Effects of space allowance and marketing strategy on growth performance of pigs raised to 165 kg

Authors: LERNER, ANNIE - Kansas State University; RICE, EMILY - Kansas State University; TOKACH, MIKE - Kansas State University; DEROUCHEY, JOEL - Kansas State University; DRITZ, STEVE - Kansas State University; GOODBAND, ROBERT - Kansas State University; WOODWORTH, JASON - Kansas State University; O'QUINN, TRAVIS - Kansas State University; GONZALEZ, JOHN - Kansas State University; ALLERSON, MATT - Holden Farms; DILGER, ANNA - University Of Illinois; BOLER, DUSTIN - University Of Illinois; PRICE, HANNAH - University Of Illinois; LOWELL, JESSICA - University Of Illinois; RICHARDSON, ELAINE - University Of Illinois; BARKLEY, KAYLA - University Of Illinois; HONEGGER, LAUREN - University Of Illinois; HARSH, BAILEY - University Of Illinois; Shackelford, Steven; Wheeler, Tommy; King, David - Andy; FIELDS, BRANDON - Pig Improvement Company

Submitted to: Translational Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/7/2020
Publication Date: 5/18/2020
Citation: Lerner, A.B., Rice, E.A., Tokach, M.D., DeRouchey, J.M., Dritz, S.S., Goodband, R.D., Woodworth, J.C., O'Quinn, T.G., Gonzalez, J.M., Allerson, M.W., Dilger, A.C., Boler, D.D., Price, H.E., Lowell, J.E., Richardson, E., Barkley, K.E., Honegger, L.T., Harsh, B.N., Shackelford, S.D., Wheeler, T.L., King, D.A., Fields, B. 2020. Effects of space allowance and marketing strategy on growth performance of pigs raised to 165 kg. Translational Animal Science. 4:1252-1262. https://doi.org/10.1093/tas/txaa065.
DOI: https://doi.org/10.1093/tas/txaa065

Interpretive Summary: Market weights of pigs have increased over time and are projected to increase in the future. As animal size increases, space requirements in feeding facilities for optimum growth will likely increase. Pigs were fed to heavy market weights and penned at differing stocking densities and with differing numbers of marketing events during the feeding period. Reducing space for heavy pigs decreased intake and growth rate, and consequently total weight. Increasing the number of marketing events to decrease stocking density increased total weight gain. Thus, pig removal during the feeding period may allow maximization of total number of pigs produced and total weight of pigs marketed when feeding pigs to heavy weights.

Technical Abstract: A total of 976 pigs (PIC 327 × Camborough; PIC, Hendersonville, TN; initially 22.0 ± 1.53 kg body weight [BW]) were used in a 160-d growth study to evaluate the effects of increasing space allowance and varying removal strategies on growth performance of pigs raised to heavy market weights of approximately 165 kg. Pens of pigs were blocked by location within the barn and allotted to one of six treatments. Pen served as the experimental unit, and there were eight replicate pens per treatment. The first four treatments consisted of increased initial stocking density and did not utilize topping strategies: 1) 14 pigs/pen (1.17 m2/pig), 2) 17 pigs/pen (0.97 m2/pig), 3) 20 pigs/pen (0.82 m2/pig), and 4) 23 pigs/pen (0.71 m2/pig). The fifth treatment began with 25 pigs/pen (0.66 m2/pig) and had four marketing events with the heaviest 3 pigs/pen removed on day 93, and additional pigs removed to a common inventory of 20 pigs/pen on day 122 and 17 pigs/pen on day 147 with final marketing on day 160. The final treatment began the experiment with 23 pigs/pen (0.71 m2/pig) with three marketing events to achieve a common inventory of 20 pigs/pen on day 108 and 17 pigs/pen on day 147. Pens of pigs were weighed and feed disappearance measured on days 0, 55, 93, 108, 122, 135, 147, and 160. As space allowance decreased from 1.17 to 0.71 m2/pig via increased initial pen inventory (treatments 1 to 4), overall average daily gain (ADG) and (ADFI) decreased (linear, P < 0.001), while feed efficiency (G:F) did not differ (P > 0.05). The treatments with multiple marketing events were compared with each other and with the treatment that began with 0.71 m2/pig and only marketed once at the end of the study. Overall ADG and ADFI were not different (P > 0.05) between these three treatments. Marketing pigs three or four times improved (P < 0.05) G:F compared with the treatment that began the study with 0.71 m2/pig and marketed only once. Reducing floor space allowance for heavy weight pigs decreased intake, which resulted in lower growth rate and final BW, with these reductions occurring before the critical k-value was reached. Total weight gain per pen was maximized with the lowest space allowance and the multiple marketing treatments. Thus, strategic use of pig removals prior to final marketing may allow producers to maximize both number of pigs and total weight marketed through a barn when feeding to heavy weights.