RESUMEN
Datos de cortes obtenidos de ganado bovino (hasta 1197 observaciones) fueron utilizados para desarrollar ecuaciones de predicción del rendimiento en cortes de valor (RCD), Porcentaje de hueso (PHUESO) y recortes de grasa (PGRASA). La condición sexual (CONSEXUAL) explicó el 43 por ciento y 30 por ciento de la variación en RCD y PGRASA, respectivamente. La mayor parte de la variación (>50 por ciento) en RCD, PHUESO y PGRASA no pudo ser explicada por su regresión lineal simple sobre cualquiera de los 13 rasgos de la canal considerados. Las variables incluidas para el análisis de regresión fueron CONSEXUAL, peso en canal (PCANAL), espesor de grasa dorsal (ESPEGRASA), área del ojo del lomo (AOL), porcentaje de grasa interna (GPR), acabado y conformacion. Las mejores ecuaciones fueron: RCD por ciento: 47,564 +2,281(CONSEXUAL) +0,003(PCANAL) -0,302(ESPEGRASA) +0,211(AOL) -1,237(GPR) +0,219(ACABADO) 0,659(CONFORMACION) (R2: +0,629; Cp-Mallows:8); PHUESO: por ciento 17,077 0,749(CONSEXUAL) 0,005(PCANAL) -0,097(ESPEGRASA) -0,064(AOL) -0,402(GPR) +0,2(ACABADO) +0,272 (CONFORMACION) (R2: 0,387; Cp-Mallows: 8); PGRASA por ciento: 9,628 +0,345(ESPEGRASA) -0,162(AOL) +1,733(GPR) -0,725(ACABADO) 0,134(CONFORMACIÓN) (R2: 0,80; Cp-Mallows: 5,74). Es necesario, en futuras experiencias validar las ecuaciones obtenidas antes de su recomendación y uso comercial.
Carcass fabrication yield (%) data (up to 1197) of Venezuelan cattle were collected to develop prediction equations of boneless, closely trimmed cuts (high plus medium-valued) (YCV), bone percentage (PBONE), and fat trimmings (PFAT). The sex condition (SEXCON) explained 43% and 30% of the variation on YCV and PFAT, respectively. The majority of the variation (50% or more) on YCV, PBONE, and PFAT could not be explained by its simple linear regression over any of the 13 carcass traits considered. The variates included for the regression analysis were SEXCON, Carcass Weight (CWEIGHT), Back Fat Thickness (BACKFAT), Loineye Area (LEA), Internal Fat Percentage (IFP), FINISH and CONFORMATION. The best equations were: YCV%: 47.564 +2.281(SEXCON) +0.003 (CWEIGHT) -0.302( BACKFAT) +0.211(LEA) -1.237(IFP) +0.219 (FINISH) -0.659 (CONFORMATION) (R2: 0.629; Mallow´s-Cp: 8); PBONE: %17.077 -0.749(SEXCON) -0.005 (CWEIGHT) -0.097(BACKFAT) -0.064(LEA) -0.402(IFP) +0.2 (FINISH) +0.272(CONFORMATION) (R2: 0.387; Mallow´s-Cp: 8); PFAT%: 9.628 +0.345(BACKFAT) -0.162(LEA) +1.733(IFP) -0.725(FINISH) -0.134(CONFORMATION) (R2: 0.80; Mallow´s-Cp: 5.74). The equation set presented here in must be subjected to practical and statistical validation.
Asunto(s)
Bovinos , Animales , Carne/economía , Industria Agropecuaria/economíaRESUMEN
A total of 145 beef carcasses derived from cattle produced under tropical conditions in different regions of Venezuela were graded by the current grading system. Rib (longissimus) samples were excised, trimmed to zero fat cover and subjected to spectrophotometric analyses to examine the variation in ash, macro- and micro-mineral contents, according to the beef carcass grade. The analysis of variance indicated that the Venezuelan carcass grade did not affect significantly the ash or individual mineral content of the raw longissimus muscle; only the Na content tended to decrease (P < 0.10) as the beef carcass quality decreased from grade AA to grade C. Overall means +/- standard deviations are given for ash percentage (1.06 +/- 0.16) and content (mg/100g) of Ca (2.77 +/- 1.57), Mg (21.62 +/- 3.11), P (211.4 +/- 35.88), Na (76.06 +/- 30.88), K (243.81 +/- 63.93), Fe (1.93 +/- 0.58), Zn (4.13 +/- 0.82), Cu (0.084 +/- 0.041) and Mn (0.026 +/- 0.016). It was concluded that the variation in mineral composition of beef longissimus observed for this sample of tropical beef cattle, cannot be attributed to the Venezuelan carcass grade.