Effect of high level of copper on meat quality in Iranian Mahabadi goat kids
This study was carried out to determine the effects of supplementing high level of copper(Cu) on meat quality in goat kids. Fourteen male kids (BW = 21 ± 2 kg, 4mo of age) were used in a completely randomized design with 2 treatments: (1) control (without Cu) and (2) 100 mg Cu as copper sulfate/animal/d. Diet was formulated to meet the requirements recommended by NRC with forage (alfalfa and corn silage): concentrate ratio of 30:70 in TMR form. Diets were the same, except for top-dress addition of Cu-So4 fed in 2 equal meals (0700 and 1700h) and orts were collected before morning meal. Experimental period was 90 d. The end of trial following 16h fasting kids were weighed and slaughtered. Meat samples were taken from the longissimus dorsi muscle (LDM). Color (lightness (L*), redness (a*) and (b*) yellowness) and Warner-Bratzler shear force (WBS) were measured at 24h after slaughter. Cooking loss (CL) was determined by weighing the samples before and directly after cooking in a water bath at 700C for 1 h. Percentage of CL was calculated. Data were analyzed by GLM procedure of SAS 9.1 and adjust Tukey test (P ≤ 0.05). Addition of Cu failed to significantly affect lightness (L*) and CL percentage (P > 0.05). However, Cu supplementation decreased WBS (41.31 and 38.00 in control to 2, respectively) but increased redness (a*: 14.90 and 16.43 for treatment 1 and 2 respectively) and yellowness (b*: 12.53 and 17.60 for treatment 1 and 2; P < 0.05). These results indicated that dietary supplementations of Cu did not influence CL and lightness. Although Cu supplement increased redness, yellowness, and improved tenderness of LDM in Mahabadi goat kids.
Mahabadi goat kid