RESUMO

This study aimed to assess nutrient intake, performance, intake behavior, carcass characteristics, and meat quality of sheep managed on Masai grass pastures along with intermittent concentrate supplementation, in addition to the economic impacts of applying that strategy. A sample of 24 Santa Inês sheep (12 males and 12 females) was kept for 80 days on Panicum maximum cv. Massai pastures and was supplemented daily or every other day. The voluntary intake of dry matter and nutrients was estimated. Mean daily weight gain and total weight gain were calculated and intake behavior parameters were assessed. The males were slaughtered and the weight and yield of the carcasses and meat cuts were assessed. The meat was analyzed for cooking losses, shear force, and color. The gross margin of the system was estimated from the difference between total income and operational cost. No effect was seen of the interaction between supplementation frequency and sex for any parameter assessed (p > 0.05). Intermittent supplementation of Santa Inês sheep managed with Masai grass is recommended since the strategy does not impact nutrient intake, performance, intake behavior, carcass characteristics, or meat quality, but lowers the costs of producing 1 kg of meat by 15%.

RESUMO

Abstract Background: Although it is possible to preserve the aerial part of cassava in the form of silage, as demonstrated in previous studies, its low dry matter content can result in undesirable fermentation and increased effluent losses during silage, leading to a reduction in the final quality of the silage. A possible way to get around this problem would consist in mixing this silage with dehydrated by-products from the agroindustry. Objective: To evaluate the addition of dehydrated grape marc (DGM) to a silage of aerial parts of cassava (Manihot esculenta, Crantz) on the chemical composition, degradability and in vitro gas production of silage. Methods: A completely randomized experimental design was used, with two treatments: (I) silage of the aerial part of cassava without additive; (II) silage of the aerial part of cassava added with 10% dehydrated grape marc (DGM) in the natural matter, as an additive. After 30 days of fermentation, silages were evaluated to estimate the contents of dry matter (DM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), total digestible nutrients (TDN), as well as pH, in vitro degradability, and cumulative gas production by semi-automatic in vitro gas production. Results: Addition of DGM did not affect CP, EE, NDF, nor TDN levels in silage. The DGM, however, promoted an increase in DM content (32.61 vs 30.31%) and a reduction in pH (4.00 vs 4.75) of the silage. The silage that received DGM presented higher degradability coefficients of soluble and potentially degradable fractions, which led to higher values of potential and effective degradability. Similarly, DGM promoted a reduction in particle colonization time (6.74 vs 10.01 h) and increased cumulative gas production (62.03 vs 57.82 mL/g DM). Conclusion: Addition of 10% dehydrated grape marc in the silage of aerial parts of cassava can be useful to reduce pH and increase dry matter contents of the silage.

Resumen Antecedentes: Si bien es posible preservar la parte aérea de la yuca en forma de ensilaje, como se demostró en estudios anteriores, el bajo contenido de materia seca puede resultar en fermentaciones indeseables y mayores pérdidas de efluentes durante el ensilaje, levando a una reducción en la calidad final del ensilaje. Una de las formas de solucionar este problema sería el ensilaje mixto de la parte aérea de la yuca con subproductos deshidratados de la agroindustria. Objetivo: Evaluar el efecto de la adición de bagazo de uva deshidratado (BUD) a la parte aérea del ensilaje de yuca (Manihot esculenta, Crantz) sobre la composición química, degradabilidad y producción de gas in vitro del ensilado. Métodos: El diseño experimental utilizado fue completamente al azar y los tratamientos consistieron en: (I) ensilado de brotes de yuca sin aditivos; (II) ensilaje de la parte aérea de yuca con 10% de BUD en materia natural, como aditivo. Luego de 30 días de fermentación, los ensilajes fueron evaluados para materia seca (MS), proteína cruda (PC), extracto de éter (EE), fibra detergente neutra (FDN), nutrientes digestibles totales (NDT), pH, degradabilidad in vitro y producción acumulada de gas mediante la técnica de producción de gas in vitro semiautomática. Resultados: La adición de BUD no cambió los contenidos de PB, EE, FDN y NDT del ensilaje. Sin embargo, BUD promovió un aumento en el contenido de MS (32,61 vs 30,31%) y una reducción en el pH (4,00 vs 4,75) del ensilaje. El ensilado que recibió la BUD mostró mayores coeficientes de degradabilidad de las fracciones solubles y potencialmente degradables, lo que resultó en mayores valores de degradabilidad potencial y efectiva. De manera similar, BUD promovió una reducción en el tiempo de colonización de partículas (6,74 vs 10,01 h) y un aumento en la producción acumulada de gas (62,03 vs 57,82 mL/g MS). Conclusiones: La adición de 10% de bagazo de uva deshidratado al ensilaje de la parte aérea de yuca puede ser útil para reducir el pH y aumentar el contenido de materia seca del ensilaje.

Resumo Antecedentes: Embora seja possível preservar a parte aérea da mandioca na forma de silagem, conforme demonstrado em estudos anteriores o baixo teor de matéria seca, pode resultar em fermentação indesejável e aumento das perdas de efluentes durante a silagem, levando à redução da qualidade final da silagem. Uma das formas de contornar esse problema seria a silagem mista da parte aérea da mandioca com subprodutos desidratados da agroindústria. Objetivo: Avaliar o efeito da adição do bagaço desidratado de uva (BDU) na ensilagem da parte aérea de mandioca (Manihot esculenta, Crantz) sobre a composição química, degradabilidade e produção de gases in vitro da silagem. Métodos: O delineamento experimental utilizado foi inteiramente casualizado e os tratamentos constituíram-se por: (I) silagem da parte aérea da mandioca sem aditivo; (II) silagem da parte aérea da mandioca com 10% de bagaço desidratado de uva (BDU) na matéria natural, como aditivo. Após 30 dias de fermentação, as silagens foram avaliadas quanto aos teores de matéria seca (MS), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN), nutrientes digestíveis totais (NDT), pH, degradabilidade in vitro e produção cumulativa de gases por meio da técnica semiautomática de produção de gases in vitro. Resultados: A adição do BDU não alterou os teores de PB, EE, FDN e NDT da silagem. No entanto, o BDU promoveu aumento no teor de MS (32,61 vs 30,31%) e redução no pH (4,00 vs 4,75) da silagem. A silagem que recebeu o BDU apresentou maiores coeficientes de degradabilidade das frações solúvel e potencialmente degradável, o que acarretou em maiores valores de degradabilidade potencial e efetiva. Do mesmo modo, o BDU promoveu uma redução no tempo de colonização da partícula (6,74 vs 10,01 h) e um aumento na produção cumulativa de gás (62,03 vs 57,82 mL/g MS). Conclusões: A adição de 10% do bagaço desidratado de uva na silagem da parte aérea de mandioca pode ser útil para reduzir o pH e aumentar os teores de matéria seca da silagem.

RESUMO

Weaning weight (WW) is one of the most important information within production systems, as it is a reflection of management during the breastfeeding phase and will influence the performance of animals in subsequent phases. This study aimed to develop and evaluate linear, quadratic, and exponential models to predict WW using the body volume (BV) formula in Santa Inês lambs for meat. Eighty-five lambs at 90 days of age with WW 17.52 ± 3.79 kg and BV 13.29 ± 2.86 dm3 were evaluated. The quality of fit of the models was evaluated using the coefficient of determination (R2), mean squared error (MSE), and root MSE (RMSE). For the external evaluation of the models, an independent dataset from 43 lambs at 90 days of age was used. The first-degree linear model showed the lowest values of MSE (1.02) and RMSE (1.01). In the external evaluation, all models exhibited estimates of mean WW and standard deviation of this weight similar to the external dataset, as well as high values (above 0.89) for the R2 of predicted vs. observed data. Concordance correlation coefficient (CCC) analysis also revealed that all models showed accuracy and precision (CCC > 0.90). There was no difference between the models in terms of accuracy (P > 0.05). The comparison in terms of precision indicated that the linear model is more precise than the exponential model and that the quadratic model is as precise as the linear model. The first-degree linear model should be used due to its simplicity of interpretation and ease of estimation.

Assuntos

RESUMO

This study was undertaken to determine whether equations for prediction of dry matter intake (DMI) by meat sheep are valid for animals raised solely on tropical pastures and to propose a new equation to predict the DMI of sheep raised on tropical pastures. The DMI prediction from published equations was evaluated by regressing the predicted and observed values, using the F test, for the identity of the parameters (ß0 = 0 and ß1 = 1) of the regression of predicted on observed data. If the null hypothesis is not rejected, the tested equation accurately estimates DMI. The proposed equation was evaluated in the same way as the published equations. The animal performance and pasture structure and chemical composition data used originated from an experiment conducted with 32 Santa Inês sheep raised on tropical pastures. In the analysis of model adequacy, the null hypothesis was rejected (P < 0.001) and the equations generated predictions that differ (ß0 = 0 and ß1 = 1) from the DMI observed under practical feeding conditions for grazing sheep. The proposed equation, DMI (%LW) = 7.16545 (± 0.76522) - 0.21799 (± 0.01812) * LW + 0.00273 (± 0.00034) * LW2-0.00688 (± 0.00299) * GT + 0.000007 (± 0.000002) * GT2 + 0.00271 (± 0.00108) * GHA, where LW is live weight (kg), GT is grazing time (min/day), and GHA is green herbage allowance (kg DM/100 kg LW), should be used to more accurately predict DMI by grazing sheep.

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RESUMO

This study was undertaken to examine biometric measurements during the growth phase of male and female Santa Inês sheep reared in Brachiaria brizantha pastures in northeastern Brazil. The experiment involved 24 castrated males and 24 females at an initial age of 90 days, with an average body weight of 19.04 ± 0.96 kg. Treatments consisted of the effect of four cultivars (Marandu, Xaraés, Piatã and Paiaguás) and two sexes. Six animals were used per treatment, in a randomized-block experimental design. The following characteristics were evaluated: abdominal circumference (AC), body condition score (BCS), body length (BL), body weight (BW), body capacity 1 (BC1), body capacity 2 (BC2), chest width (CW), heart girth (HG), leg circumference (LC), leg length (LL), rump height (RH), rump width (RW) and withers height (WH). Data were subjected to descriptive analysis, Pearson's correlation, ANOVA and Tukey's, Kruskal Wallis and Mann-Whitney tests. Univariate and multiple regressions were applied to estimate BW with a maximum error level of 5%. Significant differences were observed for the biometric measurements between sexes and cultivars (p<0.05). Body weight was highly correlated (>70%) with AC, WH, CG, RW, BC1 and BC2. The male sheep grazed on cultivars Piatã showed the best values for BW (40.43 kg), HG, RW, WH, LL, LC (102.46; 20.8; 65.23; 60.44; 42.54 cm respectively) and BC1 (4.25 kg/cm). Females grazed on cultivar Marandu had higher values for RW, CW, LL (17.26; 20.1; 75.98 cm respectively), BC1 (6.03 kg/cm) and BC2 (0.422 kg/cm). The equations that best estimated live weight were BC1 and HG. In male and female Santa Inês sheep, biometric parameters grow differently depending on the cultivar where they are grazed during the growth phase. Cultivars Marandu and Piatã are the most recommended for sheep production, as they provided the best performance and body development in those animals.

Assuntos

RESUMO

The study aimed to evaluate the use of β-mannanase and mannan oligosaccharides (MOS) to replace growth promoters in broiler diets. Four hundred male Cobb broiler chicks were used, with initial weight of 45±1g, distributed in a completely randomized design with five treatments and eight repetitions of ten birds. The treatments were: basal feed; basal feed without growth promoter; basal feed without growth promoter + β-mannanase; basal feed without growth promoter + MOS; and basal feed without growth promoter + β-mannanase + MOS. The feed intake of the birds increased in response to dietary treatments compared to basal diet during the period 1-21 days of age. A higher weight gain and improved feed conversion was found at 42 days of age among birds that had received the basal diet without growth promoter + MOS. The absolute weight at slaughter, relative carcass and prime cuts except breast weights improved in response to dietary treatments compared to the basal diet at 42 days of age. No difference was observed in relative weight of the liver, while significant differences were found in the weight of heart, gizzard, and abdominal fat. It was concluded that β-mannanase and MOS can replace the growth promoters in broiler diets without compromising production and economic performance. However, the association of these products into the feed may cause negative interaction that reduces the broiler chickens' performance.

O experimento teve como objetivo avaliar a utilização de β-mananase e mananoligossacarídeos em substituição aos promotores de crescimento nas rações para frangos de corte. Foram utilizados 400 pintos de corte machos da marca Cobb, com peso inicial de 45±1g, distribuídos em delineamento inteiramente ao acaso, com cinco tratamentos e oito repetições de 10 aves. Os tratamentos foram: ração basal; ração basal sem promotor de crescimento; ração basal sem promotor de crescimento + β-mananase; ração basal sem promotor de crescimento + MOS; e ração basal sem promotor de crescimento + β-mananase + MOS. O consumo de ração das aves aumentou em resposta aos tratamentos dietéticos, quando comparados à ração basal no período de 1 a 21 dias de idade. Observou-se maior ganho de peso e melhora na conversão alimentar das aves aos 42 dias de idade que receberam a dieta basal sem promotor de crescimento + MOS. Os pesos absolutos ao abate e relativos de carcaça e de cortes nobres, com exceção de peito, melhoraram em resposta aos tratamentos dietéticos, quando comparados à ração basal aos 42 dias de idade. Não houve diferença sobre o peso relativo de fígado, enquanto os pesos de coração, moela e gordura abdominal foram influenciados pelos tratamentos. Concluiu-se que a β-mananase e o MOS podem substituir os promotores de crescimento em rações de frangos de corte sem comprometer o desempenho produtivo e econômico, no entanto, a associação destes produtos à ração pode causar interação, reduzindo o desempenho das aves.

RESUMO

The study aimed to evaluate the use of β-mannanase and mannan oligosaccharides (MOS) to replace growth promoters in broiler diets. Four hundred male Cobb broiler chicks were used, with initial weight of 45±1g, distributed in a completely randomized design with five treatments and eight repetitions of ten birds. The treatments were: basal feed; basal feed without growth promoter; basal feed without growth promoter + β-mannanase; basal feed without growth promoter + MOS; and basal feed without growth promoter + β-mannanase + MOS. The feed intake of the birds increased in response to dietary treatments compared to basal diet during the period 1-21 days of age. A higher weight gain and improved feed conversion was found at 42 days of age among birds that had received the basal diet without growth promoter + MOS. The absolute weight at slaughter, relative carcass and prime cuts except breast weights improved in response to dietary treatments compared to the basal diet at 42 days of age. No difference was observed in relative weight of the liver, while significant differences were found in the weight of heart, gizzard, and abdominal fat. It was concluded that β-mannanase and MOS can replace the growth promoters in broiler diets without compromising production and economic performance. However, the association of these products into the feed may cause negative interaction that reduces the broiler chickens' performance.(AU)

O experimento teve como objetivo avaliar a utilização de β-mananase e mananoligossacarídeos em substituição aos promotores de crescimento nas rações para frangos de corte. Foram utilizados 400 pintos de corte machos da marca Cobb, com peso inicial de 45±1g, distribuídos em delineamento inteiramente ao acaso, com cinco tratamentos e oito repetições de 10 aves. Os tratamentos foram: ração basal; ração basal sem promotor de crescimento; ração basal sem promotor de crescimento + β-mananase; ração basal sem promotor de crescimento + MOS; e ração basal sem promotor de crescimento + β-mananase + MOS. O consumo de ração das aves aumentou em resposta aos tratamentos dietéticos, quando comparados à ração basal no período de 1 a 21 dias de idade. Observou-se maior ganho de peso e melhora na conversão alimentar das aves aos 42 dias de idade que receberam a dieta basal sem promotor de crescimento + MOS. Os pesos absolutos ao abate e relativos de carcaça e de cortes nobres, com exceção de peito, melhoraram em resposta aos tratamentos dietéticos, quando comparados à ração basal aos 42 dias de idade. Não houve diferença sobre o peso relativo de fígado, enquanto os pesos de coração, moela e gordura abdominal foram influenciados pelos tratamentos. Concluiu-se que a β-mananase e o MOS podem substituir os promotores de crescimento em rações de frangos de corte sem comprometer o desempenho produtivo e econômico, no entanto, a associação destes produtos à ração pode causar interação, reduzindo o desempenho das aves.(AU)

Assuntos