Imagine being a piglet, lying comfortably with brothers and sisters next to mum. And then – without prior notice, you are picked up and dropped off somewhere else in a busy place with loads of others. Gone is the milk, gone is the peace and quiet, help! What can producers do to help this piglet through weaning?
Despite the advances in technology, research, and experience, post-weaning feed intake remains low compared to the genetic growth potential of early-weaned pigs (weaned at 21-28 days of age).
This persistent and expensive problem is a side effect of early weaning, but is also due to problems in feed presentation and overall management. Under modern commercial conditions, most pigs experience some degree of post-weaning appetite depression. This invariably increases production cost and hampers performance and profitability throughout the finishing stage. Today, even in the best managed facilities, it is not uncommon for some pigs to starve for as long as three to five days after weaning, whereas others may start eating a few minutes after placement in the nursery.
The reasons for post-weaning anorexia are many and complex. The consensus is that weaned pigs do not eat because of radical changes in their feeding behaviour, and feed form and composition after weaning. Before weaning, the sow is responsible for feeding the piglets at regular and frequent intervals, whereas communal liquid feeding is the norm for piglets. After weaning, the same piglets are faced not only with a stressful physical and social environment, but also with the decision of when and how much to feed by themselves. To make things worst, where water was provided in conjunction with solid matter in sow’s milk, now the weaned pig needs to distinguish between thirst and hunger and also to realise that these needs must be satisfied via separate media.
High feed intake
Ensuring a high feed intake during the early post-weaning period is highly important. Research and experience has repeatedly demonstrated that low feed intake during the early post-weaning period severely limits growth potential, increases temperature and management requirements, intensifies morbidity and mortality, and reduces turnover of facilities and capital. In general, for every 100 g of extra feed per day consumed during the first week post-weaning, body weight increases by 1 to 2 kg at the end of the fourth week post-weaning. This has a dramatic effect on overall performance during the growing-finishing period as pigs that barely maintain their weaning weight during the first week post-weaning may require an extra 10 to 20 days to reach market weight compared to pigs that grow at their pre-weaning gain rates during the same period.
Early weaned pigs require about 300 g of dry feed per day, during the critical first week post-weaning, to maintain their pre-weaning growth rate. Actual feed intake, however, rarely exceeds 200 g per day during this period and this is barely enough to maintain body weight at thermo-neutral conditions. In most cases, an average feed intake of 150 g per day is considered the best case scenario.
Fortunately, progress in nutrition and feeding management has equipped producers with an array of measures to prevent starvation and enhance post-weaning feed intake. All or some of the following are used successfully in profitable operations.
This is rather obvious, but it cannot be over-emphasised how important a high health status is in creating an environment for maximum post-weaning performance. Anything that can be done to improve the health status of individual pigs and the whole farm facility should be done: the expenses are always justified.
2. Feed quality
Feed intake generally increases by enhancing the digestibility of the diet. This is the main reason why most nursery diets are fortified with cooked cereals, milk proteins, fish meal, and simple sugars such as lactose and sucrose. Although such diets are more expensive than simpler diets (based on corn and soybean with a bit of whey), the benefits are tremendous in terms of improved performance and health during the whole grow-out period. Ingredients of poor digestibility pass rather intact along the gastro-intestinal tract to the large intestine where they promote bacterial proliferation that invariably leads to diarrhoea. Spending on high quality piglet feeds is a good investment.
Antimicrobial agents (including antibiotics) at growth promoting levels, zinc oxide and copper sulfate at pharmacological doses, certain organic acids, and sources of immunoglobulins improve post-weaning feed intake and growth. Other highly-digestible protein sources such as fish meal, skim milk, and wheat gluten do offer growth promoting advantages, as well. An improvement of 10 to 50% in growth performance can be easily realised when the proper combination of these ingredients is used. Generally, these ingredients are more efficacious when health, facilities, and management are sub-optimal.
4. Feeding on a budget
Even though high-quality piglet diets are very helpful in promoting growth performance after weaning, their advantages can be easily lost if they are fed for too long or at the wrong amount for each weight class of weaner pigs. A properly designed feed budget has a higher allowance of the complex diets for light-weight pigs than for heavy-weight pigs. However, a common mistake is to disregard the fact that heavy pigs are accustomed to consume large quantities of milk and thus, they tend to take longer than light-weight pigs to adapt to dry diets. Therefore, a small allotment of the first diet should always be budgeted even for the heaviest pigs.
5. Aromas and flavours
These are controversial additives, but they do work sometimes if used correctly. These products entice piglets to explore and ingest solid feed based on aroma and flavour incentives. Finding the correct aroma or flavour is a life-long quest for most nutritionists. Keeping the same product in the pre- and post-weaning diets is the only sure advice one can impart regarding these additives.
This is probably the most cost-effective way to increase post-weaning feed intake by spreading a small quantity of feed on sleeping mats. This practice greatly encourages pigs to rut and ingest solid feed as early as the first day post-weaning. A mash provides equal results with pellets, but on mats without a rim pigs like to roll and push pellets instead of picking them up. Placing the mat near the feeder seems to encourage pigs further to consume more feed from the feeder. Pigs require only two to three days of floor feeding before they become accustomed eating from regular feeders. Frequent feeding stimulates pigs to eat more and prevents wastage of uneaten portions. However, based on our own research, feeding more than three times daily is not advised because pigs become too fond of mat-feeding.
7. Milk replacers
Nursery pigs will readily consume a warm liquid milk replacer of the proper temperature and composition. Feeding a milk replacer three to four days can easily double dry matter intake compared to a pelleted feed. However, pigs reared solely on a liquid diet may fail to relate to dry feed unless the milk replacer is combined with a high quality starter diet or milk pellets. Good sanitation and frequent feeding are essential to prevent spoilage and attract pigs to eat. Milk replacers are best suited for low-weight and orphan pigs because of cost constrains. An investment in equipment and labour is also required to reap the full benefits of milk replacers.
8. Gruel feeding
In farms where pigs are fed dry diets on a regular basis, a warm gruel (50:50) of feed and water (or a liquid milk co-product) can be offered to weaned pigs in special bowl-type feeders during the first two to three days post-weaning. This practice prevents starvation and more importantly, dehydration. Unless the gruel is gradually thickened (70:30), some piglets may fail to adapt to dry feed. Precipitation of solid matter in bowls is not problematic as long as the bowls remain filled with water. Field results with this practice are very encouraging.