Luis Fernando Glasenapp de Menezes

Composição Física da Carcaça, Qualidade da Carne e Conteúdo de Colesterol no Músculo Longissimus dorsi de Novilhos Red Angus Superprecoces, Terminados em Confinamento e Abatidos com Diferentes Pesos

The carcass physical composition, meat quality and cholesterol content in the Longissimus dorsi muscle of 24 Red Angus steers finished in feedlot with different weights were evaluated. Steers average age and weight at the beginning of the feedlot were, respectively, eight months and 189 kg. The number of days on feed was 114, 144, 173 and 213 days to reach the slaughter weight (PA) of 340, 373, 400.6 or 433.6 kg. The carcass composition was affected by the slaugther weight, with a quadratic response for bone percentage (%bone= 92.81 ¾ 0.402PA + 0.0005PA2), being the minimum value of 12% at a PA of 402 kg. The muscle percentage decreased linearly (%musc.= 78.38 ¾ 0.042PA) while the fat percent increased (%fat= 3.92 + 0.052PA). The edible portion:bone ratio showed a quadratic relation with slaughter weight (EP:B= -31.88 + 0.194PA ¾ 0.0002PA2) showing the maximun value of 6.47 for the carcasses produced by animals slaughtered with 395 kg. Muscle:bone ratio did not change with slaughter weight, being the average of 4.4 for all slaughter weights. Meat color and texture were not affected by slaughter weight, while marbling score increased linearly (Marb.= -13.35 + 0.051667PA). Increasing the slaughter weight resulted in lower thawing losses and higher cooking losses. The meat tenderness was not affected by slaughter weight and was classified as tender and very tender. Meat juiciness and palatability were sligthtly above average. The Longissimus dorsi ether extract concentration and cholesterol content were not affected by slaughter weight being 2.35% and 43.07 mg of cholesterol/100 g of muscle, respectively.

Características da carcaça de novilhos de gerações avançadas do cruzamento alternado entre as raças Charolês e Nelore, terminados em confinamento

The objective of this work was to evaluate the carcass characteristics of feedlot finished steers, straightbreds (Charolais - C and Nellore - N), and crossbreds from second (G2) (¾C ¼N and ¾N ¼C), third (G3) (5/8C 3/8N and 5/8N 3/8C) and fourth (G4) (11/16C 5/16N and 11/16N 5/16C) generations of rotational crossbreeding. Crossbreds showed higher slaughter, hot and cold carcass weights than the average of the purebreds, being the total heterosis, respectively, 14.95; 18.72 and 18.39% in G2, 19.98; 24.16 and 24.59% in G3 and, 18.38; 22.55 and 22.88% in G4. Total heterosis for the three characteristics followed the fluctuation of individual heterozygosis. Heterosis for hot and cold carcass dressing percentage was significant in all generations, being the retained heterosis, respectively, 3.22 and 3.71%. Carcass chilling loss in G2 did not differ from purebreds, but was significantly lower in G3 (-16.73%) and G4 (-12.84%). For carcass physiological maturity, heterosis was negative and significant in G3 and G4. Subcutaneous fat thickness was higher for the crossbreds of the three generations, however, was only significant in G4. For the characteristics related to carcass muscling, heterosis was significant in the three generation for conformation and Longissimus dorsi area, for cushion thickness and arm perimeter, although positive in the three generations, reached significance only in G3 and G4, being the retained heterosis, respectively, 8.09; 11.33; 7.45 and 5.95%. The characteristics related to corporal development showed significant heterosis in all generations, being the retained heterosis 8.55; 5.73 and 4.99%, respectively, for carcass, leg and arm length. The proportion of commercial cuts of the carcass was not affected by heterozygosis, but for their absolute values, heterosis was significant following the carcass weight behavior.

Órgãos internos e trato gastrintestinal de novilhos de gerações avançadas do cruzamento rotativo entre as raças Charolês e Nelore terminados em confinamento

The objective of this trial was to investigate the effect of heterosis and genetic group on the yield and weight of internal organs and gastrointestinal tract (GIT) of feedlot purebred (Charolais C and Nellore N) and crossbred steers from second (G2) (¾C ¼N and ¾N ¼C), third (G3) (5/8C 3/8N and 5/8N 3/8C) and fourth (G4) (11/16C 5/16N and 11/16N 5/16C) generations of rotational crossbreeding slaughtered at 23 month of age. Crossbred steers from G2, G3 and G4 had, respectively, 14.95, 17.25 and 18.46% higher empty body weight (EBW) than that from purebred animals. A positive heterosis for cold carcass yield expressed as a proportion of EBW (CCYEBW) was observed in G2, G3, and G4. Weights of heart, lungs, and kidneys adjusted for EBW were lower on crossbred compared to purebred steers; the heterosis was significant for the weights of heart (-18.29%) and kidneys (-14.29%) in G3 and for that of lungs (-13.45%) in G4. Weights of all organs of the GIT either expressed as 100 kg of EBW or as proportion of slaughter body weight (SBW) were lower on crossbred than on purebred steers with the exception of rumen weight in G2. Retained heterosis was positive and significant for EBW, CCYEBW and liver weight. However, it was negative for amount of blood and weights of heart and small plus large intestines when expressed as 100 kg of EBW and SBW. Within purebred animals, N showed greater CCYEBW (61.64%) than C (57.09). Conversely, weights of rumen, abomasum, small plus large intestine, and GIT were all higher on C than N steers; excepting for small plus large intestine, the same was observed when weights of the remaining GIT components were expressed as proportion of EBW and SB. These differences partially explain the increased carcass yield on N steers.

Desempenho e Características da Carcaça de Vacas de Diferentes Grupos Genéticos em Pastagem Cultivada com Suplementação Energética

The objective of this work was to evaluate different levels of enegetic supplementation, in the form of grounded sorghum for finishing of cull cows from different genotypes of Charolais (C) x Nellore (N), kept on cultivated pasture during the last half of the vegetative cycle. Thirty C, N, 3/4 C + 1/4 N (CN) and 3/4 N + 1/4 C (NC) beef cows, kept on cultivated pasture of oats (Avena strigosa) + ryegrass (Lolium multiflorum) were allotted in three supplementation levels: .0, .4 or .8% of live weight. In the study of the genetic group effect, it was observed that the average daily gain was 1.03, 1.06, 1.36 and 1.02 kg, respectively, for C, N, CN and NC. Final live weigth was 453, 412, 515 and 478kg, respectively. The gain in body condition during the finishing was higher for the N cows (1.81 points) than for the C (1.09 points) and CN ( .99 points), while the NC cows showed an intermediate value (1.42 points). Carcasses from C cows showed higher weight, better conformation and Longissimus dorsi area than from the N, while the last ones, showed higher bone percentage in the carcass. Between the crossbreds, the CN meat exhibited brighter color than the NC. With relation to the supplementation level, the average daily gain was .92, 1.23 and 1.20 kg, respectively, for .0, .4 and .8%.

Desempenho de novilhos de gerações avançadas do cruzamento alternado entre as raças Charolês e Nelore, terminados em confinamento

The objective of this study was to evaluate body condition, weight, weight gain, food intake and efficiency of feedlot finished steers, purebreds (Charolais - C and Nellore - N), crossbreds from second (G2) (¾C ¼N and ¾N ¼C), third (G3) (5/8C 3/8N and 5/8N 3/8C) and fourth (G4) (11/16C 5/16N and 11/16N 5/16C) generations of rotational crossbreeding. The steers were fed the same diet containing 12.32% crude protein, 2.96 Mcal digestible energy/kg of dry matter and roughage:concentrate ratio of 52: 48. Average daily intakes of dry matter, digestible energy, neutral and acid detergent fiber expressed by kg/animal were higher for crossbreds in all generations. However, when these intakes were expressed per 100 kg of body weight differences were not significant. Retained heterosis (5.46%) was significant for average daily weight gain. Heterosis for efficiency of feed (kg of weight gain/kg of dry matter) and energy (kg of weight gain/Mcal of digestible energy) were negative in all generations, indicating that crossbred steers were less efficient than purebreds. Heterosis (%) for initial and final body weights and condition were expressive and significant in all generations and the level of heterosis for these traits followed the fluctuation of individual heterozygosis. Rotational crossbreeding animals were superior to purebreds for dry matter intake, body weight and condition, similar to Nellore for feed efficiency and inferior to Charolais for feed efficiency and average daily weight gain.

Características da carcaça de vacas de descarte de diferentes grupos genéticos terminadas em confinamento com distintos pesos

The objective of the experiment was to evaluate the carcass characteristics of crossbred cull cows, from the second (G2- 3/4Charolais (C) Nellore (N) and 3/4NC) and third (G3-5/8CN and 5/8NC) generations of Charolais - Nellore rotational crossbreeding, feedlot finished and slaughtered with 465, 507 and 566 kg. At the beginning of the experiment the average age, weight and body condition were, respectively, 8.5 years, 388.6 kg and 2.35 points. The diet, with 48:52 roughage:concentrate ratio, contained 12.5% crude protein and 2.99 Mcal of digestible energy per kg of dry matter. Cows slaughtered with 566 kg produced heavier carcasses (318.5 kg), higher dressing percentage (56.24%) and subcutaneous fat thickness (7.54 mm) than cows slaughtered with 465 kg (245.0 kg, 52.71% and 4.72 mm, respectively) or 507 kg (264.6 kg, 52.12% and 4.4 mm, respectively). The increase of slaughter weight (465, 507 and 566 kg) did not alter the sawcut percentage (51.17, 50.64 and 50.63%), reduced the forequarter (36.93, 37.26 and 35.23%) and increased the sidecut percentage (11.9, 12.09 and 14.14%), respectively. For the measurements related to the carcass muscular expression, conformation was improved by slaughter weight increase (8.13, 9.47 and 10.9 points), respectively. Cushion thickness increased significantly when slaughter weight raised from 465 to 507 kg and Longissimus dorsi muscle area increased only in cows with the highest slaughter weight. The 3/4CN cows showed higher sidecut and lower forequarter percentages in relative to 3/4NC cows.

Efeito de dietas que contêm cana-de-açúcar ou silagem de milho sobre as características das carcaças de novilhos confinados

Este estudo teve o objetivo de avaliar as caracteristicas quantitativas e qualitativas da carcaca e da carne de doze novilhos Charoles, submetidos a dois tratamentos alimentares durante a fase de terminacao em confinamento, aos 30 meses de idade: TC- cana-de-acucar (Saccharum officinarum ssp.) e TM- silagem de milho (Zea mays), compondo 43,65 e 45,14% da materia seca (MS) da dieta, respectivamente. A dieta oferecida foi isonitrogenada, com 11,76% proteina bruta na MS, o concentrado foi constituido de grao de sorgo moido, farelo de arroz desengordurado e farelo de soja, de igual composicao para os tratamentos, com adicao de ureia junto ao TC. Os animais foram mantidos em regime de confinamento ate que a media dos tratamentos atingiu o peso de abate de 420 kg (TC - 110 dias e TS - 88 dias). O peso de carcaca quente foi 214,23 e 222,23 kg para TC e TS, respectivamente. A percentagem de rendimento de carcaca quente foi de 50,71 e 52,60%, (P=0,0612) e a de carcaca fria de 50,38 e 52,24% (P=0,0478). A quebra no resfriamento nao diferiu entre os tratamentos alimentares (P=0,7901); comportamento igual obteve-se para conformacao (P=0,3334), espessura de gordura subcutânea (P=0,9262), area do musculo Longissimus dorsi em kg e em % (P=0,5834; P=0,2094, respectivamente). As carcacas dos novilhos do TC apresentaram maior percentagem de corte serrote (50,04 vs. 49,36%, P=0,0984). Os cortes dianteiro e costilhar nao foram diferentes (P=0,9963 e P=0,1295) entre os tratamentos. A percentagem de musculo foi superior para TS em relacao ao TC, de 70,67 e 68,08% (P=0,0142), comportamento similar ao da percentagem de gordura na carcaca 11,92 e 15,58 % (P=0,0137) para TC e TS, respectivamente.

Composição física da carcaça e qualidade da carne de novilhos de gerações avançadas do cruzamento alternado entre as raças Charolês e Nelore, terminados em confinamento

The objective of this work was to evaluate the carcass physical composition and meat quality of steers, straightbreds (Charolais - C and Nellore - N), and crossbreds from second (G2) (¾C ¼N and ¾N ¼C), third (G3) (5/8C 3/8N and 5/8N 3/8C) and fourth (G4) (11/16C 5/16N and 11/16N 5/16C) generation of rotational crossbreeding, feedlot finished with 52% corn silage plus 48% of concentrate in the diet. Crossbred steers were superior to the straightbreds mean for absolute weight of muscle, bone and fat of the carcass in all crossbreeding generations. Crossbreds showed lower bone percentage in the carcass than the straightbreds mean, being the difference more evident in G2 and G3. Heterosis for muscle/bone and edible portion/bone ratio was positive in all crossbreeding generations, reaching significance only in G3. Meat of crossbreds was more tender than straightbreds mean when evaluated by panel test or by the Warner-Bratzler Shear, being the retained heterosis 9.39 and -11.36%, respectively. Heterosis for meat juiciness although positive in all crossbreeding generations, was significant only in G3. Comparing the crossbreds versus the straightbreds Charolais or Nellore carcasses, it was observed that the crossbreds showed higher absolute quantity of muscle, but lower muscle/bone ratio than the Charolais and, higher absolute quantity of muscle, bone and fat and higher muscle/bone and edible portion/bone than the Nellore. The carcasses of the crossbreds showed higher muscle and lower bone percentage than the Nellore and, higher fat and lower muscle percentage than the Charolais. Meat of the crossbreds showed lower amount of marbling and similar tenderness to the Charolais, but had more marbling and was more tender than the Nellore meat.The objective of this work was to evaluate the carcass physical composition and meat quality of steers, straightbreds (Charolais - C and Nellore - N), and crossbreds from second (G2) (¾C ¼N and ¾N ¼C), third (G3) (5/8C 3/8N and 5/8N 3/8C) and fourth (G4) (11/16C 5/16N and 11/16N 5/16C) generation of rotational crossbreeding, feedlot finished with 52% corn silage plus 48% of concentrate in the diet. Crossbred steers were superior to the straightbreds mean for absolute weight of muscle, bone and fat of the carcass in all crossbreeding generations. Crossbreds showed lower bone percentage in the carcass than the straightbreds mean, being the difference more evident in G2 and G3. Heterosis for muscle/bone and edible portion/bone ratio was positive in all crossbreeding generations, reaching significance only in G3. Meat of crossbreds was more tender than straightbreds mean when evaluated by panel test or by the Warner-Bratzler Shear, being the retained heterosis 9.39 and -11.36%, respectively. Heterosis for meat juiciness although positive in all crossbreeding generations, was significant only in G3. Comparing the crossbreds versus the straightbreds Charolais or Nellore carcasses, it was observed that the crossbreds showed higher absolute quantity of muscle, but lower muscle/bone ratio than the Charolais and, higher absolute quantity of muscle, bone and fat and higher muscle/bone and edible portion/bone than the Nellore. The carcasses of the crossbreds showed higher muscle and lower bone percentage than the Nellore and, higher fat and lower muscle percentage than the Charolais. Meat of the crossbreds showed lower amount of marbling and similar tenderness to the Charolais, but had more marbling and was more tender than the Nellore meat.

Características das partes não-integrantes da carcaça de novilhos 5/8Nelore 3/8Charolês abatidos em três estádios de desenvolvimento

The characteristics of the body parts non-integrant of the carcass of 5/8 Nellore 3/8 Charolais steers feedlot finished and slaughtered with 425, 467 and 510 kg, were evaluated. The feeding periods were 30, 65 and 94 days, respectively. The average initial age and weight were 660 days and 361 kg, respectively. The diet, with 60% roughage and 40% concentrate dry matter basis (DM), contained 10.25% of crude protein and 3.18 Mcal of digestible energy/kg DM. According to regression equation estimate, the hot and cold carcass dressing increased as slaughter weight (SW) increased. However, when expressed per empty body weight (EBW), similarity among the different treatments was verified. When the components were expressed in absolute values, rawhide, total external components (TEC), liver, total vital organs (TVO), total internal fats (TFAT) and total empty gastrintestinal tract (TEGT) showed increase with increase in SW. When expressed per 100 kg of body weight and EBW, the rawhide, TEC, liver and TEGT components showed similarity; heart and TVO showed decrease; and TFAT showed increase, with increase in SW. Positive correlations between liver weight with dry matter intake (r=.91) and with net energy maintenance (NEm) (r=.91), and between TFAT with NEm (r=.78) were observed.

Perfil de ácidos graxos na carne de novilhos de diferentes idades e grupos genéticos terminados em confinamento

Foram utilizados 24 bovinos machos castrados, pertencentes a quatro grupos geneticos (⅝Charoles (CH) ⅜Nelore (NE); ⅝NE ⅜CH; ¾ CH ¼ NE e ¾ NE ¼ CH) e duas idades (jovem e superjovem), mantidos com dieta composta de silagem de milho e concentrado, com relacao volumoso:concentrado de 50:50. As carcacas, apos o abate, foram identificadas e resfriadas retirando-se um bife da porcao do musculo Longissimus dorsi, que foi seco em estufa, moido, identificado e armazenado para extracao dos lipideos e determinacao dos acidos graxos, realizada em cromatografo a gas. Nao houve interacao significativa categoria × grupo genetico para marmoreio, espessura de gordura e relacao musculo:gordura, utilizados como co-variaveis. O total de acidos graxos trans18 nos animais superjovens foi maior (2,46%) que nos jovens (1,87%). A maioria dos acidos graxos de cadeia curta (75%) e de cadeia media (91,7%) nao foi influenciada pelo grupo genetico. Os valores de acido linoleico conjugado (CLA) nao diferiram entre os grupos geneticos. Animais com predominância Nelore apresentaram maior grau de saturacao nos acidos graxos (media de 54,7%) em comparacao aos de predominância Charoles (media de 49,5%). A relacao de acidos graxos insaturados/saturados nos animais Charoles foi maior que nos animais Nelore.