Otávio Rodrigues Machado Neto

Características de carcaça e cortes comerciais de tourinhos Red Norte e Nelore terminados em confinamento

The objective of this study was to evaluate the characteristics of carcass and weight of the commercial meat cuts from carcass of Red Norte and Nellore young bulls finished in feedlot. Forty four animals - 22 Red Norte with initial average weight of 367±30 kg and 22 Nellore at initial average weight of 361±30 kg - were used. The animals received feed ad libitum with concentrate:roughage ratio of 50:50 during 112 days, from which 28 days were for adaptation. Red Norte and Nellore animals were slaughtered at 519 and 482 kg, respectively. The subcutaneous fat thickness (FT) and longissimus muscle area (LMA) were measured between 12th and 13th ribs. Higher carcass yield of the Nellore breed was observed (57.7 vs 54.7%). However, there was no difference for weight of hot and cold carcass between the groups. Red Norte animals showed greater LMA, and hindquarter and spare ribs with higher weight and yield, and forequarter with lower weight and yielding. The Red Norte genetic group showed higher weight for cap and rump and striploin, while Nellore showed higher weight for shoulder and flatround. Nellore animals had better carcass yield, which contributes to hot carcass weight. Nevertheless, the group Red Norte have higher hindquarter yield and more weight from cuts of highest commercial value.

VIABILIDADE ECONOMICA DA TERMINAÇÃO DE NOVILHOS NELORE E RED NORTE EM CONFINAMENTO NA REGIÃO DE LAVRAS-MG

Conduziu-se este trabalho, com o objetivo de verificar a viabilidade economica da terminacao em confinamento de novilhos Nelore e Red Norte na regiao de Lavras, MG. Foram utilizados 41 novilhos, nao castrados, de dois grupos geneticos, sendo: 19 Nelore e 22 Red Norte, com pesos vivos iniciais medios de 315 ±31 kg e 321 ±30 kg, respectivamente. O periodo experimental foi de 112 dias, divididos em quatro periodos de 28 dias. A viabilidade economica foi analisada utilizando o modelo de custo, considerando os custos operacionais, alternativos e de depreciacao. Todos os indicadores economicos gerados apresentaram resultados negativos. A atividade apresentou prejuizo de R

Composição química e de ácidos graxos do músculo longissimus dorsi e da gordura subcutânea de tourinhos Red Norte e Nelore

6,88 e 19,74/arroba para os animais Red Norte e Nelore, respectivamente. Os resultados negativos obtidos nessas condicoes ocorreram porque o custo operacional efetivo foi maior que o preco de venda da arroba. Em um cenario com a aquisicao de animais a atividade de confinamento apresentou residuo proximo de zero para o grupo Red Norte. A pratica do confinamento nao apresentou viabilidade economica para a regiao de Lavras, MG, no ano de 2007.

Grãos de oleaginosas na alimentação de novilhos zebuínos: consumo, digestibilidade e desempenho

The objective of this study was to evaluate the chemical composition and the fatty acid profile of the longissimus dorsi muscle and the backfat thickness of Red Norte and Nellore young bulls finished in feedlot. Fourty-four animals (22 Red Norte with initial average weight of 367±30 kg and 22 Nellore at initial average weight of 361±30 kg) were used. The animals were fed ad libitum during 112 days, slaughtered at 519 and 482 kg, respectively. Samples of the longissimus dorsi muscle and backfat thickness were collected 24 hours after slaughter between the 12th and 13th ribs for analysis of the chemical composition and the fatty acids profile. Fatty acid analyses were performed by gas chromatography with a 100-m capillary column. There was no difference for the chemical composition of the meat between the genetic groups. Red Norte animals showed higher contents of pentadecanoic, palmitic, palmitoleic, linoleic and conjugated linoleic acid (CLA) fatty acids, while Nellore animals had the highest content of oleic acid. The muscle longissimus dorsi showed greater concentrations of lauric, heptadecenoic, stearic, linoleic, α-linoleic and arachidonic acids. Comparing the fatty acid deposited in the longissimus dorsi muscle with backfat thickness, the latter showed higher contents of miristic, miristoleic, pentadecanoic, palmitic, palmitoleic, oleic and CLA acids. Red Norte animals showed higher contents of saturated fatty acid than Nellore. In bovine, the profile of fatty acids deposited in the muscle is different than the that in the backfat thickness. The fatty acids profile of the meat from young bulls differs between genetic groups.

Reactivity, performance, color and tenderness of meat from Zebu cattle finished in feedlot

This study was conducted to evaluate feed intake, performance and of digestibility diet containing different oilseeds to beef cattle finished in feedlot. Thirty zebu steers (388.0±37.5 kg of body weight) were used in a completed randomized design. The diets consisted of corn silage and four different concentrates: one without lipids and three with inclusion of soybeans, cottonseed and linseed. The diets, which were isonitrogenous, had roughage:concentrate ratio of 60:40 and were offered ad libitum. To determinate the total apparent digestibility of nutrients, the fecal output was estimated through internal marker indigestible neutral detergent fiber. The lowest dry matter intake was observed for cottonseed (7.20 kg/d), but among the other diets, the dry matter intake did not differ. The average daily gain was lower when cottonseed was used, in comparison with linseed (0.93 vs. 1.16 kg/d, respectively). However, there was no difference on average daily gain in relation to other diets. There was reduction in the digestibility of neutral detergent fiber in linseed diet. Additionally, there was a reduction in the neutral detergent fiber digestibility in diets with cottonseed and linseed compared with soybeans, which did not differ from the control diet. The inclusion of ground cottonseed in feedlot beef cattle diets should be realized with caution, since it can decrease dry matter intake and average daily gain. However, feed efficiency is not affected by the addition of oilseeds in beef cattle diets when the maximum ether extract level in total dry matter diet does not exceed 6%.

Feed intake and prediction assessments using the NRC, CNCPS and BR-CORTE systems in Nellore and Red Norte steers finished in feedlot.

The objective of this study was to study the animal reactivity and correlate it with performance and meat quality of cattle finished in feedlots. A total of 20 animals of the Tabapua breed and 20 animals of the Nellore breed were confined for 112 days: 28 days of adaptation and 84 days of data collection. Performance was determined by the average daily weight gain (ADG) and average dry matter intake (DMI) estimated through the use of indicators. On the 1st, 42nd and 84th days of the experiment, two methods were used to measure the animal reactivity: animal reactivity in mobile cage and visual reactivity during handling. The characteristics of meat quality were evaluated by the color, shear force and pH24 after slaughter (pH24). Through the study of correlation, the degree and direction of linear association on animal reactivity, performance and meat quality were established. Regression equations were generated for the parameters evaluated according to the values of animal reactivity. Correlations between mobile cage and visual reactivity were 0.77, 0.56 and 0.45 in the 1st, 2nd and 3rd evaluations, respectively. There was no correlation between animal reactivity and DMI. The correlations between ADG, pH24, and color with animal reactivity were -0.31, 0.40, 0.47 and -0.34, and -0.33 for mobile cage, 0.74, 0.71 and -0.51, for visual reactivity, respectively. The parameters of meat quality varied according to the reactivity. Undesirable values of pH24, animal reactivity and color were found when mobile cage reactivity was higher than 780, 590 and 540, respectively. In general, animals that show greater reactivity tend to have lower daily weight gain and lower meat quality. The reactivity can be used in animal breeding programs, in order to improve performance and meat quality of Zebu cattle finished in feedlot.

Performance, carcass traits, meat quality and economic analysis of feedlot of young bulls fed oilseeds with and without supplementation of vitamin E

Este trabalho foi realizado com os objetivos de avaliar o consumo de materia seca (CMS) e dos nutrientes da dieta em novilhos Nelore e Red Norte terminados em confinamento e comparar os valores observados aos preditos por meio dos sistemas NRC (2000), CNCPS 5.0 e BR-CORTE. Utilizaram-se 41 novilhos, nao-castrados, de dois grupos geneticos, sendo 19 Nelore com peso vivo inicial medio de 361 ± 31 kg e 22 Red Norte com peso vivo inicial de 367 ± 30 kg. No inicio do periodo de adaptacao, com duracao de 28 dias, os animais foram pesados apos jejum alimentar de 16 horas e tratados contra endo e ecto parasitas. O periodo experimental teve duracao de 56 dias e, alem das pesagens nestes periodos, foram realizadas mensuracoes do consumo individual, utilizando-se os indicadores LIPE, oxido cromico e materia seca indigestivel (MSi). A comparacao entre os dados de consumo observados com aqueles preditos pelos sistemas NRC (2000), CNCPS 5.0 e BR-CORTE foi feita por meio do procedimento PROC REG do software SAS. O consumo de materia seca expresso em kg/dia nao apresentou diferencas entre os grupos geneticos (10,66 vs 10,44). Quando expresso em porcentagem do peso vivo (%PV), o consumo foi maior para os animais da raca Nelore (2,55 vs 2,39%, respectivamente) e, quando expresso em g/kg PV0,75, tendeu a ser maior para a raca Nelore (115 vs 109 g/kg PV0,75). Todos os sistemas avaliados subestimam o consumo de materia seca, entretanto ha menores diferencas entre o consumo observado e o predito para animais mesticos.

Lipids in the diet and the fatty acid profile in beef: a review and recent patents on the topic.

The objective of this research was to evaluate average daily gain (ADG), carcass traits, meat tenderness and profitability of keeping cattle fed different oilseeds and vitamin E in feedlot. A total of 40 Red Norte young bulls with initial average body weight of 339±15 kg were utilized. The experimental design was completely randomized in a 2 × 2 factorial arrangement. The experiment lasted 84 days and experimental diets presented soybeans or cottonseeds as lipid sources associated or not to daily supplementation of 2,500 UI vitamin E per animal. The concentrate:roughage ratio was 60:40. Diets had the same amount of nitrogen (13% CP) and ether extract (6.5%). The data were analyzed by means of statistical software SAS 9.1. Neither vitamin supplementation nor lipid source affected ADG. There was no interaction between lipid source and vitamin supplementation for the variables studied. The inclusion of cottonseed reduced the carcass yield. There was no effect of diets on hot and cold carcass weights or prime cuts. The inclusion of cottonseed reduced the backfat thickness. No effect of experimental diets on the rib-eye area was observed. There was no effect of lipid source or vitamin supplementation on meat tenderness, which was affected, however, by ageing time. Diets with soybeans presented higher cost per animal. The utilization of soybean implied reduction of the gross margin (R

Performance and carcass traits of Nellore and Red Norte steers finished in feedlot

59.17 and R

Consumo alimentar e sua predição pelos sistemas NRC, CNCPS e BR-Corte, para tourinhos zebuínos confinados

60.51 for diets based on soy with and without supplemental vitamin, respectively, vs. R