Abstract The objective of this study was to evaluate the effects of different sealing strategies on aerobic stability and feed value of corn silage supplied to finishing lambs. The treatments were set up according to the silo sealing strategy: BP (black polyethylene film), BP + Bagasse (black polyethylene film + sugarcane bagasse) and BP + Silostop (Silostop® Orange oxygen barrier film + black polyethylene film). Six lambs per treatment were used, totaling 18 animals in an experimental period of 63 days. The silage from LP treatment presented the highest aerobic stability, however with lower dry matter digestibility coefficients. No significant differences were detected among treatments for intake and performance of lambs. But for final body weight, weight gain, daily average gain, feed efficiency and dry matter intake, the best results, in absolute value, were found for lambs fed with silage from LP + Bagasse treatment. The silage sealed exclusively with black polyethylene film showed greater aerobic stability. The different sealing strategies used in this experiment did not influence the performance of finishing Dorper x Santa Inês lambs.

Resumo Objetivou-se avaliar os efeitos de differentes estratégias de vedação sobre a estabilidade aeróbia e o valor alimentício da silagem de milho fornecida para cordeiros em terminação. Os tratamentos foram definidos de acordo com a estratégia de vedação do silo: LP (lona preta de polietileno), LP + Bagaço (lona preta de polietileno + bagaço de cana) e LP + Silostop (lona preta de polietileno + filme de barreira de oxigênio Silostop® Orange). Foram utilizados seis cordeiros por tratamento, totalizando 18 animais, em um período experimental de 63 dias. A silagem do tratamento LP apresentou maior estabilidade aeróbia, porém proporcionou menor coeficiente de digestibilidade da matéria seca. Não foi observada diferença significativa entre os tratamentos para o consumo e desempenho dos cordeiros. Todavia, para o peso corporal final, ganho de peso, ganho médio diário, eficiência alimentar e consumo de matéria seca, os melhores resultados, em valor absoluto, foram encontrados para os cordeiros alimentados com dieta à base da silagem coberta com LP + Bagaço. A silagem vedada exclusivamente com a lona preta de polietileno apresentou maior estabilidade aeróbia. As diferentes estratégias de vedação utilizadas nesse experimento não influenciaram o desempenho de cordeiros Dorper x Santa Inês em terminação.

ABSTRACT The objective was to evaluate the inclusion of chitosan (CHI) and technical cashew nut shell liquid (CNSLt) as natural feed additives in cattle diets on nutrient digestibility, ruminal fermentation, and in vitro gas production kinetics. We conducted a completely randomized design with 5×4 factorial arrangement, with 20, 35, 50, 65, and 100% Tifton 85 hay and four additives, monensin (200 mg/kg DM), CNSLt (500 mg/kg DM), CHI (500 mg/kg DM), and CNSLt+CHI (500 mg/kg DM/each). Dry matter (DM) and organic matter (OM) digestibility showed a linear reduction according to forage levels. The highest DM digestibility was observed with CHI on cattle diets. Inclusion of CHI increased DM digestibility. The highest in vitro organic matter and crude protein (CP) digestibilities were observed for CNSLt+CHI. The in vitro dry matter digestibility increased linearly with concentrate in the diet. There was interaction of forage:concentrate ratio and the additives for neutral detergent fiber, acid detergent fiber and hemicellulose digestibility. Chitosan, CNSLt, and CNSLt+CHI promoted the lowest acetate:propionate ratio compared with monensin. Total gas production showed interaction of the forage:concentrate ratio and additives. Lag time was lowest with CNSLt+CHI. Chitosan and CNSLt can be considered alternative fermentation modulators to ionophores by improving nutrient digestibility and increasing ruminal propionate concentrations.

ABSTRACT. The experiment was carried out to evaluate total and partial digestibility of nutrients, the efficiency of microbial protein synthesis, in situ degradability and ruminal parameters in cattle fed diets with rehydrated corn grain silages, okara or soybean grain. Three Holstein steers were distributed in a 3 x 3 Latin square design. The treatments evaluated were: SO (corn grain silage + 30% okara), SSG (corn grain silage + 20% soybean grain) and CG (dry corn grains). The ruminal digestibility of non-fiber carbohydrates (NFC) increased in SO (88.34%) and SSG treatments (87.87%), compared to the CG treatment (63.48%). The minimum ruminal pH value was 6.01, observed 4.13 hours after feeding a diet with SO. The highest ammonia-N contents were 15.25 and 15.07 mg dL-1 observed in SSG and SO, respectively, 2.45 and 2.61 hours after feeding. Treatments SO and SSG showed higher fraction A content (readily degradable fraction) and C (constant rate of degradability of fraction B). The effective degradability (ED) of dry matter (DM) was higher for the diets SO and DE of CP was higher for treatments SO and SSG. SSG and SO result in better utilization of nutrients by animals.

ABSTRACT. The objective of this study was to evaluate the effect of the inclusion of sunflower cake replacing soybean meal in beef cattle diets on the in vitro digestibility of dry matter (IVDDM), organic matter (IVDOM), crude protein (IVDCP) and the ruminal fermentation kinetics and parameters. The experiment was analyzed according to a completely randomized design. The treatments consisted of four levels of sunflower cake, 0, 200, 400, 600 g kg-1, replacing soybean meal in the concentrate of beef cattle diets. The coefficients of IVDDM, IVDOM and IVDCP presented a quadratic effect with the addition of sunflower cake. The soluble fraction (fraction B) degradation rate and total gas production decreased linearly with the inclusion of sunflower cake. Values of pH in ruminal fluid were higher for levels 0, 200 and 600 g kg-1 sunflower cake. Sunflower cake can replace soybean meal by up to 280 g kg-1 in the concentrate of beef cattle diets, improving the in vitro digestibility of dry matter organic, matter and crude protein. Levels above 400 g kg-1 reduce ruminal digestion rate, digestibility and release of final fermentation products.

RESUMO. Objetivou-se no presente trabalho caracterizar alimentos utilizados nas rações de cabras Saanen. Os alimentos avaliados foram: feno de Tifton 85 (Cynodon spp.), farelo de soja, milho moído, casca do grão de soja, milho desintegrado com palha e sabugo e resíduo seco de fecularia de mandioca. Foram determinados os teores de matéria seca, cinzas, proteína bruta, extrato etéreo, fibra em detergente neutro, fibra em detergente ácido, fibra fisicamente efetiva e lignina, e estimados a matéria orgânica, os carboidratos totais e os carboidratos não fibrosos. Os carboidratos foram divididos nas frações A + B1 (rapidamente degradáveis), B2 (potencialmente degradáveis) e C (não degradáveis); e a proteína, nas frações: A (solúvel), B1 (rápida degradação ruminal), B2 (degradação intermediária), B3 (lenta degradação) e C (indigestível). Para determinar a produção de gás foi utilizada a técnica automática in vitro, modificada pela Ankom(r). Foram observadas diferenças entre os alimentos para os parâmetros A, B, C, E e A + D da cinética de degradação ruminal, sendo que os alimentos com alto teor de carboidratos não fibrosos apresentaram maior fração A (rápida degradação), e o feno apresentou maior tempo de colonização (fração C). A produção total de gás foi maior para o milho moído, milho desintegrado com palha e sabugo e resíduo seco de fecularia de mandioca.

ABSTRACT. This study was performed to characterize feed used in diets for Saanen goats. The feedstuffs were: Tifton 85 hay (Cynodon spp.), soybean meal, ground corn, soybean hulls, ground ear corn and dried cassava residue. Contents were determined for dry matter, ash, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, physically effective fiber and lignin, and organic matter, total carbohydrates and non-fiber carbohydrates were estimated. Carbohydrates were divided into fractions A + B1 (rapidly degradable), B2 (potentially degradable) and C (non-degradable); and the protein in fractions A (soluble), B1 (rapid ruminal degradation), B2 (intermediate degradation), B3 (slow degradation) and C (indigestible). To determine the gas production an automatic technique in vitro was used, modified by Ankom(r). Significant differences were observed among feed for the parameters A, B, C, E and A + D of ruminal degradation kinetics, and feed with high non-fibrous carbohydrates content presented higher fraction A (rapid degradation), and the hay showed longer lag time (fraction C). The total gas production was higher for ground corn, ground ear corn and dried cassava residue.

O estudo avaliou os efeitos da suplementação com líquido da casca da castanha de caju (LCCC) em ração de vacas em lactação sobre o consumo, a digestibilidade dos nutrientes, a produção e composição do leite, e a composição de ácidos graxos da gordura do leite. Foram usadas quatro vacas Holandesas (600±43 kg), e o delineamento estatístico foi o quadrado latino 4 x 4, com períodos experimentais de 21 dias. Os tratamentos experimentais consistiram na inclusão de LCCC na ração total misturada, como segue: 1) LCCC 0% (controle, CON); 2) LCCC 0,012% (0,012); 3) LCCC 0,024% (0,024) e 4) LCCC 0,036% (0,036). O consumo de matéria seca e de nutrientes, a digestibilidade aparente dos nutrientes, a composição e a produção de leite corrigida para gordura não foram influenciados pelos tratamentos (p > 0,05). O uso de LCCC diminuiu linearmente a concentração de C6:0 (p < 0,02), produziu uma resposta quadrática na concentração de C13:1n-5 (p < 0,03) e um aumento linear no C16:1n-7 (p < 0,04). Os resultados mostram que o consumo de até 7 g dia-1 de LCCC por vacas leiteiras pode alterar a composição de ácidos graxos da gordura do leite, mas não influencia o consumo, a digestibilidade dos nutrientes e a produção de leite.

The study evaluated the effects of supplementing cashew nut shell liquid (CNSL) in the diet of lactating dairy cows on the intake, nutrient digestibility, milk yield and composition, and fatty acids composition of milk fat. Four Holstein cows (600±43 kg) were used in a 4 x 4 Latin square design with 21 days experimental periods. Experimental treatments consisted of CNSL inclusion in a total mixed ration (dry matter basis), as follows: 1) CNSL 0% (control, CON), 2) CNSL 0.012% (0.012), 3) CNSL 0.024% (0.024) and 4) CNSL 0.036% (0.036). Dry matter and nutrients intake, apparent digestibility of nutrients, fat corrected milk yield and milk composition were not affected (p > 0.05) by the inclusion of CNSL in the ration. CNSL linearly decreased the C6:0 concentration (p < 0.02), produced a quadratic response on C13:1n-5 concentration (p < 0.03) and a linear increase on C16:1n-7 concentration (p < 0.04). Results show that an intake of up to 7 g cow-1day-1 (0.036%) of CNSL may alter the milk fatty acid composition but does not influence intake, nutrient digestibility and milk yield.