This study was carried out to evaluate fi nal weight, carcass characteristics, chemical composition and fatty acid profi le in Longissimus muscle

. 1992. Comparison of nonlinear functions for describing the growth curves of three genotypes of dairy cattle. Can. J. Anim. . The Richards (RCD), the Gompertz (GMP), the monomolecular (MON) and the logistic (LOG) functions were compared for describing the growth curve of 343 female dairy cattle for which 12-18 body-weight measures were available. The animals were divided into four groups, and each function was assigned to one of the groups. Analyses of variance of growth traits estimated by the four functions and of the residual mean iquaies (RMS) indicated that all differences between functions in estimated mature weight (24) were stitistically significant (P < 0.01 to P < 0.0001) except for RCD vs. GMP (P < 0.27). Differences between functions in RMS were significant for RCD vs. LOG (P < 0.0026), MON vs. LOG (P < 0.0044) and GMP vs. LOG (P < 0.0584). RCD differed from all other functions in average lifetime growth rate (P < 0.1 to P < 0.0001) and from MON (P < 0.0004) and GMP (P < 0. (MON) et la fonction logistique (LOG) ont 6td compar6es pour la description de la courbe de croissance chez 343 bovins laitiers femelles pour lesquels on disposait des donn6es de 12 it l8 pes6es.Les animaux 6taient r6partis entre quatre groupes, chaque fonction 6tant affect6e I un groupe. Les analyses de la variance des caractbres de croissance estim6es par les quatre fonctions ainsi que les carr6es moyens r6siduels (RMC), r6vdlent que toutes les diff6rences entre les fonctions pour I'estimation du poids )r l'dge adulte (A) 6taient statistiquement significatives (P < 0,01 a P < 0,0001), sauf pour la comparaison RCD contre GMP (P < 0,27) . Les diff6rences de RMS entre les fonctions 6taient significatives pour les comparaisons RCD-LOG (P < 0,0026), MON-LOG (P < 0,0044) et GMP-LOG (P < 0,0584). RCD diff6rait de toutes les autres fonctions pour la pr6diction du taux de croissance moyenne i vie (P < 0,01 e P < 0,0001) et de MON (P < 0,0004) et de GMP (P < 0,0003)

This experiment was carried out to study the carcass characteristics, chemical composition and fatty acid profile of the Longissimus muscle (LM) of bulls (10) and steers (17) finished in a pasture system. Animals (1/2 Zebu vs. 1/2 Aberdeen Angus) were fed in a pasture system (Hermatria altissima) and with a supplement of soybean meal, cracked corn, urea, limestone and mineral salts, twice a day. Both animal groups were slaughtered at 27 months of age, with an average 508.88 kg of live weight. Final weight, hot carcass weight and texture were similar (p>0.05) between bulls and steers. Carcass dressing, fat thickness, color and marbling were higher (p<0.02) in steers. Conversely, the Longissimus area was greater (p<0.05) in bulls. Moisture levels were higher (p<0.01) in bulls. Ash, crude protein, total lipids and total cholesterol levels were higher (p<0.10) in steers. C14:0, C16:0, C16:1 n-7 and C18:1 n-9 fatty acids percentages were higher (p<0.06) in steers.

This work was carried out to study the carcass characteristics, the chemical composition and the fatty acid profile in Longissimus muscle (LM) of bull breeds Nellore, NEL (11), Caracu, CAR (12) and Holstein-Friesian, HFR (12) finished in a feedlot. The bulls were fed twice a day with corn silage, cotton meal, cracked corn, urea, limestone and mineral salt. NEL and CAR bulls had similar (p>0.05) final weight and hot carcass weight. However, NEL and CAR bulls had higher (p<0.05) final weight and hot carcass weight than HFR bulls. Carcass hot dressing, carcass conformation, cushion thickness, Longissimus muscle area and texture were similar (p>0.05) among NEL, CAR and HFR bulls. NEL and HFR bulls had higher (p<0.05) carcass length in comparison to the CAR breed. Nellore breed had higher (p<0.05) leg length in comparison to CAR and HFR breeds. Leg length was similar (p>0.05) between CAR and HFR breeds. Thickness fat, color and marbling score were lower (p<0.05) in NEL breed in comparison to CAR and HFR breeds. LM of NEL bulls had higher (p<0.05) meat moisture content in comparison to CAR and HFR bulls. In contrast, lipid content was lower (p<0.10) in HFR bulls. LM ash and crude protein contents were similar (p>0.05) among breeds. Saturated fatty acids (SFA) were higher (p<0.10) in HFR animals. Monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-6, n-3 and PUFA/SFA ratio were similar (p>0.05) among the different breeds. N-6/n-3 ratio was higher (p<0.05) in CAR animals.

This experiment was carried out to evaluate the carcass characteristics, chemical composition and fatty acid profile of the Longissimus muscle (LM) of three cattle genetic groups (Purunã, PUR, 11; 1/2 Purunã vs. 1/2 British, PUB, 6 and 1/2 Charolais vs. 1/2 Caracu, CHC, 10) finished in pasture systems. The field work took place at the Lapa Research Farm of the Agronomic Institute of Paraná, in the city of Lapa, south Brazil. The animals were fed during the winter with corn silage, cottonseed meal, cracked corn, urea, limestone and mineral salts as sources of protein, as well as an energy supplement, in pasture systems of Brachiaria decumbens Stapf. The animal groups were slaughtered at 20 months of age, at 501±22.6 kg live weight. CHC bulls had higher (p<0.05) final weight than PUR and PUB bulls. Hot carcass weight was similar (p>0.10) between PUR and PUB. Hot carcass dressing percentage was higher (p<0.05) for PUB bulls than for PUR and CHC bulls. On the other hand, hot carcass dressing percentage was similar (p>0.05) between PUR and CHC bulls. Fat thickness was similar (p>0.10) among all genetic groups. However, the Longissimus area of CHC bulls was greater (p<0.05) than in PUR and PUB genetic groups. The genetic groups did not affect (p>0.10) the marbling of Longissimus. There was no observed difference (p>0.10) in moisture, ash, crude protein and total cholesterol contents among the three genetic groups. On the other hand, the total lipid percentage was higher (p<0.05) for the PUB genetic group in comparison with PUR and CHC. CLA percentage was highest for PUR animals. However, total CLA amounts were not altered by the different genetic groups.