ABSTRACT: The objective was to evaluate the animal production and ingestive behavior of the steers fed different supplements during the growth phase in Aruana grass, and the influence of this supplementation on production performance in feedlot phase. The treatments consisted of three supplements during the growing phase: mineral salt (0.12 g/kg of body weight - BW), low intake energy-protein supplement (1.26 g/kg of BW), and medium intake (3.76 g/kg of BW). Forage canopy characteristics, animal production, and animal behavior on pasture were evaluated in a completely randomized design with three replicates (paddocks). The titanium dioxide marker was used to determine the intake and apparent digestibility during the pasture phase. The production performance in feedlot was evaluated in a completely randomized design with eight replicates (animals). Twenty-four Aberdeen Angus steers (15 ± 1.5 months old; 364.8 ± 21.7 kg BW) were used. At the end of the growth phase the animals were confined and fed a single diet. Dry matter, crude protein, and neutral detergent fiber (NDF) contents of forage and intake were not influenced by the treatments. The average daily gain was higher for the medium intake supplement in pasture phase. The apparent digestibility of NDF (P = and chewing rate were higher for the medium intake supplement. The average daily gain and fat thickness of carcasses were higher for the medium intake supplement in the feedlot phase. The supplements of medium intake increase animal productivity during the growing phase on pastures and cattle’s finishing performance in intensive production systems.

RESUMO: O objetivo deste trabalho foi avaliar a produção animal e o comportamento ingestivo de novilhos alimentados com diferentes suplementos durante a fase de crescimento em capim Aruana, e a influência desta suplementação sobre o desempenho produtivo durante a fase de terminação em confinamento. Os tratamentos consistiram de três suplementos durante a fase de crescimento: sal mineral (0,12 g/kg do peso corporal - PC), suplemento energético-proteico de baixo consumo (1,26 g/kg do PC) e suplemento energético-proteico de médio consumo (3,76 g/kg do PC). As características do dossel forrageiro, a produção animal e o comportamento ingestivo em pastos de capim Aruana foram avaliados utilizando um delineamento inteiramente ao acaso com três repetições (piquetes). O marcador externo dióxido de titânio foi utilizado para determinar o consumo e digestibilidade aparente dos nutrientes na fase de pastagem. O desempenho em confinamento foi avaliado utilizando-se um delineamento inteiramente ao acaso com oito repetições (animais). Vinte e quatro novilhos Aberdeen Angus (15 ± 1,5 meses de idade; 364,8 ± 21,7 kg de peso corporal médio inicial) foram utilizados. Ao final da fase de recria, os animais experimentais foram confinados e alimentados com uma dieta única. Os teores de matéria seca, proteína bruta e fibra de detergente neutro (FDN) da forragem, bem como o consumo destas frações não foram alterados pelos tratamentos. O ganho médio diário foi superior para o suplemento de ingestão média na fase de pastagem. A digestibilidade da FDN e a taxa de ruminação na fase pastagem foram mais elevadas para o suplemento de média ingestão. O ganho médio diário e a espessura de gordura das carcaças foram mais elevados para o suplemento de ingestão média na fase de acabamento em confinamento. Suplementos de ingestão média aumentam a produtividade animal durante a fase de crescimento em pastagens e o desempenho em confinamento de bovinos provenientes de sistemas intensivos de produção.

ABSTRACT The objective of this study was to evaluate the growth performance and meat quality of feedlot Aberdeen Angus steers fed high-concentrate diets with or without a natural feed additive composed of a mixture of yeasts and essential oils (EO). A completely randomized design with two diets (with or without natural feed additive) and 12 replicates was used. Twenty-four steers with initial shrunk body weight of 402.62±48.2 kg and average age of 18±2.0 months were used. Steers were fed ad libitum a diet containing 777.3 g of concentrate/kg dry matter (DM) and 222.7 g of corn silage/kg DM for 74 days. The mixture of yeast and EO was supplied at the rate of 10.0 and 0.117 g/animal/day, respectively. Average daily weight gain and feed efficiency in the adaptation period was greater in animals fed natural feed additive; however, there was no difference for the total experimental period. Dry matter intake, carcass weight, carcass yield, proportion of carcass bone, carcass muscle + fat:bone ratio, round thickness, and arm length were not altered by treatments. The inclusion of a natural feed additive in the diet increased the cooling loss (0.98 vs. 1.25%), proportion of carcass muscle (51.32 vs. 54.56%), carcass muscle:fat ratio (1.70 vs. 2.11%), leg length (68.79 vs. 70.71 cm), and arm perimeter (36.70 vs. 37.88 cm) and reduced the proportion of carcass fat (30.17 vs. 25.92%). Carcass length was greater in animals fed the diet with a natural feed additive. Meat color, texture, and marbling were not altered by treatments. The addition of natural feed additive to high concentrate diets does not alter the productive performance of feedlot Aberdeen Angus steers, although it can increase the proportion of lean meat of carcasses.

Resumo O objetivo deste trabalho foi analisar a agregação e a desagregação de valores dos animais comercializados em busca das bonificações do programa Carne Angus no estado do Rio Grande do Sul, Brasil. Foram analisados os dados de 40.698 carcaças de bovinos abatidos em uma indústria frigorífica que realiza a certificação para o programa Carne Angus, durante o ano de 2014. A agregação de valor foi calculada pela diferença entre o preço base negociado para o lote e o preço final obtido pelo animal depois do processo de certificação. A desagregação foi calculada em função dos fatores que impediram os animais de serem enquadrados no programa de certificação. Os resultados mostram que o maior motivo para a desclassificação de animais com o padrão racial foi a dentição e o acabamento, os quais desclassificam, respectivamente, 34,3 e 12,7% dos animais com padrão racial. A desagregação de valor resultante de 7.177 animas que foram desclassificados por falta de acabamento ou por dentição avançada atingiu um valor de R$ 1.213.528,00, ou US$ 369.077,86 (US$ 51,43 por cabeça), quantia esta que deixou de ser repassada da indústria aos produtores rurais.

Abstract The objective of this work was to analyze price aggregation and disaggregation in commercialized animals searching for “Programa Carne Angus” benefits in the state of Rio Grande do Sul, Brazil. Data from 40,698 carcasses with Angus cattle racial pattern, slaughtered in a meat industry that performs the “Programa Carne Angus ”certification, during the 2014 year were analyzed. The aggregated value was calculated by the difference between the negotiated base price for the lot and the final price obtained by animal after the certification process. The disaggregation was calculated based on the factors preventing the animals from being included in the certification program. The results show that the major disqualifying factor in males with the racial pattern was carcass fatness, and for females was the dentition, which disqualified 34.3 and 12.7% respectively. Value breakdown from 7,177 disqualified animals due to lack of finishing, or advanced dentition, reached R$ 1,213,528.00, or US$ 369,077.86 (US$ 51.43 per head), an amount that is no paid on from the industry to rural producers.

Resumo O objetivo deste estudo foi analisar o comportamento da precocidade ao longo de nove anos de novilhos da raça Hereford e suas cruzas abatidas com dentição de leite até seis dentes. Foram analisadas aproximadamente 144 mil carcaças certificadas no programa Carne Pampa, entre os anos 2010 e 2018. Avaliou-se o incremento no peso de carcaça fria por ano em três épocas do ano: a estação quente foi definida de 26 de dezembro a 25 de maio, o vazio de outono foi definido entre 26 de maio a 25 de julho e a estação fria de 26 de julho a 25 de dezembro. Para avaliar o comportamento dos pesos de carcaça fria ao longo dos anos por estação, os dados foram submetidos à análise de regressão linear simples. Os pesos médios por estação foram comparados por teste de comparação de médias. A época que apresentou maior peso médio de carcaça foi a estação fria, com 239,1 kg, que mostrou um incremento anual de 6,45 kg. Analisando o comportamento do peso médio de carcaça por dentição na estação fria, animais com dentição de leite apresentaram maior incremento de peso ao longo dos anos, na estação quente, animais abatidos com dois dentes apresentaram maior incremento de peso, assim como na estação vazio de outono. A categoria que apresentou menor incremento de peso nas três estações foram os animais abatidos com seis dentes. Concluiu-se que, ao longo dos nove anos, houve aumento na precocidade de abate em bovinos machos certificados no programa Carne Pampa.

Abstract The aim of this study was to analyse precocity behaviour over nine years in Hereford steers and their crosses, slaughtered with from zero to six teeth. Approximately 144,000 certified carcases in the Carne Pampa programme were analysed between 2010 and 2018. The increase in cold carcase weight per year was evaluated for three periods of the year: the hot season was defined as 26 December to 25 May, the autumn void was defined as 26 May to 25 July, and the cold season from 26 July to 25 December. To assess the behaviour of cold carcase weight over the years per season, the data were submitted to simple linear regression analysis. The average weights per season were compared by the mean value comparison test. The cold season had the highest mean carcase weight, with 239.1 kg, showing an annual increase of 6.45 kg. Analysing the behaviour of mean carcase weight by dentition, animals with zero teeth showed a greater weight increase over the years during the cold season as well as during the autumn void; during the hot season, animals slaughtered with two teeth showed the greater increase in weight. The category that showed the least increase in weight for all three seasons were animals slaughtered with six teeth. It was concluded that over the nine years, there was an increase in slaughter precocity in male cattle certified in the Carne Pampa programme.

ABSTRACT This study was performed to determine and quantify the inherent auction factors that affect the selling price of beef calves (weanlings - from six to nine months old). Data on the selling price, location and month of the auction, genetic group, lot size live weight, and sex of animals were collected in 148 auctions from January 2004 to December 2014. A total of 4,312 lots corresponding to 48,588 calves were classified into seven genetic groups according to their phenotypic characteristics. The values were deflated using the General Price index (IGP-DI) inflation index and met the parametric assumptions. The selling price was standardized by the yearly median, assuming that its value corresponds to 100%, and the other values varied in their function. Path analysis quantified the direct and indirect effects of the variables taken as explanatory of the selling price, followed by regression analysis and Tukey test. Overall, the direct effect of the average weight was the highest (0.7), followed by sex (0.38). The smallest direct effect was the genetic group (−0.075). There was a growing exponential relationship between average weight of the lot and selling price and a decreasing ratio between price per kilo and the average weight of the lot (−0.0003 percentage points per kilogram). Males were generally 15.7% more valued than females. The British × Zebuine crossbreed was the most valued breed, followed by the British breed (8.9 and 3.6%, respectively). The highest premium was in November, followed by February (9.57 and 8.84%, respectively, compared with median year). The selling price increases linearly by 0.3284 percentage points for each additional animal in the lot. The average weight of the lot was found to be the most important variable in the formation of the selling price, followed by the sex of the animals.

<title>Resumo</title><p>O objetivo do experimento foi realizar a avaliação do rendimento de componentes não carcaça provenientes do abate de machos Nelore, não castrados, abatidos com diferentes pesos. Foram utilizados 40 animais com peso corporal médio de 350 kg no inicio do confinamento. Em delineamento inteiramente casualizado, os animais foram divididos em quatro grupos: animais 0 e 2 dentes, com peso de carcaça de até 238,0 kg (jovens e carcaças leves); animais 2 dentes com peso de carcaça variando de 238,1 a 258,0 kg (jovens e carcaças médias); animais 2 dentes com peso de carcaça superior a 258,0 kg (jovens e carcaças pesadas) e animais com 4 ou 6 dentes, independente do peso de carcaça (adultos). Os animais foram confinados por 84 dias com dieta calculada para atingir ganho de peso médio de 1,2 kg/dia. O peso do couro foi maior nos animais jovens e pesados em relação aos jovens e leves e aos adultos. Foi verificada diferença no percentual de fígado, que foi maior nos animais jovens pesados (1,91%) em relação aos jovens com carcaça média (1,49%). A análise econômica mostrou que os animais jovens com carcaça pesada deixam a maior receita com componentes não carcaça (R$ 208,00), seguidos dos jovens médios (R$ 193,56), sendo a receita dos animais adultos e dos jovens e leves R$ 21,42 e R$ 23,42, respectivamente, inferior aos primeiros. Os componentes não carcaça agregam à indústria de R$ 0,71 a R$ 0,80 por quilograma de carcaça.</p>

<title>Abstract</title><p>The objective of the experiment was to evaluate byproducts yield of non-castrated Nellore males slaughtered at different weights. Forty Nellore males with average weight of 350 kg at the beginning of the feedlot were used. In a completely randomized design, the animals were divided into four groups: 0 to 2-teeth animals with carcass weight up to 238.0 kg (young and light carcasses); 2-teeth animal with carcass weights ranging from 238.1 to 258.0 kg (young and middle weight carcasses); 2-teeth animal with carcass weight over 258.0 kg (young and heavy carcasses) and animals with four or six teeth, regardless of carcass weight (adults). Animals were fed during 84 days with diet calculated to reach average weight gain of 1.2 kg/day. Hide weight was higher for young and heavy animals in relation to young and light and adult animals. Regarding the non-carcass components yield, we verified difference for liver percentage, which was higher for young and heavy animals (1.91%) in relation to young with middle weight carcasses (1.49%). Economic analysis showed that the non-carcass components of young animals with heavy carcass result in higher income (R$ 208.00), followed by young animals with middle weight carcasses (R$ 193.56), and the incomes of adult and of young and light animals, respectively, R$ 21.42 and R$ 23.42 lower than the first one. No carcass components add to industry from R$ 0.71 to R$ 0.80 per carcass kilogram.</p>