Feeding strategies for weaned pigs, sows

Feeding and nutritional strategies for weaned pigs, regardless of age, should be thoroughly reviewed on a regular basis to ensure success of your weaning age program.

Properly designed nutritional programs and feed budgets cannot, by themselves, ensure a successful nursery program.

It's important when moving to an older pig at weaning that nutritional feeding strategies can be modified to maintain growth performance targets and decrease feed cost per pig.

Nursery pig management

Several key management factors are required to maximize growth and profitability of the weaned pig regardless of age at weaning:

Feed and water intake: The factors necessary to maximize feed intake include a warm, draft-free environment, appropriate water and disease control programs.

Newly weaned pigs dehydrate rapidly and must have ready access to drinking water. Whether you are providing water through nipple or bowl drinkers, proper positioning and sanitation of watering devices are essential elements of proper pig hydration.

Also, to maximize feed intake, pigs must be provided unrestricted access to feed. Producers often limit-feed pigs to reduce postweaning diarrhea. However, recent research indicates that limit feeding highly digestible nursery diets actually increases the risk for diarrhea. Thus, limit feeding is a frequent cause of reduced nursery exit weights.

A number of management lapses may also result in limited feed intake. These include failure to investigate all potential contributing areas such as improper air temperature or ventilation settings, poor sanitation or undetected disease challenges.

Social interaction between the piglets while eating is critical to develop feeding behavior. Feeders with solid partitions prevent this feeding interaction because piglets cannot see each other while eating. A properly designed feeder without solid partitions encourages proper social interaction and maximum feed intake, while preventing the small pigs from lying and defecating in the feeders.

Feeding mats are also useful to facilitate social interaction during feeding for the first few days after weaning.

However, mats can lead to higher levels of feed wastage and disease risk from improper sanitation if kept in the nursery pen too long.

Feeder adjustment: Proper and frequent feeder adjustments are the keys to excellent feed efficiency and low feed cost in the nursery. Feeder adjustment must start with the first feed placed in the feeder. Regardless of whether the first diet comes in bags or bulk, the feed gate in all feeders should be closed before placement of the first pellets. The feed gate then should be opened so a small amount of feed is visible in the feed pan.

Avoid placing pelleted feed into an empty feeder with the agitation gate open, because it will result in large amounts of feed filling the trough, leading to feed wastage and difficulty in achieving the proper feeder adjustment.

Although adequate amounts of feed must be present in the feeder at all times after weaning, too much feed in the pan of the feeder can also decrease growth rate.

In an attempt to stimulate feeding behavior, some producers place large amounts of the first diet in the feeding pan. Although the intention is positive, the outcome is negative. Energy deficiency can result from pigs “sorting” the diet and producing a buildup of fine feed particles (“fines”) in the feeding pan that pigs can find less palatable. These fines then lodge in the feed agitator mechanism, making it difficult for new feed to flow from the feeder.

To correct this problem, manage the amount of feed flow in the pan to stimulate the development of feeding behavior. Approximately 50% of the feeding pan should be visible in the first few days after weaning. As the pigs become more accustomed to the location of the feed and adjust their feeding behavior, the amount of the feed in the feeding pan should be decreased rapidly to less than 25% coverage.

Also, feed agitators need to be tested and adjusted frequently to ensure that the buildup of fines does not prevent them from working freely.

Identifying starve-outs: In our experience, weaning an older pig will reduce but not eliminate starve-out pigs. It's essential to have a dedicated workforce who can identify the signs of a starve-out pig, and then gently teach the pig where and how to eat with either a mat or individual feeding system.

Some pigs simply don't start eating readily after weaning — regardless of age. Producers who have the ability to teach these starve-out pigs to eat, rather than treating them with an antibiotic, will save more pigs.

The main signs to help identify starve-out pigs include:
• Mental status — depressed;
• Body condition — thin;
• Abdominal shape — gaunt;
• Skin — fuzzy;
• Appetite — huddled with no activity at the feeder, and
• Signs of dehydration — sunken eyes.

Pen space: One of the largest advantages with later weaning is the improvement in pig growth rate, both in the nursery and finishing stages. For every day of increased weaning age up to 21 days of age, producers should expect pigs to be over 3 lb. heavier from weaning until marketing on a fixed-day system, or marketed 1.7 days faster.

However, nursery pen space must be managed carefully. With a higher initial weight and the expected increase in growth rate, space allotments per pig need to be adjusted accordingly. Pig space will need to be increased if pigs remain in nursery pens for the same number of days before being moved to finishing barns.

In wean-to-finish facilities, this is not a concern unless producers are double stocking during the nursery phase of growth.

Phase feeding and feed budgets

The goal of the nutritional program remains the same regardless of the number of diet phases used. That goal is to transition pigs to a low-cost, grain-soybean meal-based diet as quickly as possible after weaning without sacrificing growth performance. In most cases, pigs achieve this goal without higher-cost products such as whey or fish meal.

A four-phase feeding approach replaced the traditional, three-phase system in the nursery phase when younger weaning ages were implemented in multi-site pig production.

With later weaning, many producers are reevaluating feed budgets or reverting back to the three-phase approach (see Tables 1 and 2).

No matter what feeding strategy is chosen, the concept of matching the digestive capacity of the pig to the ingredients used in the rations should not change.

Table 1: Feed Allowances/Pig (weaning to 50 lb.) for a Four-Phase Feeding Program

Table 2: Feed Allowances/Pig (weaning to 50 lb.) for a Three-Phase Feeding Program

Postweaning nutrition and feed budget: As weaning age increases, two different approaches can be used for diets fed immediately after weaning.

Some producers use the same segregated early weaning (SEW) and transition-type diets that were used with younger-weaned pigs, but alter the feed budgets to decrease the amount of each diet fed.

A producer may provide 0.5 or 1 lb. of a SEW diet/pig and 1 to 3 lb. of a transition diet. If the pigs exceed the desired weight target for consumption of these diets, the budget for the subsequent diet is reduced accordingly.

Other producers have replaced the two separate phases with a hybrid Phase 1 diet. This diet is a compromise between the SEW and transition diet on levels of expensive ingredients, such as plasma, and therefore is a compromise on cost.

As weaning ages and weights increase, ingredients such as plasma and lactose — the cornerstones of most SEW and transition diets — can be dramatically reduced.

Another consideration that influences the feed budget is the variability of age at weaning within a group. Large variations in weaning age may require an increased budget amount to ensure that the youngest pigs receive an adequate amount of the proper diet.

Nutrition and feed budget from 15 to 25 lb.: This diet is typically a grain-soybean meal-based diet with 7 to 10% of a high-quality source of lactose and a small amount of a specialty protein source, such as spray-dried blood meal or high-quality fish meal.

Other specialty protein sources may be used, depending on economic considerations or location. Many producers make this diet in meal form on their farms.

Growth-promoting antibiotics and zinc oxide are typically used in this diet. Research indicates that 2,000 ppm zinc is the optimal inclusion level. When zinc oxide is used for growth promotion, high levels of copper sulfate do not provide any additional growth response. Typically, 15 lb. of feed is budgeted for pigs during this phase.

Nutrition and feed budget from 25 to 50 lb.: This diet should resemble a grow-finish diet, which in most cases will be a simple grain-soybean meal diet without any specialty protein products or lactose sources. The digestive capacity of the pig at this weight is such that these ingredients are unwarranted; including them will increase feed cost/pig.

This diet is the lowest-cost diet in the nursery program. However, since consumption of this diet is the greatest during the nursery phase, it usually accounts for more than half the total feed cost from weaning to 50 lb. Typically, 45 to 50 lb. of feed is budgeted for pigs during this phase.

High usage makes it critical to monitor diet costs from 25 to 50 lb. Because long-term feeding of high levels of zinc oxide has not been shown to be beneficial, growth-promotion levels of zinc should not be used in this ration. Copper sulfate at 125 or 250 ppm of a complete diet and the proper antibiotics can serve as effective growth promoters in this phase.

Added fat: The fat level of the diet will depend on the ability of the producer or feed company to economically purchase fat. By increasing levels of fat in nursery diets, pigs will often respond with improvements in average daily gain and feed efficiency. Between 3% to 5% added fat is a common recommendation.

Regardless of the phase-feeding strategy, development of a proper feed budget will help keep nursery feed costs competitive. The feed budget should be used as a target for the amount of each diet that each pig receives from weaning to 50 lb. This budget should be adapted to the weight of pigs on a particular operation after the optimal weaning age is determined.

It's critical to practice strict discipline when using a feed budget to prevent overfeeding of the more expensive nursery diets past the desired weight range. Often, this is the major cause of high feed costs in the nursery.

Ingredient quality

With increasing weaning age, some pigs may be fed only a limited amount of an SEW or transition-type diet that contains higher levels of specialty protein and lactose sources. However, this does not dismiss the importance of using high-quality, highly digestible sources of these products.

While older-weaned pigs have a more advanced digestive tract to digest protein products, they can't utilize poorly processed or heat-damaged ingredients any better than a younger, lighter pig.

The use of high-quality ingredients, such as spray-dried blood meal and lactose purchased from a reputable source can assure producers that ingredient quality is not a limiting nutritional factor in nursery pig diets.

Producers who decide to manufacture on-farm nursery diets in meal form may choose to utilize granular specialty and lactose sources that have better flowability properties. Products with poor flow characteristics can lead to problems with bridging and getting feed out of feeders, thus limiting feed intake.

Don't forget the sows

As lactation length increases, it becomes essential to maximize feed intake to supply adequate levels of protein and energy to the sow. Research is clear, and nutritionists agree, that restricting protein or energy intake during any period of lactation will reduce milk production and impair subsequent reproductive performance. The negative influence on reproduction is particularly evident during summer months and can contribute to seasonal infertility.

The most practical method of increasing energy intake is to increase total feed consumption. However, when feed consumption is problematic, high levels of fat (5% or greater) are sometimes added to lactation diets to compensate for low feed intake.

Because dietary fat is preferentially shifted into milk fat, it doesn't directly help the sow as much as an increase in total feed intake. While high fat levels can help improve litter performance, some research indicates that very high levels (>5% added fat) can impair sow reproductive performance.

Therefore, we recommend that some dietary fat be added to lactation diets, but avoid excess levels in an attempt to compensate for poor lactation feed intake.

While most swine nutritionists and veterinarians agree that maximum feed intake throughout lactation is the correct goal, considerable debate exists as to the proper method to achieve maximum intake.

The debate concerns how quickly feed intake should be increased in early lactation. Some observers advocate feeding extremely low levels of feed (2 lb. or less) prior to and immediately after farrowing. Field experience indicates that extremely low intake during this period limits the ability to increase feed intake rapidly during early lactation.

In extreme cases, ulcers can be created by the extended period of low intake after farrowing. After the long period without feed, sows often overeat if provided free access to feed. The sows then typically go off feed or have a noticeable dip in feed intake.

To compensate for a dip at Days 5 to 10 of lactation, some nutritionists or veterinarians prescribe limit feeding rather than correcting the management that originally caused the problem (the extended period of little or no feed intake prior to and immediately after farrowing).

We recommend that just before farrowing, sows be fed at least 4 lb./day to prevent excess body condition loss, regardless of lactation length.

Feeding first-parity sows

First-parity sows require special consideration when formulating lactation diets for two reasons:

First, their level of feed intake is typically about 20% less than the herd average. If the average sow is consuming 12 lb./day, first-parity sows will average about 10 lb. per day. So first-parity sows require approximately 0.20% higher lysine lactation diets to maximize litter weaning weight.

Second, researchers have demonstrated that first-parity sows can require higher lysine levels for maximum reproductive performance than required for maximum milk production.

When segregated-parity sow farms are used, a separate diet can be provided for first-parity sows. But when segregated-parity flow is not an option, nutritionists and producers must decide to either provide higher amino acid levels than required by the older sows in order to meet the requirements of young sows, or to formulate diets closer to the requirements of the older sows, and not meet the requirements of the young sows.

Typically, we advocate formulating diets closer to the requirements of the young sows and oversupplying nutrients to the older sows. Small improvements in reproductive performance of young sows rapidly pay for the added feed cost in the older sows.

Feeding for sow condition

We recommend that sows be fed at least three times/day to assure that they have a constant supply of fresh feed available. As weaning age increases, and feed consumption increases in the later stages of lactation, this practice cannot be emphasized enough.

To minimize sow body condition loss, feeding sows to maximum feed consumption, especially in the later stages of lactation, is critical to future reproductive success and longevity.

While research data is sparse in documenting the benefits of high feed intake levels after weaning and prior to breeding, we recommend that sows be fed to consume as much feed as possible during the period from weaning to rebreeding. High intake in this period, however, won't make up for increased losses of body reserves resulting from low feed intake during lactation.

Creep feeding

The effectiveness of creep feeding is an area open to considerable debate. During the past decade, providing creep feed to early-weaned pigs typically has not been advocated.

However, with older-weaned pigs and longer lactation lengths, this practice, if properly managed, can help alleviate pressure on the sow while helping pigs get off to a more rapid start in the nursery.

For creep feeding, supplying a high-quality starter diet equivalent to a SEW diet for earlier-weaned pigs is sufficient. Creep feed must be kept fresh and in feeders or troughs that prevent excess wastage.

Even though only small amounts are actually fed, the cost of creep feeding, if not managed properly, will increase the cost/weaned pig beyond the returned benefit.

Also, supplying pigs with an easily accessible water source can aid in pigs becoming accustomed to drinking water before they enter the nursery.

Summary

The basic concepts and management practices for feeding older-weaned pigs are not different than those for younger weaning ages. Intense management of newly weaned pigs to get them started on feed as soon as possible is critical to the success of the nutritional program.

Ultimately, producers who have high nursery feed intake, follow strict nursery feed budgets, use high-quality ingredients and maximize sow lactation feed intake will also maximize profitability.