Effect of castration on animal growth, in vivo carcass quality and post mortem yield of Brahman, Brangus (Black) and Wag yu-Char bray cross breeds, in a stabled system in Guapiles, Pococi, Limon

The Brahman, Brangus and Wagyu-Charbray cross breeds were evaluated, in total twenty-four animals were worked on, divided into four pens, each one composed of six animals (three entire and three castrated), one entire and one castrated of each breed. Periodic weighings were carried out once a month, to make growth curves and to know the differences between initial weight (PI), final weight (PF), daily weight gain (GDP) and total weight gain (GTP). Quarterly, the variables of dorsal fat thickness (EGD), loin eye area (AOL), height at withers (AC), chest circumference (CT), length at withers (LC), height at croup ( Ag), width of the rump (ANG) and body length (LNC). At the end of the trial, the animals were sent to the harvest plant where the farm exit weight (PSF), the slaughter weight (PS), the loss in the transfer process until slaughter (MTS), the carcass weight (PC) and carcass yield percentage (RC). Correlations between body measurements and animal weight were also calculated for weight prediction through linear regression equations. The interaction between race and condition for the variables PI, PF; GDP, GTP, AOL, EGD, AC (at 0 and 268 days), CT, LC, ANG, LNC, PSF, PS, MTS, PC, RC, was not significant in any of the measurements (p>0.05 ), but if differences in AC were observed in two of the times (81 (p=0.0001) and 175 days (p=0.0408)), where the castrated Brahman and entire Brahman groups presented higher AC compared to the other groups, there were also differences in AG in the four measurement times (0 (p=0.0027), 81 (p=0.0191), 175 (p=0.0478) and 268 days (p=0.0199), where the entire Brahman group presented greater AG compared to the other groups, less so with the castrated Brahman.Significant differences were found between races for the variables PI (p=0.0055), PF (p=0.0237), GDP (p =0.0132), GTP (p=0.0237), PSF (p=0.0303), PS (p=0.0169) and PC (p=0.0032), not so for MTS, nor for CR The Brahman breed obtained the highest value for PI, but for PF, GDP, GTP, PSF, PS and PC it presented the lowest values with respect to the Brangus breed and the Wagyu-Charbray cross. differences (p>0.05) between conditions for PI, PF, GDP, GTP, PSF, PS, MTS, PC and RC. For AWOL, EGD, AC (at 0 and 268 days), CT, LC, ANG (at 81, 175 and 268 days) and LNC, no differences (p>0.05) were found between races at any time. measurement. But if they were observed between races in two of the AC times (81 (p=<0.001) and 175 (p=0.0069) days); at all times for AG (0 (p=0.0002), 81 (p=0.0378), where the Brahman breed presented higher values compared to the Brangus breed and the Wagyu-Charbray cross, in the three variables. (author)