Achieving a better piglet feed intake

Preparing a well-balanced, palatable, and highly digestible diet at optimal cost is, of course, of the highest importance in providing appropriate nutrition to piglets. This is however not enough if diets are simply placed in self-feeders, especially for pigs immediately following weaning at an early age, thus leaving young pigs to cater for themselves.

Feeding management is the frontline in the battle to increase feed intake at an age when pigs do not really associate nourishment with dry diets. Below several well-established feeding practices are briefly described.

Creep feeding

The use of pre-weaning supplementary feed (creep feeding) has been debated without conclusion for over 30 years. The arguments for this practice are two-fold: (1) less body condition loss for the sow and thus improved reproduction performance, and (2) better piglet condition at weaning expressed as heavier weaning weights, advanced enzymatic system development, and thus a less expensive starter feed programme. There are, however, arguments against creep feeding and not the least of which are potential problems with allergenic reactions in the gut wall initiated by certain feed antigens (e.g., soy proteins). Work carried out at Bristol University over a number of years clearly showed that small sensitising doses of feed allergens when given over a period of days pre-weaning can drive massive hypersensitivity reactions post-weaning when piglets are exposed to larger amounts of the same feed proteins.

The solution, therefore, is to apply a creep feeding regime that will involve relatively high feed intakes before weaning takes place to properly expose the digestive system to dry feed. Most nutritionists would agree that approximately 500 g of feed per piglet before weaning will cause immunological tolerance to in-feed antigens and prevent most adverse reactions after weaning.

To achieve this target feed intake, a rigorous management protocol has to be applied to every litter. Fresh, highly digestible and palatable feed should be offered at least three times daily and the feeding should start at between seven to ten days after birth. The use of appetisers and palatants may offer additional benefits in the achievement of target feed intake. In commercial practice, the first stage post-weaning feed is frequently used also for creep feeding.

Creep feeding is strongly recommended when weaning age exceeds 21 days, but most research has failed to demonstrate any benefits from creep feeding piglets less than three weeks of age. In contrast, when weaning age exceeds 21 days, then there are clear benefits from creep feeding (see Figure 1).

Liquid feeding

The use of liquid feeding systems for weaned piglets has been explored both commercially and experimentally. There have been successes and failures over the years and the technology has proved difficult to translate into commercial practice, because the control of all aspects of nutrition, microbiology, engineering, and practical management has been difficult to achieve. However, this image is changing rapidly with great improvements done in the last ten years or so. There are significant benefits in terms of animal performance when liquid feeding systems work well. Feed intake, growth rate, and feed efficiency are generally enhanced compared to dry feeding systems, because of the higher gut health achieved with liquid feeding systems. The sudden withdrawal of sow’s milk, with its protective IgA molecules and growth factors, at weaning causes villi regression that takes several days to recover. This is clearly avoided with liquid feeding.

Liquid feeding is not without its problems. In commercial practice, there are large variations in the performance of weaned pigs on liquid feed systems because of the enormous array of equipment, feed ingredients, and management protocols used. Moreover, the level of feed intake can be occasionally so high that nutritional scours result. The control of the microbiological content of feed can be difficult. Liquid feeds contain around 20%-25% dry matter and tend to ferment quickly with a rapid decline of acidity. This is useful if fermentation leads to lactic acid production, which is supportive of animal gut health, but fermentation, or lack of fermentation, often leads to an inappropriate overgrowth of gram negative bacteria and a severe propensity towards acute diarrhoea.

Recently, advances in fermented liquid feeding promise the delivery of a more stable and beneficial microbiological load in feeding systems. Fermentation of feed for about eight hours at around 21˚C can ensure rapid decline of pH and production of lactic acid. The control of fermentation with pre-fermented feed or starter cultures is the newest development.

Mat-feeding

Mat- or floor-feeding is a powerful technique to start early weaned pigs on dry diets, especially when they have none or limited exposure to creep feeding. Research and practice have both demonstrated that pigs could more than double their feed intake and weight gain if they are offered feed on a floor-mat during the first few days post-weaning. Yet, without proper management, results can be unsatisfactory. Practical experience indicates that a high quality and very digestible diet is important in mat-feeding as this will be the first diet that most pigs consume. The ideal starter diet is a sticky meal that sticks to the pigs’ snouts and requires them to lick it. Pellets and blends of pellets with mash (meal) are also very effective, but pellets are wasted easier because pigs tend roll them over the edges of the mat. Large mats with at least 1-cm rims and surface grooves are required to minimise wastage. Mats should be placed next to feeders but away from corners, waterers, and heat lamps to avoid fouling. For the first day post-weaning a small amount of feed should be placed on the mats, four to six hours after pigs arrive and frequently be replenished as pigs start eating dry feed.

Feed should always be available for ad libitum consumption in self-feeders, which must be clean and properly adjusted. On the second day post-weaning a blend of mash and pellets encourages pigs to consume more pellets for a smoother transition to feed in self-feeders. Mat feeding should be discontinued after the third or fourth day unless pigs appear thin and challenged. As a general rule, most nursery managers feed on mats at least three times per day for a total of 100-150 g/pig per day to force piglets to use the feeders.

Feeder adjustment

Proper adjustment of feeders is a labour- and time-intensive task, but an essential one that markedly reduces feed wastage, especially during the nursery period when diets are expensive. Research on feed wastage is practically unavailable, yet it is rather easy to comprehend that wasted feed adds to the cost of production. Wastage ranges from less than 5% in properly managed feeders to more than 15% when inadequate feeder design is combined with inadequate management.

Based on practical experience, it is normally suggested to close the feeder adjustment gate initially and then fill the feeders with the first starter pellet, and then to adjust gates to the proper height whilst slightly shaking or tapping the feeder. During the first week post-weaning, allowing 2/3 of the feeder pan to be covered with feed ensures that pigs are attracted to the feed. In the following weeks of the nursery period, allowing less than 1/3 of the feeder pan to be covered with feed ensures minimal feed wastage. Care should be taken to adjust feeders again when switching from pellets to mash or vice versa. Mash (meal) diets rich in milk products tend to bridge in feeders more often than simpler diets based on cereals and vegetable proteins. Mash diets on the other hand tend to flow better when particle size is increased, but this may also reduce feed efficiency and increase nutrient load in excreta.

Observing pigs and watching for wastage around feeders and underneath slats is the most appropriate way to determine how much feed is wasted and whether the feeder gates need further adjustment. Moistened feed from environmental moisture and saliva tends to stick on gate openings reducing flow, and feed tends to bridge more during periods of increased temperature and humidity.

Gruel-feeding

Pigs offered gruel easily increase dry matter intake during the pre- and post-weaning period. Pigs offered liquid or semi-liquid (gruel) feed benefit from improved gut health and metabolic status. Because gruel-feeding is a labour- and time-intensive technique, its application is often limited to feeding runt or fallback pigs after weaning, and surplus neonatal piglets.

Based on practical experience, it is frequently advised to use a milk replacer instead of water for gruel to markedly increase acceptability. Lock-down feeders and bowls are sufficient for gruel-feeding, but a highly digestible starter diet must be used. Preferably, runt pigs should be penned separately and started on gruel immediately after weaning. In addition, a special pen should be assigned for fallback pigs that usually appear during the first two weeks post-weaning. Pigs should receive gruel no more than three times per day; otherwise, they fail to eat dry pellets, which should be offered ad libitum in dry feeders. Feeding gruel for three to five days is usually enough for most piglets to recover and associate dry pellets with nourishment. A gradual change from gruel to an all-dry diet is recommended and thus, gruel consistency must be gradually thickened to allow pigs to adapt to dry diets. Pigs should receive only enough gruel so that all is consumed in a single feeding in about 20 minutes. At least one feeder for every ten piglets is recommended to ensure sufficient consumption of gruel by all pigs. Good hygiene is a very important ingredient in successful gruel feeding programmes.

Water management

Water is always the last nutrient to mention in every nutrition publication. Yet, it is the first nutrient needed for survival. During the first few days post-weaning, piglets might consume more water than they actually need as a measure against hunger and the absence of sow’s milk. Once consumption of dry feed commences, piglets consume 2-4 litres water per kilogramme feed.

Restriction of water intake clearly depresses feed intake. When water intake is limited because of blocked nipples, inadequate pressure, or excessive competition, feed intake is drastically reduced. High-protein diets, such as those usually fed during the first two weeks post-weaning also require an ample supply of water to excrete excess nitrogen via urine. Based on practical experience, it is strongly suggested to thoroughly clean the watering system before pigs arrive. Products that remove organic matter from pipes in addition to disinfecting from bacteria are usually more effective than disinfectants alone. All nipples and cups should be tested for proper operation periodically. Flow rate at the beginning, middle, and end of the pipe system should be at least 250 ml per minute until pigs reach 10 kg body weight, and 500 ml per minute until pigs reach 30 kg body weight. At least one nipple or cup for every 10-20 pigs, depending on pen design and feeder placement, is essential, and nipples should be adjusted to pigs’ shoulder height throughout the nursery period. To start pigs on water, nipples should be allowed to drip for the first 6-12 hours post-weaning. Finally, frequent checks for sulfates (may cause diarrhoea), hardness (increase maintenance of the watering system), and microbial contamination (salmonella and colibacillus) should be performed, although piglets can tolerate a rather wide array of water quality according to a Canadian study.