PSVII-14 Feeding carbohydrases to grazing beef cattle under different nutritional strategies on dry season: Ruminal fermentation

The aim with this trial was to evaluate two nutritional plans with the addition of carbohydrases enzyme blend (CEB) on ruminal fermentation of grazing Nellore bulls in dry season. Five rumen cannulated Nellore steers (BW = 350 kg) were used. Animals were randomly assigned to a treatment sequence in a 5×5 Latin square experiment with 15 d-periods (10 d to diet adaptation and 5 d for data collection), following a completely randomized design, being the treatments: mineral-proteic supplementation (Fosbovi® Proteico 35; PS) offered at 0,1% BW (0 or 4.75 g/animal/day of CEB) or mineral-protein-energetic supplementation (Fosbovi® Proteico-Energético 25; PES) offered at 0.3% BW (0, 4.75 or 9.50 g/animal/day of CEB). The CEB was mainly composed by beta-glucanase and xylanase enzymes (Ronozyme® VP and Ronozyme® WX). Both enzymes and supplements were provided by DSM Nutritional Products Brasil S.A. Rumen fluid samples were collected on the last day of each experimental period before (0), and 2, 4, 6, and 8 h after supplements were offered. Data were analyzed using PROC MIXED of SAS. Steers fed PSE had greater (P ≤ 0.041) rumen concentration of acetate, propionate, and butyrate, and lower (P = 0.028) acetate to propionate ratio in comparison with animals fed PS. Rumen acetate concentrations were 61.6 and 58.8 mmol/L and rumen propionate concentrations were 15.2 and 13.7 mmol/L for animals under the PSE and PS, respectively. A quadratic effect (P = 0.048) for carbohydrases enzyme blend was observed in NH3-N ruminal concentration of PES animals, where 4.75 g/day level presented the lower concentrations compared to control (24.13 vs. 32.20 mg/dL). Furthermore, rumen concentrations of acetate (P = 0.002) and propionate (P = 0.021) linearly increased with enzymes inclusion for PSE plan. PSE nutritional strategy positively influence ruminal fermentation of Nellore steers in dry season and its effects can be enhanced with CEB inclusion of 4.75 g/day.

PSXVI-25 25-hydroxy-vitamin-D3 improves productive performance of grazing Nellore cattle during dry season

The aim with this trial was to evaluate three nutritional plans with the addition of 25-hydroxy-vitamin-D3 (HyD®) on performance of grazing Nellore steers in dry season. One hundred and twenty Nellore calves (iBW ± 267 kg; age, 9 mo) were randomly allocated to six paddocks (n = 20/paddock), in the following nutritional plans: mineral-proteic supplementation (PS; Fosbovi® Proteico 35; at 0.1% BW); PS with sodium monensin (PSM; Fosbovi® Proteico 35 M; at 0.1% BW); and mineral-protein-energetic supplementation (PES; Fosbovi® Proteico-Energético 25; at 0.3% BW); all three fed with or without addition of 1 mg/animal/d of 25-hydroxy-vitamin-D3 (HyD®), totaling six treatments. Both HyD® and supplements were provided by DSM Nutritional Products Brasil S.A. The intake and animal weight were collected daily and individually using an automatic feeder/scale system located in each paddock. Data were analyzed using the mixed procedure of SAS and means were compared by orthogonal contrasts (P < 0.05). Animals fed PSE, when compared to PSM and PS, presented higher ADG (PSE = 0.290 vs. PSM= 0.130 and PS = 0.030 kg/day; P < 0.01), FBW (PSE = 302.5 vs. PSM = 282.6 and PS = 271.7 kg; P < 0.01) and supplement intake (PSE = 1.640 vs. PSM = 0.190 and PS = 0.210 kg/day; P < 0.01). Additionally, regardless of nutritional strategy, HyD® supplementation increased ADG in 32 g/day (0.165 vs. 0.133 kg/day; P = 0.05) and FBW in 3.9 kg (287.5 vs. 283.6 kg; P = 0.05), compared to not-supplemented calves. No effects on supplement intake (either expressed in kg/day or %BW) were observed for HyD®. We conclude that 1 mg of HyD® can optimize performance of protein and protein-energetic supplemented cattle raised in tropical conditions during dry period.

PSXIV-13 Supplemental essential oil blends plus 25-hydroxy-vitamin-D3 improve carcass characteristics in cattle finished under tropical conditions

A total of 90 young crossbreed bulls (initial weight=228.04±7.06 kg) were used in a 171-day feeding trial in order to evaluate the combination of supplemental blend of essential oils (Crina® Ruminants; DSM Nutritional Products) plus 25-hydroxy-vitamin-D3 (HyD®, DSM Nutritional Products; EO+HyD) on growth performance and carcass characteristics in cattle finishing under tropical conditions. Cattle were blocked by weight into 2 blocks and randomly allocated to 2 treatments (9 pens/treatment, 5 bulls/pen). Cattle were fed with a steam-flaked corn-based diets (average diet NEm= 1.95 Mcal/kg during first 84-d, and 2.15 Mcal/kg during the remaining 87-d). Treatments consisted of: 1) EO+HyD supplementation along fattening period (171-d), or 2) supplementation with monensin (Rumensin®, Elanco Animal Health; 20 mg/kg diet) during the first 84-d and monensin (20 mg/kg diet) plus virginiamycin (Stafac®, Phibro Animal Health; 20 mg/kg diet) during remaining time (87-d). The average THI during course of the experiment was 76.67±2.7 with a maximum of 85.46±2.2 and minimum of 68.29±2.6. There were no statistical differences (P > 0.10) between EO+HyD and ionophores/antibiotic supplemented cattle on DM intake (7.575 vs 7.534 kg/d), average daily gain (1.433 vs 1.406 kg), or gain-to-feed ratio (0.189 vs 0.187). However, cattle fed with EO+HyD tended (P = 0.07) to have heavier carcass weight in 5.2 kg (304.9 vs 299.7 kg), showed greater LM area (89.89 vs. 82.77 cm², P < 0.01) and greater estimated retail yield (1.6%, P = 0.02) than cattle receiving ionophores/antibiotic mixture. Cattle receiving EO+HyD showed more percentage of carcass classified as Choice (14.28 vs 13.33%) and “Select” (59.52 vs 44.44%) and lower percentage of carcass classified as “Standard” (26.20 vs 42.23%). The combination of a blend of essential oils plus 25-hydroxy-Vit-D3 (EO+HyD) in finishing phase improve carcass characteristics. Supplemental EO+HyD is a viable alternative to supplemental monensin, or monensin plus virginiamycin used in growing-finishing diets for feedlot cattle.

PSVII-24 Blend of essential oils plus 25-hydroxy-vitamin-D3 as alternative to the use monensin on growth performance and dietary energetics in feedlot cattle raised under high ambient temperature

Ninety young crossbreed bulls (approximately 25% Zebu breeding with the remainder represented by continental and British breeds in various proportions, initial weight=228.04±7.06 kg) were used in a 84-day feeding trial to assess the effects of treatments in feedlot cattle fed transition diets during high ambient temperatures. Treatments consisted of a steam-flaked corn-based diets (average 1.95 Mcal ENm/kg) supplemented with: 1) 20 mg monensin/kg diet (MON, Rumensin, Elanco Animal Health, Indianapolis, IN], and 2) 100 mg of blend of essential oils /kg diet plus 0.1 mg 25-hydroxy-vitamin-D3/kg diet (EO+HyD; CRINA® Ruminants and HyD®, DSM Nutritional Products, Basel, Switzerland). Both dry matter intake (DMI) and climatic variables were measured daily and the temperature humidity index (THI) was estimated. Daily maximal THI remained over 80 during the whole trial (avg. THI = 82.67). Cattle supplemented with EO+HyD increased average daily gain in 8.7% (1.446 vs. 1.320 kg/day, P < 0.01), gain-to-fed ratio in 4.5% (0.199 vs. 0.190; P = 0.03), final weight in 10.05 kg (349.48 vs. 339.43; P = 0.04) and tended (P = 0.07) to shown greater dietary net energy (2.5%) and observed-to-expected dietary NE ratio (3%). Even when EO+HyD tended to increase (4.3%; P = 0.06) DM intake, intake pattern variation were not different (P = 0.38) between MON and EO+HyD (Figure 1). Then, difference in ADG and final BW between MON and EO+HyD was not only a reflection of difference in energy intake, was also caused by difference in efficiency of energy utilization during conditions of high ambient temperature (a reduction of 7% in the estimated increase of coefficient of maintenance by heat load). Results indicate that supplementation with a combination of essential oil blend plus 25-hydroxy-vitamin-D3 can have greater beneficial effects than supplemental monensin on daily weight gain, final weight and feed intake during initiation-transition phase of cattle raised under high ambient temperature.

PSXIII-13 Feeding carbohydrases to grazing beef cattle under different nutritional strategies on dry season: feeding behavior

The aim with this trial was to evaluate two nutritional plans with the addition of dosages of carbohydrases enzyme blend on feeding behavior of grazing Nellore bulls in rainy season. One hundred and two contemporary Nellore steers (BW = 294.10 ± 3.35 kg) were equally distributed in six paddocks (17 steers/paddock) following a completely randomized design in a 2x3 factorial arrangement, being the factors two nutritional plans: mineral-proteic supplementation (Fosbovi® Proteico 35; PS) offered at 0,1% BW or mineral-protein-energetic supplementation (Fosbovi® Proteico-Energético 25; PES) offered at 0.3% BW); and three levels of enzymatic carbohydrases blend (0, 4,75 or 9,50 g/animal/day). The enzymatic blend was mainly composed by beta-glucanase and xylanase enzymes (Ronozyme® VP and Ronozyme® WX); Both enzymes and supplemented were provided by DSM Nutritional Products Brasil S.A. Feeding behavior data were collected daily and individually by an automatic scale/feeder system installed in the paddocks. Data were analyzed using PROC MIXED of SAS. Animals fed PES presented greater number of visits to the feed bunks (19.73 vs. 10.12 visits/day; P < 0.0001), to the water fountains (2.95 vs. 2.32 visits/day; P < 0.0001) and greater water intake (22.43 vs. 17.73 L/day; P < 0.0001) in comparison with animals fed PS treatments. Also, animals receiving PES spent more time taking supplement (1.332 vs. 545 seconds/visit; P < 0.0001) and water (203 vs. 153 seconds/visit; P < 0.0001) then PS animals did. No linear and quadratic effects were observed for feeding behavior when including carbohydrases enzymes to PES or PS supplement. PSE nutritional plan positively influence feeding behavior of Nellore bulls in dry season, increasing cattle feed bunk access and water intake in a daily basis.

PSXI-26 Blend of essential oils supplemented alone or combined with exogenous amylase compared with virginiamycin on performance of finishing lambs

Forty-eight Pelibuey × Katahdin (27.87±4.71 kg) intact lambs were used in a growth-performance trial lasted 87 days to assess the effects of treatments. Lambs were assigned to one of six weight groupings in 24 pens (6 replicas per treatment). Basal diet was comprised by cracked corn (14% CP and 2.08 Mcal ENm/kg) and was supplemented as follows: 1) No additives (Control); 2) supplemented with a blend of essential oils at dose of 150 mg EO/kg diet DM (EO, CRINA® Ruminants, DSM Nutritional Products); 3) supplemented with 150 mg EO plus 560 mg alpha-amylase/kg diet DM (EO+ENZ, RONOZYME® Rumistar, DSM Nutritional Products), and 4) supplemented with antibiotic virginiamycin (VM, Stafac 500, Phibro Animal Health) at dose of 28 mg virginiamycin/kg diet DM. Growth performance and dietary energetics were very similar (P > 0.97) between EO and VM. In such way that, compared to Control, lambs supplemented with EO and VM tended (P = 0.09) to shown greater final weight (3.1%) and average daily gain (ADG; 5.9%) without difference on DMI (P = 0.99); thus, gain-to-feed ratio (GF) and observed dietary net energy (NE) were average improved in 5.7% (P < 0.01). Compared to Controls, combining EO plus ENZ tended to increased DMI (6.8%, P = 0.09), but increased in 10.4% ADG (P < 0.01) and in 4.4% (P = 0.02) feed efficiency. Lambs supplemented with EO shown lower (P ≤ 0.10) kidney-pelvic-heart fat than Controls and VM lambs. Compared to Controls, additive supplementation decreased (P ≤ 0.03) the relative weight of intestines, the effect being more pronounced with EO supplementation. Compared to VM, supplemental EO (alone or combined with enzyme) shown lower (10.1%, P ≤ 0.04) visceral fat. Supplemental essential oils is a viable alternative to virginiamycin in finishing high-energy diets for lambs. Combining essential oils plus amylase can be a strategy to promote better daily gain weights allowing target final weight at shorter time.

314 Carbohydrases Enzymes Improve the Productive Performance of Grazing Nellore Bulls Fed Different Nutritional Plans During the Rainy Season

The aim with this trial was to evaluate two nutritional plans with the addition of dosages of carbohydrases enzyme blend on productive performance of grazing Nellore bulls in rainy season. One hundred and two contemporary Nellore steers (BW = 294.10 ± 3.35 kg) were equally distributed in six paddocks (17 steers/paddock) following a completely randomized design in a 2x3 factorial arrangement, being the factors two nutritional plans: mineral-proteic supplementation (Fosbovi® Proteico 30; PS) offered at 0,1% BW or mineral-protein-energetic supplementation (Fosbovi® Proteico-Energético 25; PES) offered at 0.3% BW); and three levels of enzymatic carbohydrases blend (0, 4,75 or 9,50 g/animal/day). The enzymatic blend was mainly composed by beta-glucanase and xylanase enzymes (Ronozyme® VP and Ronozyme® WX); Both enzymes and supplemented were provided by DSM Nutritional Products Brasil S.A. Supplement intake and animal weighting were carried out daily and individually by an automatic scale system installed in each paddock. Data were analyzed using PROC MIXED of SAS and means were compared by polynomial regression. Animals that received PES had greater ADG (0.896 vs. 0.775 kg/day; P < 0.001) compared to those fed PS. Intermediary level (4.75 g/day) of carbohydrate enzymes also presented the highest ADG in PES compared to 0.0 level (0.941 vs. 0.896 kg/day; P = 0.006). Still, higher enzyme levels (9.5 g/day) presented greater ADG on PS, when compared to 0.0 level (0.852 vs. 0.775 kg/day, P = 0.006). PES animals presented greater intake, compared to PS (1.112 vs. 0.432 kg/day, P < 0.001). According to polynomial regression, it is recommended to include 4.75 g/day of these carbohydrases enzymes in PS and 4.39 g/day in PES for growing Nellore bulls in rainy season.

PSII-3 Carbohydrases enzymes improve the productive performance of grazing Nellore steers fed different nutritional plans during dry season

The aim was to evaluate two nutritional plans with the addition of dosages of carbohydrases enzyme blend on productive performance of grazing Nellore bulls in dry season. A total of 102 Nellore bulls (BW = 294.10 ± 3.35 kg) were equally distributed in six paddocks (17 bulls/paddock) following a completely randomized design in a 2x3 factorial arrangement, being the factors different nutritional plans (2): mineral-proteic supplementation (PS; Fosbovi® Proteico 35) offered at 0,1% BW or mineral-protein-energetic supplementation (PES; Fosbovi® Proteico-Energético 25) offered at 0.3% BW; and levels of enzymatic carbohydrases blend (3):0,00 (control), 4,75 or 9,50 g/animal/day. The enzymatic blend was mainly composed by beta-glucanase and xylanase enzymes (Ronozyme® VP and Ronozyme® WX) and included in the supplements (both enzymes and supplements provided by DSM Nutritional Products Brasil S.A.). Supplement intake and animal weighting were carried out daily and individually by an automatic scale system installed in each paddock, thus, animal was considered the experimental unit. Data were analyzed using PROC MIXED of SAS and means were compared by polynomial regression. A quadratic effect was observed on enzyme level for ADG in both nutritional plans (P = 0.014), with intermediary dosages presenting the highest values of ADG for PS (0,283 vs. 0,188 kg/day) and PES (0.429 vs. 0.391 kg/day), over control respectively. Although no linear and quadratic enzyme effect was observed for final BW (FBW), animals supplemented with PES presented 20,06 kg higher FBW compared to PS (341,63 vs. 321,57 kg, P < 0.001). An increasing linear effect was observed for supplement intake (kg/day), for both PS and PES (P = 0.020). According the polynomial regression, it is recommended to include 4.67 g/day of carbohydrases blend in PS and 3.77 g/day in PES, being the carbohydrases blend a viable technology to grazing cattle. Moreover, mineral-protein-energetic supplementation can optimize Nellore bulls performance during dry season.

215 Supplementation with beta-carotene and vitamins improves pregnancy rate after timed-AI in beef Nellore cows grazed in pasture systems

The aim was to evaluate the effects of beta-carotene and vitamins (A, D3, E and biotin) on reproductive performance of grazing Nellore cows calving in different moments. A total of 497 multiparous cows (5.68 ± 0.11 parities) were homogeneously divided in 4 paddocks (Brachiaria brizantha spp.) according to BCS (2.8 ± 0.27), following a completely randomized design in a 2 x 2 factorial arrangement, being the factors: calving moment [CM = early October (EO; 1st-15th) or late October (LO; 16th-31st)]; and supplementation (SUP): control [(mineral supplementation, Fosbovi® Reprodução; n = 251) or vitamins (control + beta-carotene (150 mg), vitamins A (40.000IU), D3 (5.000IU), E (300 mg) and biotin (20 mg)/cow/day; n = 246)]. Mineral supplement and vitamins were daily offered for 60 days (30d before to 30d after 1st FTAI), and provided by DSM Produtos Nutricionais Brasil S.A. Cows were synchronized (1st FTAI) with a P4/E2-based FTAI protocol, and open cows were resynchronized (2nd FTAI) 30 days after the first insemination. The 1st FTAI conception rate (CR) tended to be greater for vitamins group, compared to control [64.2%(158/246) vs. 56.6%(142/251); P = 0.08], regardless of CM. The CM*SUP interaction was significant for CR at 2nd FTAI, with vitamins presenting higher CR over control in LO moment [52.1% (38/73) vs. 41.4% (24/58), P = 0.0053]. Greater cumulative CR (1st + 2nd FTAI) was observed for vitamins over control [83% (204/246) vs. 79% (198/251); P = 0,058], and for LO compared to EO [86% (157/183) vs. 78% (245/314); P = 0.01], without CM*SUP significance. The BCS was higher for the vitamins group, compared to control, at AI moment (3.00 vs. 2.81, P < 0.0001) and 30 days after AI (3.11 vs. 3.03, P < 0.0001), regardless of CM. The inclusion of beta-carotene and vitamins A, D3, E and biotin in mineral supplements is a tool to optimize reproductive performance and BCS of grazing Nellore beef cows during breeding season.

PSVII-6 Effects of 25-hydroxycholecalciferol supplementation on gene expression of feedlot cattle

The objective was to evaluate the effects of 25-hydroxycholecalciferol (HyD®, DSM Produtos Nutricionais Brasil S.A.) supplementation in expression of genes related to anabolism and catabolism of feedlot cattle. A total of 120 Nellore bulls (IBW = 370±20 kg) were distributed in 24 fully roofed-pens with concrete floor (5 animals/pen) in a randomized complete block design (8 pens/treatment). The treatments were T1 (control): no supplementation of HyD®; T2: HyD® supplementation at 1 mg/animal/day; T3: HyD® supplementation at 3 mg/animal/day. Basal diet was formulated to meet requirements of finishing bulls, considering an ADG of 1.6 kg/day (Level 2 Nutrition System, Fox et al., 2004). Adaptation to diets followed a step-up scheme for 14 days, with concentrate inclusion being gradually increased from 76 to 91% DM. Finishing diets were offered from 15th to 100th day of feedlot period and animals fed twice a day (0800 and 1500), with bunks managed for a maximum of 5% orts. After slaughter, muscle samples were collected for quantitative evaluation of gene expression using RT-qPCR method, considering the following genes: SOD1 (antioxidant marker), IGF1, IGF2 and MTOR (anabolism), FOXO1, MURF1, Atrogin-1 and MSTN (catabolism). Statistical analysis was performed using PROC MIXED of SAS® and means compared by Tukey test at 5% probability. No significant differences among treatments were observed for SOD1, FOXO1, MURF1 and Atrogin-1 expression (P >0.05). However, tendencies (0.05 > P ≤0.10) could be observed for IGF1, IGF2, MTOR and MSTN expression in animals receiving HyD®, regardless of dosage. These results indicate a positive effect of HyD® on muscular anabolism and protein synthesis on feedlot finishing cattle. Moreover, the greater expression on MSTN suggest a higher protein turnover and muscular growth regulation. In conclusion, HyD® supplementation increased expression of genes correlated to muscular growth and protein synthesis, being a viable technology for beef cattle finished in feedlot systems.

391 Effects of increasing carbohydrases levels on productive performance of beef cattle fed feedlot finishing diets

Our objective was to evaluate the effects of feeding increasing exogenous carbohydrases levels on cattleˈ performance, when fed a 90-d feedlot finishing diet. A total of 240 Nellore bulls (IBW = 389 ± 27 kg) were distributed in 24 pens (10 animals/pen), in a randomized complete block design (6 pens/treatment). The basal diet was composed by 15% sugarcane bagasse, 72.8% ground corn, 7.6% soybean meal and 4.6 % mineral-vitamin premix (DM basis). The treatments were: 1) control: No addition of carbohydrases blend; 2) Blend1, in g/animal/d: 1 g of Ronozyme® WX (xylanase) + 3.75 g of Ronzyme® VP (beta-glucanase); 3) Blend2, in g/animal/d: 2 g of Ronozyme® WX + 7.5 g of Ronzyme® VP and 4) Blend3, in g/animal/d: 4 g of Ronozyme® WX + 15 g of Ronzyme® VP. The animals were fed once a day and had free access to fresh water. Statistical analysis was performed using the MIXED procedure of SAS 9.4, and comparisons were performed out by orthogonal contrasts, which compared the control and treatments, and the linear and quadratic effects of the increasing carbohydrases levels. Statistical significance was declared at P < 0.05, and tendencies considered when 0.05 < P < 0.10. Animals fed carbohydrases had greater (P = 0.045) ADG (1.59 vs. 1.51 kg/d) and tended to have greater (P = 0.069) final BW (533.4 vs. 527.7 kg) compared with control; although no difference were observed on these variables among carbohydrases levels. Feeding carbohydrases increased DM intake, expressed either as kg/d (10.17 vs. 9.92; P = 0.019) and as percentage of BW (2.20 vs. 2.16 %; P = 0.038), compared to control group, respectively. However, no difference was observed among treatments on G:F, and dressing percentage. In conclusion, the addition of carbohydrases blend can improve performance of finishing cattle.

PSIX-40 Exogenous carbohydrases improve carcass characteristics of Nellore beef cattle grazed in tropical conditions

The objective was to evaluate the effects of feeding levels of an exogenous carbohydrases blend on performance and carcass characteristics of grazing Nellore beef cattle. A total of 168 bulls were distributed to twenty Brachiaria brizantha cv. Xaraés paddocks (8 or 10 animals/paddock) in a randomized complete block design, with five replicates (paddocks) per treatment. Bulls were assigned according initial BW (IBW; 369.07±21.13 kg) to receive treatments for 231 days: 1) Control (basal mineral-protein-energetic supplement, no enzyme; PES), Carb1 (PES + 0.83 g of xylanase, RONOZYME® WX; and 3.09 g of beta-glucanase, RONOZYME® VP, both offered/kg PES), Carb2 (PES + 1.65 g of xylanase and 6.18 g of beta-glucanase/kg PES) and Carb3 (PES + 3.30 g of xylanase and 12.38 g of beta-glucanase/kg PES). Evaluated parameters were final BW (FBW), average daily gain (ADG), supplement intake, hot carcass weight (HCW) and dressing %. IBW and FBW were measured after a 12-hour fastening period. Treatments were offered daily in covered group feeders located in each paddock. Animals had free access to supplements and water. Supplements and enzymes were provided by DSM Nutritional Products. Data were analyzed using MIXED procedure of SAS® 9.3, being each paddock the experimental unit. Orthogonal contrasts were used to detect linear and quadratic effects on enzyme levels, with values P ≤ 0.05 considered significant. No linear or quadratic effects (P > 0.05) were observed on supplement intake (2.11 kg/animal/d), FBW (492.03 kg) and ADG (0.532 kg/day). However, a quadratic effect was observed for HCW and dressing %, with animals fed Carb1 presenting 5.69 kg heavier carcass (272.67 vs. 266.98; P = 0.039) and 1.4 p.p. higher dressing % (55.3% vs. 53.9%, P < 0.001) compared with control group. In conclusion, to use carbohydrases enzyme blend improves carcass characteristics and is an interesting technology for Nellore beef cattle grazed in tropical conditions.

PSXII-30 The combination of essential oils and exogenous amylases reduces fecal starch of feedlot finishing cattle fed different roughage sources

Eighty-eight feedlot finishing Nellore bulls (358 ± 38.5 kg BW) were used in a randomized block design (initial BW) with a 2×2 factorial arrangement to test the effects of two feed additives (MON - Sodium Monensin, 26 mg/kg DM vs. Crina®RumistarTM - combination of blend of essential oils - 90 mg/kg DM + exogenous α-amylase - 560 mg/ kg DM; DSM Produtos Nutricionais Brasil S.A.) and two roughage sources (CS - corn silage vs. SB - sugarcane bagasse) on fecal starch. Animals were adapted to the high grain diets, starting with 20% of physically effective NDF of each roughage source, and gradually decreased to 10% after 20-d. Final diets contained 19.5% CS or 12% SB, corn grain (70.7 and 78.2% for CS and SB diets, respectively), 5.5% soybean meal, 4% mineral and vitamin mixture and 0.3% urea, on DM basis. Feed intake was daily recorded individually during 104 days using individual pens or Calan-gate system. To determine fecal starch concentration, feces from each animal were sampled on days 0, 58 and 85-d of the feeding period. Data were analyzed using the Mixed procedure of SAS considering roughage source, feed additives and interaction as fixed and block as random effects. No interaction between feed additives and roughage sources was observed. Animals fed CS had 20% higher DMI (P < 0.0001) than those fed SB, but roughage sources not affected (P = 0.15) fecal starch concentration. Diets containing different additives did not affect DMI (P = 0.17); however, animals fed Crina®RumistarTM had 21% lower fecal starch concentration (15.9 vs. 21.1 %DM; P = 0.01) than animals fed MON, respectively. Therefore, supplementation with Crina®RumistarTM is an effective substitute of monensin in finishing cattle fed high concentration diets regardless of roughage source, improving the use of starch by the animals and reducing its excretion, reflecting on a lower environmental impact.

386 Effect of essential oil and exogenous enzyme on feed intake, digestibility and rumen fermentation of finishing cattle fed different roughage sources

Eight rumen-cannulated Nellore steers (327 ± 30 Kg BW) were used in a 4x4 duplicate Latin square to evaluate the effects of two feed additives (MON - Sodium Monensin 26 mg/kg DM vs. Crina® RumistarTM - combination of blend of essential oils - 90 mg/kg DM + exogenous α-amylase - 560 mg/kg DM, respectively; DSM Produtos Nutricionais Brasil S.A.) and two roughage sources at 10% of peNDF (CS - corn silage vs SB - sugarcane bagasse, on DM basis). Final diets contained 19.5% CS or 12% SB, corn grain (70.7 and 78.2% for CS and SB diets, respectively), 5.5% soybean meal, 4% mineral-vitamin mixture and 0.3% urea, on DM basis. The experimental periods had 14-d for adaptation and 5-d of collections. Data were analyzed with PROC MIXED of SAS and means compared by Tukey test. No interaction between additives and roughage sources was observed. Animals fed Crina® RumistarTM had 0.600 kg increase (P = 0.03) on DM intake and decreased (P = 0.01) apparent crude protein digestibility (CP; 75.3 vs. 77.5%, respectively) compared to MON. Animals fed SB presented greater apparent CP digestibility (77.6 vs 75.2%, respectively; P = 0.003) compared to CS. No difference in apparent NDF digestibility for additives and roughage source was observed. Animals fed Crina® RumistarTM had lower acetate concentration (P = 0.01) compared to MON on time 9, 12, 15, 18 and 21 hours. Animals fed CS had higher acetate:propionate (P = 0.03) compared to SB at all collection times–24 hours. Ruminal ammonia-nitrogen was lower (P = 0.01) in animals fed Crina® RumistarTM compared to MON. To use Crina® RumistarTM increased DM intake and decreased ruminal ammonia-nitrogen compared to monensin, suggesting a higher CP by-passing the rumen. Crina® RumistarTM increased DM intake without negative impacts on nutrients digestibility, regardless roughage source, thus a higher amount of nutrients reaches the intestine to be absorbed and animal performance can be increased.

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