The effect of elevated dietary citrus pulp on the growth, feed efficiency, carcass merit, and lean quality of finishing pigs

Abstract

The objective of this study was to evaluate the effect of elevated dietary citrus pulp (DCP) on the growth, feed efficiency, carcass merit, and lean quality of finishing pigs. Over a 49-d trial period, pigs (n = 40) were fed 1 of 4 diets: a corn–soybean meal control diet (CON; n = 10) or the same diet with DCP replacing 15% (n = 10), 22.5% (n = 10), or 30% (n = 10) of the total diet DM. Pigs fed the CON and 22.5% DCP diets had greater (P < 0.02) G:F than pigs fed 30% DCP. Fat over the LM received greater (P < 0.04) lightness values in animals fed the CON diet than those consuming either 22.5 or 30% DCP diets. Pigs fed CON or 15% DCP exhibited lower (P ≤ 0.03) lean redness scores than lean from pigs fed 22.5 or 30% DCP. When evaluated objectively, bellies from CON-fed pigs were firmer (P < 0.01) than all other dietary treatment groups, but bellies from CON- and 15% DCP–fed pigs garnered greater (P < 0.04) subjective firmness scores than pigs fed 22.5 or 30% DCP. Belly thickness at both the blade and flank ends decreased with increasing DCP, whereas pigs fed the CON diet exhibited the thickest (P < 0.03) bellies. Overall, DCP inclusion above 15% of the diet DM appeared to be economically detrimental to overall production because of negative effects on growth performance and pork belly quality.