.61lb) per day during the suckling period, so that extending weaning age is a very effective way of improving weaning weight. Although a longer lactation results in a slight drop in litters per sow per year, farrowing rate and litter size are improved in the subsequent cycle. Consequently, producers around the world are moving towards later weaning. Assuming a weaning age of 24 to 26 days, it is possible to achieve a weaning weight of 7kg (15lb) or more.

Lactation feed intake

Feed intake during the suckling period is by far the biggest influence on weaning weight and also has a major effect on subsequent reproductive performance. Therefore attention to the following areas is essential in order to maximize weaning weight.

Feed intake during gestation

Total gestation feed intake has a major effect on lactation intake. This is especially relevant in the gilt, where over-feeding in gestation is a common cause of reduced lactation intake. Therefore feed levels in gestation should be carefully adjusted so that sows enter the farrowing room in condition score 3.0 to 3.5 on a 1 to 5 scale. Sows that are over-conditioned at farrowing are also likely to have a higher level of stillbirths and more udder problems.

Feeding prior to farrowing

Sows that are fed too much prior to farrowing will eat less in lactation and are much more likely to lose their appetite at seven to 10 days after farrowing. Therefore, feed intake should be reduced to 2.0kg(4.4lb) per day for sows and 1.8kg (4.0lb) per day for gilts at four to five days prior to the expected farrowing date. Overfeeding at this stage is one of the most common reasons for reduced lactation feed intake and health problems in the sow and piglets.

Water availability

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 minimum flow rate for bite or nose drinkers in farrowing crates is 2.0 litres (67.6fl oz) per minute. Even where flow rate is adequate, provision of additional water, particularly just prior to and immediately after farrowing, will lead to increased feed intake, especially where meal is fed. This 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 therefore maintaining a high temperature will significantly reduce sow appetite. The ideal temperature at farrowing (assuming no draughts) is 21 to 22°C (69.8 to 71.6°F) and this can be reduced by 1°C/3.8°F every three to four days to reach 17 to 18°C (62.6 to 64.4°F) 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 build-up of uneaten feed should be removed.

Lactation feed scale

Sows are not able to produce large amounts of milk if they are not provided with sufficient feed. On the other hand, overfeeding, especially early in the lactation period, may result in loss of appetite and feed wastage. Also, individual sows show considerable variation in their feed intake, which makes a standard feed scale ineffective. Despite these challenges, it is possible to apply a scale based on the stage of lactation and individual appetite.

In the first two to three days after farrowing, feed can be increased by 0.5kg (1.1lb) per day from a starting level of 2.5kg (5.5lb) per day such that by day four or five, feed intake is ad libitum. All sows and gilts should consume as much feed as they want. In barns where ad libitum feeding is not possible due to the type of feed system in use, feeding three or four times a day is often necessary to get similar results. Close observation of the sows and gilts is required to adjust feed requirements to individual needs. Not all sows will eat tremendous amounts of feed but it is important to offer the feed and let the sows eat what they want when they want.

Feed intake can be maximized when ad-lib feeding from a self-feeder from day 4 of lactation onwards. This works where a dry feeder is used. Our experience with wet-dry feeders has produced mixed results due to management difficulties in some barns.

Lactation Diets

Hypor’s lean, efficient sows have the potential to produce large amounts of milk and require adequate energy and protein to do so. Depending on the feed intake achieved during lactation, milk production may be improved by increasing total dietary lysine, typically from 1.0 per cent to 1.2 per cent. Where it is practically possible, feeding a higher lysine diet to gilts and second parity females is beneficial. In the summer months, when appetite is reduced, nutrient intake can be improved by increasing ration density through the addition of oils and extra amino acids. Oils and fats are high in energy and, importantly in hot weather, produce little heat when they are metabolized.

Piglet Management

High litter size results in the need to ensure that all piglets receive adequate colostrum after birth and have a good supply of milk right up to weaning.

This may require the judicious use of split suckling and fostering.

Stimulation of high milk production in gilts is also essential to ensure correct development of the udder and maximise milk production. It has been shown that placing 12 to 13 large piglets on gilts results in higher milk production in subsequent litters because the milk glands are better developed.

November 2009