A comprehensive case study on the sustainability of tropical dairy cattle farming in Oaxaca, Mexico / Um estudo de caso abrangente sobre a sustentabilidade da pecuária leiteira tropical em Oaxaca, México

Tropical dairy cattle farming is one the most relevant economic activities for food production; although, currently faces increasing scrutiny from society due to its potential harm to natural resources and the environment. Moreover, some factors are paramount for the evaluation of the sustainability and productive potential of any given tropical dairy farm: soil quality, profitability, and energy efficiency. This study carried out a sustainability analysis in four types of tropical dairy cattle ranches, through three key indicators (economic profitability, energy efficiency and soil quality) and with a comprehensive approach in the Costa region of Oaxaca, Mexico. Therefore, four farms of different sizes (i.e., small, medium, large, and very large) were selected in Costa de Oaxaca, Mexico. The data collection was carried out for daily milk production, the dynamics of farm inputs (introduction or removal) from the production system, alongside with collection of soil samples. The agroecosystems evaluated were economically profitable, and those with greater intensification of their pasture areas display higher profit margins and energy efficiency. In terms of soil quality, there is a regular potential for its rational utilization.

A pecuária leiteira tropical é uma das atividades econômicas mais relevantes para a produção de alimentos, embora atualmente enfrente crescente discussão da sociedade devido ao seu potencial dano aos recursos naturais e ao meio ambiente. Além disso, alguns fatores são primordiais para a avaliação da sustentabilidade e potencial produtivo de qualquer popriedade leiteira tropical: qualidade do solo, rentabilidade e eficiência energética. O objetivo deste estudo foi realizar uma análise de sustentabilidade em quatro tipos de propriedades de gado leiteiro tropical, por meio de três indicadores chave (rentabilidade econômica, eficiência energética e qualidade do solo) e com uma abordagem abrangente na região da Costa de Oaxaca, México. Portanto, quarto propriedades de diferentes tamanhos (isto é, pequenas, médias, grandes e muito grandes) foram selecionadas na Costa de Oaxaca, México. A coleta de dados foi realizada para a produção diária de leite, a dinâmica dos insumos da fazenda (introdução ou retirada) do sistema de produção, juntamente com coleta de amostras de solo. Os agroecossistemas avaliados foram economicamente rentáveis, sendo que aqueles com maior intensificação de suas áreas de pastagens apresentam maiores margens de lucro e eficiência energética. Em termos de qualidade do solo, existe um potencial regular para a sua utilização racional.

Economic viability of irrigated cultivation of table cassava cultivars under phosphate fertilization / Viabilidade econômica do cultivo irrigado de cultivares de mandioca de mesa sob fertilização fosfatada

Phosphate fertilization of cassava cultivars leads to increased production costs that may be economically viable depending on the quantity used and the corresponding productivity. In this sense, the objective of the work was to analyse the economic viability of the irrigated cultivation of table cassava cultivars in response to the application of phosphorus doses in the Brazilian semiarid region. Two agricultural crops were conductedat the Experimental Farm Rafael Fernandes, Mossoró, RN, from June 2018 to April 2019 and from June 2019 to April 2020. The experimental design was in randomized blocks arranged in subdivided plots, with four replications. The doses of phosphorus (0, 60, 120, 180, and 240 kg ha-1of P2O5) were applied to the plots and the table cassava cultivars (Água Morna, BRS Gema de Ovo, Recife and Venâncio) arranged in the subplots. The total costs for one hectare of cultivation were estimated and the gross income, netincome, rate of return, and profitability index were calculated. The use of phosphatefertilizer was economically viable for the cassava cultivars studied in the two crops. The cultivars Água Morna, BRS Gema de Ovo, and Recife are the best cultivation options for the semiarid region of Rio Grande do Norteas they give high yields with the highest profitability. The Recife cultivar was the region's most profitable cultivation, with a profit ranging from R$ 40,331.07 ha-1to R$ 57,603.46 ha-1in both seasons,with an average recommendation of 120 kg ha-1of P2O5.(AU)

A adubação fosfatada de cultivares de mandioca leva ao aumento dos custos de produção que podem ser economicamente viáveis dependendo da quantidade utilizada e da respectiva produtividade. Nesse sentido, o objetivo dotrabalho foi analisar a viabilidade econômica do cultivo irrigado de cultivares de mandioca de mesa em resposta à aplicação de doses de fósforono semiárido brasileiro. Foram conduzidos duas safras agrícolas na Fazenda Experimental Rafael Fernandes, Mossoró, RN, nos meses de junho de 2018 a abril de 2019 e junho de 2019 a abril de 2020. O delineamento experimental foi em blocos casualizados dispostos em parcelas subdivididas, com quatro repetições. As doses de fósforo (0, 60, 120,180 e 240 kg ha-1de P2O5) foram aplicadas nas parcelas e as cultivares de mandioca de mesa (Água Morna, BRS Gema de Ovo, Recife e Venâncio) dispostas nas subparcelas. Estimaram-se os custos totais de um hectare de cultivo e calcularam-se a receita bruta,a receita líquida, a taxade retorno e o índice de lucratividade. O uso da adubação fosfatada mostrou-se economicamente viável para as cultivares de mandioca estudadas nas duas safras. As cultivares Água Morna, BRS Gema de Ovo e Recife são as melhores opções de cultivo para o semiárido do Rio Grande do Norte, pois apresentam altas produtividades com maior rentabilidade. A cultivar Recife foi o cultivo mais rentável da região, com rendimento variando de R$ 40.331,07 ha-1a R$ 57.603,46 ha-1nas duas safras,com recomendação média de120 kg ha-1de P2O5.(AU)

Interação reprodução x produção na ovinocultura: Aspectos reprodutivos relacionados com produtividade / Reproduction x production interaction in sheep farming: Reproductive aspects related to productivity

A importância dos manejos reprodutivos, que contribui para o avanço da ovinocultura e rentabilidade dos sistemas, revela oportunidades para trabalho com a interação reprodução x produção. Estratégias para incremento produtivo no setor, através de biotécnicas reprodutivas, que permitem redução da idade a puberdade, diminuição da estacionalidade reprodutiva e aumento da taxa ovulatória. Além das possibilidades hormonais, métodos alternativos que consideram efeito macho e nutrição, são considerados eficiente para controle do ciclo. Este artigo tem como objetivo revisar os protocolos de controle do ciclo estral e incremento produtivo na ovinocultura.(AU)

The importance of reproductive management, which contributes to the advancement of sheep farming and the profitability of the systems, reveals opportunities for work with the reproduction x production interaction. Strategies to increase production in the sector, through reproductive biotechniques, which allow reducing the age at puberty, reducing reproductive seasonality and increasing the ovulatory rate. In addition to hormonal possibilities, alternative methods that consider male effect and nutrition are considered efficient for cycle control. This article aims to review the estrous cycle control protocols and productive increase in sheep farming.(AU)

Effect of Housing Design and Location on Production and Economic Performance of Broiler Chickens during Summer in Botswana

Botswana experiences long, hot summer periods which negatively affect broiler productivity and results in economic losses. To determine these negative effects, two parallel broiler production studies were conducted in the North eastern (NE) and South eastern (SE) regions. In each region, three large scale commercial broiler farms were randomly selected based on similarities in bird management and housing systems. In each farm, one house type (Gable, Hoop and See-saw) was selected for long term flock monitoring (1 to 35 days) over three production cycles. Results showed that the production performance of the broilers in the SE region was superior to that in the NE region, with temperatures on being average higher in the NE than in the SE. The European Production Efficiency Factor (EPEF) was significantly higher (p0.05) between the regions at 9.0% and 7.4% for the NE and SE, respectively. In the NE, the Gable structure had the highest profitability and economic efficiency and was thus superior in comparison to the other house structures.(AU)

Seleção de reprodutores caprinos e ovinos para produção de sêmen / Selection of caprine and ovine sires for semen production

A presente revisão propôs analisar quais características são desejáveis para seleção de reprodutores caprinos e ovinos, visando à produção de sêmen. A escolha dos reprodutores deve ser feita de acordo com os padrões exigidos da raça, além da higidez reprodutiva dos animais. Biotecnologias reprodutivas oferecem oportunidades consideráveis para a produção animal, como a inseminação artificial, transferência de embriões e congelamento de sêmen. Análises da produção de espermatozoides são de grande importância, pois está diretamente relacionada com a atividade sexual. A genética do criatório é um fator crítico que influencia o resultado final e a saúde animal. A utilização de marcadores moleculares é uma ferramenta que temos para selecionar características desejáveis em uma prole, através da identificação de biomarcadores. Técnicas de genética molecular potencializam o efeito de biotécnicas reprodutivas e consequentemente a lucratividade da pecuária intensiva.(AU)

The present review proposed to analyze which characteristics are desirable for the selection of goat and sheep breeders, aiming at the production of semen. The choice of breeders must be made in accordance with the standards required for the breed, in addition to the reproductive health of the animals. Reproductive biotechnologies offer considerable opportunities for animal production, such as artificial insemination, embryo transfer and semen freezing. Analyzes of sperm production are of great importance, as it is directly related to sexual activity. Farm genetics is a critical factor that influences the end result and animal health. The use of molecular markers is a tool that we have to select desirable characteristics in an offspring, through the identification of biomarkers. Molecular genetic techniques enhance the effect of reproductive biotechniques and consequently the profitability of intensive livestock farming.(AU)

Corn productivity and topdressing application cost of nitrogen fertilizers / Produtividade de milho e custo da aplicação em cobertura de fertilizantes nitrogenados

Nitrogen(N) is the most required nutrient in the cultivation of corn (Zea maysL.), also representing a significantshare in the production costs. The objective was to evaluate the efficiency for one experimental year of different sourcesof nitrogen fertilizers applied in topdressing on the corn grain yield and their respective fertilization costs. The experiment was carried out under field conditions and without irrigation under no-tillage system, in a Red Oxissol. For sowing, 280 kg ha-1of NPK fertilizer 12-30-20 was used for all treatments. In addition to the control treatment (NPK), four nitrogen formulations wereapplied in topdressing: Urea, Super N, Nitromag, and Sulfammo, both formulations applied 50% in the V3/V4 and 50% V7/V8 stages, in four replicates.Grain yield was determined at the physiological maturation. The type of nitrogen fertilizer did not influence corn grain yield, an average of 9016 kg ha-1. The largest profits were achieved with the application of Super N, Urea and Nitromag. Nitrogen fertilizers with slow and controlled N release does not promote an increase in corn grain yield in relation to Urea. The use of Super N in topdressing has the highest profitability in corn cultivation.(AU)

O nitrogênio (N) é o nutriente mais requerido no cultivo do milho (Zea maysL.), ainda representa significativa participação no custo de produção. O objetivo foi avaliar a eficiência em um ano experimental de diferentes fontes de fertilizantes nitrogenados aplicados em cobertura na produtividade de grãos demilho e os seus respectivos custos da adubação. O experimento foi realizado em condições de campo e sem irrigação sob sistema plantio direto, em Latossolovermelho. Na semeadura foi utilizado 280 kgha-1de adubo NPK 12-30-20 para todos os tratamentos. Além do tratamento testemunha (NPK), quatro formulações nitrogenadas foram aplicadas em cobertura: Ureia, Super N, Nitromag, e Sulfammo, ambas as formulaçõesaplicadas 50% no estádioV3/V4 e 50% V7/V8,em quatro repetições. Na maturação fisiológica foi determinada a produtividade de grãos.O tipo de fertilizante nitrogenado não influenciou na produtividade de grãos de milho, média de 9016 kg ha-1. Os maiores lucros foram com a aplicação de Super N, Ureia e Nitromag. O uso em cobertura de fertilizantes nitrogenados de lenta e controlada liberação de N não promovem aumento na produtividade de grãos de milho em relação a Ureia. O uso de Super N em cobertura apresenta a maior lucratividadeno cultivo do milho.(AU)

Assisted Reproductive Technologies (ART) and genome editing to support a sustainable livestock

This article provides an overview of assisted reproductive technologies (ART) and genome engineering to improve livestock production systems for the contribution of global sustainability. Most ruminant production systems are conducted on grassland conditions, as is the case of South American countries that are leaders in meat and milk production worldwide with a well-established grass-feed livestock. These systems have many strengths from an environmental perspective and consumer preferences but requires certain improvements to enhance resource efficiency. Reproductive performance is one of the main challenges particularly in cow-calf operations that usually are conducted under adverse conditions and thus ART can make a great contribution. Fixed-time artificial insemination is applied in South America in large scale programs as 20 to 30% of cows receive this technology every year in each country, with greater calving rate and significant herd genetic gain occurred in this region. Sexed semen has also been increasingly implemented, enhancing resource efficiency by a) obtaining desired female replacement and improving animal welfare by avoiding newborn male sacrifice in dairy industry, or b) alternatively producing male calves for beef industry. In vitro embryo production has been massively applied, with this region showing the greatest number of embryos produced worldwide leading to significant improvement in herd genetics and productivity. Although the contribution of these technologies is considerable, further improvements will be required for a significant livestock transformation and novel biotechnologies such as genome editing are already available. Through the CRISPR/Cas-based system it is possible to enhance food yield and quality, avoid animal welfare concerns, overcome animal health threats, and control pests and invasive species harming food production. In summary, a significant enhancement in livestock productivity and resource efficiency can be made through reproductive technologies and genome editing, improving at the same time profitability for farmers, and global food security and sustainability.(AU)

Paternal effects on fetal programming

Paternal programming is the concept that the environmental signals from the sire's experiences leading up to mating can alter semen and ultimately affect the phenotype of resulting offspring. Potential mechanisms carrying the paternal effects to offspring can be associated with epigenetic signatures (DNA methylation, histone modification and non-coding RNAs), oxidative stress, cytokines, and the seminal microbiome. Several opportunities exist for sperm/semen to be influenced during development; these opportunities are within the testicle, the epididymis, or accessory sex glands. Epigenetic signatures of sperm can be impacted during the pre-natal and pre-pubertal periods, during sexual maturity and with advancing sire age. Sperm are susceptible to alterations as dictated by their developmental stage at the time of the perturbation, and sperm and seminal plasma likely have both dependent and independent effects on offspring. Research using rodent models has revealed that many factors including over/under nutrition, dietary fat, protein, and ingredient composition (e.g., macro- or micronutrients), stress, exercise, and exposure to drugs, alcohol, and endocrine disruptors all elicit paternal programming responses that are evident in offspring phenotype. Research using livestock species has also revealed that sire age, fertility level, plane of nutrition, and heat stress can induce alterations in the epigenetic, oxidative stress, cytokine, and microbiome profiles of sperm and/or seminal plasma. In addition, recent findings in pigs, sheep, and cattle have indicated programming effects in blastocysts post-fertilization with some continuing into post-natal life of the offspring. Our research group is focused on understanding the effects of common management scenarios of plane of nutrition and growth rates in bulls and rams on mechanisms resulting in paternal programming and subsequent offspring outcomes. Understanding the implication of paternal programming is imperative as short-term feeding and management decisions have the potential to impact productivity and profitability of our herds for generations to come.(AU)

Genetic correlation between feed efficiency and carcass traits in Nellore cattle in Brazil / Correlação genética entre características de eficiência alimentar e de carcaça em bovinos da raça Nelore no Brasi

The aim was to estimate the genetic correlations between residual feed intake (RFI) and dry matter intake (DMI) with carcass finish (CF), rib eye area (REA), and marbling (MAR) of Nellore cattle. Data from 7,808 animals were considered. In addition, data from 2,261 females included in the complete database were also considered. Estimates of variance and covariance components, as well as heritabilities and genetic correlations were obtained by means of two-character analysis under animal model. Heritability estimates were found to be moderate for the RFI (0.22) and DMI (0.29) traits. It was observed that genetic correlation was close to zero for all traits, except between RFI and REA (-0.11). However, considering the female population, there was an increase in the estimated genetic correlation between RFI and DMI, although still a favorable genetic association of low magnitude (-0.30). There was also an increase in the genetic association of REA with RFI (-0.21). It can be concluded that the direct selection for RFI and DMI will not influence the CF, MAR, or REA of Nellore cattle. However, this selection may generate some favorable responses in MAR and REA in Nellore females.

Objetivou-se estimar as correlações genéticas entre consumo alimentar residual (CAR) e ingestão de matéria seca com acabamento de carcaça (ACAB), área de olho de lombo (AOL) e marmoreio (MAR) para bovinos da raça Nelore. Foram consideradas informações de 7.808 animais. Além disso foram consideradas informações de 2.261 animais fêmeas que compunham o banco de dados completo. As estimativas dos componentes de variâncias e covariâncias, bem como das herdabilidades e correlações genéticas foram obtidas por meio de análises bicaracterísticas sob modelo animal. Verificou-se que as estimativas de herdabilidade foram moderadas para as características de CAR (0,22) e IMS (0,29). Observou-se que as estimativas de correlação genética foram próximos a zero para todas as Características, exceto entre CAR e AOL (-0,11). No entanto, considerando a população de fêmeas, houve um aumento na estimativa de correlação genética com CAR e IMS, apesar de ainda ser uma associação genética favorável de baixa magnitude (-0,30). Também houve um aumento na associação genética da AOL com o CAR (-0,21). Conclui-se, assim, que a seleção direta para o CAR e IMS não influenciará no ACAB, MAR e AOL de bovinos da raça Nelore. No entanto, essa seleção poderá gerar alguma resposta favorável em MAR e AOL em fêmeas Nelore.

Bioeconomic evaluation of pasture sheep finishing using castor bean cake / Avaliação bioeconômica da terminação de ovinos sob pastejo utilizando torta de mamona

This study evaluates the economic viability of sheep finishing systems on irrigated Tamani grass pasture under continuous stocking, using castor bean cake. Four production systems were simulated: sheep supplemented with soybean meal on pasture fertilized with urea (SMUR), sheep supplemented with detoxified castor bean cake on pasture fertilized with urea (CCdUR), sheep supplemented with soybean meal on pasture fertilized with in natura castor bean cake (SMCC) and sheep supplemented with detoxified castor bean cake on pasture fertilized with in natura castor bean cake (CCdCC). A minimum unit of 3 hectares and an average slaughter weight of 28 kg were considered. A minimum selling price, at which the least profitable system would become profitable, was stablished: US$ 2.38 and US$ 4.45/kg per kilogram of body weight and carcass weight equivalent, adopting a minimum rate of return of 3.5% per year, based on the Selic rate. The costs for organic fertilization were 46.01% higher than in systems using chemical fertilization. The selling of live animals was not attractive in any of the systems evaluated, and the opposite was observed for the selling of carcasses and non-carcass components. System SMUR proved to be more profitable, with a gain of US$ 0.53 per kg carcass.

Objetivou-se avaliar a economicidade de sistemas de terminação de ovinos em pastagem irrigada de capim-tamani sob lotação contínua, utilizando torta de mamona. Foram simulados quatro sistemas de produção: ovinos suplementados com farelo de soja e o pasto adubado com ureia (FSUR), ovinos suplementados com torta de mamona destoxificada e o pasto adubado com ureia (TMdUR), ovinos suplementados com farelo de soja e o pasto adubado com torta de mamona in natura (FSTM) e ovinos suplementados com torta de mamona destoxificada e o pasto adubado com torta de mamona in natura (TMdTM). Foi considerada a unidade mínima de 3 hectares e determinado um peso médio ao abate de 28 kg de peso corporal. Estabeleceu-se um preço de venda mínimo, no qual o sistema de criação menos lucrativo se tornasse rentável de 2,38 e 4,45 dólares por quilograma de peso corporal e por equivalente de peso da carcaça, dotando uma taxa mínima de atratividade de 3,5% ao ano, com base na taxa Selic. Os custos com adubação orgânica, em média, são 46,01% superiores aos sistemas que utilizam adubação química. A venda de animais vivos não é atrativa em nenhum dos sistemas avaliados, sendo o contrário observado para a comercialização de carcaças e dos não componentes da carcaça de ovinos. O sistema de produção FSUR se mostrou mais lucrativo, com ganho de US$ 0.53 centavos por kg de carcaça.

Epidemiological survey of gastrointestinal infections by gastrointestinal nematodes and coccidia in cattle in the semiarid region of Northeastern Brazil / Levantamento epidemiológico das infecções gastrintestinais por nematóides astrintestinais e coccídios em bovinos no Semiárido do Nordeste do Brasil

The aim of the present study was to carry out an epidemiological survey on gastrointestinal infections by nematodes and coccidia in cattle herds in the semiarid region of Paraíba, northeastern Brazil. A total of 832 cattle were sampled, of both sexes and different ages, on 21 farms in 21 municipalities in the state of Paraíba, Brazil. Fecal samples were collected individually to perform eggs per gram (EPG) and oocysts per gram (OoPG) counts in feces, and to perform fecal cultures. To assess factors associated with nematode and coccidia infections, epidemiological survey forms were applied to the farmers. The total frequency of infections by nematodes was 59.6% (496/832) and it was 36.9% (307/832) for coccidia. The levels of infection by nematodes and coccidia were most frequently low (EPG < 300; OoPG < 1,000), in 72.4% (359/496) and 75.2% (231/307), respectively. The most frequent nematode genera was Haemonchus spp. (78.8%). The risk factors for nematode infections in cattle were beef production trait (odds ratio = 2.99) and extensive rearing system (odds ratio = 3.8); the factors for coccidia were age ≤ 12 months (odds ratio = 2.9) and body score between 1 and 2 (odds ratio = 5.2). These results prove that there are high frequencies of gastrointestinal infections by nematodes and coccidia in cattle herds in the semiarid region of Paraíba, with predominantly low levels of infection. However, given the importance of subclinical infections, adjustments to sanitary management measures can contribute to reduction of parasite indices and better performance among the animals, thus generating greater profitability for farmers.

O objetivo do presente estudo foi realizar uma análise epidemiológica sobre as infecções gastrintestinais por nematóides e coccídios em rebanhos bovinos na região semiárida da Paraíba, Nordeste do Brasil. Um total de 832 bovinos foram utilizados, de ambos os sexos e diferentes idades, oriundos de 21 fazendas em 21 municípios do estado da Paraíba, Brasil. Amostras fecais individuais foram coletadas para a realização de contagens de ovos por grama (OPG) e oocistos por grama (OoPG) de fezes e para realizar coproculturas. Para obter os fatores associados às infecções por nematódeos e coccídios, questionários epidemiológicos foram aplicados aos produtores. A frequência total de infecções por nematóides foi 59,6% (496/832) e 36,9% (307/832) para coccídios. O nível de infecção para nematóides e coccídios mais frequente foi o baixo (OPG < 300; OoPG < 1.000), em 72,4% (359/496) e 75,2% (231/307), respectivamente. O gênero de namatóide mais frequente foi Haemonchus spp. (78,8%). Os fatores de risco para infecções por nematóides em bovinos foram aptidão para corte (odds ratio = 2.99) e sistema de criação extensivo (odds ratio = 3,8); os fatores para infecções por coccídios foram idade ≤ 12 meses (odds ratio = 2,9) e escore corporal entre 1 e 2 (odds ratio = 5,2). Estes resultados demonstraram que são elevadas as frequências de infecções gastrintestinais por nematóides e coccídios em rebanhos bovinos no Semiárido da Paraíba, com predominância de infecções em nível baixo. Entretanto, devido a importância das infecções subclínicas, ajustes em medidas de manejo sanitário podem contribuir para a redução dos índices de infecções por parasitos e melhorar a performance entre os animais, gerando maiores benefícios econômicos aos produtores.

Soil tillage and sugarcane planting: an assessment of cost and economic viability

ABSTRACT Yield and profitability levels in sugarcane crops demonstrate the importance of the agricultural practices adopted, especially for soil preparation and planting systems. This study evaluated the costs involved in 40 alternative methods for the establishment of sugarcane crops resulting from the combination of eight soil preparation systems and five planting options, followed by an assessment of the economic viability of sugarcane production for suppliers and sugar mills. Data were collected from 31 sugar mills and 42 suppliers in São Paulo State, Brazil, from the 2016/17 season. The cost analysis and discounted cash flow analysis were used to calculate economic viability. Localized soil preparation with a fixed application rate of inputs (soil amendments) and mechanized planting with a variable application rate of fertilizers were the least costly systems to establish the sugarcane crop. Regarding the sugarcane establishment system, the mediumsized sugar mills were the most economically viable when compared to independent sugarcane producers. There was no significant difference in cost to establish sugarcane crops across the various sized groups of suppliers and we identified that costs rose as the size of the sugar mills increased.

Productivity and profitability of maize as affected by nitrogen sources and rates / Produtividade e lucratividade do milho afetadas pela aplicação de fontes e doses de nitrogênio

The use of nitrogen (N) sources that reduce N losses may be an interesting management strategy to increase the economic and environmental sustainability of maize crops. This study aimed to assess the effects of different N sources and rates on maize grain yield and crop profitability. The experiment was conducted in the field on a Red Nitisol of clay texture during two growing seasons. The experimental design was a randomized block with split plots. Four sources of N were applied to the main plots: conventional urea, protected urea, urea treated with nitrification inhibitor, and urea treated with urease inhibitor. Split plots were treated with four N rates: 0, 140, 280, or 420 kg N ha−1. The four N fertilizer sources produced no differences in grain yield, which ranged from 3.2 to 15.9 Mg ha−1. This parameter showed a quadratic response to increasing N rates, regardless of N source. Theoretical N rates for optimal grain yield were estimated at 407 and 411 kg N ha−1 in 2016/2017 and 2017/2018, respectively. The highest profitability indices were obtained by applying 378 kg N ha−1 from conventional urea in 2016/2017 and 278 kg N ha−1 from urea treated with urease inhibitor in 2017/2018.(AU)

A utilização de fontes nitrogenadas que reduzam perdas de N pode ser uma estratégia de manejo adequada para aumentar a sustentabilidade econômica e ambiental no cultivo do milho. Este trabalho foi conduzido com o objetivo de avaliar os efeitos de fontes e doses de nitrogênio sobre a produtividade de grãos do milho e a lucratividade da lavoura. O experimento foi conduzido a campo, em dois anos agrícolas, num Nitossolo Vermelho de textura argilosa. O delineamento experimental foi de blocos ao acaso, dispostos em parcelas subdivididas. Na parcela principal foram testadas quatro fontes de N: ureia convencional, ureia protegida, ureia com inibidor de nitrificação e ureia com inibidor de urease. Nas subparcelas foram testadas quatro doses de nitrogênio: 0, 140, 280 e 420 kg de N ha-1. As quatro fontes de fertilizantes nitrogenados não apresentaram diferenças no rendimento de grãos. A produtividade de grãos variou de 3,2 a 15,9 Mg ha-1. Ela apresentou uma resposta quadrática ao aumento da dose, independentemente da fonte de N. As doses teóricas que otimizaram a produtividade de grãos foram de 407 e 411 kg N ha-1 em 2016/2017 e 2017/2018, respectivamente. Os maiores índices de lucratividade foram obtidos pela aplicação das doses de 378 kg de N ha-1 com ureia convencional em 2016/2017 e 278 kg de N ha-1 de ureia com inibidor de uréase em 2017/2018.(AU)

Profitability analysis of backgrounding and finishing of beef cattle in western amazon: a multiple-case study / Análise da rentabilidade de sistemas de recria e engorda de bovinos de corte na amazônia ocidental: estudo de múltiplos casos

This study aimed to evaluate the economic profitability of farms for backgrounding and finishing of beef cattle located in the mesoregion of Acre valley, in a multi-case study format. The data used originated from three pre-selected farms from January to December 2018. Data were collected from an inventory of assets and cash flow, which were later tabulated in Excel® software using descriptive statistics through mean, percentage, and standard deviation to present the indicators. The average effective operating cost (EOC) was BRL 1,399,014.34 and the total operating cost (TOC) was BRL 1,444,068.53 and the total cost (TC) was BRL 1,673,860.38. The items that compose the EOC which exerted greater representation on the activity costs were the purchase of animals (79.6%), food (7.8%), and labor (5.9%), respectively. Under these conditions, the three properties studied showed positive gross margins, net margins, and positive results, indicating their profitability in the short, medium, and long term, with possibilities for expansion in the region.(AU)

Objetivou-se avaliar a rentabilidade econômica de propriedades rurais de recria e engorda de bovinos de corte localizadas na mesorregião do vale do Acre, no formato de estudo multicasco. Os dados utilizados foram provenientes de três propriedades rurais pré-selecionadas durante o período de janeiro a dezembro de 2018. Foram coletados dados de inventário de bens e fluxo de caixa, posteriormente tabulados no software Excel® utilizando estatística descritiva por meio da média, porcentagem e desvio padrão para apresentar os indicadores. A média do custo operacional efetivo (COE) foi de R $1.399.014,34 e a do custo operacional total (COT) de R$1.444.068,53 e custo total (CT) de 1.673.860,38. Os itens componentes do COE respectivamente, que exerceram maiores representatividades sobre os custos da atividade foram o de compra de animais (79,6%), alimentação (7,8%) e mão de obra (5,9%). Nessas condições, as três propriedades estudadas apresentaram margem bruta, margem líquida e resultado positivos, indicando sua rentabilidade a curto, médio e longo prazo, com possibilidades de expansão na região.(AU)

Economic performance of highenergy diets and supplementation with chromium propionate or calcium salts of palm oil in ewes' production

The experiment aimed to analyze the economic viability of using highenergy diets and the supplementation of chromium propionate or calcium salts of palm oil in the diet of ewes from the late gestation until the end of lactation. Seventy-two ewes of Santa Ines × Dorper crossbreeds were allocated to five treatments: CTL (n = 14) with 100% of NRC recommendation for metabolizable energy per kg dry matter intake (ME/kg DMI), LOW (n = 14) with 90% ME/kg DMI, HIGH (n = 15) with 110% ME/kg DMI, Cr (n = 15) HIGH diet plus chromium propionate, and FAT (n = 14) HIGH diet plus calcium salts of palm oil. Based on the performance data, a short-term analysis was performed for a module of 1000 ewes, evaluating costs, revenues, and profitability, and long-term analysis was performed by an additional cash flow of 120 months. The CTL and FAT treatments were not viable due to higher costs and lower revenues, and they also had a negative net present value (NPV) and internal rate of return (IRR). The LOW treatment, despite lower costs and positive profitability, had a negative NPV (-$872.90) and IRR (1.85%) that was below the discount rate, making it unprofitable in the long run. The HIGH and Cr treatments were considered feasible because they had lower unit costs and higher profitability, in addition to a high NPV ($64,894.11 and 104,902.05, respectively) and a higher IRR (9.03% and 13.65%, respectively) than the discount rate. The use of high-energy diets, with added chromium propionate, promoted better performance and, consequently, better economic return.(AU)

Financial efficiency in the confinement system for beef cattle / [Eficiência financeira no sistema de confinamento de bovinos de corte]

The beef cattle breeding system in Brazil has been growing more and more in the history of animal production, leading the country to fit into the world scenario as the main exporter of beef. Seeking to increase this efficiency, the objective of this paper is to evaluate factors that affect the confinement of beef cattle, influencing the Profitability and Return of the system, to define values that maximize them. To do so, a database was used. It consisted of the observation of 1961 animals, collected in the commercial confinement of Fazenda Bragança, in the city of Lucas do Rio Verde - MT. Data were analyzed using multiple linear regression models, in which the financial gain, Profitability and Return variables were explained by the variables: race, entry weight and days in confinement, selected by the stepwise method. Based on the results, there is greater financial efficiency for animals that enter the feedlot with greater weight and that remain for 163 days. It is concluded that the entry weight and days in confinement significantly influence the financial efficiency, allowing the adjusted equations to help producers in making decisions regarding the formation of lots and, mainly, in the purchase of animals.

O sistema de criação de gado de corte no Brasil vem crescendo cada vez mais no histórico de produção animal, enquadrando-se no cenário mundial como o principal exportador de carne bovina. A fim de aumentar essa eficiência, tem-se como objetivo avaliar fatores que afetam o confinamento de bovinos de corte e influenciam na lucratividade e rentabilidade do sistema, de modo a definir máximos valores. Para isso, utilizou-se um banco de dados, composto pela observação de 1961 animais, os quais haviam sido coletados no confinamento comercial da Fazenda Bragança, na cidade de Lucas do Rio Verde - MT. Esses dados foram analisados por meio de modelos de regressão linear múltipla, em que as variáveis de eficência financeira, lucratividade e rentabilidade foram explicadas pelas variáveis raça, peso de entrada e dias em confinamento, selecionadas pelo método stepwise. Com base nos resultados, tem-se maior eficiência financeira para animais que entram no confinamento com maior peso e que lá permanecem por 163 dias. Conclui-se que o peso de entrada e os dias em confinamento influenciam na eficiência financeira de forma significativa, permitindo que as equações ajustadas auxiliem os produtores na tomada de decisão para a formação de lotes e, principalmente, na compra de animais.

Biological inputs, more economy and greater sustainability / Insumos biológicos, mais economia e maior sustentabilidade

The problems generated by the inappropriate use of agrotoxins and imported and costly chemical products to guarantee the health of the plants have been a great challenge for Brazilian farmers. The growing development and supply of new products of biological origin on the market is strengthening the portfolio of available bio-inputs for the production system. Among the benefits of the use of bioinputs is the greater sustainability of the productive system, with less frequent outbreaks of pests, reduction in application costs, greater efficiency of biological nitrogen fixation and promotion of plant growth. These benefits will promote greater profitability and contribute to a more sustainable agriculture. In this way, this review intends to discover some of the techniques that can be used in agriculture within two preceitos of sustainable agriculture.(AU)

Os problemas gerados pelo uso inadequado de agrotóxicos e produtos químicos importados e custosos para garantir a sanidade das plantas têm sido um grande desafio para os agricultores brasileiros. O crescente desenvolvimento e oferta de novos produtos de origem biológica no mercado vêm fortalecendo o portfólio de bioinsumos disponíveis para o sistema de produção. Entre os benefíciosda utilização de bioinsumos está a maior sustentabilidade do sistema produtivo, com surtos de pragas menos frequentes, redução dos custos de aplicação, maior eficiência da fixação biológica de nitrogênio e promoção de crescimento de plantas. Esses benefícios irão propiciar maior lucratividade e contribuir para uma agricultura mais sustentável. Dessa forma, esta revisão tem o intuito de descrever algumas das técnicas que podem ser utilizadas na agricultura dentro dos preceitos da agricultura sustentável.(AU)

Viabilidade econômica na produção de frango de corte de crescimento lento em Rio Branco/Acre / Economic viability in the production of slow-growing broiler chicken in Rio Branco/Acre

O Brasil é destaque mundial na produção de frango de corte baseada no modelo de integração. Alguns produtores têm migrado para a produção independente no sistema semiconfinado de criação de frangos caipiras a fim de atender a um nicho de mercado e obter maior lucratividade. Diante disso, o objetivo deste estudo foi conhecer os custos de produção e o resultado de um ciclo de produção de frangos de corte de crescimento lento criados em sistema semi-intensivo em Rio Branco/Acre. O estudo foi desenvolvido a partir da simulação da criação de frangos de crescimento lento da linhagem Vermelho Pesadão no sistema semiconfinado. O custo de produção foi calculado por meio de duas metodologias, o custo operacional e o custo total. A margem bruta (MB), a margem líquida (ML) e o resultado também foram calculados. Realizou-se a análise de cenários MOP (mais provável, otimista e pessimista). O item alimentação foi o custo mais elevado. Em todos os cenários, o faturamento foi suficiente para cobrir o COT. Porém, no cenário pessimista, a lucratividade foi baixa e o resultado negativo. O elevado valor dos insumos da ração torna a atividade inviável economicamente.

Brazil stands out worldwide in the production of broiler chickens based on the integration model. Some farmers have migrated to independent models in the semi-confined system of free-range chickens to meet a niche market and obtain greater profitability. Thus, this study aimed to know the production costs and the result of a production cycle of slow-growing broiler chickens raised in a semi-intensive system in Rio Branco, Acre. The study was developed from the simulation of the creation of slow-growing chickens from the "heavy red" lineage in a semi-confined system. The production cost was calculated using two methodologies, the operating cost and the total cost. The gross margin (GM), the net margin (NM), and the result were also calculated. The MOP scenario analysis (most likely, optimistic, and pessimistic) was performed. The food item was the highest cost. In all scenarios, the revenues was sufficient to cover costs. However, in the pessimistic scenario, profitability was low and the result was negative. The high value of feed inputs makes the activity economically unviable.

Soil tillage and sugarcane planting: an assessment of cost and economic viability

Yield and profitability levels in sugarcane crops demonstrate the importance of the agricultural practices adopted, especially for soil preparation and planting systems. This study evaluated the costs involved in 40 alternative methods for the establishment of sugarcane crops resulting from the combination of eight soil preparation systems and five planting options, followed by an assessment of the economic viability of sugarcane production for suppliers and sugar mills. Data were collected from 31 sugar mills and 42 suppliers in São Paulo State, Brazil, from the 2016/17 season. The cost analysis and discounted cash flow analysis were used to calculate economic viability. Localized soil preparation with a fixed application rate of inputs (soil amendments) and mechanized planting with a variable application rate of fertilizers were the least costly systems to establish the sugarcane crop. Regarding the sugarcane establishment system, the medium­sized sugar mills were the most economically viable when compared to independent sugarcane producers. There was no significant difference in cost to establish sugarcane crops across the various sized groups of suppliers and we identified that costs rose as the size of the sugar mills increased.(AU)

Soil tillage and sugarcane planting: an assessment of cost and economic viability

Yield and profitability levels in sugarcane crops demonstrate the importance of the agricultural practices adopted, especially for soil preparation and planting systems. This study evaluated the costs involved in 40 alternative methods for the establishment of sugarcane crops resulting from the combination of eight soil preparation systems and five planting options, followed by an assessment of the economic viability of sugarcane production for suppliers and sugar mills. Data were collected from 31 sugar mills and 42 suppliers in São Paulo State, Brazil, from the 2016/17 season. The cost analysis and discounted cash flow analysis were used to calculate economic viability. Localized soil preparation with a fixed application rate of inputs (soil amendments) and mechanized planting with a variable application rate of fertilizers were the least costly systems to establish the sugarcane crop. Regarding the sugarcane establishment system, the medium–sized sugar mills were the most economically viable when compared to independent sugarcane producers. There was no significant difference in cost to establish sugarcane crops across the various sized groups of suppliers and we identified that costs rose as the size of the sugar mills increased.