MEAT QUALITY IN YEARLING BULLS FATTENED IN THREE PRODUCTION SYSTEMS FROM MEXICAN DRY TROPIC
The objective was to evaluate the effect of the production system and genetic group in carcass measurements in yearling bulls from mexican dry tropic. Fortyeight animals of two genetic groups (Brahman*Charolais Bh*CH and Brahman*Brown Swiss Bh*BS) were randomly asigned to Intensive Silvopastoral (ISP, n=19), Silvopastoral + Suplementation (ISP+S, n=15) and Feedlot (F, n=14). Animals were harvested in a commercial abattoir when they target 450 ± kg live weight, to evaluate hot carcass weight (HCW), yield (Y), ribeye area (REA), fat thickness (FT), and marblilng score. As well as bromatological (humidity, ash, crude protein, ether extract) and physicochemical characteristics (pH, meat and fat color for L, a*b*). Proc Mixed Model of SAS was used. Difference was found (P<0.05) for systems, marbling score was higher in F (446.36±31.77), followed by ISP+S (245.7±26.2) and ISP (167.6±26.9). Genetic group was different (P<0.05), in yield better response was in Bh*CH (58.9±0.7%) than Bh*BS (57.7±0.6%), as well as, REA (74.0±2.7 cm2 vs 66.2±2.5 cm2. Cattle fattened in F had DFD meat with highiest pH at 48 h postmortem (6.7±0.06) while bulls in ISP+S and ISP were similar (P>0.05) because they were near to normal pH value. In meat color F had lower L, higher a* and b* 36.9±1.1, 15.9±0.8 and 20.1±0.9) respectively; while ISP+S and ISP had similar values (P>0.05). Fat color ass well as protein and humidity. But,in ash ISP and ISP+S were similar (P>0.05; 4.0±0.07% y 4.0±0.07) but they were higher than F (3.4±0.08%). Ether extract was high in F (5.76±0.5%) vs 2.03±0.4% in ISP+S vs1.5±0.4% to ISP. It was conclude that cattle in ISP can produce the same carcass characteristics, nutritional facts than F, however has the advantage to produce lean meat. Also carcass characteristics may be afected by genetic group. Sumplementation can inprove beef quality related with marblig score.
Silvopastoral, feedlot, marbling, cattle