Avaliação fenotípica e medidas biométricas de fêmeas Marchangus

Abstract

Ezoognosis and biometrics are important tools in the selection of superior beef cattle animals. The present work was at the São Marcos Ranch, Dois Vizinhos, PR, with Bos taurus animals (1/2 Marchigiana + 1/2 Aberdeen Angus, within a maximum of 25% of Senepol blood) raised on pasture (cynodon sp). Were used 23 adult cows (AC), 15 young cows (YC), 7 heifers (HE) and 13 females calves (FC), It was measured body weight (BW), body volume (BV), body length (BL), height (H), thoracic depth (TD), height/depth ratio (HDR), thoracic perimeter (TP) and rump width (RW). The mean weight of the animals in kg was 530 (AC), 420 (YC), 340 (HE) and 198 (FC). For BV in dm³, 452.4 (AC), 364.9 (YC), 288.5 (HE) and 166.9 (FC). The following results were obtained for the various body measurements in cm: BL 148 (AC), 134 (YC), 124 (HE) and 103 (FC); for H: 133 (AV), 129 (YC), 123 (HE) and 107 (FC); for TD: 69 (AC), 64 (YC), 57 (HE) and 49 (FC); for TP: 197 (AC), 185 (YC), 171 (HE) and 141 (FC); for RW: 54 (AC), 47 (YC), 44 (HE) and 33 (FC). For HDR in %: 51.56 (CA), 48.89 (YC), 45.97 (HE) and 44.14 (FC). The stand cow to the Marchangus composite has the following measurements: 580 (weight), 535 (BV), 160 (BL), 135 (H), 60 (HDR), 205 (TP) and 60 (RW). Thus, the cows of the Marchangus composite, currently, presente mean biometric measurements lower than those of the stand cow: weight (-50kg), body length (-12 cm), body volume (-82 dm³), height/depth ratio (-8%) and rump width (-6 cm). In this work is being proposed an individual morphological evaluation for taurine beef cattle, in which it is evaluated: carcass (40 points, divided into cylinder and musculature); legs, feet and body structure (20 points, divided into limbs and spine); race, head and neck (15 points); reproductive system (15 points); and rump (10 points), totaling 100 points, referring to the animal stand. We describe the evaluation of cow number 787 as an example: 36 points (cylinder 18 and musculature 18); legs, feet, and structure 20 points (members 10 and column 10); reproductive system 14 points; race, head and neck 15 points; and rump 9 points, totaling 94 points, being a cow classified with excellent. Because the current herd is presenting average biometric measurements lower than those of the stand cow, it is suggested to mate them with bulls that present superior measurements, larger animals, so that they can be increased in the next generations. Reproductive biotechnologies can be used in cows present in the herd, similar to the stand, to accelerate the multiplication of this genetics. The use of biometrics is valid and easy to use, being an important tool in the selection of animals and genetic improvement. The visual evaluation is an important tool, used for the selection of animals, being easy to perform, simple and economical. The suggested evaluation form can be used as an aid for the evaluations, demonstrating points to be evaluated, thus facilitating the work of selection in European beef cattle.