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 We investigated the effects of corn grain, finely or coarsely ground, rehydrated and ensiled to 35% moisture in substitution of dry corn grain on performance of beef cattle in the feedlot. Forty non-castrated young Angus crossbred bulls with average age of 13±1.4 months and average initial body weight (BW) of 374±14 kg. The experiment was conducted in blocks by weight, and bulls were randomly assigned into four groups of five animals each in a 2 × 2 factorial scheme. The factors evaluated were particle size (finely and coarsely ground) and two grain sources (dry ground corn and rehydrated corn grain silage). The treatments were diets containing dry corn grain, finely ground (DCF; 1.86 mm); dry corn grain, coarsely ground (DCC; 3.53 mm); rehydrated and ensiled corn grain, finely ground (RCF; 1.86 mm); and rehydrated and ensiled corn grain, coarsely ground (RCC; 3.53 mm). Initial BW, final BW, average daily gain (ADG), feed efficiency, and intake of dry matter (DMI), acid detergent fiber, and metabolizable energy were not affected by treatment. Ensiling corn grain decreased DMI by 10.3% (11.6 vs. 10.4 kg/d for dry and ensiled, respectively) and increased feed efficiency by 13.3% (0.13 vs. 0.15 kg/d for dry and ensiled, respectively), but there was no effect of particle size, grain source, and their interaction on ADG. Effects of particle size and grain source were observed for fecal starch and total tract starch digestion, with evidence that treatments containing rehydrated corn diets showed greater efficiency in the utilization of dietary starch. Animals fed RCF diets showed lower fecal starch losses of 37, 55, and 75% when compared with treatments RCC, DCF, and DCC, respectively. Our results suggested that ensiled rehydrated corn grain improves feed efficiency in substitution of dry corn grain. The finely and coarsely ground of rehydrated and ensiled corn grain increases the digestibility of starch for finishing cattle in feedlot.

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 aim of this study was to relate the occurrence of visible losses in silage (effluent, spoiled top-layer and during feedout) with silage-making practices, physical and chemical characteristics of silage, and milk composition in Brazilian dairy herds. One-hundred and eight silos from 95 farms, in the State of Parana, were visited for data collection. Data were analyzed by Fisher's Exact and Pearson Correlation Test. Effluent loss was higher in silages with the lowest dry matter content. Using unwalled clamp (drive-over piles) silos, neglecting a protection over the plastic film, and unloading silage with a bucket increased the occurrence of top spoilage. Feedout losses were higher in farms where: the crop was harvested with self-propelled machines; the particle size was larger, and the silage density was lower. There was no relationship between visible losses and silage composition or milk composition, except for milk fat content that, unexpectedly, there was a positive correlation with spoiled silage in the top-layer. Silage losses are reduced by adopting good practices during silage production and feedout.

RESUMO Para se avaliar a inclusão de grãos inteiros das culturas de canola, crambe e soja na dieta de bovinos em confinamento, sobre o consumo, digestibilidade, parâmetros ruminais e recuperação dos grãos nas fezes, delineou-se um ensaio estatístico em quadrado latino com três dietas e três bovinos providos de cânula ruminal. Os resultados constataram que a inclusão do grão de crambe reduziu o consumo de matéria seca em 21,02%, e proporcionou aumento na digestibilidade do extrato etéreo e fibra em detergente neutra. O percentual de extrato etéreo recuperado nas fezes foi de 44,15% para grão de canola e 61,53% para o grão de crambe. Encontrou-se menor digestibilidade da fibra em detergente neutra para dietas contendo grão de soja 0,203g/kg, embora seu consumo aumentou em relação ao crambe 7,86 kg/dia. A inclusão de crambe apresentou redução nos teores de amônia ruminal (N-NH3), com valores médios de 10,97 mg/dL. Portanto, o grão de crambe pode ser incluído na dieta de bovinos de corte em 14% da MS, sendo uma alternativa em potencial como grão de oleaginosa na alimentação de ruminantes. Assim como, os grãos de canola e soja sem afetar a digestibilidade da matéria seca e da proteína bruta, contudo, devem ser usados com cautela.

ABSTRACT Oilseed grains are used as a protein and energy source, increasing the energy density of the feed. The goal of the present study was to determine the nutritional profile of canola, crambe and soybean grains recovered from feces, and to evaluate the intake and digestibility of nutrients, rumen fermentation parameters of beef cattle receiving whole grains of oilseeds. Three steers, 350 ± 23.5 kg body weight were distributed in a not contemporary, 3 × 3 double Latin square, and fed oilseed grains. Inclusion of crambe grain reduced dry matter intake by 21.02%, with a higher digestibility coefficient for EE and NDF. The crude protein content of canola and crambe grains recovered were similar, but the EE content was higher for the crambe grain (26.46%). Soybean showed the lowest values of chemical composition for grains recovered from feces. The highest dry matter intake (7.86 kg/day), and the lowest NDF digestibility (0.203g/kg), were found for animals fed soybean. The inclusion of crambe grains reduced the rumen ammonia content (10.97 mg/dL); however, the ruminal pH was not altered by the inclusion of grains in the diet. Canola and soybean grains can be included in the cattle diet without altering dry matter intake; while the inclusion of crambe grains reduces the dry matter intake and the ruminal ammonia content of the animals. Crambe grain showed the highest recovery of dry matter and ether extract from feces.

RESUMO. O objetivo da pesquisa foi avaliar os efeitos da reidratação do grão de milho em dois diâmetros geométricos médios (DGM = 0,55 e 1,83 mm) sobre perfil fermentativo e composição química das silagens. O experimento foi conduzido em delineamento inteiramente casualizado sendo os tratamentos: silagem de milho finamente reidratado (SMFR) e silagem de milho moído e reidratado (SMMR), com seis repetições. Os materiais foram reidratados com água objetivando níveis de umidade próximos a 350 g kg-1. Em ambas as silagens foram verificadas uma recuperação da matéria seca superior a 97%; porém sem diferença entre ambas. Houve influência do tamanho de partícula sobre a porção fibrosa, com valores inferiores observados para a SMFR. A concentração de ácido acético e lático foi maior para a SMFR, porém sem promover alterações significativas no pH da silagem. O pH foi diferente apenas na fase de exposição ao oxigênio, com valores de 4,25 e 4,38 para a SMFR e SMMR, respectivamente. Após a abertura dos silos, ambas as silagens demonstraram alta estabilidade aeróbia, acima de 90 horas, evidenciando menor atividade de espoliação e menor perda de qualidade. Concluiu-se que o DGM dos grãos de milho afetou o perfil fermentativo e nutricional da silagem.

ABSTRACT. This study evaluated the effects of the rehydration and ensiling of corn grain with two geometric mean diameters (GMD) of 0.55 and 1.83 mm obtained by the diameter of the sieved used on the fermentation characteristics and chemical composition of the silage. The experimental design was completely randomized with two treatments and six replications, as follows: rehydrated fine-corn grain silage (RFS) and rehydrated coarse-corn grain silage (RCS). Ground corn was rehydrated with water to achieve moisture levels close to 350 g kg-1. There was no effect on the dry matter recovery, though the recovery rate was high, with values greater than 97% in both silages. The particle size influenced the fiber content, with lower values in the RFS. The acetic and lactic acid concentrations were higher in the RFS, but the pH of the silages did not change. Oxygen exposure changed the pH of silages to 4.25 and 4.38 for RFS and RCS, respectively. After opening the silos, the silages showed high aerobic stability after 90 hours, which resulted in lower deterioration and lesser loss of quality. The geometric mean diameter of corn grain affects the silage fermentative profile and nutritional value.

RESUMO. O uso de fontes proteicas alternativas para ruminantes pode alterar a produtividade e reduzir os custos na produção animal. O objetivo da pesquisa foi avaliar o desempenho, a digestibilidade aparente e as características quantitativas dos componentes de carcaça das ovelhas alimentadas com níveis crescentes (0, 50, 100 e 150 g kg-1 de matéria seca) de torta de crambe nas dietas. Foram distribuídas 24 ovelhas em um delineamento inteiramente casualizado. Todos os animais foram mantidos em instalação, com baias individuais equipadas com cocho, bebedouro e chão de concreto coberto com cascas de arroz. Os animais receberam silagem de milho como forragem e as dietas foram isoenergéticas com 700 g kg-1 de NDT. Os animais foram abatidos quando atingiram o escore de condição corporal de 3,5 pontos. A ingestão de matéria seca (948,53 g dia-1) e o ganho médio diário (0,15 kg dia-1) não foram influenciados pela inclusão de torta de crambe na dieta. A torta de crambe aumentou a digestibilidade do extrato etéreo e diminuiu a ingestão e digestibilidade da proteína bruta. Não houve efeito da torta de crambe nas características da carcaça e nos componentes não carcaça, no entanto houve redução no rendimento da carcaça fria. A substituição total da farinha de soja e a torta de crambe na dieta para as ovelhas não alteraram as características de desempenho, carcaça e não carcaça.

ABSTRACT. The use of alternative sources of protein for ruminant can alter productivity and reduce costs in animal production. The aim of this study was to evaluate the performance, apparent digestibility and quantitative characteristics of carcass components of ewes fed increasing levels (0, 50, 100 and 150 g kg-1 dry matter) of crambe crushed in the diets. Twenty-four culling ewes were distributed in a completely randomized design. All animals were kept in a shed, with individual stalls equipped with feeder, drinker and concrete floor covered with rice hulls. The animals received corn silage as roughage and diets were isoenergetic with 700 g kg-1 of TDN. Animals were slaughtered when reached a body condition score of 3.5 points. The dry matter intake (948.53 g day-1) and average daily gain (0.15 kg day-1) were not influenced by the inclusion of crambe crushed in the diet. The crambe crushed increased ether extract digestibility and decreased crude protein intake and digestibility. There was no effect of the levels of crambe crushed on carcass characteristics and non-carcass components but rather a reduction in the cold carcass yield. Total replacement of soybean meal with crambe crushed in the diet for ewes did not alter performance, carcass and non-carcass characteristics.

ABSTRACTThe objective of this study was to evaluate the production practices and use of corn silage in dairy farms in Southern Brazil, and to evaluate their impact on the nutritional quality and occurrence of mycotoxins. The data were collected by application of questionnaires among the producers, and by analysis of silage samples. The variables were subjected to factorial analysis of data reduction through the principal components method, thus obtaining 84.12% of the variance associated with the location, corn hybrid, crop production management, and inoculant used, characterizing the farms into four distinct groups. In farms from Paraná, the silage production technologies were more associated with implantation and crop management processes, and investment in equipment related to ensilage/silo feed-out was less frequent. Farms of Rio Grande do Sul showed high adoption of outsourced services, self-propelled machines, bunker silos, double-sided plastic film, and inoculant to control aerobic deterioration, and the silages showed higher levels of propionic acid (7.95 g/kg DM), and lower concentrations of aflatoxins (7.7 ppb) and total mycotoxins (26.58 ppb). The farms evaluated in Southern Brazil have good production efficiency and corn silages with excellent quality, regardless of their production characteristics.

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.

Foram avaliados o desempenho, composição física, rendimento de cortes comerciais e a qualidade da carne de vinte e oito vacas Charolês, Nelore e suas cruzas, com peso vivo médio inicial de 409 kg, terminadas em campo nativo com alta participação de Eragrostis plana Nees., suplementadas por 99 dias com farelo de trigo (FTR) ou farelo de arroz integral (FAI), a 0,5% do peso vivo na matéria seca, com ou sem a inclusão de monensina sódica, separados em grupos de sete para a composição dos tratamentos. O uso de farelo de trigo proporcionou melhor conformação da carcaça (P<0,05), classificando essa como "regular +" (9,90 pontos). As demais características estudadas não foram influenciadas (P>0,05) pelo tipo de suplemento. A inclusão de monensina sódica não proporcionou diferenças significativas (P>0,05) nas variáveis estudadas.

The performance, physical composition, income of commercial cuts the quality of the meat of twenty eight cows Charolais, Nellore and its cross, were evaluated with initial average live weight of 409kg, finished in native grass with high participation of Eragrostis plana Nees., supplemented per 99 days with wheat bran or rice bran 0.5% of the alive weight in the DM with or without the inclusion of sódica monensina. The use of wheat bran provided a better conformation of the carcass (P<0.05), classifying it as "regulate +" (9.90 points). The others characteristic studied was not influenced (P>0.05) by the type of supplement. The inclusion of sodic monensin did not provide significant differences (P>0.05) in the variable studied.

Foram avaliados, durante a terminação, os efeitos da heterozigose e do grupo genético nas medidas corporais de novilhos puros (Charolês - C e Nelore - N) e mestiços da segunda (G2) (3/4C1/4N e 3/4N1/4C), da terceira (G3) (5/8C3/8N e 5/8N3/8C) e da quarta (G4) (11/16C5/16N e 11/16N5/16C) geração de cruzamento rotativo. Os novilhos foram confinados durante 97 dias, sendo alimentados com a mesma dieta, contendo 12,32% de proteína bruta e 2,96Mcal de energia digestível kg-1 de matéria seca, com relação volumoso:concentrado de 52:48. Os mestiços apresentaram maiores alturas de cernelha e garupa que a média dos puros tanto no início como no final do confinamento em todas as gerações do cruzamento. No entanto, os animais da G3 tiveram menor taxa de crescimento de garupa que os puros, com heterose de -35,97%. A heterose para as alturas de cernelha e garupa acompanhou a flutuação do grau de heterozigose do cruzamento, porém com diferentes magnitudes. A heterose da G2 para a G3 teve aumento de 48,18; 18,32; 55,15 e 3,20% para as alturas de cernelha inicial e final e para a altura de garupa inicial e final, respectivamente. Dentro dos sistemas de acasalamento, os animais com predominância de Nelore apresentaram maiores alturas de cernelha e garupa que aqueles com maior predominância de Charolês. Os animais mestiços apresentaram maior perímetro torácico e comprimento inicial em todas as gerações, resultando em heteroses de 5,56; 7,73 e 5,91% e de 7,23; 8,98 e 8,99%, respectivamente, na G2, na G3 e na G4. Todas as medidas corporais foram correlacionadas significativamente com o peso, tanto no início como no fim do confinamento.

The objective of this research was to evaluate the heterozygosis and genetic group effects on body measurements of feedlot finished steers, straightbreds (Charolais - C and Nellore - N), and crossbreds from second (G2) (3/4C 1/4N and 3/4N 1/4C), third (G3) (5/8C 3/8N and 5/8N 3/8C) and fourth (G4) (11/16C 5/16N and 11/16N 5/16C) generation of rotational crossbreeding. The steers were fed during 97 days with the same diet, containing 12.32% crude protein and 2.96Mcal of digestible energy kg-1 of dry matter, with roughage: concentrate ratio of 52: 48. Crossbred steers showed higher withers and rump heights, at the beginning and at end of the feedlot period, in relation to straightbreds in alls generations of crossbreeding. However, G3 animals showed lower rump growth rate than the straightbreds, with the heterosis -35.97%. The heterosis for rump and withers heights followed the fluctuation of the degree of heterozygosis of the crossbreeding, however, with different magnitudes. Heterosis from G2 to G3 increased 48.18; 18.32; 55.15 and 3.20% for initial and final heights of withers and for initial and final heights of rump, respectively. Within the crossbreeding systems, animals with Nellore predominance had higher rump and withers heights than those with Charolais predominance. Crossbred animals had greater thoracic perimeter and initial body length in all crossbreeding generations, with the heterosis 5.56; 7.73 and 5.91% and, 7.23; 8.98 and 8.99%, respectively, in G2, G3 and G4. All the body measurements were significantly correlated with body weight at the beginning and at the end of the feedlot period.

Foi avaliado o desempenho em confinamento de vacas de descarte recebendo dietas sem ou com (200mg animal-1 dia-1) monensina sódica. A dieta continha 12,5% de proteína bruta e 2,99Mcal de energia digestível kg-1 de matéria seca, composta de 48% de volumoso e 52% de concentrado. Os consumos de matéria seca e energia digestível sofreram redução com a presença de monensina sódica na dieta, representando uma queda de 20,9%. Esta redução no consumo de energia digestível por parte dos animais alimentados com monensina afetou negativamente o desempenho dos mesmos, demonstrando redução no ganho de peso de 22,6%. Com maior consumo de alimento e, conseqüentemente, desempenho superior, os animais-controle apresentaram maior peso vivo ao abate (527,49 vs 498,00kg), sendo 5,8% mais pesados em relação aos animais alimentados com monensina. Quanto à conversão alimentar e eficiência energética, ambas as características não sofreram efeito significativo quando da presença de monensina na dieta (médias de 7,78 e 23,24; respectivamente). A presença de monensina sódica na dieta resultou em decréscimo do consumo de matéria seca e no ganho de peso, porém não alterou a conversão alimentar.

The feedlot performance of beef cull cows receiving diets without or with monensin (200mg animal-1 day-1), was evaluated. The diet, 48% of roughage and 52% of concentrated, contained 12.5% of crude protein and 2.99Mcal of digestible energy kg-1 of dry matter. The intake of dry matter and digestible energy was reduced 20.9% with the presence of monensin in the diet. The reduction in digestible energy intake by the animals fed with monensin affected negatively their performance, causing a decrease of 22.6% in their weight gain. With higher food intake and consequently superior performance, the control animals presented higher live weight at slaughter (527.49 vs 498.00kg), being 5.8% heavier in relation to the animals fed with monensin. The feed:gain ratio and energy efficiency, were not affected significantly by the presence of monensin in the diet (being the averages 7.78 and 23.24, respectively). The presence of monensin in diet resulted in reductions of dry matter intake and weight gain, however, it did not alter the feed:gain ratio.