Nutritional evaluation, performance and meat quality of beef cattle fed with crude glycerin diets

O presente trabalho foi desenvolvido a partir de três experimentos. O primeiro foi conduzido para caracterizar quimicamente os compostos presentes na glicerina bruta proveniente da indústria do biodiesel e determinar o seu valor energético em dietas para bovinos de corte. Para o ensaio de determinação do valor energético da glicerina foram utilizados oito bovinos, machos não castrados, mestiços e com peso inicial médio de 334 ± 121,13 kg. O delineamento experimental utilizado foi o quadrado latino 2×2 com agrupamento de quatro quadrados simultâneos. Dentro de cada quadrado foram implementados duas proporções de glicerina e volumoso (5:95 e 15:85) e dois períodos experimentais. A glicerina apresentou 105.4g.kg-1 de umidade, 90.09 g.kg-1 de matéria mineral, 805,5 g.kg-1 de glicerol e 160 mg.kg-1 de metanol. Para os valores energéticos foram encontrados 934,46 g.kg-1 e 4,01 e 3,64 Mcal.kg-1 para NDT, Energia digestível e metabolizável, respectivamente. No segundo experimento, utilizaram-se cinco bovinos mestiços (Nelore x Red Angus), não-castrados, com peso inicial médio de 346 ± 21,42 kg, fistulados no rúmen e no abomaso e distribuídos em um quadrado latino 5 x 5, com objetivo de avaliar o efeito de inclusão da glicerina bruta em substituição ao milho em dietas de bovinos de corte terminados em confinamento, sobre o consumo, digestibilidade aparente total e parcial da matéria seca e dos nutrientes, cinética de passagem e digestão ruminal, pH, concentrações de amônia e ácidos graxos voláteis (AGV), estimativa da produção microbiana e excreção de compostos nitrogenados na urina. A alimentação basal foi composta por 50% de silagem de milho e o restante do concentrado à base de milho e farelo de soja. Os tratamentos consistiam de cinco níveis de substituição do milho do concentrado por uma mistura de glicerina e glúten de milho, em que a glicerina compunha 0, 5, 10, 15 e 20% da matéria seca da dieta. Foram utilizados cinco períodos experimentais com 15 dias cada, sendo sete para adaptação e oito para coletas. Com exceção do consumo de EE, não houve efeito (P> 0,05) da glicerina sobre o consumo de MS e dos nutrientes. A inclusão de glicerina aumentou (P 0,05) pelos níveis de glicerina, mas a taxa de digestão da MS, MO e FDNcp aumentaram (P 0,05), no entanto, a concentração de amônia reduziu linearmente (P 0,05) sobre consumo de energia metabolizável e relação entre insulina e glicose. Da mesma forma, a proporção de fibras no músculo não foi afetada (P > 0,05). No entanto o diâmetro das fibras do tipo I e IIA aumentou (P 0,05) pela inclusão de glicerina bruta. Em relação às perdas da carne também não foram detectadas diferenças (P>0,05) entre os tratamentos. Os valores de luminosidade (L*), intensidade de vermelho (a*) e intensidade de amarelo (b*) da carne não diferiram (P>0,05). A inclusão de glicerina bruta até 20% da matéria seca pode ser usada em dietas de terminação de bovinos de corte, pois não promove nenhum efeito deletério a nenhuma das principais variáveis qualitativas da carne.This thesis consists of three experiments. The first experiment was conducted aiming to determine the crude glycerin compounds from the biodiesel industry and the energy value on diets for beef cattle. For the test for determining the energy value of glycerin were used eight cattle, steers, and crossbred with an average initial weight of 334 ± 121.13 kg. The experiment was evaluated following the four-by-four Latin Square design. Within each square, two treatments were implemented according crude glycerin and roughage ratio (5:95 and 15:85 on DM) and two experimental periods. Crude glycerin had 105.4g.kg-1 of moisture and 90.09 g.kg-1 of mineral matter, 805.5 g.kg-1 of glycerol and 160 mg.kg-1 of methanol on DM. For energy values were found 934.46 g.kg-1 and 4.01 and 3.64 for Mcal.kg-1 TDN, digestible and metabolizable energy, respectively. In the second experiment five crossbred bulls were used, with 346 ± 21.42 kg of body weight cannulated in te rumen and abomasum. The experimental design was Latin Square 5 x 5 (five periods and five treatments). Each experimental period had duration of 15d, seven days to adaptation and eight to the collections. Animals were fed a basal diet based containing 50% corn silage and 50% concentrate, in dry matter basis (DM). It was used five diets with five levels of crude glycerin inclusion (0, 5, 10, 15 and 20%DM). Corn was replaced by an equivalent amount of food grade glycerin and corn gluten feed. This study was conducted aiming to evaluate the effect of replacing corn by crude glycerin on feed intake, ruminal and total digestibility, ruminal digestion an passage rate, fermentation characteristics, protein efficiency, microbial protein yield and urinary nitrogenous excretion. Only the EE intake was increased (P 0.05) but digestion rate of DM, OM and NDFap were linearly increased (P 0.05) in ruminal pH and volatile fatty acid concentration were observed, however ammonia concentration decreased (P 0.05) of crude glycerin levels on protein efficiency, microbial protein yield and urinary nitrogenous excretion. . It can be concluded Crude glycerin should replace corn up to 20%DM in diets in finishing diets of beef cattle. The third trial consists of two different works. The fist study was developed with the objective of evaluating the effect of replacing corn with crude glycerin on the intake and total apparent digestibility of diet components, performance, carcass traits, yields of commercial cuts, and carcass composition of beef cattle under feedlot conditions. Thirty-four crossbreed Red Angus x Nellore bulls with an average initial weight of 343.9 ± 16.56 kg were used. Four animals that served as the control group were slaughtered at the beginning of the experiment, and the remaining animals (n = 30) were assigned to a complete randomized design with five treatments and six replications per treatments (0, 5, 10, 15 or 20% glycerin inclusion on DM basis). At the end of the experiment all the animals were slaughtered. The insulin was linearly increased (P > 0.05) by the treatments, but the glucose was unaffected. The dry matter feed intake (DMI), nutrients digestibility were unaffected (P>0.05) by treatment. Similarly, glycerin level did not affect (P > 0,05) the empty body average daily body weight gain, carcass daily weight gain, carcass deposition efficiency, carcass composition and physical and chemical composition of carcass gain. Dietary treatments also unaffected (P > 0.05) dressing percentage (59.72 ± 1.2950 %), LM (78.09 ± 7.3424 cm2) a carcass backfat (5.28 ± 2.13 mm). It can concluded that Crude glycerin substitution of corn ground could be included in finishing cattle diet up to 20% of the DM without lead to detrimental effects on intake, growth performance, carcass performance or basic cut yields. In the second study were used carcasses from the previous study. After 24-h chill, data of carcass weight and pH. After carcass data collection, a boneless Longissimus section between the 9th and 11th ribs was removed, vacuum packaged, frozen and held at -200C. No effect of inclusion level of glycerin (P> 0.05) on metabolizable energy intake and insulin to glucose ratio. Similarly, muscle fibers proportions were unaffected by treatment. However, an increased fiber diameter to type I and IIA was observed (P 0.05) by the crude glycerin level. No changes were observed (P > 0,05) to meat losses by the treatments. The grude glycerin level did not affect (P>0.05) the instrumental color of the Longissimus. The means to L *, a * and b * were unaffected. In addition, diets containing up to 20% of crude glycerin on dry matter can be used in diets for finishing beef cattle because it does not lead to detrimental effects on carcass traits and meat quality variables.Fundação de Amparo a Pesquisa do Estado de Minas Gerai

Saccharomyces cerevisae and monensin in high-grain diet to finishing steers

O presente trabalho foi desenvolvido a partir de um experimento em que objetivou-se avaliar os efeitos da suplementação com culturas de levedura em relação à monensina sódica e ao não uso de aditivos sobre o consumo e digestibilidade de nutrientes, perfil de ácidos graxos voláteis no rúmen, pH ruminal, concentração de amônia ruminal, produção de proteína microbiana, excreção de nitrogênio urinário e balanço de compostos nitrogenados em novilhos de corte alimentados com dietas de alto nível de concentrado com dois níveis de amido (23 e 38%). Foram utilizados oito novilhos de corte cruzados (Bos taurus x Bos indicus), com peso corporal (PC) médio de 499± 50,49 kg e fistulados no rúmen, que foram divididos em dois grupos de quatro, em que cada grupo recebeu um tipo de concentrado. A alimentação basal foi composta de duas rações contendo 80% de concentrado constituída de silagem de milho e os concentrados à base de milho moído em peneira de 6mm, farelo de soja, caroço de algodão, casca de soja e mistura mineral. O experimento foi avaliado segundo delineamento em quadrado latino, com agrupamento de dois quadrados simultâneos, em esquema fatorial 4 x 2. Dentro de cada quadrado, foram implementados quatro tratamentos relativos ao esquema de suplementação (controle, monensina, levedura 1,0 g/100 kg PC/dia, levedura 2,5 g/100 kg PC/dia). As dietas com diferentes níveis de amido foram aplicadas independentemente em cada um dos quadrados latinos. Verificou-se que os consumos de carboidratos não fibrosos, amido, de matéria seca em função do peso corporal e do peso metabólico foram menores (P0,10) pela inclusão de aditivos nas dietas, mas apresentaram menores valores (P0,10) para os tratamentos de menor nível de amido, monensina e levedura 1 g. As concentrações de lactato foram inferiores (P0,10) por nenhum dos aditivos estudados. Entretanto, o propionato foi influenciado (P0,10) por nenhum dos tratamentos avaliados. O emprego de monensina e de culturas de levedura até o nível testado não promove melhorias nos valores pH ruminal, na digestibilidades da FDN e da matéria seca, nem aumentam a síntese de proteína microbiana e balanço de nitrogênio, tampouco reduzem as perdas de compostos nitrogenados urinários e as concentrações de amônia no rúmen em dietas com altos teores de amido.The present work was developed to evaluate the effects of different levels of yeast culture supplementation in comparison to monensin and no feed additives on feed intake, nutrient digestibility, profile of volatile fatty acids (VFA) in the rumen, ruminal pH, concentration of ruminal ammonia, production of microbial protein, nitrogen excretion in urine and balance of nitrogen compounds in beef steers fed by high-concentrated diets with two levels of starch (23 and 38%). Eight steers cannulated in the rumen (Bos taurus x Bos indicus; BW: 489 kg body weight [BW]) were used. Animals were sorted out in two groups of four and each group received one kind of concentrate. The diet was composed of two rations including 80% of concentrated. The roughage used was corn silage and the concentrate composed of ground corn, soybean meal, cottonseed, soybean shell and mineral mixture. The experiment was evaluated following the two-by-two Latin Square design. Within each square, four treatments were implemented according to the supplementation plan (control, monensin, yeast 1.0 g/100kg BW/day, yeast 2.5 g/100kg BW/day). The diets with different levels of starch were independently applied in each Latin squares. The feed intake of non- fibrous carbohydrates, starch and dry matter were observed in relation to body weight and metabolic weight when the yeast level used was 1.0g/100 kg. The ruminal pH values were not influenced by the additive inclusion in the diets. However, the ruminal pH observed was lower (p0.10) in the animals receiving a lowest level of starch, monensin and 1g of yeast. A lower concentration of lactate (P0.10) by any of the additives used in this study. However, the propionate was positively influenced (P<0.10) by the treatment with a lower level of starch. A lower concentration of N-NH3 and a higher NDF digestibility coefficient was observed in the treatment with the lowest level of starch. All the additives used in this study improved (P<0.10) the digestibility of ether extract. The treatment with 2.5g of yeast showed better results compared to the others additives used in this study. The urinary excretion of the nitrogen compounds, purine derivatives, purine absorbed as purine derivatives, synthesis of microbial nitrogen, efficiency of microbial protein synthesis and balance of nitrogen compounds were not influenced by any of the treatments in this study.Fundação de Amparo a Pesquisa do Estado de Minas Gerai

Capim-braquiária diferido e adubado com nitrogênio: produção e características da forragem

Este trabalho foi conduzido com o objetivo de avaliar a massa de forragem e de seus componentes morfológicos, a altura e o índice de tombamento do pasto, a densidade volumétrica e o valor nutritivo da forragem em pastos de Brachiaria decumbens cv. Basilisk diferidos e adubados com nitrogênio (N). Avaliaram-se três períodos de diferimento (73, 95 e 116 dias) e quatro doses de nitrogênio (0, 40, 80 e 120 kg/ha) em um delineamento experimental de blocos casualizados, com três repetições, segundo o esquema de parcelas subdivididas. As massas de forragem total, forragem verde e de colmo verde, bem como a altura do pasto e a densidade volumétrica da forragem aumentaram com o período de diferimento e a dose de nitrogênio. Pastos diferidos por maior período apresentaram maior massa de forragem morta e índice de tombamento. O percentual de fibra em detergente neutro elevou e o teor proteína bruta (PB) diminuiu com o aumento do período de diferimento. O teor de PB aumentou com a elevação da dose de nitrogênio. O período de diferimento e a adubação nitrogenada afetam a produção e as características da forragem diferida de forma semelhante, entretanto o período de diferimento da pastagem possui efeito de maior magnitude. A realização da adubação nitrogenada permite diminuir o período de diferimento do pasto, sem reduzir a produção de forragem

Variabilidade espacial e temporal da vegetação em pastos de capim braquiária diferidos

Avaliou-se a variabilidade espacial e temporal de características descritoras da condição de pastos diferidos de Brachiaria decumbens cv. Basilisk (capim-braquiária). Os tratamentos consistiram de combinações dos períodos de diferimento da pastagem (73, 103, 131 e 163 dias) com os períodos de pastejo (29, 57 e 85 dias). Utilizou-se esquema de parcelas subdivididas e delineamento em blocos casualizados com duas repetições. Foi determinada a dispersão dos valores de altura do pasto, altura da planta estendida e do índice de tombamento do pasto. A variabilidade espacial da altura do pasto aumentou de forma linear com o período de diferimento, porém não foi influenciada pelo período de pastejo. O coeficiente de variação da altura da planta estendida diminuiu linearmente em pastos submetidos aos maiores períodos de diferimento e não foi afetado pelo período de pastejo. A variabilidade do índice de tombamento, no entanto, apresentou resposta quadrática ao período de diferimento, com ponto de máximo correspondente ao coeficiente de variação de 38,25% aos 130 dias. Em pastagens diferidas por curto período (73 dias), ocorreu variação negativa do coeficiente de variação durante o período de pastejo. Pastos de capimbraquiária sob diferimento por longos períodos possuem maior variabilidade da altura do pasto e menor heterogeneidade da altura da planta estendida. Além do efeito temporal, ocorre grande variabilidade espacial nas pastagens de capim-braquiária diferidas.It was evaluated spatial and temporal variability of status descriptive characters of Brachiaria decumbens (signalgrass) cv. Basilisk deferred pastures. Treatments consisted of combinations of pasture deferring periods (73, 103, 131 and 163 days) with grazing periods (29, 57 and 85 days). Randomized block design with two repetitions and subdivided plots was used. It was determined the dispersion of pasture height (PH), stretched plant height (SPH) and falling index (FI) values. Pasture height spatial variability increased linearly with the deferring period, although it was not influenced by the grazing period. The coefficient of variation of stretched plant height decreased linearly on pastures subjected to longer deferring periods, and it was not affected by the grazing period. However, falling index variability showed a quadratic response to the deferring period, with maximum range corresponding to the coefficient of variation of 38.25% on the 130th day. On pastures deferred for short periods (73 days), negative variation of the coefficient of variation was revealed during the grazing period. Brachiaria decumbens pastures under longer deferring periods have higher pasture height variability and lower stretched plant height heterogeneity. Besides the temporal effect, high spatial variability occurs on Brachiaria decumbens deferred pastures

Caracterização dos perfilhos em pastos de capim-braquiária diferidos e adubados com nitrogênio

Este trabalho foi conduzido com o objetivo de avaliar o perfilhamento e as características estruturais de perfilhos em pastos de Brachiaria decumbens cv. Basilisk sob três períodos de diferimento da pastagem (73, 95 e 116 dias) e quatro doses de nitrogênio (N) (0, 40, 80 e 120 kg/ha). O delineamento experimental foi em blocos casualizados, com três repetições, em esquema de parcelas subdivididas. O número de perfilhos vegetativos (PV) reduziu com o aumento do período de diferimento. Houve interação entre período de diferimento e dose de N para a densidade populacional de PV. O maior período de diferimento elevou o número de perfilhos reprodutivos (PR) nos pastos de capim-braquiária, mas não houve efeito da dose de N sobre o número de perfilhos reprodutivos. O número de perfilhos mortos não foi influenciado pelos fatores estudados. Tanto o período de diferimento quanto a adubação nitrogenada aumentaram o peso de todas as categorias de perfilhos de capim-braquiária. As características estruturais dos perfilhos presentes nos pastos diferidos foram alteradas pelo período de diferimento e pela dose de nitrogênio. A redução do período de diferimento e a adubação nitrogenada são estratégias de manejo adequadas para aumentar o número de perfilhos vegetativos em pastos de Brachiaria decumbens cv. Basilisk.This work aimed to evaluate the tilling and tiller structural characteristics on Brachiaria decumbens cv. Basilisk pasture fertilized with nitrogen (N) under different deferring periods. The treatments had 73, 95 and 116-day deferring periods, and 0, 40, 80 and 120 kg/ha N doses. A randomized block design with three replicates and subdivided plots was used. The number of vegetative tillers (VT) reduced as the deferring period increased. Interaction between the deferring period and N doses on the VT population density was verified. The longest deferring period increased the number of reproductive tillers (RT) on the B. decumbens cv. Basilisk pasture; however, N doses did not affect the number of RT. The number of dead tillers was not influenced by the studied factors. Both deferring periods and nitrogen fertilization increased the weight of all tiller categories of B. decumbens cv. Basilisk. The tiller structural characteristics found on deferred pastures were altered by the deferring periods and N doses. Reducing the deferring period and nitrogen fertilization are appropriate handling strategies for increasing the number of vegetative tillers on Brachiaria decumbens cv. Basilisk pastures

CARACTERÍSTICAS ESTRUTURAIS DE PERFILHOS VEGETATIVOS E REPRODUTIVOS EM PASTOS DIFERIDOS DE CAPIM-BRAQUIÁRIA

The aim of this work was to compare the structural characteristics of vegetative and reproductive tillers on Brachiaria decumbens cv. Basilisk pastures diferred for 73, 95 and 116 days. Randomized block design in a split plot scheme with three replications was used. The stockpiling period did not influence (P>0.10) the number of vegetative tillers (VT) but increased (P<0.10) the number of reproductive tillers (RT) (from 16 to 117 tillers/m2). On pastures diferred for up to 95 days, RT were heavier (P<0.05) than VT. Contrarily to VT, the relation between the number and weight of reproductive tillers was positive (P<0.10). A linear increase (P<0.01 and P<0.10) for tiller pseudostem length in relation to the diferring periods of the pasture was found. The number of living leaves (NLL) per tiller was not increased (P>0.10) by the deferring period. The RT revealed (P<0.05) a higher pseudostem length, higher number of dead leaves (NDL) and lower NLL when compared to VT. RT showed (P<0.05) higher percentages of stem and dead leaf as well as a lower percentage of living leaf (P<0.05) than VT. VT showed a better morphological composition than RT. The deferring period alters the structural characteristics and worsens the morphological composition of tillers on deferred Brachiaria decumbens cv. Basilisk pastures.KEYWORDS

Effects of Saccharomyces cerevisiae and monensin on digestion, ruminal parameters, and balance of nitrogenous compounds of beef cattle fed diets with different starch concentrations

This study was carried out aiming to evaluate the effects of yeast or monensin supplementation on dry matter intake, nutrients digestibility, ruminal volatile fatty acids profile, ruminal pH and ammonia concentration, microbial protein synthesis, and the balance of nitrogen compounds of cattle fed high concentrate diet (80 % dry matter (DM) basis) with two different levels of starch. Eight crossbred beef steers fitted with rumen cannula were assigned to two simultaneous 4 × 4 Latin squares arranged in a 4 × 2 factorial design. Two different starch levels (23 and 38 % of DM) were assigned to each Latin square, independently. Within each Latin square, four treatments were randomly assigned to the experimental animals (control; monensin; 1-g yeast [1 g/100 kg body weight (BW)/day] treatment; and 2.5-g yeast [2.5 g/100 kg BW/day] treatment). Feed additives did not influence ruminal pH (P > 0.05). Total ruminal volatile fatty acids (VFA) concentration was greater (P  0.05) by none of the additives evaluated. However, propionate concentration was greater (P  0.05). Monensin or yeast inclusion in high concentrate beef cattle diets in tropical regions as in Brazil is not justified by do not alter nutrient digestibility, nitrogen balance, and main ruminal parameters

Performance and carcass characteristics of young cattle fed with soybean meal treated with tannins

This study aimed to evaluate the effects of replacement of soybean meal (SBM) with soybean meal treated with tannin (SBMT) on the intake, digestibility, performance and characteristics of the carcasses of young cattle fed a high-concentrate diet. Forty- two Nellore bulls with body weight of 244.5 ± 4.99 kg were used. Diets had the inclusion of 7.5% SBM, with a proportion of that SBM (0, 33, 66 or 100%) replaced for SBMT; and other treatment (SBMT + urea) just with 2.5% of SBM which was treated with tannins. Seven animals were randomly selected and slaughtered, and the remaining animals were distributed on treatments and remained for 112 days. After, all animals were slaughtered. There was a linear decline in dry matter intake (P = 0.026) when SBM was replaced with SBMT. No decrease in carcass weight (P > 0.05) was observed. The efficiency of carcass weight gain showed a quadratic function effect (P = 0.049). There were changes in carcass gain composition when SBMT was added (P < 0.05), with an increase in muscle and reduction in fat deposition. The use of SBMT in place of SBM causes changes in body gain composition in animals and reduces DM intake by the animals, achieving a better feed conversion efficiency