Kansas State University research details nutrition and management steps to bolster efficiency and producer returns.

Over the last 15 years, pork producers have successfully adopted technologies to reduce weight variation, improve health and cut the cost of production in the finishing stage.

Those technologies have included single-sourcing pigs; all-in, all-out (AIAO) pig flow; multi-site production; split-sex feeding; standardized genetics; and wean-to-finish barns.

Today, producers have turned to different packer buying programs and lean premiums to improve returns.

But producers need to realize one simple fact, points out Joel DeRouchey, swine researcher at Kansas State University (KSU): the majority of the money they make on their hogs depends on selling weight.

“Regardless of where producers are selling their pigs, they need to make sure they are getting them to the weight that fits within the packer matrix, and not selling their pigs light,” he explains.

When continuous-flow production was common, producers would just roll light pigs back to the previous group, observes DeRouchey. But with AIAO production systems, and marketing groups over a set number of days, the light pigs have become much more burdensome when trying to close out a barn.

For producers facing the challenge of improving uniformity in market hogs, DeRouchey offers these suggestions:

  • Wean pigs older

    Typically, producers are moving to later weaning because it boosts pig performance and cuts production costs.

    “The one area that has not been talked about with later weaning is the reduction in whole-herd variation from increases in market weight,” he comments.

    Figure 1 shows the influence of weaning age, from 12 to 21 days, on variation in weight at 156 days after weaning. The graph illustrates as weaning age increases, the lines on the graph become higher and narrower. In other words, more pigs fall in a tighter weight window, DeRouchey states.

    “As we move to some of these higher weaning ages, it is certainly going to help in the finisher in terms of marketing, because of less total variation within that given population,” he adds.

    For producers sourcing pigs from sow units/co-ops, DeRouchey says be sure to ask suppliers about variation in weaning age. Ideally, weaned pigs should be in a very tight window of 19-22 days of age to minimize variability in growth.

  • Add fat to grow-finish diets

    In a recently completed research trial by KSU graduate student Chad Hastad, 1,176 pigs with 28 pigs/pen were individually weighed and placed in one of three weight groups: “light” (71.6 lb.); “heavy” (83.1 lb.); and “mixed” or unsorted (77.6 lb.). Pigs received either no fat or 6% choice white grease through to finish. In practical situations, 5 or 6% added fat is the maximum that should be used for bin and auger flowability, says DeRouchey.

    Adding fat to diets is known to improve average daily gain and feed efficiency. The goal of this trial was to find out if it paid to sort pigs into different weight groups to improve performance in the lightest pigs, thereby reducing whole-barn variation.

    Figure 2 bears out that the heavy pigs fed fat throughout the finishing period showed a 4-lb. improvement in performance (final weight of 271 lb.) vs. 267 lb. for the non-fat-fed heavy group.

    In contrast, the light group of pigs showed an improvement of 7 lb. from the non-fat to the fat-fed group.

    The mixed group of pigs improved by about 5 lb. when the untreated group was compared to the fat-treated group.

    But more importantly, the total weight variation of the entire group (Figure 2) was reduced by feeding fat to only the light pigs, as it improved their weight gain and brought their average weight closer to the average of the heavier pigs that were not fed fat.

    In the non-fat-fed groups, the heavy pigs finished 17 lb. heavier than the light pigs (267 lb. vs. 250.4 lb.) When fat was added to the finisher diets, the heavy group finished only about 13 lb. heavier than the light group, decreasing the whole-barn weight variance.

    When looking at returns based on sorting and fat level on margin over feed costs, as shown in Figure 3, there was an advantage of more than $2/pig when fat was added to the diets of light pigs. However, adding fat to heavy pigs' diets produced negative margins, and feeding fat to the mixed group of pigs was just about an economic wash.

    Based on these results, it may pay to divide finishers into light and heavy groups so that light pigs can be fed fat to improve whole-barn uniformity, provided that separate feeding systems are available.

    For this study, corn was $2.16/bu., soybean meal was $186.19/ton and fat was $13.34/cwt.

    When determining the economics of feeding fat, DeRouchey reminds that fat does increase the cost of the diet. But it provides a 2% improvement in feed-to-gain ratios for every 1% added fat. Average daily gain is increased 1% for every 1% added fat (on average).

    Added fat provides a 2% improvement in growth in the early grower, but no improvement in the late finisher (past about 175 lb.), says DeRouchey.

  • Don't shortchange pigs on amino acids late in finishing

    KSU studies on early and late finishing reveal that producers can't get by with shortchanging the level of amino acids late in finishing without hurting average daily gain and lean percentage.

Producers are able to get by, however, with limiting amino acid levels early in finishing, provided the pigs are compensated with levels at or above the norm in late finishing, he concludes.