Abstract Background: Ruminant feed containing animal byproduct proteins (ABPs) is prohibited in many countries due to its risk of transmitting prion diseases (PD). In most cases the entire herd is sacrificed, which causes great harm to the producer countries by preventing their exportation of ruminant derived-products. Methods: We used stable isotope ratio mass spectrometry (IRMS) of carbon (13C/12C) and nitrogen (15N/14N) to trace the animal protein in the blood of 15 buffaloes (Bubalus bubalis) divided into three experimental groups: 1 - received only vegetable protein (VP) during 117 days; 2 - received animal and vegetable protein (AVP); and 3 - received animal and vegetable protein with animal protein subsequently removed (AVPR). Groups 2 and 3 received diets containing 13.7% bovine meat and bone meal (MBM) added to a vegetable diet (from days 21-117 in the AVP group and until day 47 in the AVPR group, when MBM was removed). Results: On the 36th day, differences were detectable in the feeding profile (p <0.01) among the three experimental groups, which remained for a further 49 days (85th day). The AVPR group showed isotopic rate reversibility on the 110th day by presenting values similar to those in the control group (VP) (p> 0.05), indicating that it took 63 days to eliminate MBM in this group. Total atoms exchange (> 95%) of 13C and 15N was observed through incorporation of the diet into the AVP and AVPR groups. Conclusions: IRMS is an accurate and sensitive technique for tracing the feeding profile of ruminants through blood analysis, thus enabling investigation of ABP use.

RESUMO. Objetivou-se com o estudo avaliar os efeitos de diferentes tempos de maturação sobre as características da carne de búfalos Murrah jovens abatidos com 20-24 meses de idade (experimento I; n=10) e novilhas bubalinas Murrah abatidas com 32-36 meses de idade (experimento II; n=10), com a finalidade de determinar o melhor tempo de maturação para ambos os experimentos. As amostras do músculo longissimus thoracis foram maturadas durante 7, 14 e 21 dias (0 ± 1°C). Após esse período, foi realizada análise de colesterol, pH, perdas de peso por cocção, força de cisalhamento, índice de fragmentação miofibrilar, cor da carne e perfil de ácidos graxos. A maturação melhorou a maciez (p < 0,05), no entanto, modificou a cor da carne (p < 0,05), a qual, mesmo sem diferença entre os tratamentos para percepção subjetiva da cor (ΔE; p > 0,05), foi considerada como muito perceptível ao olho humano. Além disso, a maturação reduziu os ácidos graxos polinsaturados (p < 0,05) e não afetou os níveis de colesterol (p > 0,05) na carne de búfalos jovens e novilhas bubalinas com idade avançada. Com base nas características avaliadas, conclui-se que sete dias de maturação são suficientes para as novilhas bubalinas mais velhas, mas 21 dias de maturação são necessários para o grupo de búfalos mais jovens.

ABSTRACT. The aim of this study was to evaluate the effects of different aging times on the meat characteristics from young Murrah buffaloes slaughtered at 20-24 months of age (experiment I; n=10) and Murrah buffalo heifers slaughtered at 32-36 months of age (experiment II; n=10), with the purpose of determining the best aging time to tenderize meat from both experiments. Samples of the longissimus thoracis muscle from buffaloes slaughtered at each age were aged for 7, 14, and 21 days (0±1°C). After this period, analysis of cholesterol, pH, cooking loss, shear force, myofibrillar fragmentation index, meat color, and fatty acid profile was performed. Aging greatly improved the tenderness (p < 0.05) but caused a change in color (p < 0.05), which, even without difference between the treatments for subjective perception of the color (ΔE; p > 0.05), was considered very noticeable to the human eye. Furthermore, aging reduced the polyunsaturated fatty acids (p <0.05) and did not affect the levels of cholesterol (p > 0.05) in the meat of young buffalo and buffalo heifers of advanced age. Based on the evaluated meat characteristics, concludes that seven days of aging are sufficient for older buffalo heifers, but 21 days of aging are required for the younger male group.

Resumo:O objetivo deste trabalho foi avaliar o efeito da inclusão de simbióticos e de monensina sódica em dietas sobre o desempenho, as características de carcaça e a qualidade da carne de novilhas mestiças Angus em confinamento. Utilizou-se um delineamento inteiramente casualizado, com 64 animais distribuídos em quatro tratamentos: controle, dieta sem suplementação; dieta suplementada com simbióticos; dieta com monensina sódica; e dieta com simbióticos e monensina sódica. A dieta com monensina sódica e a dieta com simbióticos e monensina sódica proporcionaram maior ganho de peso médio diário e ganho de peso vivo total, além de melhorar a eficiência alimentar e biológica dos animais em comparação ao controle. A dieta de simbióticos, a de monensina e a de simbióticos com monensina sódica ocasionaram a redução da ingestão de matéria seca, elevaram o peso do filé da costela e os teores de lipídeos totais na carne. A dieta com simbióticos proporcionou a redução da força de cisalhamento da carne em relação ao controle. A inclusão de simbióticos, com ou sem monensina sódica, na dieta de novilhas mestiças Angus confinadas, beneficia o desempenho animal e algumas características físico-químicas da carne.

Abstract:The objective of this work was to evaluate the effect of inclusion of synbiotics and sodic monensin on the performance, carcass characteristics, and meat quality of Angus crossbred heifers on feedlot. A completely randomized block design was carried out with 64 animals distributed in four treatments: control, a diet without supplementation; a diet supplemented with synbiotics; a diet with sodic monensin; and a diet with synbiotics and sodic monensin. The diet with sodic monensin and the diet with synbiotics and sodic monensin increased the average daily gain and total live weight gain, besides improving the feed and biological efficiency of animals compared to control treatment. The diet with synbiotics, with sodic monensin, and with synbiotics and sodic monensin decreased dry matter intake, and increased the rib fillet weight (noix) and the total lipid concentration in the meat. The diet with synbiotics facilitated the reduction of meat shear force compared to control treatment. The inclusion of synbiotics, with or without sodic monensin, in diet of Angus crossbred heifers, improves animal performance on feedlot and some physicochemical characteristics of meat.

The objective of this study was to evaluate the effects of feeding cattle with isoprotein and isoenergetic diets, with and without the addition of polyclonal antibody preparation (PAP), yeasts (YST) or monensin sodium (MON) on performance, carcass characteristics and gain cost in feedlot. Ninety-five 20-month old bullocks (323.3±21.8 kg) were distributed in 25 pens. The completely randomized experimental design had a 2 × 2 + 1 factorial arrangement and the treatments were replicated 5 times. There was no effect of MON for DMI throughout the feedlot period; however, MON reduced the dry matter intake (DMI) in g/kg of BW in the first 28 days when compared with the other treatments. The gain cost decreased with MON addition in relation to the other treatments. Inclusion of YST decreased average daily gain (ADG), final body weight, hot carcass weight, carcass weight, gain to feed ratio and DMI in g/kg body weight, worsening feed conversion and increasing the gain cost in the feeding periods. Inclusion of PAP increased ADG and decreased the gain cost, besides improving feed conversion. For MON and PAP, a difference was found for kidney-pelvic fat and kidney-pelvic fat per 100 kg of hot carcass weight. For MON and YST, there was a difference in ADG, feed conversion, gain cost and carcass yield and kidney-pelvic fat per 100 kg of hot carcass. Treatment YST worsened performance in relation to the non-supplemented treatments. Feeding PAP to animals did not influence performance and carcass characteristics of bullocks in feedlot negatively. Thus, PAP shows potential to substitute MON in cattle feeding using isoprotein and isoenergetic diets.

Real-time ultrasonography (RTU) was used to measure the longissimus dorsi muscle (LM) volume in vivo and to predict the carcass composition of rabbits. For this, 63 New Zealand White × Californian rabbits with 2093±63 g live weight were used. Animals were scanned between the 6th and 7th lumbar vertebrae using an RTU equipment with a 7.5 MHz probe. Measurements of LM volume were obtianed both in vivo and on carcass. Regression equations were used for the prediction of carcass composition and LM volume using the LM volume measured obtained with RTU (LMVU) as independent variable. Carcass meat, bone and total dissectible fat weights represented 780, 164 and 56 g/kg of the reference carcass weight, respectively. Regression equations showed a strong relationship between LMVU and the correspondent volume in carcass. Furthermore, LMVU was also useful in predicting the amounts of carcass tissues. It is possible to predict LM volume in the carcass using the LM volume measured in vivo by RTU. The amount of carcass tissues can be predicted by the LM volume measured in vivo by RTU.

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$ 59.17 and R$ 60.51 for diets based on soy with and without supplemental vitamin, respectively, vs. R$ 176.42 and R$ 131.79 for diets based on cottonseed). The utilization of cottonseed enables improvement of profitability of feedlot fattening, in spite of negatively affecting some carcass characteristics.

Os objetivos neste experimento foram gerar informações sobre a composição física e as relações músculo:osso, músculo:gordura e porção comestível:osso do lombo de ovelhas abatidas em diferentes estágios fisiológicos, além das possíveis correlações entre as variáveis avaliadas neste estudo. Foram utilizadas 21 ovelhas Santa Inês, distribuídas nos respectivos estágios fisiológicos: OL = ovelhas que permaneceram por 60 dias em lactação com seus respectivos cordeiros e abatidas um dia após o desmame dos mesmos; OSC = ovelhas que permaneceram por 60 dias em lactação com seus respectivos cordeiros e por mais um período aproximado de 30 dias sem os cordeiros e posteriormente abatidas; e ONP = ovelhas que permaneceram por 60 dias em confinamento e que não pariram durante o ano. Os percentuais de músculos e gorduras intermuscular e comestível foram semelhantes entre os estágios fisiológicos. O abate de ovelhas em diferentes estágios fisiológicos alterou a relação porção comestível:osso do lombo. Maiores proporções de gordura subcutânea corresponderam a menores quantidades de gordura intermuscular no lombo ou vice-versa.

The objectives of this paper were to generate data on physical composition and muscle:bone, muscle:fat and edible portion:bone ratios of the loin of ewes slaughtered at different physiological stages in addition to the possible correlations among the variables analyzed in this study. Twenty-one Santa Inês ewes were distributed to the following physiological stages: EL = ewes which remained in lactation for 60 days with their respective lambs and slaughtered at one day after weaning of the lambs; EWL = ewes which remained in lactation for 60 days with their respective lambs and one more period of approximately 30 days without the lambs and slaughtered afterwards; and ENP = ewes which remained in confinement for 60 days and did not give birth during the year. Muscles and edible and intermuscular fat percentages were similar among physiological stages. The slaughter of ewes at different physiological stages altered the edible portion:bone of the loin ratio. Higher proportions of subcutaneous fat correspond to lower amounts of intermuscular fat in loin or vice-versa.

Objetivou-se estudar as medidas de espessura de gordura subcutânea, área de olho-de-lombo, comprimento e profundidade máxima do músculo longissimus dorsi entre a 13ª costela e 1ª vértebra lombar determinadas por ultrassom e na carcaça de ovelhas de descarte abatidas em diferentes estágios fisiológicos, além dos coeficientes de correlação e determinação das medidas avaliadas. Utilizaram-se 21 ovelhas da raça Santa Inês, distribuídas nos seguintes grupos: OL = ovelhas que permaneceram por 60 dias em lactação com seus cordeiros e foram abatidas um dia após o desmame dos mesmos; OSC = ovelhas que permaneceram por 60 dias em lactação com seus cordeiros e mais 30 dias sem os cordeiros e foram posteriormente abatidas; e ONP = ovelhas que não pariram durante o ano. O comprimento máximo do músculo longissimus dorsi obtido pelo ultrassom e na carcaça dos animais não foi influenciado pelos estágios fisiológicos. O ultrassom pode ser utilizado com razoável precisão para estimar características da carcaça de ovelhas de descarte, em particular a espessura de gordura subcutânea.

The objective of this paper was to study subcutaneous fat thickness, loin eye area, length and maximum depth measurements of the longissimus dorsi muscle between the 13th rib and the 1st lumbar vertebra determined by ultrasound examination and on the carcass of discard ewes slaughtered in different physiological stages, besides correlation and determination coefficients among measurements evaluated. It was used 21 Santa Ines ewes distributed into the following treatments: EL = ewes that remained in lactation for 60 days with their respective lambs and slaughtered one day after weaning; EWL = ewes that remained in lactation for 60 days with their respective lambs one more period of approximately 30 days without the lambs and slaughtered afterwards; and ENC = ewes that did not give birth during the year. Results showed that the maximum length of the longissimus dorsi muscle obtained by ultrasound examination and on carcass of the animals were not influenced by the experimental treatments. The ultrasound can be used with reasonable accuracy to estimate characteristics of the carcass of discard ewes, particularly the thickness of subcutaneous fat.

Objetivou-se avaliar o crescimento de novilhas de diferentes grupos genéticos no sistema de produção superprecoce. Utilizaram-se 132 novilhas dos seguintes grupos genéticos: 18 ¾ Canchim × ¼ Nelore (¾ CN); 18 ½ Canchim × ½ Nelore (½ CN); 24 Simbrasil -⅝ Simental × ⅜ Nelore; e 72 Three-cross ¼ Simental × ¼ Nelore × ½ Angus. As novilhas foram desmamadas aos 210 dias de idade, com 247,4 ± 16,5 kg de peso vivo (PV), mantidas em creep-feeding durante a fase de cria e confinadas por 132 ± 14 dias até atingirem 350 kg PV e 5 mm de gordura subcutânea, quando, então, foram abatidas. Os grupos genéticos não influenciaram o ganho de peso médio diário, porém a espessura de gordura subcutânea do dorso (EGS) e da garupa (EGG) foi maior nos animais Three-cross, que apresentaram os maiores valores iniciais (1,07 kg/dia). Não houve diferença na área de olho-de-lombo (AOL) inicial, porém a os animais Three-cross apresentaram os maiores valores iniciais. Nos animais do grupo Three-cross, a área de olho-de-lombo (AOL) final e ajustada para 100 kg de peso vivo (PV) foi inferior à observada nos demais grupos, porém o peso final foi superior ao do grupo Simbrasil, com tempo intermediário de confinamento. Ajustando-se os valores de AOL e EGG para o menor número de dias de confinamento (114 dias), animais Simbrasil apresentam maior valor de AOL final e os animais Three-cross e Simbrasil, maior EGG final.

The objective of this study was to evaluate the growth of young heifers from different genetic groups in an intensive meat production system. One hundred and thirty two heifers from four different genetics groups were used: 18 - ¾ Canchim × ¼ Nellore (¾ CN), 18 - ½ Canchim × ½ Nellore (½ CN), 24 Simbrasil - ⅝ Simmental × ⅜ Nellore (SIMB) and 72 - Three way cross ¼ Simmental × ¼ Nellore × ½ Angus. The heifers were weaned at 210 days of age with 247.4 ± 16.5 kg live weight (LW), from creep-feeding during the rearing phase and 132 ± 14 days in feedlot system. The animals were slaughtered when they reached 350 kg LW and 5 mm backfat thickness (BFT). There was no difference among the genetic groups for average daily weight gain but the three way cross heifers presented the highest values (1.07 kg/day). There were no differences for initial ribeye area (REA), but the three cross animals obtained larger values of initial backfat thickness (BFT) and initial rump fat thickness (RFT). In the animals in the three – cross group, the final ribeye area and adjusted to 100 kg live weight (LW) was lower than that observed in the other groups, but the final body weight was superior to the Simbrasil group, with intermediate feedlot time. When the REA and RFT values are fitted to the smallest number of days in feedlot (114 days), the Simbrasil animals present greater REA and the three-cross and Simbrasil higher RFT.

Objetivou-se determinar as medidas in vivo e na carcaça de ovelhas de descarte abatidas em diferentes estágios fisiológicos, assim como as possíveis correlações entre essas medidas objetivas (in vivo e na carcaça) e o peso corporal ao abate e da carcaça fria. Foram utilizadas 21 ovelhas da raça Santa Inês, distribuídas nos seguintes estágios fisiológicos: OL = ovelhas mantidas por 60 dias em lactação com seus cordeiros e abatidas um dia após o desmame dos mesmos; OSC = ovelhas que foram mantidas por 60 dias em lactação com seus respectivos cordeiros e mais um período aproximado de 30 dias sem os cordeiros e posteriormente abatidas; e ONP = ovelhas que permaneceram por 60 dias em confinamento e que não pariram durante o ano. Não se observou diferença entre os estágios fisiológicos na maioria das características medidas in vivo e na carcaça. O perímetro da garupa determinado na carcaça e o perímetro torácico, as larguras do peito e da garupa obtidos in vivo mostraram-se altamente correlacionados aos pesos corporal e de carcaça fria dos animais. Portanto, essas medidas podem auxiliar na determinação do peso corporal de ovelhas em diferentes estágios fisiológicos.

The objective was to determine in vivo and carcass measurements of culled ewes slaughtered at different physiological stages and the possible correlations between the objective measurements (in vivo and in the carcass) and the body weight at slaughter and cold carcass weight. Twenty-one Santa Inês ewes were used, placed in the following treatments: EL = ewes which remained in lactation for 60 days with their respective lambs and slaughtered one day after weaning the lambs; EWL = ewes which remained in lactation for 60 days with their respective lambs and a further period of approximately 30 days without their lambs and, afterwards, slaughtered; and ENP = ewes that remained in feedlot for 60 days and did give birth during the year. No difference was observed between rearing systems in most of the characteristics measured in vivo and in the carcass. The croup perimeter determined in the carcass and the thoracic perimeter and chest and croup width obtained in vivo were highly correlated to the body and cold carcass weights of the ewes in this study. Therefore, these measurements can assist in determining the body weight of ewes at different physiological stages.

Os objetivos neste trabalho foram estimar as correlações entre medidas obtidas por ultrassonografia e na carcaça e acompanhar o desenvolvimento da área de olho-de-lombo e a deposição de gordura de búfalos em diferentes períodos de confinamento. Foram utilizados 20 bubalinos da raça Murrah, castrados, abatidos aos 75, 100, 125 ou 150 dias de confinamento. As medidas realizadas foram área de olho-de-lombo, espessura de gordura subcutânea do dorso e espessura de gordura da garupa, mensuradas por ultrassonografia quando os búfalos atingiram o tempo de abate e na carcaça, após o abate. A espessura de gordura subcutânea da carcaça foi avaliada utilizando-se paquímetro e a área de olho-de-lombo da carcaça, régua do quadrante de pontos. O período de confinamento apresentou efeito linear crescente na área de olho-de-lombo e nas espessuras de gordura do dorso e da garupa avaliadas por ultrassom e na carcaça. O efeito linear positivo entre 75 e 150 dias de confinamento, tanto para a área de olho-de-lombo como para espessura de gordura medidas no dorso e na garupa, comprovou que os animais ainda não haviam atingido a maturidade. As correlações entre as medidas obtidas por ultrassom e na carcaça foram 0,82 para área de olho-de-lombo e 0,85 para espessura de gordura subcutânea no dorso. As características de carcaça medidas por ultrassom em bubalinos apresentam boas correlações com as medidas realizadas na carcaça no momento do abate, o que permite, em bubalinos da raça Murrah castrados e oriundos de rebanho leiteiro, acompanhar as alterações dessas características durante o desenvolvimento.

The objective of this study was to evaluate the correlations between the measurements obtained by ultrasound and from the carcass and follow the development of the ribeye and fat thickness in buffaloes at different feedlot stages. Twenty castrated, hornless Murrah buffaloes were used. The buffaloes were separated into four groups that were slaughtered at 75, 100, 125, 150 days of feedlot. The measurements taken by ultrasound when the buffaloes reached the slaughter point and from the carcass after the slaughter were ribeye, back fat thickness and rump fat thickness. The fat thickness was evaluated using a paquimeter and the ribeye was evaluated by using a quadrant grade ruler. The ribeye, back fat thickness and rump fat thickness presented a linear increase effect in function of the feedlot stages. The linear increase from 75 to 150 days of feedlot for ribeye, back fat thickness and rump fat thickness showed that the buffaloes had not reached maturity. The increase in the fat thickness measurement obtained in days of feedlot from the carcass and by ultrasound was similar between the back and rump. The correlations measured by ultrasound and from the carcass were 0.82 for ribeye and 0.85 for back fat thickness. The characteristics of the measurements taken by ultrasound, in buffaloes, correlated well with measurements at the time of slaughter, so that the alterations could be followed in these characteristics in castrated Murrah buffaloes from a dairy herd during their development.

Um experimento foi conduzido no intuito de avaliar ovelhas de descarte abatidas em diferentes estágios fisiológicos e terminadas em confinamento, quanto aos rendimentos de carcaça e seus cortes, assim como os percentuais de cada não-componente da carcaça. Utilizaram-se 21 ovelhas da raça Santa Inês com idade média de 6 anos, distribuídas nos tratamentos: OL = ovelhas mantidas por 60 dias em lactação com seus cordeiros e abatidas um dia após o desmame dos mesmos; OSC = ovelhas mantidas por 60 dias em lactação com seus cordeiros e mais um período de aproximadamente 30 dias sem os cordeiros, no intuito de recuperar o peso corporal perdido na amamentação, e posteriormente abatidas; e ONP = ovelhas mantidas por 60 dias em confinamento e que não pariram durante o ano. As ovelhas que permaneceram por 60 dias em confinamento e que não pariram durante o ano apresentaram maiores rendimentos de carcaça quente 45,00 e fria 44,73% em comparação àquelas mantidas por 60 dias em lactação com seus cordeiros e abatidas um dia após o desmame: 40,80 e 40,66%. Os rendimentos dos cortes da carcaça (perna, lombo, paleta, costelas e pescoço) foram similares entre todas as ovelhas abatidas nos distintos estágios fisiológicos. Os rendimentos dos não-componentes da carcaça, com exceção dos valores do fígado, do sangue, do úbere e da gordura interna, foram similares entre as ovelhas.

The objective of the experiment was to evaluate discarded ewes slaughtered at different physiological stages and terminated in feedlot for yields of carcass and cuts and the percentage of each non carcass component. Twenty-one Santa Inês ewes were used, with average age of six years old, distributed into the following treatments: EL = ewes that had remained in lactation for 60 days with their respective lambs until slaughtering; EWL = ewes that remained in lactation for 60 days with their respective lambs and a further 30 days approximately without lambs to recover lost of body weight during suckling, and were subsequently slaughtered; and ENC = ewes that remained in feedlot for 60 days and did not deliver during the year. The results obtained in this research showed that ewes that remained in feedlot for 60 days and did not deliver during the year presented higher hot (45.00) and cold (44.73%) carcass yields, compared to ewes that had remained in lactation for 60 days with their respective lambs until slaughtering (40.80 and 40.66%). Carcass cut (leg, loin, shoulderblade, ribs and neck) yields were similar among all ewes slaughtered in the different physiological conditions. Non carcass component yields were similar among the ewes slaughtered in different physiological stages, except for the liver, blood, udder and internal fat values.

Este estudo teve como objetivo avaliar a qualidade da carne de cordeiros terminados em regime de confinamento que receberam dietas com diferentes teores de concentrado. Foram utilizados 18 cordeiros ½ Ile de France ½ Santa Inês não castrados, com peso inicial de aproximadamente 15 kg, distribuídos em dois lotes, representados pelo tratamento 1 (T1) animais que receberam na dieta relação volumoso:concentrado de 35:65 e (T2) cordeiros que receberam relação volumoso:concentrado de 65:35 até atingirem 32 kg de peso corporal em regime de confinamento, peso pré-determinado para o abate dos animais. Os cordeiros do tratamento 1 e 2 apresentaram valores similares de pH, força de cisalhamento, perdas por cocção e capacidade de retenção de água da carne, com valores médios de 5,70, 1,03 kgf/cm², 35,20 e 59,31%, respectivamente. A relação volumoso:concentrado não influenciou na qualidade centesimal da carne dos cordeiros alimentados com dietas mais concentradas ou mais volumosas, para umidade, proteína, extrato etéreo e matéria mineral. Concluiu-se que os cordeiros terminados em confinamento recebendo diferentes teores de concentrado na dieta apresentaram qualidade da carne similar; portanto, a escolha da dieta vai depender do custo dos ingredientes no momento do confinamento.

The objective of this study was to evaluate the meat quality of lambs terminated in confinement and fed diets with different concentrate contents. 18 non-castrated ½ Ile de France ½ Santa Inês lambs were used. Their initial weight was approximately 15 kg and they were divided into two separate groups represented by Treatment 1 (T1) - animals fed with diets containing the ratio voluminous:concentrate 35:65 - and Treatment 2 (T2) - lambs fed with diets containing the ratio voluminous:concentrate 65:35 until reaching 32 kg of body weight in confinement, which is the pre-established weight for slaughtering. T1 and T2 lambs presented similar values for pH, shear force, losses due to cooking and water retention capacity; the average values found were 5.70, 1.03 kgf/cm², or 35.20, and 59.31%, respectively. The voluminous:concentrate ratio did not influence the centesimal quality of meat of lambs fed with more concentrated or more voluminous diets for humidity, protein, ethereal extract, and mineral matter. It can be concluded that lambs terminated in confinement fed with different concentrate contents diets presented similar meat quality; therefore, the diet choice depends on the cost of the ingredients at the time of the confinement.

Objetivou-se avaliar o efeito da suplementação com cromo complexado à molécula orgânica do suplemento no desempenho produtivo, nas características de carcaça e na qualidade da carne de bovinos terminados em regime de pastagem. Foram utilizados 18 bovinos Nelore e 18 F1 Brangus × Nelore castrados, com 16 meses de idade, mantidos com suplementação mineral protéica, com ou sem cromo complexado à molécula orgânica e abatidos aos 22 meses de idade. O ganho médio diário de peso vivo (GMD) não diferiu entre grupos genéticos, entretanto animais mantidos com suplemento contendo cromo apresentaram maior GMD (494 g) em comparação aos demais (420 g). A adição de cromo orgânico no suplemento não promoveu alterações na área de olho-de-lombo (63,42 cm²) e na espessura de gordura subcutânea do dorso (5,46 mm) e da garupa (5,58 mm), tomados por meio do ultra-som. O peso médio de carcaça quente foi 235 kg e o rendimento médio de carcaça quente, 52,09%, com superioridade do suplemento contendo cromo (238 kg e 52,9%) em relação ao controle (231 kg e 51,2%). Animais Nelore e F1 Brangus × Nelore apresentam potencial similar de produção de carne a pasto. A suplementação mineral protéica com adição de cromo complexado à molécula orgânica aumenta o ganho de peso e o rendimento de carcaça, mas não influencia os parâmetros qualitativos da carne.

The present work was aimed to evaluate the effect of mineral protein supplementation with addition of chromium attached to the organic molecule on the productive performance, carcass traits and beef quality in steers finished under grass conditions. For this, 18 Nellore and 18 F1 Brangus × Nellore steers were used, with 16 months of average initial age and slaughtered at 22 months, distributed equally into two treatment of mineral protein supplementation with and without addition of chromium attached to the organic molecule. There was no observed difference between genetic groups regarding the average daily gain (ADG). However, animals supplied with chromium showed better ADG (494 g) than control animals (420 g). There was no observed difference between experimental treatments regarding the rib eye area, subcutaneous fat thickness at the back and rump measured through ultrasound, reaching final mean values of 63.42 cm²; 5.46 and 5.58 mm, respectively. It was observed an average of 235 kg for hot carcass weight and 52.09% for dressing percentage, with a superiority for the chromium treatment (238 kg and 52.9%) versus control (231 kg and 51.2%), and without difference between genetic groups. Nellore and F1 Brangus × Nellore steers show equal beef production potential under grass conditions. Mineral protein supplementation with chromium attached to the organic molecule increases the weight gain and dressing percentage, not influencing the beef quality parameters evaluated in this study.

Utilizaram-se 32 bubalinos machos não-castrados, da raça Mediterrâneo, divididos aleatoriamente em cinco categorias. Os animais de uma categoria foram abatidos imediatamente, enquanto os demais foram alimentados, à vontade, com ração contendo 70% de concentrado (na matéria seca) e abatidos ao atingirem 450, 480, 510 ou 540 kg de peso corporal. Adotou-se a equação de regressão do logaritmo da quantidade corporal de carcaça e de seus tecidos (muscular, adiposo e ósseo) em função do logaritmo do peso de corpo vazio. A carcaça apresentou valor de alometria, o que indica desenvolvimento proporcionalmente igual ao do peso corporal vazio. Derivando as equações, obtiveram-se as equações de predição da participação dos componentes corporais no ganho de 1 kg de peso de corpo vazio. Na carcaça, o tecido adiposo teve maior impulso de crescimento em idade mais tardia, enquanto os tecidos ósseo e muscular tiveram maior impulso para crescimento em idade mais precoce.

Thirty-two non castrated Mediterranean male buffaloes were used, being divided into five groups (categories). One group was randomly assigned to immediate slaughter, four groups were fully fed with ration containing 70% of concentrate, dry matter basis until reaching the slaughter weights of 450, 480, 510 and 540 kg. Regression equations of log content of carcass and their tissues (muscle, adipose tissue and bone) were adopted as a function of log empty-body-weight. Carcass presented positive allometry value close to 1, reflecting development proportionally equal to the empty-body-weight. Deriving the equations above, the prediction equations of body components in the body gain of 1 kg of the empty-body-weight were obtained. In the carcass, the adipose tissue presented late growth while bone and muscular tissues developed in an earlier age.