Feeding 3-nitrooxypropanol reduces methane emissions by feedlot cattle on tropical conditions

Our objective was to evaluate the effects of feeding 3-nitrooxypropanol (3-NOP; Bovaer, DSM Nutritional Products) at two levels on methane emissions, nitrogen balance, and performance by feedlot cattle. In experiment 1, a total of 138 Nellore bulls (initial body weight, 360 ± 37.3 kg) were housed in pens (27 pens with either 4 or 5 bulls per pen) and fed a high-concentrate diet for 96 d, containing 1) no addition of 3-NOP (control), 2) inclusion of 3-NOP at 100 mg/kg dry matter (DM), and 3) inclusion of 3-NOP at 150 mg/kg DM. No adverse effects of 3-NOP were observed on DM intake (DMI), animal performance, and gain:feed (P > 0.05). In addition, there was no effect (P > 0.05) of 3-NOP on carcass characteristics (subcutaneous fat thickness and rib eye area). In experiment 2, 24 bulls (initial BW, 366 ± 39.6 kg) housed in 12 pens (2 bulls/pen) from experiment 1 were used for CH4 measurements and nitrogen balance. Irrespective of the level, 3-NOP consistently decreased (P < 0.001) animals' CH4 emissions (g/d; ~49.3%), CH4 yield (CH4/DMI; ~40.7%) and CH4 intensity (CH4/average daily gain; ~38.6%). Moreover, 3-NOP significantly reduced the gross energy intake lost as CH4 by 42.5% (P < 0.001). The N retention: N intake ratio was not affected by 3-NOP (P = 0.19). We conclude that feeding 3-NOP is an effective strategy to reduce methane emissions, with no impairment on feedlot cattle performance.

Feedlot performance, rumen and cecum morphometrics of Nellore cattle fed increasing levels of diet starch containing a blend of essential oils and amylase or monensin

Feed additives used in finishing diets improve energy efficiency in ruminal fermentation, resulting in increased animal performance. However, there is no report evaluating the effect of BEO associated with exogenous α-amylase in response to increased starch content in feedlot diets. Our objective was to evaluate increasing levels of starch in the diet associated with a blend of essential oils plus amylase or sodium Monensin on performance, carcass characteristics, and ruminal and cecal morphometry of feedlot cattle. 210 Nellore bulls were used (initial body weight of 375 ± 13.25), where they were blocked and randomly allocated in 30 pens. The experiment was designed in completely randomized blocks in a 3 × 2 factorial arrangement: three starch levels (25, 35, and 45%), and two additives: a blend of essential oils plus α-amylase (BEO, 90 and 560 mg/kg of DM, respectively) or sodium Monensin (MON, 26 mg/kg DM). The animals were fed once a day at 08:00 ad libitum and underwent an adaptation period of 14 days. The diets consisted of sugarcane bagasse, ground corn, soybean hulls, cottonseed, soybean meal, mineral-vitamin core, and additives. The animals fed BEO35 had higher dry matter intake (P = 0.02) and daily weight gain (P = 0.02). The MON treatment improved feed efficiency (P = 0.02). The treatments BEO35 and BEO45 increased hot carcass weight (P < 0.01). Animals fed BEO presented greater carcass yield (P = 0.01), carcass gain (P < 0.01), rib eye area gain (P = 0.01), and final rib eye area (P = 0.02) when compared to MON. The MON25 treatment improved carcass gain efficiency (P = 0.01), final marbling (P = 0.04), and final subcutaneous fat thickness (P < 0.01). The use of MON reduced the fecal starch% (P < 0.01). Cattle-fed BEO increased rumen absorptive surface area (P = 0.05) and % ASA papilla area (P < 0.01). The MON treatment reduced the cecum lesions score (P = 0.02). Therefore, the use of BEO with 35 and 45% starch increases carcass production with similar biological efficiency as MON; and animals consuming MON25 improve feed efficiency and reduce lesions in the rumen and cecum.

Effects of feeding 25-hydroxyvitamin D3 with an acidogenic diet during the prepartum period in dairy cows: Mineral metabolism, energy balance, and lactation performance of Holstein dairy cows

Our objective was to determine the effects of feeding 25-hydroxyvitamin D₃ [25(OH)D₃], or vitamin D₃ (cholecalciferol) on plasma, mineral, and metabolite concentrations, mineral balance, mineral excretion, rumination, energy balance, and milk production of dairy cows. We hypothesized that supplementing 3 mg/d of 25(OH)D₃ during the prepartum period would be more effective than supplementing vitamin D₃ at the National Research Council (2001) levels to minimize calcium imbalance during the transition period and improve milk production of dairy cows. Forty multiparous, pregnant nonlactating-Holstein cows were enrolled in this study. Body weight, body condition score, parity, and milk yield in the previous lactation (mean ± standard deviation) were 661 ± 59.2, 3.46 ± 0.35, 1.79 ± 0.87, and 33.2 ± 6.43 kg/d, respectively. Cows were enrolled into the blocks (n = 20 for each treatment) at 30 d of the expected day of calving to receive an acidogenic diet (373 g/kg of neutral detergent fiber and 136 g/kg of crude protein, dry matter basis; -110 mEq/kg) associated with the treatments: (1) control (CTRL), vitamin D₃ at 0.625 mg/d (equivalent to 25,000 IU of vitamin D₃/d) or (2) 25(OH)D₃ at 3 mg/d (equivalent to 120,000 IU of vitamin D₃/d). All cows were fed with the base ration for 49 d after calving. Blood samples were taken on d 7, 0, 1, 2, 21, and 42, relative to calving. No effect of treatment was observed for prepartum dry matter intake or body condition score. A trend for increase of ionized Ca was observed for the cows fed 25(OH)D₃, compared with the CTRL, but no effect of treatment was detected for total Ca or total P. Feeding 25(OH)D₃ increased colostrum yield. The plasmatic concentration of 25-hydroxyvitamin D₃ was increased with 25(OH)D₃ supplementation. 25-Hydroxyvitamin D₃ supplementation increased plasma glucose concentration at parturition. The postpartum dry matter intake was not influenced by treatments. Feeding 25(OH)D₃ increases milk yield, 3.5% fat-corrected milk, and energy-corrected milk and improves milk yield components in early lactation. Overall, these findings suggest that 25(OH)D₃ at 3 mg/d can improve the energy metabolism and lactation performance, compared with the current-feeding practice of supplementing vitamin D₃ at 0.625 mg/d.

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 &lt; 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 &lt; 0.01), FBW (PSE = 302.5 vs. PSM = 282.6 and PS = 271.7 kg; P &lt; 0.01) and supplement intake (PSE = 1.640 vs. PSM = 0.190 and PS = 0.210 kg/day; P &lt; 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 &gt; 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 &lt; 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 &lt; 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 &lt; 0.0001), to the water fountains (2.95 vs. 2.32 visits/day; P &lt; 0.0001) and greater water intake (22.43 vs. 17.73 L/day; P &lt; 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 &lt; 0.0001) and water (203 vs. 153 seconds/visit; P &lt; 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.

299 Combination of Essential Oils, α-amylase and 25-hydroxy-vitamin-d3 Increases Carcass Production by feedlot Cattle

Our objective was to evaluate the effects of associating feed additives on feedlot performance of Nellore bulls. One hundred and sixtieth Nellore bulls (iBW, 380± 5.8 kg; age, 18 mo) were allocated in 20 pens (n = 8/pen), in a completely randomized block design, according to the treatments: 1) MON+VM - Sodium Monensin (MON, 25 mg/kg DM, Elanco Animal Health, Indianapolis, IN), + Virginiamycin (VM, 30 mg/kg DM, Phibro Animal Health Corporation, Guarulhos, São Paulo), and 2) CRD - Crina® RumistarTM + HyD® - a blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM + 25-hydroxy-vitamin-D3 at 1 mg/animal/d (DSM Nutritional Products, Basel, Switzerland). The initial BW was utilized as a criterion for block formation. Pens were considered experimental units (10 pens per treatment). Animals were adapted to the diets during 14 days with gradually increasing concentrate level from 70% to 86% of diet DM, and fed for 90 days. Weight assessments were performed at day 0 and 90 after 14h fasting. Data were analyzed using PROC MIXED of SAS and means were separated using the PDIFF statement, adopting P &lt; 0.05. Feeding CRD increased the DMI (12.13 kg vs. 10.52 kg, P &lt; 0.01), ADG (1.86 vs. 1.63 kg/d, P &lt; 0.01) and final BW (542 vs. 521 kg, P &lt; 0.01) compared to animals fed MON+VM. In addition, feeding CRD increased final HCW in 15 kg (311 vs. 296 kg; P &lt; 0.01), carcass ADG in 0,16 kg/d (1.31 vs. 1.15 kg/d; P &lt; 0.01) and dressing percentage in 0.48 percent points (57.34 vs. 56.86%; P &lt; 0.01) compared to MON+VM. The G:F (0.155, P = 0.53) and biological efficiency (137.9 kg DM/15 kg carcass, P = 0.87) were similar among treatments. Therefore, the inclusion of Crina® RumistarTM +HyD® can be used as a tool to increase carcass gain of feedlot finishing cattle.

300 Effects of Associating Feed Additives on Rumen Ph Dynamics by Feedlot Cattle Fed a High-concentrate Diet

Our objective was to evaluate the effects of feed additives on ruminal pH of finishing cattle fed a 90%-concentrate diet. Twenty four 18-mo Angus-Nellore crossbred bulls (IBW, 456 ± 6,5 kg) were allocated in a completely randomized design to three treatments with eight replicates each, as follows: 1) Control (MON) - Sodium Monensin (26 mg/kg DM, Rumensin, Elanco Animal Health); 2) Crina® RumistarTM (CR) - a blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM) and 3) CR + HyD® (25-hydroxy-vitamin-D3 at 1 mg/animal/d, CRD, DSM Nutritional Products). The ruminal pH and temperature was monitored individually for 98 days, using a wireless bolus, (SmaXtec Animal Care, Austria). Data were analyzed using the Mixed procedure of SAS and means comparison evaluated by Tukey test at P&lt; 0.05. During adaptation period (i.e. first 14 days), bulls fed CR and CRD had increased rumen mean pH (6.40 and 6.36 vs. 6.16; P &lt; 0.01) and minimum pH (5.89 and 5.87 vs. 5.57; P &lt; 0.01) than bulls fed MON. In addition, rumen pH from bulls fed CR spent less time below 6.0 than bulls fed MON (256.07 vs. 452.62 min/d; P = 0.05). Regarding the total period, bulls fed MON had lower mean (6.22 vs. 6.51 and 6.42, P &lt; 0.01) and minimum rumen pH (5.60 vs. 5.92 and 5.85, P &lt; 0.01) than bulls fed CR and CRD. Additionally, feeding MON increased time duration of rumen pH (390.79 min/day, P &lt; 0.01) and had a larger area below 6.0 (81.52 min x pH units/day; P &lt; 0.01). Moreover, the addition of monensin increased pH time duration below 5.8 (161.10 vs. 121.13 and 122.56 min/day; P = 0.02) compared with CR and CRD, and increased ruminal temperature (39.60 vs. 39.51 and 39.5 °C; P &lt; 0.01). We conclude that feeding Crina® RumistarTM and Crina® RumistarTM HyD® increased the rumen pH of bulls.

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 &gt; 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 &lt; 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 &lt; 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 &lt; 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 &lt; 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.

PSXIII-3 Effects of mineral source and additive in mineral supplementation on productive performance of growing beef cattle on tropical pastures

Our objective was to evaluate the effects of mineral supplementation using the association of carboaminophosphochelates as mineral source plus Salinomycin on grazing beef cattle performance during growing phase. A total of 80 Nellore bulls (IBW = 292.72 ± 13.55 kg; Age, ~13 mo) were distributed in 8 paddocks (~2.7 hectares each) planted with Palisade Grass cv. Xaraés during the rainy to rainy-to-dry transition seasons (February to May). The experiment was a randomized complete block design (10 animals/paddock, 4 paddocks per treatment). The mineral supplementation was provided ad libitum and treatments were: Control; Mineral supplementation containing inorganic minerals, and TM+Salinomycin = Mineral supplementation containing carboaminophosphochelates (TM, Tortuga® Minerals) as minerals source (Cr, Se, Zn, Mn, S, Cu e Co) plus Salinomycin (~108 mg per animal/day). The supplement orts were removed and weighted daily to calculate supplement intake. The animals were weighed after a 14 h-fasting at the beginnig and end of the trial (84 days) to calculate weight gain. The paddock was considered the experimental unit and data were analyzed using PROC MIXED of SAS, whereby means were separated using the PDIFF statement (P &lt; 0.05). Supplement intake was similar between treatments (P = 0.13). Animals supplemented with TM+Salinomycin tended to have greater final BW (358 vs. 347, P = 0.07) and increased ADG in 22,3% (0.730 vs. 0.597 kg/d, P = 0.03) compared with animals fed Control. In conclusion, the combination of carboaminophosphochelates minerals plus salynomicin improves grazing beef cattle weight gain, with no deleterious effect on mineral supplement intake.

PSX-A-1 Late-Breaking: A fully automated system for 3D image acquisition, classification and processing for real-time monitoring growth of finishing cattle in feedlots

Computer vision has been proposed as an alternative to monitor livestock growth, for example using 3D cameras to estimate body weight and condition. However, implementing this technology outdoors and with unrestrained animals poses a great challenge, because of harsh conditions for the equipment, as well as varying lighting and animal movement. Here we propose an automated system to acquire 3D images of individual animals, integrate the animal ID in the image file, and process images. This comprises a fundamental step for implementing a real-time assessment tool of growth of animals grouped in pens, to aid optimal feed management and marketing decision. The study comprised 50 beef cattle of Nellore breed during a finishing phase at DSM Innovation and Applied Center, in Brazil. Animals were tagged with RFID eartags, and 5 Intel RealSense D435 cameras were installed on the top of the water sources in each pen. For each animal approaching the water tank, an RFID antenna read the animal ID and triggered the camera to acquire a top-down view image. Images were then sent to a central computer using Wi-Fi, and later to the cloud. A decision tree algorithm was trained to sort images as usable or unusable, where the retained images had one single animal on the frame, with full body and relatively straight position. Selected frames were then processed using a threshold Otsu’s method to segment the animal body and obtain the necessary biological features, including body length, multiple width and height values, body area and volume. A total of 16,000+ images were collected, from which 3,100 were deemed usable. The algorithm successfully extracted the animal body from each image and obtained the biological features (cross-correlation values above 0.90). The proposed system was demonstrated to be extremely promising and the next stage of the study will be devoted to individual body weight prediction.

Increasing doses of carbohydrases: Effects on rumen fermentation, nutrient digestibility, and performance of mid-lactation cows

The objective of this study was to evaluate the effects of exogenous enzymes on nutrient intake and digestibility, rumen fermentation, and productivity of mid-lactating cows. Experiment 1 was designed to test increasing doses [0, 0.5, 1.0, or 1.5 g/kg of dry matter (DM)] of a combination of 2 enzyme products with xylanase and β-glucanase activities (Ronozyme Wx and Ronozyme VP, respectively; DSM Nutritional Products) on rumen fermentation and total apparent digestibility. Enzyme combinations had a ratio of endo-1,3(4)-β-glucanase to endo-1,4-β-xylanase of 8:2 (wt/wt). For experiment 1, 8 rumen cannulated lactating cows were used into a double 4 × 4 Latin square design experiment with 14 d of diet adaptation and 7 d of sampling. Despite no differences in feed intake, carbohydrases linearly increased neutral detergent fiber digestibility. Treatments marginally affected rumen fermentation, where a linear trend for lower rumen pH and a linear trend for greater isobutyrate concentration were observed with increasing enzyme dose. A trend for lower rumen NH₃-N concentration was observed for cows receiving carbohydrases in comparison with control group. When comparing all enzyme treatments against control group, cows fed enzymes tended to produce more 3.5% fat-corrected milk (FCM), produced more milk fat, and had greater blood glucose concentration. Experiment 2 evaluated 3 doses (0, 0.5, or 0.75 g/kg of DM) of the same combination of enzyme products on performance of cows (n = 36) in a complete randomized block (n = 12) design. Cows received treatments for 9 wk. No interaction effects between treatments and time were observed for all variables assessed in this study. In agreement with experiment 1, no differences were detected for feed intake, but cows fed the enzyme products tended to produce more 3.5% FCM and milk fat compared with control. In addition, cows fed enzymes exhibited greater efficiency of FCM production (FCM ÷ DM intake) compared with control. No differences were detected for intake and productivity when comparing the 2 doses of carbohydrases. In summary, the enzyme products tested in this study may improve feed efficiency due to greater milk fat concentration.

212 Feedlot performance of Nellore bulls fed different starch levels in the diet associated with feed additives

This study, conducted at DSM Beef Center, Mato Grosso do Sul, Brazil, was designed to evaluate the effects of different starch levels in the diets associated to feed additives on performance of Nellore bulls. The experiment was designed as a completely randomized block, with a 3 x 2 factorial arrangement of treatments, in which 210 18-mo-old yearling Nellore bulls (375.8 ± 16.8 kg) were fed in 30 pens (n = 7/pen), for 90 d according to the treatments: 25% starch (Low-S) + monensin (MON, 26 mg/kg DM); 35% starch (Med-S) + monensin; 45% starch (High-S) + monensin; Low-S + Essential Oils and amylase (CR, Crina®, 90 mg/kg DM and RumistarTM, 560 mg/kg DM, DSM Nutritional products); Med-S + CR; High-S + CR. Each treatment was replicated five times. Weight assessments were performed at day 0 and 90 of the study after 14 h fasting. A significant interaction was observed for final BW (P = 0.04) and HCW (P = 0.01). Cattle fed Med-S and High-S diets containing CR had heavier carcasses than those fed Med-S + monensin (287.4 vs. 270.9 kg) and High-S + monensin (281.4 vs. 263.0 kg), respectively; however, bulls fed Low-S diets with either monensin or CR had similar HCW (P &gt; 0.05, 279.9 vs. 282.8 kg, respectively). In addition, cattle fed CR had greater dressing percentage (P &lt; 0.01; 55.4 vs. 54.6%) regardless of starch levels. An interaction was observed (P = 0.02) for ADG, in which cattle fed Med-S + CR had greater ADG (1.58 kg) than cattle fed MON across all starch levels (1.48, 1.37 and 1.28, respectively) and then those fed High-S + CR (1.48 kg/d; P &lt; 0.01). Similar responses were observed for DMI (P = 0.02). Cattle fed monensin improved G:F in 2.7% compared to those fed CR (0.150 vs. 0.146, P = 0.02). In conclusion, Crina® and RumistarTM increases carcass production of feedlot cattle fed medium and high-starch diets.

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 &lt; 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 &lt; 0.0001) and 30 days after AI (3.11 vs. 3.03, P &lt; 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.

213 Feeding essential oils and α-amylase or its association with 25-hydroxy-vitamin-D3 improves productive performance by feedlot cattle

Our objective was to evaluate the effects of associating feed additives on performance of finishing cattle when fed a high-concentrate diet for 105 days. Twenty-four Angus-Nellore crossbred bulls (iBW, 456 ± 10.04 kg; age, 18 mo) were randomly allocated to three treatments with eight replicates per treatment (animal as experimental unit). The treatments were: 1) Control (MON) - Sodium Monensin, 26 mg/kg DM; 2) Crina® RumistarTM (CR) - a blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM) and 3) CR + HyD® (25-hydroxy-vitamin-D3 at 1 mg/animal/d). The DM intake and animalsˈ weight variables were assessed individually, by using the Intergado® electronic system and the Bosch® Precision Livestock platform placed in the feedlot pen, respectively. Data were analyzed using the Mixed procedure of SAS and means comparison evaluated by Tukey test at P &lt; 0.05. The initial BW was used as a covariate when significant. Feeding CR and CR+HyD increased DMI (13.18 and 12.82 kg vs. 10.77 kg P &lt; 0.01) and tended to increase ADG (1.94, 1.92 vs. 1.68kg/d, P = 0.07) and final BW (654, 652 vs. 628 kg, P = 0.08) compared with MON. Likewise, animals fed CR and CR+HyD had greater carcass ADG (1.38, 1.41 vs. 1.14 kg/d, P &lt; 0.01), and HCW (368.53 and 371.87 vs. 344.13 kg; P &lt; 0.01) compared to MON. In addition, feeding CR+HyD increased the dressing percentage in 2.1 percent points compared with MON (57.4 vs. 55.3%; P &lt; 0.03). The G:F and the biological efficiency were similar among treatments (P = 0.50). We conclude that including Crina® RumistarTM +HyD® can be used as a tool to increase carcass production by feedlot cattle.

PSIX-2 Feeding 3-nitrooxypropanol reduces methane emissions by feedlot cattle

Our objective was to evaluate the effects of feeding 3-nitrooxypropanol (3NOP; Bovaer®, DSM Nutritional Products) at two doses on methane emissions and performance by feedlot cattle. The experiment was designed as a completely randomized block, in which 138 Nellore bulls (iBW, 360 ± 37.3 kg) were placed in collective pens (9 pens per treatment) and fed a high-concentrate diet (R:C, 11:89) according with the following three treatments: 1) 0ppm 3NOP /day; 2) 100ppm 3NOP/day, or 3) 150ppm 3NOP/day. For performance and DMI assessments the pen was the experimental unit. For methane emission evaluations, CH4 and DMI were assessed individually in 12 pens (2 bulls/pen, 8 bulls (experimental units)/treatment). Methane emission was measured for 6 consecutive days using the sulfur hexafluoride (SF6) tracer technique in two times over the experimental period (d15d -d21) and (105d to 111d), whereby the gross energy (GE) variables were calculated using equations. The individual DMI was measured using the two markers technique (Chromium oxide and indigestible NDF). The data were analyzed using the Mixed procedure of SAS and means comparison were carried out by Tukey’s test. Regardless of the level, dietary supplementation with 3NOP decreased (P &lt; 0.001) methane emissions by 49.7% as expressed as g/d (146.0 vs. ~74 g/d−1); by 38.6% when expressed as g/kg ADG (91 vs ~56 g/kg ADG), and by 40.7% when expressed as g/kg DMI (13.5 vs. ~8 g/kg DMI). Likewise, dietary supplementation with 3NOP decreased (P &lt; 0.001) the GE loss as a percentage of the GE intake by 42.4% (4.74 vs ~2.73%). However, feeding 3NOP had no effect on animalsˈ DM intake (~2.43 %BW; P = 0.23), ADG (~1.52 kg/d; P = 0.11) and HCW (~284 kg, P = 0.26). We conclude that Bovaer® can be used to effectively reduce methane emission by feedlot cattle without adverse effects on performance.

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 &gt;0.05). However, tendencies (0.05 &gt; 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 &lt; 0.05, and tendencies considered when 0.05 &lt; P &lt; 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 &gt; 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 &lt; 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 &lt; 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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Effect of selected feed additives to improve growth and health of dairy calves

The aim was to evaluate the effect of different feed additives on intake, performance, and fecal consistency index (FCI) of dairy calves from 6-60 d of age and its residual effect 15 d after weaning. Fifty Holstein calves (38 ± 1.0 kg BW) were fed 5 L/d of milk plus starter feed until weaning, and corn silage and concentrate after weaning. The treatments were: control (CON), monensin (MON; 30 mg/kg of starter), probiotic E. faecium (PROB; 70 mg/kg of starter), essential oils (EO; 300 mg/kg of starter), or PROB + EO (EOPROB). Fecal score and dry matter intake (DMI) were measured daily, and animals were weighed every 15 d. A DNA extraction from feces was performed to identify the presence of microorganisms (E. coli, Hafnia, Shiguella, Lactobacillus spp, Enterococcus spp, and Enterococcus faecium NCIMB 10415) by PCR. Two 72-h digestibility trials were performed at days 20-28 and 50-56, by total fecal collection. The DMI before weaning was greater for EO (903.0 g/d) compared with MON (794.3 g/d) and EOPROB (783.1 g/d). The FCI decreased during pre-weaning for EO and MON. Average daily gain (ADG) and feed efficiency (FE) did not differ among treatments before weaning. After weaning, DMI and FCI did not differ among treatments. The EO had greater ADG (917.5 g/d) compared with CON (615.8 g/d) and PROB (592.6 g/d). The FE improved with EO (0.72 g/g) over CON (0.36 g/g), MON (0.49 g/g), and PROB (0.36 g/g). The PCR results showed absence of E. faecium NCIMB 10415 in animals fed PROB and CON. Animals fed PROB had greater intake of CP and NDF than animals fed EOPROB. The EO can be added to the dairy calf ration to improve fecal score and increase DMI. The pre-weaning FCI decrease with MON and increase with PROB.

Feeding the combination of essential oils and exogenous α-amylase increases performance and carcass production of finishing beef cattle

Two experiments were conducted to evaluate the performance responses of finishing feedlot cattle to dietary addition of essential oils and exogenous enzymes. The treatments in each experiment consisted of (DM basis): MON-sodium monensin (26 mg/kg); BEO-a blend of essential oils (90 mg/kg); BEO+MON-a blend of essential oils plus monensin (90 mg/kg + 26 mg/kg, respectively); BEO+AM-a blend of essential oils plus exogenous α-amylase (90 mg/kg + 560 mg/kg, respectively); and BEO+AM+PRO-a blend of essential oils plus exogenous α-amylase and exogenous protease (90 mg/kg + 560 mg/kg + 840 mg/kg, respectively). Exp. 1 consisted of a 93-d finishing period using 300 Nellore bulls in a randomized complete block design. Animals fed BEO had higher DMI (P < 0.001) but similar feed efficiency to animals fed MON (P ≥ 0.98). Compared with MON, the combination of BEO+AM resulted in 810 g greater DMI (P = 0.001), 190 g greater average daily gain (P = 0.04), 18 kg heavier final body weight (P = 0.04), and 12 kg heavier hot carcass weight (P = 0.02), although feed efficiency was not significantly different between BEO+AM and MON (P = 0.89). Combining BEO+MON tended to decrease hot carcass weight compared with BEO alone (P = 0.08) but not compared with MON (P = 0.98). Treatments did not impact observed dietary net energy values (P ≥ 0.74) or the observed:expected net energy ratio (P ≥ 0.11). In Exp. 2, five ruminally cannulated Nellore steers were used to evaluate intake, apparent total tract digestibility of nutrients, and ruminal parameters in a 5 × 5 Latin square design. Feeding BEO increased the total tract digestibility of CP compared to MON (P = 0.03). Compared to MON, feeding the combination of BEO+MON increased the intake of CP (P = 0.04) and NDF (P = 0.05), with no effects on total tract digestibility of nutrients (P ≥ 0.56), except for a tendency (P = 0.09) to increase CP digestibility. Intakes of all nutrients measured, except for ether extract (P = 0.16) were greater in animals fed BEO+AM when compared with MON (P ≤ 0.03), with no differences on total tract nutrient digestibilities (P ≥ 0.11) between these two treatments. In summary, diets containing the BEO used herein enhanced DMI of growing-finishing feedlot cattle compared with a basal diet containing MON without impair feed efficiency. A synergism between BEO and AM was detected, further increasing cattle performance and carcass production compared to MON.