Effects of preslaughter electrolyte supplementation on the hydration and meat quality of cull dairy cows

Two studies were conducted to evaluate the effect of preslaughter electrolyte supplementation on weight loss, hydration, and beef quality of cull dairy cows. Cows were withheld from feed before slaughter for 36 or 24 h, and ambient temperature ranged from 22 to 32°C or from 12 to 17°C for Exp. 1 and 2, respectively. In Exp. 1, cull dairy cows (n = 60) were given the control treatment (CON; n = 30) or the on-farm electrolyte supplementation treatment (PRE; n = 30). Cows on the PRE treatment tended to have a greater (P = 0.06) decrease in packed cell volume than did CON cows throughout the preslaughter period. Longissimus samples from PRE cows exhibited greater drip loss (P = 0.04) and tended (P = 0.06) to have a lower 24-h pH than did samples from CON cows. In Exp. 2, cull dairy cows (n = 46) were given the CON (n = 16), PRE (n = 16), or posttransportation electrolyte supplementation treatment (n = 14). Cows on the PRE treatment tended to have a lower (P = 0.06) percentage of weight loss during transport than did untreated cows. Results from both experiments demonstrated the potential for preslaughter electrolyte supplementation to attenuate the negative effects of stressors on cull dairy cows, but supplementation appears to be more effective during periods of hot weather and extended feed withdrawal.