Growth performance parameters, carcass traits, and meat quality of lambs supplemented with zinc methionine and (or) zinc oxide in feedlot system

Zinc (Zn) is a micromineral with structural, catalytic, and regulatory functions in muscle tissue. It improves growth in ruminants because it modulates energy metabolism. The objective of this study was to evaluate the effect of Zn methionine (Zn-Met) and (or) Zn oxide (ZnO) addition in the diet of Katahdin x Dorper lambs on performance, carcass traits, and meat quality characteristics. Forty non-castrated Katahdin x Dorper F1 lambs were randomly assigned to the following experimental groups: (1) Zn-Met (65 ppm), (2) ZnO (65 ppm), (3) Zn-Met + ZnO (32.5 + 32.5 ppm), and (4) basal diet (BD, without Zn). The duration of experiment was 93 d. Treatment Zn-Met + ZnO vs. control improved (P <= 0.05) average daily gain (ADG) and feed conversion (FC); ZnO increased leg perimeter and decreased visceral fat. Intramuscular fat (IMF) and marbling of chop with Zn-Met + ZnO vs. control were higher (P <= 0.05). Oxidative stability of cooked meat was delayed (P <= 0.05) with Zn-Met + ZnO. Myristic acid was lowest (P <= 0.05) with ZnO, and arachidonic acid was higher (P <= 0.05) in Zn-Met. Therefore, compared with the BD, Zn-Met + ZnO improved the ADG and FC, decreased the shear force, and delayed the stability oxidative in cooked meat; Zn-Met and ZnO increased the IMF and marbling; additionally, Zn-Met increased arachidonic acid and ZnO decreased visceral fat and myristic acid.