Explore the vast range of titles available.

This study investigated the effect of treatment of wheat straw using ammonia fiber expansion (AFEX) and exogenous fibrolytic enzymes (Viscozyme) on fiber digestibility, rumen fermentation, microbial protein synthesis, and microbial populations in an artificial rumen system [Rumen Simulation Technique (RUSITEC)]. Four treatments were assigned to 16 vessels (4 per treatment) in 2 RUSITEC apparatuses in a randomized block design. Treatments were arranged as a 2 × 2 factorial using untreated or AFEX-treated wheat straw with or without exogenous fibrolytic enzymes [0 or 500 µg of protein/g straw dry matter (DM)]. Fibrolytic enzymes were applied to straw, prior to sealing in nylon bags. The concentrate mixture was provided in a separate bag within each fermentation vessel. The RUSITECs were adapted for 8 d and disappearance of DM, neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein (CP) was measured after 48 h of incubation. Ammonia fiber expansion increased (P < 0.01) the disappearance of wheat straw DM (69.6 vs. 38.3%), NDF (65.6 vs. 36.8%), ADF (61.4 vs. 36.0%), and CP (68.3 vs. 24.0%). Total dietary DM, organic matter (OM), and NDF disappearance was also increased (P ≤ 0.05) by enzymes. Total microbial protein production was greater (P < 0.01) for AFEX-treated (72.9 mg/d) than untreated straw (63.1 mg/d). Total gas and methane (CH4) production (P < 0.01) were also greater for AFEX-treated wheat straw than untreated straw, with a tendency for total gas to increase (P = 0.06) with enzymes. Ammonia fiber expansion increased (P < 0.01) total volatile fatty acid (VFA) production and the molar proportion of propionate, while it decreased (P < 0.01) acetate and the acetate-to-propionate ratio. The AFEX-treated straw had lower relative quantities of fungi, methanogens, and Fibrobacter succinogenes (P < 0.01) and fewer protozoa (P < 0.01) compared to untreated straw. The pH of fermenters fed AFEX-treated straw was lower (P < 0.01) than those fed untreated straw. Both AFEX (P < 0.01) and enzymes (P = 0.02) decreased xylanase activity. There was an enzyme × straw interaction (P = 0.02) for endoglucanase activity. Enzymes increased endoglucanase activity of AFEX-treated wheat straw, but had no effect on untreated straw. The addition of enzymes lowered the relative abundance of Ruminococcus flavefaciens, but increased F. succinogenes. These results indicate that AFEX increased the ruminal disappearance of wheat straw and improved fermentation and microbial protein synthesis in the RUSITEC.

The use of near infrared spectroscopy (NIRS) as an alternative to the techniques commonly employed in the study of forage composition needs to be explored. The objective was to construct calibration curves to predict the physical-chemical composition of tropical grasses (Brachiaria brizantha (Hochst. ex A. Rich.) Stapf 'Marandu', 'Piata'; B. decumbens Stapf, Panicum maximum Jacq. 'Coloniao'), by NIRS and compare two multivariate regression method. Forage samples were analyzed for crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), ash, ether extract (EE), lignin, and moisture. The values obtained by the Official Methods of Analysis of Association of Official Agricultural Chemists (AOAC) were reference values for the creation of multivariate calibration models. The samples were scanned on the NIRS. The multivariate calibration models were created by the partial least squares (PLS) method and by the multiple linear regression (MLR) method. The predictive capacity of the models was evaluated by the correlation coefficient (R) and parameters of the mean squared deviation (RMSE). When the MLR was used, only the prediction model of ash (R = 0.82) of the P. maximum, EE (R = 0.87) and moisture (R = 0.90) of ' Piata' showed approximate predictive capacity, for the other components R indicated good prediction. After the validation of the models developed by the PLS regression method, the CP (0.78-0.91), NDF (0.88-0.95), lignin (0.85-0.91), and moisture (0.79-0.96) predictions presented good results. The NIRS technique can be used to determine the physical-chemical composition of tropical grasses. The MLR multivariate regression method as well as PLS can be used to predict the physical-chemical composition of tropical grasses.

Agro-industrial by-products are a great option for ruminant feeding. Alternative feedstuffs in ruminant diets are important to increase diets and reduce production costs. The present study evaluated different levels of palm (Elaeis guineensis Jacq.) kernel cake inclusion in diets for feedlot-finished cull cows and their implications on the intake and digestibility of dry matter (DM) and nutrients, as well as animal performance. The experiment was carried out in Ribeirao do Largo, Bahia, Brazil. Thirty-six Holstein x Zebu crossbred cows were assigned to four treatments at the rate of nine cows per treatment. The animals were fed sugarcane bagasse (roughage 15%) and concentrate (85%). The treatments were no addition of palm kernel cake, 8%, 16%, or 24% palm kernel cake inclusion in the total DM diet. Palm kernel cake inclusion influenced DM and nutrient intakes, which responded quadratically. The digestibility of DM, crude protein, and neutral detergent fiber corrected for ash and protein showed a quadratic response and maximum digestibility at 1.67%, 5.24%, and 3.68% cake inclusion levels, respectively; values decreased thereafter. The total digestible nutrients decreased linearly based on cake inclusion levels. Treatments affected final body weight, mean daily gain, and feed conversion, which showed a quadratic response to increasing levels of the by-product in the diet and maximum values were at 11.98%, 13.07%, and 16.32% inclusion, respectively. Palm kernel cake is a viable alternative ingredient for animal biological efficiency. The 16% inclusion level in the total DM diet was the most appropriate for the finishing of cull cows in the feedlot. Key words: Body weight, cattle, Elaeis guineensis, intake, performance.

The objective of this trial was to evaluate intake, digestibility, and growth performance of Girolando bulls submitted to two nutritional planes while grazing on Brachiaria brizantha cv. Marandu pasture. Twenty-two animals, with average initial body weight = 209.1 ± 8.2 kg, were used in this trial. The experimental design was repeated measurements, in a 2 × 3 factorial arrangement, with two nutritional planes (NP1 and NP2) and three seasons of the year, with 11 replicates per treatment. The animals of the NP1 received mineral mixture ad libitum during rainy season 1 (15 February through 5 July 2014), energy protein supplement in the amount of 1 g d kg BW−1 during the dry season (from 6 July through 22 November 2014), and again mineral mixture ad libitum during rainy season 2 (from 23 November 2014 through 9 March 2015). The NP2 animals received 2 g d kg BW−1, 2 g d kg BW−1, and 1 g d kg BW−1 of energy-protein supplement in the respective seasons of the year. Forage intakes were similar between nutritional planes, 6.8 and 7.6 kg DM day−1 and 2.1 and 2.22% BW for NP1 and NP2, respectively. There was no statistical difference (level) between the intakes of neutral detergent fiber corrected for ash and protein (4.1 and 4.3 kg day−1 and 1.2 and 1.3% BW, respectively for nutritional planes 1 and 2). For the other nutrients, NP2 showed greater values. The highest intakes and digestibilities of dry matter, organic matter, and non-fiber carbohydrate were in rainy season 2. Performance and feed conversion were similar among NPs. This study showed that lower levels of supplementation could be done in order to reduce feeding costs with no impact on performance.

Concentrate supplementation during the finishing phase in tropical pastures improves the average daily gain and carcass characteristics of the animals. The objective of this study was to evaluate the effects of increasing levels of concentrate supplementation on nutrient intake and digestibility, ruminal fermentation parameters, and the performance of heifers finished on Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs 'Mombaca' pasture. Forty heifers (1/2 Nellore x 1/2 Angus), with an average body weight of 312.65 [+ or -] 17.95 kg and 16 mo age, were distributed in a completely randomized design. To analyze ruminal parameters, four rumen-fistulated heifers were used in a 4x4 Latin square design. Supplementation was provided at four levels: 0.2%, 0.3%, 0.4%, and 0.5% of body weight (BW) over 134 d. A linear increase (P < 0.05) was observed in the intake of total DM, organic matter, crude protein (CP), and non-fibrous carbohydrates with increasing supplementation levels. However, the digestibility of neutral detergent fiber and CP decreased linearly (P < 0.05) and quadratically (P < 0.05), respectively, with increasing supplementation. Greater supplementation levels also reduced (P < 0.05) the concentrations of short chain fatty acids, acetate, and propionate in the rumen. Final body weight (398 kg) and average daily gain (0.64 kg [d.sup.-1]) were not affected (P > 0.05) by supplementation level, but gross feed efficiency declined (P < 0.05) as supplementation increased. Increasing concentrate supplementation from 0.2% to 0.5% BW in 1/2 Nellore x 1/2 Angus heifers finished on M. maximus 'Mombaca' pasture did not affect average daily gain but reduced feed efficiency. Therefore, lower supplementation levels (0.2% BW) are recommended.

Abstract This study investigated the effect of treatment of wheat straw using ammonia fiber expansion (AFEX) and exogenous fibrolytic enzymes (Viscozyme) on fiber digestibility, rumen fermentation, microbial protein synthesis, and microbial populations in an artificial rumen system [Rumen Simulation Technique (RUSITEC)]. Four treatments were assigned to 16 vessels (4 per treatment) in 2 RUSITEC apparatuses in a randomized block design. Treatments were arranged as a 2 × 2 factorial using untreated or AFEX-treated wheat straw with or without exogenous fibrolytic enzymes [0 or 500 μg of protein/g straw dry matter (DM)]. Fibrolytic enzymes were applied to straw, prior to sealing in nylon bags. The concentrate mixture was provided in a separate bag within each fermentation vessel. The RUSITECs were adapted for 8 d and disappearance of DM, neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein (CP) was measured after 48 h of incubation. Ammonia fiber expansion increased (P < 0.01) the disappearance of wheat straw DM (69.6 vs. 38.3%), NDF (65.6 vs. 36.8%), ADF (61.4 vs. 36.0%), and CP (68.3 vs. 24.0%). Total dietary DM, organic matter (OM), and NDF disappearance was also increased (P ≤ 0.05) by enzymes. Total microbial protein production was greater (P < 0.01) for AFEX-treated (72.9 mg/d) than untreated straw (63.1 mg/d). Total gas and methane (CH4) production (P < 0.01) were also greater for AFEX-treated wheat straw than untreated straw, with a tendency for total gas to increase (P = 0.06) with enzymes. Ammonia fiber expansion increased (P < 0.01) total volatile fatty acid (VFA) production and the molar proportion of propionate, while it decreased (P < 0.01) acetate and the acetate-to-propionate ratio. The AFEX-treated straw had lower relative quantities of fungi, methanogens, and Fibrobacter succinogenes (P < 0.01) and fewer protozoa (P < 0.01) compared to untreated straw. The pH of fermenters fed AFEX-treated straw was lower (P < 0.01) than those fed untreated straw. Both AFEX (P < 0.01) and enzymes (P = 0.02) decreased xylanase activity. There was an enzyme × straw interaction (P = 0.02) for endoglucanase activity. Enzymes increased endoglucanase activity of AFEX-treated wheat straw, but had no effect on untreated straw. The addition of enzymes lowered the relative abundance of Ruminococcus flavefaciens, but increased F. succinogenes. These results indicate that AFEX increased the ruminal disappearance of wheat straw and improved fermentation and microbial protein synthesis in the RUSITEC.

Agro-industrial by-products are a great option for ruminant feeding. Alternative feedstuffs in ruminant diets are important to increase diets and reduce production costs. The present study evaluated different levels of palm (Elaeis guineensis Jacq.) kernel cake inclusion in diets for feedlot-finished cull cows and their implications on the intake and digestibility of dry matter (DM) and nutrients, as well as animal performance. The experiment was carried out in Ribeirão do Largo, Bahía, Brazil. Thirty-six Holstein × Zebu crossbred cows were assigned to four treatments at the rate of nine cows per treatment. The animals were fed sugarcane bagasse (roughage 15%) and concentrate (85%). The treatments were no addition of palm kernel cake, 8%, 16%, or 24% palm kernel cake inclusion in the total DM diet. Palm kernel cake inclusion influenced DM and nutrient intakes, which responded quadratically. The digestibility of DM, crude protein, and neutral detergent fiber corrected for ash and protein showed a quadratic response and maximum digestibility at 1.67%, 5.24%, and 3.68% cake inclusion levels, respectively; values decreased thereafter. The total digestible nutrients decreased linearly based on cake inclusion levels. Treatments affected final body weight, mean daily gain, and feed conversion, which showed a quadratic response to increasing levels of the by-product in the diet and maximum values were at 11.98%, 13.07%, and 16.32% inclusion, respectively. Palm kernel cake is a viable alternative ingredient for animal biological efficiency. The 16% inclusion level in the total DM diet was the most appropriate for the finishing of cull cows in the feedlot.

This study evaluated the effect of combinations of feed-grade urea and slow-release urea (SRU) on fermentation and microbial protein synthesis within two artificial rumens (Rusitec) fed a finishing concentrate diet. The experiment was a completely randomized, dose–response design with SRU substituted at levels of 0% (control), 0.5%, 1%, or 1.75% of dry matter (DM) in place of feed-grade urea, with four replicate fermenters per dosage. The diet consisted of 90% concentrate and 10% forage (DM basis). The experiment was conducted over 15 d, with 8 d of adaptation and 7 d of sampling. Dry matter and organic matter disappearances were determined after 48 h of incubation from day 9 to 12, and daily ammonia (NH3) and volatile fatty acid (VFA) production were measured from day 9 to 12. Microbial protein synthesis was determined on days 13–15. Increasing the level of SRU quadratically affected total VFA (Q, P = 0.031) and ammonia (Q, P = 0.034), with a linear increment in acetate (L, P = 0.01) and isovalerate (L, P = 0.05) and reduction in butyrate (L, P = 0.05). Disappearance of neutral detergent fiber (NDF) and acid detergent fiber (ADF) was quadratically affected by levels of SRU, plateauing at 1% SRU. Inclusion of 1% SRU resulted in the highest amount of microbial nitrogen associated with feed particles (Q, P = 0.037). Responses in the efficiency of microbial protein synthesis fluctuated (L, P = 0.002; Q, P = 0.001) and were the highest for 1% SRU. In general, the result of this study showed that 1% SRU in combination with 0.6% urea increased NDF and ADF digestibility and total volatile fatty acid (TVFA) production.

Agro-industrial by-products are a great option for ruminant feeding. Alternative feedstuffs in ruminant diets are important to increase diets and reduce production costs. The present study evaluated different levels of palm (Elaeis guineensis Jacq.) kernel cake inclusion in diets for feedlot-finished cull cows and their implications on the intake and digestibility of dry matter (DM) and nutrients, as well as animal performance. The experiment was carried out in Ribeirao do Largo, Bahia, Brazil. Thirty-six Holstein x Zebu crossbred cows were assigned to four treatments at the rate of nine cows per treatment. The animals were fed sugarcane bagasse (roughage 15%) and concentrate (85%). The treatments were no addition of palm kernel cake, 8%, 16%, or 24% palm kernel cake inclusion in the total DM diet. Palm kernel cake inclusion influenced DM and nutrient intakes, which responded quadratically. The digestibility of DM, crude protein, and neutral detergent fiber corrected for ash and protein showed a quadratic response and maximum digestibility at 1.67%, 5.24%, and 3.68% cake inclusion levels, respectively; values decreased thereafter. The total digestible nutrients decreased linearly based on cake inclusion levels. Treatments affected final body weight, mean daily gain, and feed conversion, which showed a quadratic response to increasing levels of the by-product in the diet and maximum values were at 11.98%, 13.07%, and 16.32% inclusion, respectively. Palm kernel cake is a viable alternative ingredient for animal biological efficiency. The 16% inclusion level in the total DM diet was the most appropriate for the finishing of cull cows in the feedlot.