Producers should provide optimal intake of an optimal diet for the correct weight pig.
Pigs moving into the early finishing stage are entering an unprecedented phase of rapid lean growth.
Every producer would like these pigs to finish like “peas in a pod.” However, variation is an inevitable part of pork production. Some pigs grow faster than others. This can be due to a multitude of factors including genetics, nutrition, environment and health.
Some pigs will reach market weight earlier than others. The majority of the group will follow, including the lightweight hogs shipped to empty the finisher.
Plotting all of the weights in a group on a given day reveals a typical bell-shaped curve. Our job is to look for ways to tighten up that bell-shaped curve (Figure 1).
Many production concepts will not help the best pigs to grow faster. Tightening the curve is achieved by not allowing the slow pigs to lag too far behind the leaders.
Optimal Feed Intake
Producers should provide optimal intake of an optimal diet for the correct weight pig. The process sounds simple, but in reality this is not so easy to accomplish.
There are many points to consider when starting a feeder pig vs. managing the 40- to 80-lb. pig in a wean-to-finish production system. For instance, the wean-to-finish system does not have the added movement/mixing stress that a feeder pig encounters at this stage of production.
Some of the points below apply to all pigs in the early finishing stage of production, while others only apply to feeder-to-finish production flows. All are attempts to tighten up the bell-shaped curve.
Many pigs today see a lot of countryside as they move within a production system. Whether groups are moved down a hallway or transported across the country, the first nutrient they are presented with is water.
Plenty of clean, fresh water is important to rehydrate pigs. The lack of proper water intake is the number one limiting factor to dry matter (feed) intake. If pigs do not drink, they will not eat.
Pigs consume 2-3 lb. of water for every pound of feed. The water flow rate for the early finishing pig should be about 1.5 pints/minute. This level will provide water as fast as a pig normally desires to drink. Poor water flow and out-of-water events will decrease water intake and subsequent feed intake.
Be careful when using water as the carrier for electrolytes, citric acid, antibiotics or other nutrients. Ensure that water consumption is not limited by the off-flavor of an additive. Sometimes, additives have the opposite effect of what's intended — to assist in getting newly placed pigs off to a good start.
Presentation of feed to the pigs is important for optimizing feed intake. Providing fresh, high-quality feed is the ultimate goal.
In a perfect world, this goal would be achieved by delivering feed from bins that have been emptied and cleaned prior to the new group's arrival. It is also preferable to empty the feed bins between deliveries as well as between groups of pigs.
But with feed delivery systems, such as tube feeders with limited in-barn feed reserves, coordinating feed deliveries with emptying of the bin prior to each group's arrival becomes difficult.
Feed bins installed in a series (pictured below) have an advantage, because each bin can be emptied prior to starting the second bin.
Bins need to be checked for abnormal feed left over from condensation or water leakage into bins, which causes moldy feed to hang up and multiply in bins.
Pounding on the bins from the outside is not enough to evaluate bin cleanliness. Bins need to be checked routinely in the middle of each group of pigs and prior to the start of a new group of pigs. Moldy feed should be removed promptly.
The quality of feed is at least partially due to the quality of the individual ingredients. In the fall, when grain bins are being emptied, or during times when low-quality grains are being milled into feed, the use of mycotoxin binders and/or mold inhibitors may be necessary.
Both mold and mycotoxins can cause feed refusal. The feed may look normal, but laboratory testing is the only way to determine whether there is a mycotoxin concern.
Leftover feed from the previous group of finishing pigs usually exists in one of two scenarios:
First, the leftover feed is lower in protein, lysine and other nutrients than what is appropriate for newly placed feeder pigs. This scenario is even worse when newly weaned pigs are placed into a wean-to-finish system. Remove this feed from the bin and check to make sure the bin is clean.
Second, the leftover feed may contain ractopamine (Elanco Animal Health/Paylean). The diets containing the swine feed ingredient are closer to the early diets of finishing pigs, but ractopamine labeling restricts its use to pigs over 150 lb.; therefore, it must be removed.
Consistent particle size is important for a quality finishing diet. Pigs may sort diets with variable particle size or poorly pelleted rations.
Sorting of the feed and subsequent refusal of a fraction of the feed causes wastage, and the diet consumed is no longer the ration the nutritionist had intended.
Developing the correct diet formulas for a flow of pigs is dependent on many factors. Genetic leanness, environment, feed consumption patterns and carcass characteristics are all valuable components in putting together a nutritional program.
Producers may need to use nutritional requirement information provided by the genetic supplier. Information on feed consumption patterns, growth rates and carcass characteristics generated on the farm will aid in defining the nutritional program.
Nutritionists can choose from an array of competitive ingredients to formulate diets for early finishing pigs. Energy sources may include corn, milo, wheat, barley, tallow or other fat sources. Protein sources may include soybean meal, canola meal, field peas or synthetic amino acids.
Armed with area ingredients, growth and performance information, your nutritionist can develop a feeding program to fit pork production needs.
The very early finishing stage may not be the most opportune time to concentrate on least-cost rations. Ingredients that pigs are not accustomed to or may cause feed refusal need to be eased into rations.
For example, young pigs may decrease feed consumption for a period of time if 15% dried distiller's grains with solubles (DDGS) is fed as the first diet when they are placed in a barn. Also, large variations in diet formulation between phases need to be changed gradually.
During warm months, heat increment must be taken into account when choosing feed ingredients. Heat increment is basically the energy requirement needed to break down an ingredient. The heat released makes the pig feel warmer. Diets with lower heat increments make pigs feel cooler.
For example, high-fiber ingredients have a higher heat increment and thus give off more heat in the process of digestion. Soy hulls, wheat midds and DDGS also have higher heat increments. Fats and amino acids have lower heat increments.
Nutrient-dense finishing diets fed during the warm months help decrease the heat released by digestion and improve summer feed intake. This effectively allows the pig to tolerate a warmer environment.
Early studies with the growth promotant virginiamycin (Phibro Animal Health) show similar results. As has been shown in poultry, virginiamycin appears to decrease the heat increment in pigs, especially during times of heat stress. These heat increment concerns need to be weighed against the cost of the ingredient.
The finishing stage of production is not the place for expensive, novel ingredients. With the bulk of feed costs confined to the finishing stage, don't add feed ingredients that do not have sound science behind their use.
Feed presentation to the pig is important for early feed intake. Newly placed feeder pigs are not the best candidates to try to optimize feed efficiency. The early finishing growth phase is very efficient, because it concentrates on lean growth with virtually no fat laid down.
Feeders that are adjusted too tightly may limit feed intake, consequently growth, and have very little effect on feed conversion. Set feeders to provide 50% feed coverage in the trough for the first week, then adjust to allow 15-20% feed coverage for the remaining feeding period (photos at right).
If pigs have to work at the feeder too long, it may limit the amount of feed they consume. If feed consumption takes too long for the dominant pigs, the timid pigs may have limited consumption, which adds to the group's variation at marketing.
Studies have shown that out-of-feed events affect overall feed intake and subsequent average daily gain. Pigs need access to high-quality feed at all times.
Out-of-feed events can be caused by a number of circumstances. The problem may be mechanical, such as poorly designed feed drops causing bridging, or problems with timers and sensors.
Feed quality issues such as caking, fat balls in the winter or high fat/low particle size bridging are other concerns. Another area may be caretaker error, where bins are allowed to go empty.
Nutritional Health Effects
Some animal health concerns in finishing have nutritional implications. Hemorrhagic bowel syndrome (HBS) is a condition that causes sudden death in fast-growing finishing pigs. The cause of HBS is poorly understood. If the intestinal environment can be changed, in many cases the losses due to HBS can be limited.
DDGS has been touted as reducing the incidence of HBS. The response is dramatic on some farms, but limited on others, and the mechanism of how this reduces mortality is not well understood. Some feel that the increase in fiber or change in digestibility of DDGS alters the gut environment enough to limit the factors fueling HBS.
Some observers feel that problems with ileitis may also subside with the use of fiber ingredients, such as soy hulls or DDGS. The effectiveness of these ingredients to decrease clinical ileitis appears to be much more sporadic than the response that is seen with HBS.
Porcine circovirus type 2 (PCV2), the causative agent for porcine circovirus-associated disease (PCVAD), is being linked as a cause of severe mortality in early finishing age pigs. Stresses in pigs appear to spur the PCV2 into action.
Circovirus is known for a respiratory condition it causes in swine, but many farms see an enteric component. The virus appears to be associated with clinical signs of diarrhea on many farms. It's too early to know whether the diarrhea is a clinical sign of PCV2 or a stressor that increases the severity of disease.
When developing a receiving diet to reduce stress on the pigs, it is helpful to know the makeup of the diet they ate last. “Gut friendly” receiving diets, those with soy hulls for fiber, limited fat supplementation and limited use of soybean meal for amino acid balance, all appear to help limit the diarrhea syndrome.
Similar barn fills of single-source groups have shown a significant decrease in the mortality rate when pigs were fed a receiving diet vs. their normal entry diet (Figure 2).
Factors Affecting Feed Intake
Getting pigs to eat feed as quickly as possible is always the goal, but achieving that goal is not always easy. The longer it takes to get pigs on feed and maintain maximum intake, the greater the odds of increased weight variation at the end of the finishing period.
Pigs eat to their energy needs. Energy is first used for maintenance, then for protein deposition and finally for fat deposition. The more a pig eats after its maintenance needs are met, the more lean gain it will deposit.
Chronic and acute disease conditions decrease feed consumption. Knowing a farm's historical feed consumption patterns, by stage of production, can help in formulating diets that meet a respective pig's needs.
Temperature can affect feed intake, too. Heat stress will vary with geography, barn site and type and season.
Naturally ventilated finishing barns will likely have more summer heat stress than tunnel-ventilated barns. Adjust diets for summer by using the heat increment of ingredients, which often are not least-cost diets.
Since feed costs represent the largest portion of pork production costs, the natural tendency is to formulate diets as close to the pigs' needs as possible. However, the summer slump caused by high temperatures can decrease consumption levels enough to drop nutrient intake below the pig's requirements.
Nutritionists need to consider significant feed intake reductions due to summer weather when formulating diets.
If pigs were trucked some distance or were previously fed a very different diet, a transition diet that addresses the stress of moving or the large change from diet to diet is appropriate.
Some pigs may have been fed primarily a corn-soybean meal diet, while others were fed small grain diets, including wheat and barley. Transition diets from nursery to finishing may be necessary.
Variation is also addressed by the use of feedgrade antibiotics. The prudent use of antibiotics in a therapeutic or growth-promoting capacity is a legitimate way to control variation. Always take farm history into consideration and review Pork Quality Assurance program guidelines.
For healthy pigs in good environments, the finishing period is a time of rapid growth. Packing the correct groceries into every pound of feed is important for continued health and maximum performance.
Many factors can lead to increased variation in finishing. Any area left unresolved can lead to a widening of the bell-shaped curve, producing fewer pounds of pork and more lightweight pigs at the end of the barn closeout.