Chromium and energy restriction as substitutes for ractopamine in finishing gilts diet

Abstract

This study evaluated chromium supplements and energy restriction as substitutes for ractopamine in the diets of late finishing gilts. Sixty gilts were used, with initial weights of 98.87 ± 0.25 kg and final weights of 122.69 ± 10.97 kg, distributed in a randomized block design with five diets: control; yeast chromium (0.8 ppm); chromium picolinate (0.48 ppm); ractopamine (20 ppm) and energy restriction (reduction of 150 kcal of EM kg-1 of feed), with six replicates and two animals per experimental unit. Feeding diet containing ractopamine enabled better (P<0.05) feed conversion and greater weights of the hot carcass of the gilts. The diet containing ractopamine exhibited a lower (P<0.05) cost of feed per kilogram of gain and higher economic efficiency, when compared to diets containing chromium and energy restriction; these exhibited better outcomes, compared to the control diet. Diets supplemented with chromium and ractopamine resulted in a higher (P<0.05) percentage and quantity of lean meat and a higher rate of carcass bonus, when compared to the control diet and energy restriction. The energy reduction did not harm the gilts’ responses, compared to the control diet. Ractopamine supplementation allowed for a better feed conversion, lower feed cost per kilogram of gain, and a higher economic efficiency index. Supplements of chromium and ractopamine increased the percentage and quantity of lean meat and the bonus index of the carcasses. Therefore, chromium picolinate and chromium yeast are potential substitutes for ractopamine for optimizing the gilts carcass characteristics.

Chromium Methionine and Ractopamine Supplementation in Summer Diets for Grower–Finisher Pigs Reared under Heat Stress

“…These results are consistent with those reported by other studies that compared the effects of dietary organic Cr and RAC supplementation in finishing pigs [ 42 , 43 , 44 ]. Furthermore, Mayorga et al reported that the addition of organic Cr (CrProp) in the diets of pigs reared under heat stress conditions exerted positive effects on the ADG and final BW [ 8 ].…”

“…Therefore, the dietary supplementation of both RAC and CrMet help improve the metabolism of pigs reared under heat stress conditions. Notably, in this study, like the diets developed by Farías et al, Marcal et al, and Rincón-Folres et al, the concentration of amino acids did not increase, which normally occurs in RAC supplementation; however, the effects of RAC supplementation were considerably better than those of the CON diet [42][43][44]. The characteristics of the carcasses were closely related to the productive behavior, since they presented the same performance between the treatments, especially for the CrMet-S and RAC groups.…”

“…Conversely, Farias et al, who conducted a similar study to ours, did not report differences in the loin area and back fat when comparing RAC and organic Cr supplementation [ 42 ], which the authors attributed to an improvement in the efficiency of the pigs to metabolize fats due to Cr supplementation. Moreover, Liu et al reported that Cr supplementation could help improve metabolism, specifically of lipids, while reducing the body fat of pigs under heat stress conditions [ 49 ].…”