ABSTRACT Traditional livestock productivity is hard to estimate, since it depends on a gamut of animal production indicators that are difficult to measure for many farms. Thus, we propose an analytical method for estimating productivity and understanding the importance of animal production indicators under different full-cycle cattle production systems in Brazil. To evaluate the impact of these indicators, equations were derived from a comutational model of herd evolution for estimating the output parameters of the system as follows: productivity per hectare (PH) and offtake rate (COR), as a function of the indicators; calving rate (CR), mating age (AM), age of slaughter (AS) and stocking rate (SR). For this analysis, twenty-seven scenarios (simulation data) of low to high productivity were used, resulting from the combination of the following factors and levels: 1) calving rate of 50, 65 and 80 %; 2) mating age of heifers of one, two and three, years of age; and 3) age at slaughter of one, two and three year old steers. The scenario with the highest impact for each parameter and the indicator of highest impact for each scenario were identified for the production conditions in the region. Under most scenarios, a reduction in mating age had a greater impact on the productivity indexes compared to a reduction in slaughter age. Appropriate management of available technologies enables farmers to compare the marginal impacts of specific indicators on full-cycle production systems for beef cattle.

ABSTRACT The objective of this study was to identify types of production system and their main indicators on bioeconomic efficiency, using qualitative and quantitative methods to evaluate beef cattle farms in the western region of the state of Rio Grande do Sul. A survey was carried out with 43 farmers operating in the western region of that state. All farms operated with complete cycle production systems in areas larger or equal to 900 ha. A qualitative questionnaire with binary answers and a quantitative questionnaire with numerical answers were applied. Technology and Management drivers were used for the calculation of the efficiency index of farmers obtained by both questionnaires. Farmers were divided into three clusters: low-efficiency level (LEL), intermediate-efficiency level (IEM), or high-efficiency level (HEL), as a result of the comparison of the scores obtained for the analyzed parameters. Subfactors resulting from each comparison (LEL × IEL; LEL × HEL, and IEL × HEL) were different as a function of the comparison and of the methods applied. Low-efficiency level farmers need to improve essential production processes, such as technology and management, as well as health management practices together with the financial management of the production system. Intermediate-efficiency level farmers need to improve their routine animal management, pasture management, and calculation of financial indicators to become highly efficient. The quantitative method allowed to identify underestimation (39.3%) or overestimation (24.2%) when farmers were are classified in clusters. Different methods may be used, but those based on quantitative information have stronger discrimination power to identify different types of farmers.

O objetivo deste experimento é a identificação das demandas de melhorias para fazendas com diferentes níveis de competitividade no Oeste do RS. Entrevistaram-se 63 produtores grandes (área= +900 ha) por meio de um questionário semi-estruturado, dividido em quatro direcionadores: tecnologia (TEC), gestão (MAN), relações de mercado (MR) e ambiente institucional (IE). Utilizou-se o software SAS 2002, versão 9.0, para realização da análise de cluster, realizando a tipologia dos produtores. Nesta análise, formaram-se aleatoriamente três clusters, sendo denominados de baixo nível de competitividade (LCL), médio nível de competitividade (MCL) e alto nível de competitividade (HCL). Dividiram-se as 29 variáveis (subfatores) avaliadas na análise de cluster de acordo com nível de impacto na competitividade das fazendas de bovinos de corte, sendo classificadas em variáveis de alto, médio ou baixo impacto. Esta estratificação do ranking de demanda de melhorias foi realizada a partir dos pesos atribuídos pelos especialistas aos subfatores. Os pecuaristas com baixo nível de competitividade apresentaram status desfavorável para MAN, enquanto os pecuaristas pertencentes aos clusters MCL e HCL apresentaram, respectivamente, status neutro e favorável para o mesmo direcionador. Portanto, a gestão é determinante para definir o nível de competitividade das fazendas entrevistadas

The aim of this experiment was to identify improvement demands for farms with different levels of competitiveness in the west of Rio Grande do Sul state, Brazil. A total of 63 owners of large farms were interviewed (farms with an area greater than 900ha) by applying a semi-structured questionnaire, guided by four drivers: technology (TEC), management (MAN), market relations (MR) and the institutional environment (IE).It was used the Statistical Analysis System 9.2 software to perform the cluster analysis and identify farmers' characteristics. Three random clusters with different levels of competitiveness were observed: low competitiveness level (LCL), middle competitiveness level (MCL) and high competitiveness level (HCL). The 29 variables (sub factors) were evaluated in the cluster analysis according to level of impact on competitiveness, being classified into variables of high, medium or low impact. Stratification was carried out, ranking demands for improvements from aspects attributed by experts in relation to sub factors. The farmers with low competitiveness level (LTL) had an unfavorable status for MAN, while the farmers belonging to clusters MCL and HCL have, respectively, favorable and neutral status for the same driver. The management characteristics determined the level of competitiveness of the farms surveyed

Foram avaliados os componentes não-integrantes da carcaça de bovinos castrados (novilhos) Brahman, Brangus e Hereford terminados em confinamento ou pastejo com suplementação (capim-mombaça). Os animais foram abatidos com espessura de gordura subcutânea superior a 4mm. A dieta do confinamento foi formulada com 60% de volumoso e 40% de concentrado, com 13% PB e 62% NDT. O capim mombaça apresentou 7% de PB e 56%NDT e o suplemento apresentou 24% PB e 76% NDT. O delineamento experimental foi inteiramente casualizado, com arranjo fatorial 3x2 (três grupos genéticos e dois sistemas de terminação) e as médias foram comparadas pelo teste de Tukey ajustado. Foram observadas diferenças significativas para o peso de abate (PA) e peso do corpo vazio (PCV) favorável aos animais mantidos em pastejo com suplementação (444,03 vs 416,50kg para PA e 409,68 vs 375,24kg para PCV), entretanto não houve diferença significativa entre os sistemas de terminação para o rendimento de corpo vazio (RCV). O menor percentual de órgãos vitais foi apresentado pela raça Brahman independente do sistema de terminação utilizado (2,19%). A mesma tendência foi observada para o trato digestivo com um percentual de participação de 3,77% PCV do Brahman vs 4,87% e 4,48% PCV do Hereford e Brangus, respectivamente. Os novilhos Brahman apresentaram menores pesos de coração, pulmão e baço que os Hereford e Brangus. Os animais terminados em pastejo apresentaram maiores pesos de abomaso, pulmão e rins que os terminados em confinamento, 0,47 vs 0,35% PCV; 0,77 vs 0,71% PCV e 0,77 vs 0,71% PCV, respectivamente.

The non-carcass components of steers from Brahman, Brangus and Hereford finished in feedlot or pasture with supplementation (mombaça grass) were evaluated. The animals were finished when subcutaneous fat thickness was over 4mm. The feedlot diets have roughage:concentrate ratio of 60: 40, with 13% CP crude protein and 62% TDN. The level of CP of mombaça grass was 7% with 56% TDN, and the supplement was 24% CP and 76% TDN. The experimental design was completely randomized with a 3x2 factorial arrangement (three genetic groups and two finishing systems) and means was compared by adjust Tukey test. Significant difference was observed for the slaughter weight (SW) and empty body weight (EBW) in steers maintained at pasture with supplementation. (409.68 versus 375.24kg of empty body weight), however, no differences were observed with the percentage of empty body dressing percentage (EBD). Brahman steers has the lowest percentage of vital organs independent of finishing system (2.19%). Same trend was showed for the total empty digestive tract with 3.77% for Brahman steers vs 4.87 and 4.48% EBW of Hereford and Brangus. The Brahman steers had lower weights of heart, lung and spleen than the Hereford and Brangus. Animals finished on pasture had greater weight of abomasums lung and kidneys than animals finished on feedlot 0.47 vs 0.35% EBW; 0.77 vs 0.71% EBW and 0.77 vs 0.71% EBW, respectively.

An index was developed to estimate the bioeconomic efficiency of production systems, identifying alternative scenarios that could improve their efficiency, and building isoefficiency relations in beef cattle production systems in Rio Grande do Sul. The concept of return on investment was used to develop the indicator. Scenarios regarded as efficient showed values higher than 3. The bioeconomic efficiency index for beef cattle production in the theoretical reference scenario was considered inefficient. At least four modifications in the variables method made it a bioeconomically efficient activity. These circumstances were studied using sensitivity analyses, with theoretical changes in the scenarios by changing variables two by two, while the others were kept constant. In Rio Grande do Sul, alternatives that make the activity efficient were identified by changing productivity, production cost, land price and product price. Isoefficiency relationships were identified in other scenarios. The application of this indicator in other agricultural activities, as well as the design of bioefficiency studies including both environmental and social welfare characteristics are recommended.

Avaliou-se o impacto bioeconômico do exame andrológico na produção de bovinos de corte no Sul do Brasil. Foram comparados dois sistemas de produção similares com e sem a adoção do exame andrológico durante quatro anos no município de Júlio e Castilhos. A taxa de touros inaptos no primeiro exame foi de 22,8%. Com a realização do exame, obteve-se aumento de 31% na produção de bezerros, 13,8 bezerros/touro/ano e 24 kg de bezerros/vaca/ano. A relação benefício/custo sobre o investimento com o exame andrológico foi de R$ 35,84. O exame andrológico melhora os aspectos bioeconômicos de sistemas de cria de bovinos de corte.

It was evaluated the bioeconomic impact of the breeding soundness evaluation on beef cattle production in southern Brazil. Two similar production systems, with and without the use of breeding soundness evaluation, were compared during 4 years in the municipality of Júlio e Castilhos. The rate of unsound bulls in the first examination was 22.8%. By performing the examination, calf production increased by 31%, 13.8 calves/bull/year and 24 kg of calves/cow/year. The benefit/cost ratio on the investment with the breeding soundness evaluation was R$ 35.84. The breeding soundness evaluation improves bioeconomic aspects of beef cow-calf systems.

Os objetivos nesta pesquisa foram analisar os dados referentes ao mercado internacional de carne bovina congelada desossada e classificar seus participantes em grupos de acordo com suas relações comerciais elencando os principais fatores que influenciam a preferência de um país pela carne bovina de determinado país fornecedor. O comércio internacional de carne bovina é composto de dois mercados: num deles as relações entre fornecedor e cliente dependem do menor preço e Brasil encontra-se em condições favoráveis; e no outro as relações se dão preferencialmente em razão da qualidade sanitária do rebanho e de sistemas de rastreabilidade reconhecidos pelo comprador, cuja participação do Brasil é pequena.

The objectives of this research were to analyse data on the international market of frozen boneless beef and to classify its participants into groups according to their trade relationships, identifying the main factors that influence the preference of a country to beef from a determined supplier country. International beef trade is composed of two markets: in one of them, the relationships between supplier and client depend on the lowest price, and Brazil is found in favorable conditions; and the other, the relationships are preferably based on the sanitary quality of the herd and traceability systems recognized by the purchaser, to which Brazilian participation is low.

A produtividade do milho safrinha pode ser aumentada com a adubação nitrogenada em cobertura mesmo quando cultivado em sucessão à soja. No entanto, existem inconsistências dos resultados especialmente quanto às fontes e doses a serem empregadas nessa modalidade de cultivo. Com o objetivo de avaliar o efeito de fontes e doses de nitrogênio em cobertura no milho safrinha, cultivado após soja no sistema plantio direto, conduziu-se o experimento em um Latossolo Vermelho distrófico, em Chapadão do Céu (GO). O delineamento experimental foi o de blocos ao acaso, em esquema fatorial 4 x 4, com quatro repetições. Os tratamentos foram constituídos pela combinação de quatro fontes (uréia, sulfato de amônio, uréia extrusada com produtos amiláceos (Amiréia® 180S) e sulfonitrato de amônio com inibidor de nitrificação (Entec® 26)) e quatro doses de nitrogênio (0; 30; 60 e 120 kg ha-1). A interação fonte x dose não foi significativa para nenhuma das variáveis avaliadas. A aplicação de nitrogênio na forma de entec proporcionou maiores teores de nitrogênio na folha do milho safrinha que o sulfato de amônio e a amiréia. A produtividade de grãos do milho safrinha foi maior quando o nitrogênio em cobertura foi fornecido na forma de sulfato de amônio, em comparação com a amiréia. A aplicação de nitrogênio em cobertura aumentou os teores de nitrogênio e enxofre na folha, altura da planta, diâmetro do colmo, número de espigas por planta e grãos por espiga, massa de 1.000 grãos e produtividade de grãos do milho safrinha, em sucessão à soja, independentemente da fonte utilizada.

Out-of-season corn yield can be increased by nitrogen sidedressing fertilization even when sowed after soybean harvest. However, there is result inconsistency especially as to nitrogen sources and rates for corn in the cropping system. In order to evaluate the effect of sources and rates of sidedressed nitrogen application on out-of-season corn grown after soybean crop, an experiment was carried out on an Acrustox, in Chapadão do Céu (GO). A randomized complete block design, in 4x4 factorial scheme, and four replications was used. Treatments included four sources (urea, ammonium sulfate, urea extruded with starch (Amiréia® 180S), and ammonium sulfonitrate with nitrification inhibitor (Entec® 26)) and four rates of nitrogen (0; 30; 60 and 120 kg ha-1). The source x rates interaction was not significant for any of the variables evaluated. Sidedressing nitrogen application as entec promoted higher leaf nitrogen concentration than ammonium sulfate and amiréia. Corn grain yield was higher when fertilized with sidedressing nitrogen as ammonium sulfate than amiréia. Sidedressing nitrogen increased leaf nitrogen and sulfur concentrations, plant height, stem diameter, number of ear per plant, number of grains per ear, weight of 1,000 grains, and grain yield of out-of-season corn grown after soybean crop, regardless of the source used.