Optimising post-weaning feed intake: Effective management and nutritional strategies

Peadar Lawlor & Louise Clarke presented recently at the Teagasc Pig Farmers’ Conference 2023. They spoke about their research in optimising post-weaning feed intake.

Weaning is a critical period in the pig’s life. Piglets are confronted with abrupt changes to their physical and social environment, as well as management and nutritional changes, at a time when their immune system is not fully developed. All of these changes/stresses lead to a reduction in post-weaning feed intake and weight gain, which is commonly referred to as a post-weaning ‘growth check’. Management and nutritional strategies can be employed during the suckling period to equip piglets to deal with the major stressors encountered at weaning. In each case the objective is to improve intestinal health, reduce latency to the first feed post-weaning, and increase early post-weaning feed intake and growth. Correctly implementing these strategies will not only increase post-weaning growth and reduce mortality, but also maximize lifetime growth in pigs.

Pre-weaning Factors

Weaning age: Over the last decade, the national average weaning age recorded on the Teagasc Profit Monitor (PM) has increased from 28 days in 2010 to 31 days in 2022. However, in reality, the age at weaning ranges from 24 days right up to 34 days. Housing, feeding and management must be impeccable for earlier weaned pigs if problems with post-weaning thrive and health are to be minimised or avoided. Younger weaned pigs have a less well developed gut with poorer intake, and lower and more inconsistent daily live-weight gain. Research has shown far fewer problems when pigs are weaned at 28 days compared with 21 days, as the older pigs show better post weaning adaptation, have higher feed intakes, lower removal rates and are more feed efficient during the next four weeks. There may also be a place for increasing weaning age to 35 days on some units to improve post-weaning feed intake and growth (Table 1). If increasing weaning age is not an option, then every effort should be made to increase the weaning weight of piglets. The following have been found to be effective in this regard.

Table 1. The effect of weaning age on growth performance to 10 weeks of age.

Hygiene in the farrowing room

Measures taken to increase internal biosecurity in pig production have been shown to increase pig growth, reduce mortality and reduce antibiotic usage. Our work shows that implementing an effective hygiene routine (optimised cleaning and disinfection) in farrowing accommodation reduced the number of clinical cases of disease recorded per litter, leading to a reduction in the volume of antibiotics and anti-inflammatories that needed to be administered to piglets up to weaning. As a consequence of this, average piglet weight at weaning was also significantly increased.

Pain relief for sows

We are all very conscious that litter size in sows has increased dramatically in the past decade. This brings with it serious challenges for the producer. For instance colostrum yield per sow has not increased, so it is more difficult to ensure that each pig gets sufficient colostrum intake from the limited pool of colostrum available. We believe that ensuring adequate colostrum and milk intake to all pigs will help increase pre-weaning growth but will also reduce the need to treat suckling pigs with anti-inflammatories and antibiotics. One strategy to investigate this involved administering Meloxicam (Loxicom® Injection, Norbrook, Ireland) to sows as soon as possible after the placenta was delivered. The idea here was that administration of pain relief to the sow would facilitate greater suckling by the pigs. From this work we can conclude that the practice increases colostrum intake and weaning weight in piglets. Equally important, it will also reduce the number of clinical cases of disease in piglets thereby reducing the need to use injectable antibiotics and anti-inflammatories.

Creep feeding

Creep feeding is a strategy used to increase piglet energy and nutrient intake and familiarize them with solid food prior to weaning. Creep feed is typically composed of highly digestible ingredients and will benefit suckling piglets in several ways, including:

• Supplementing sows’ milk in late lactation to meet the pig’s energy and protein requirements
• Stimulate gut and digestive enzyme development
• Increase piglet weaning weight
• Stimulate earlier feed exploration by newly weaned pig – this mitigates some of the adverse effects of weaning stress
• Reduce the ‘growth lag’ normally observed in pigs after weaning
• Increased post-weaning and lifetime growth performance in pigs

It is important for farmers to find ways to increase creep-feed consumption in the farrowing rooms. This will help get piglets off to a better start at weaning. Steps such as feeding a good quality starter diet with a high milk powder content for at least 14 days prior to weaning, feeding on a “little and often” basis making sure feed is always fresh and available, and always using a feeder for feeding creep feed will all help to encourage feed intake for piglets. It is also important that the pellets used are not too hard, and there is some evidence to suggest that feeding larger rather than smaller pellets will help to increase creep feed intake. Liquid creep feeding will also promote increased feed intake.

Post weaning factors

Promote water intake

It is vitally important to encourage piglets to maintain fluid intake post-weaning. It can take more than a week after weaning for the pig to restore its daily fluid intake to the equivalent of that on the day prior to weaning. According to Fowler and Gill (1989) a suckling pig has equivalent water consumption prior to weaning of ~680ml; however, water intake is only ~290ml in the first day post-weaning and averages

~442ml in the first week after weaning. It is only in the second week post-weaning that water intake averages ~770ml/pig. Encouraging water intake will promote feed intake. Appropriate sizing, number, positioning and hygiene of water drinkers is essential to ensure adequate hydration and feed intake. Equally important is ensuring the chemical and microbiological quality of the water supply used.

Diet Acidification

Early weaned pigs produce insufficient levels of gastric acid which can result in a high stomach pH. As a result, the digestion of nutrients, especially protein is reduced. Moreover, high pH is favourable for the proliferation of diarrhoea-causing micro-organisms in the weaned pig. The use of organic acids has been suggested as a means of lowering gastric pH in weaned pigs and has been reported to improve growth performance. Feed intake in one experiment was increased by ~32% in week 1 and by 11% over the first 3 weeks after weaning due to the dietary addition of fumaric acid. However, the response to diet acidification is not always consistent and is likely to be higher at times of greater microbial challenge. An alternative strategy to diet acidification, to achieve similar results, is to feed a diet with a low acid binding capacity.

Reduced crude protein diets

Reducing crude protein (CP) in the diet prevents an excess of undigested protein reaching the large intestine, where it contributes to the growth of pathogenic bacteria, such as E. Coli and the production of harmful compounds. The practice can reduce the incidence of diarrhoea in pigs. The requirements of weaned pigs for amino acids are high for growth but also to counteract health challenges, and therefore low CP diets must be supplemented with synthetic amino acids. Bellego and Noblet (2002) showed that reducing CP in post-weaning diets from 20.4 to 16.9% with adequate synthetic amino acid supplementation was an effective approach to limit diarrhoea in pigs weaned at 28 days, without affecting weight gain and protein deposition.

Feeding liquid milk replacer post weaning

Recent research in Moorepark has shown that post-weaning liquid milk supplementation increased feed intake and growth in the immediate post-weaning period which will likely benefit light and vulnerable pigs at weaning. Since milk supplementation greatly increased early post-weaning feed intake, the practice could be particularly useful for delivering bio-active compounds to the pig gut during the critical post-weaning window. Providing liquid milk replacer in addition to dry pelleted starter diet, improved the intestinal structure of newly weaned piglets. The results suggest that the period of liquid milk supplementation should be for between 4 and 10 days post-weaning. However, on a dry matter basis, milk replacer is almost three times the price of a starter diet and for this reason should be used sparingly.

Summary

We have listed management and nutritional strategies to increase post-weaning feed intake in pigs and thereby improve post-weaning piglet growth and feed efficiency. All these strategies will help reduce the growth check pigs experience after weaning. This is particularly important in an era of reduced antimicrobial usage and the ban on use of therapeutic levels of zinc oxide in feed. Increasing feed intake in the first few days post-weaning will not only increase post-weaning piglet growth but is also strongly associated with lifetime pig growth, making it a goal worth achieving.

Project funding

The PigNutriStrat project is funded by the Irish Department of Agriculture, Food and the Marine’s Competitive Research Funding Programmes (Grant no: 2019R518).

MonoGutHealth, is funded from the European Union’s Horizon 2020 research and innovation programme under grant agreement N° 955374.

Read more from the Teagasc Pig Farmers’ Conference 2023