ABSTRACT. This study evaluated the effect of replacing corn silage with spineless cactus, in combination with Tifton 85 hay or sugarcane bagasse, on the carcass measurements and sensory properties of the meat of lambs finished in feedlot. Twenty-one, intact, Santa Inês males, with an initial body weight of 22.86 ± 2.87 kg and an average age of 150 days, were individually confined for 74 days and fed at will three treatments diets: Corn silage (CS); Spineless cactus + Tifton 85 hay (CT) and Spineless cactus + sugarcane bagasse (CB). Lambs fed CT had a wider croup (p < 0.05) compared to animals fed CS. The replacement of corn silage with CT or CB did not influence (p > 0.05) the body length, withers height or chest circumference of the lambs. Values of carcass length and compactness index were similar (p > 0.05) between treatments. There was a high and positive correlation (p < 0.05) between chest width (0.82) and chest circumference (0.81) of animals with cold carcass weight. The odor and taste of sheep meat fed CT or CB was more accepted when compared to the meat of animals fed corn silage. The replacement of corn silage with spineless cactus in combination with Tifton 85 hay or sugarcane bagasse improves the sensory quality of sheep meat, but does not interfere with carcass measurements.

Objetivou-se avaliar a predição de consumo de matéria seca (CMS) pelos sistemas CNCPS 5.0, NRC e BR-CORTE, bem como o consumo de nutrientes por tourinhos zebuínos confinados. Foram utilizados 44 animais em delineamento experimental inteiramente casualizado, sendo: 19 Nelore PO, 7 Nelore LA, 10 Tabapuã PO e 8 Guzerá PO, com peso vivo inicial médio de 394 ± 39; 348 ± 33; 346 ± 28 e 340 ± 30 kg, respectivamente, e idade inicial média de 13 meses. O período experimental foi de 84 dias. O consumo alimentar individual foi obtido com o uso dos indicadores LIPE®, óxido crômico e fibra em detergente ácido indigestível (FDAi). Para comparação do CMS predito pelos sistemas com o observado utilizou-se análise de regressão linear. Os animais Nelore LA apresentaram os menores valores observados para CMS (kg d-1). Ao avaliar o CMS em porcentagem do peso vivo (%PV) e em gramas por quilo de peso vivo metabólico (g kg-1 PM), foi detectada diferença entre os grupos genéticos, sendo que os maiores valores ocorreram para os animais Tabapuã PO e Guzerá PO. Os sistemas NRC, CNCPS 5.0 e o BR-CORTE apresentaram subpredição do CMS. Conclui-se que os sistemas estudados não se mostraram adequados para predizer o consumo de matéria seca em tourinhos zebuínos confinados.

The objective of this study was to evaluate the prediction of dry matter intake (DMI) using the CNCPS 5.0, NRC and BR-CUT systems, and of the nutrient intake of confined young Zebu bulls. A completely randomized experimental design of 44 animals as follows was used: 19 Nelore PO, 7 Nelore LA, 10 Tabapua PO e 8 Guzerat PO, with a mean initial live body weight of 394 ± 39, 348 ± 33, 346 ± 28 and 340 ± 30 kg respectively, and a mean initial age of 13 months. The length of the experiment was 84 days. Individual food consumption was calculated with the use of LIPE®, chromium oxide and indigestible acid detergent fiber (iADF) indicators. In order to compare the DMI as predicted by the systems to that observed, linear regression analysis was used. The Nellore LA group showed the lowest observed values for DMI (kg d-1). When assessing DMI as a percentage of live body weight (% BW) and in grams per kilogram of metabolic live weight (g kg-1 MW), a difference between genetic groups was found, with the highest values being observed for the Tabapua PO and Guzerat PO groups. The NRC, CNCPS 5.0 and BR-CUT systems under predicted the DMI. It can be concluded that the systems studied were not adequate for the prediction of the dry matter intake of confined young Zebu bulls.

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.

The objective of this study was to evaluate the residual feed intake (RFI) and its relation with performance, carcass and meat characteristics of Zebu animals. A total of 40 Zebu steers with initial age of 18 months and initial live weight of 350 kg were confined in feedlot for 112 days. The average daily gain (ADG) and dry matter intake (DMI) were obtained every 14 days. Residual feed intake was determined by the difference between observed and predicted DMI, based on the metabolic weight and the ADG. Animals were classified into the RFI groups: high (>0.5 standard deviation of the mean - least efficient), medium (±0.5 standard deviation of the mean) and low (<0.5 standard deviation of the mean - most efficient). Daily cost with feeding and per kilogram of weight gain was determined. Characteristics of carcass (weight, yield, subcutaneous fat) meat (pH, shear force and color) were assessed. Animals with low RFI presented lower DMI. The variation in DMI between the low and the high RFI groups promoted difference in the daily cost with feeding and per kilogram of weight gain, with animals of low RFI presenting costs 5 and 9% lower, respectively. Carcass and meat characteristics differed over the RFI groups. The knowledge of the RFI of the animals enables a more efficient system, with reduction in the costs with feeding, without promoting alterations on the performance and carcass characteristics of the meat from Zebu animals.

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 Tabapuã 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.

Objetivou-se determinar a influência da proporção volumoso e da fonte de gordura da dieta sobre as características de carcaça e os cortes comerciais de cordeiros. Utilizaram-se 24 cordeiros Santa Inês machos não-castrados, recebendo, à vontade, dieta com duas proporções de volumoso (30 e 70%) e de gordura (sem gordura, gordura protegida e grão de soja) e abatidos com peso corporal médio de 35,4 kg (± 1,5 kg). Os animais alimentados com dietas com 30% de volumoso apresentaram os maiores pesos e rendimentos de carcaça. As porcentagens de braço posterior e pernil foram maiores nos animais que receberam a dieta com 30% de volumoso sem adição de fonte de gordura. O comprimento total de perna e o comprimento interno foram maiores nos animais que receberam a dieta com 70% de volumoso, enquanto a largura de perna foi maior naqueles alimentados com a dieta com 30% de volumoso. A adição de fonte de gordura em dietas com alta porcentagem de concentrado pode aumentar os rendimentos de carcaça. Esse efeito é maior quando utilizada gordura protegida em relação ao grão de soja integral. Apesar de as dietas não terem efeito na maioria dos cortes, o efeito sobre o pernil confirma a influência da dieta sobre esse corte nobre.

This work aimed at determining the influence of roughage proportions and fat source of the diet on characteristics of carcass and comercial cuts of lambs. It was used 24 non-castrated Santa Inês male lambs, ad libitum fed diet with two proportions of roughage (30 and 70%) and fat (no fat, protected fat, and soybean) slaughtered at an avarage body weight of 35.4 kg (± 1.5 kg). Animals fed 30% roughage diet showed the highest weights and carcass yields. The percentages of posterior arm and ham were higher in animals fed 30% roughage with no addition of fat source. Total leg length and internal length were higher in animals fed 70% roughage diet while leg width was higher for those fed 30% roughage diet. Addition of fat source in diets with high percentage of concentrate can increase carcass yields. This effect is higher when protected fat is used regarded to whole soybean. Although diets do not have effect on most of these cuts, the effect on the ham confirms the influence of the diet on this noble cuts.

O objetivo deste trabalho foi avaliar a predição de desempenho pelos sistemas CNCPS 5.0, NRC 2000 e BR-CORTE, bem como o ganho de peso diário (GPD) e as características de carcaça em tourinhos zebuínos. Foram utilizados 44 tourinhos: 19 Nelore PO, 7 Nelore LA, 10 Tabapuã PO e 8 Guzerá PO, com peso corporal médio inicial de 266, 236, 222 e 219 kg e idade inicial média de 9, 10, 8 e 8 meses, respectivamente. O período experimental foi de 112 dias. O consumo alimentar individual foi obtido com o uso de indicadores (LIPE, óxido crômico e FDAi). Informações sobre área de olho de lombo (AOL), espessura de gordura subcutânea (EGS) e espessura de gordura na garupa (P8) foram obtidas por ultrassonografia. Para comparação do GPD predito e observado, foi utilizada análise de regressão linear. Os valores de GPD, AOL, EGS e P8 não diferiram entre os grupos genéticos. Para os sistemas CNCPS 5.0 e NRC 2000, os menores valores de GPD preditos foram estimados com base na disponibilidade de energia; para BR-CORTE, foram baseados na disponibilidade de proteína. Os sistemas NRC 2000, CNCPS 5.0 e BR-CORTE superestimaram o GPD, e não se mostraram adequados para predição do desempenho de tourinhos zebuínos.

The objective of this work was to evaluate the performance prediction by the CNCPS 5.0, NRC 2000 and BR-CORTE systems, as well as the average daily weight gain (ADG) and the carcass traits of young Zebu bulls. Fourty-four young bulls were used: 19 Nelore PO, 7 Nelore OB, 10 Tabapuã PO and 8 Guzerat PO, with initial body weight of 266, 236, 222 and 219 kg and initial average age of 9, 10, 8 and 8 months respectively. The experimental period was of 112 days. The individual intake was measured using markers (LIPE, chromic oxide and indigestible acid detergent fiber). The data on rib-eye area (REA), subcutaneous fat thickness (SFT) and rump fat thickness (P8) were obtained using ultrasonography. For the comparison of the estimated and observed ADG values, linear regression analysis was used. ADG, REA, SFT and P8 did not differ amongst the genetic groups. For the CNCPS 5.0 and NRC 2000 systems, the lowest ADG values predicted were estimated based on the available energy; for BR-CORTE, the lowest values were estimated based on available protein. The NRC 2000, CNCPS 5.0 and BR-CORTE systems overestimated the ADG, and were inadequate for predicting the performance of young Zebu bulls.