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The effects of doses CTL (0 mg), 30, 300 and 3000 mg/L of extracts from Stryphnodendron adstringens (Mart.) Coville (SA), Lafoensia pacari A. St.-Hil (LP), Copaifera spp. (CO) and Pterodon emarginatus Vogel (PE) on ruminal fermentation were investigated in eight experiments conducted in randomized complete block designs. The in vitro system contained four fermentation vessels. Each treatment was allocated in one vessel in each run. Incubation was run four and five times with diets 50:50 and 10:90 (roughage to concentrate ratio) respectively. Incubation vessel was the experimental unit, and each incubation run was a block. All plant extracts negatively affected DM degradation at 3000 mg/L. In diet 50:50, SA-3000 increased the molar proportion of propionate (p 0.05). In diet 10:90, SA-300 reduced (p < 0.001) NH3 -N and total volatile fatty acids (VFA); LP-30 increased (p < 0.05) total VFA (85 vs. 63 mM for LP-30 and CTL, respectively), molar proportions of acetate and propionate, and had lower C2 :C3 than CTL (3.6 vs. 4.3, respectively); CO-300 decreased acetate and increased propionate, reducing C2 :C3 (p < 0.001; 2.8 vs. 3.6 for CO-300 and average of other doses, respectively); PE-30 and PE-300 reduced NH3 -N by 14% and increased total VFA by 29% compared with CTL (p < 0.05). Further in vivo investigations may consider L. pacari (LP-30), Copaifera spp. (CO-300) oleoresin and P. emarginatus oleoresin (PE-30 and PE-300) in diets with high inclusion of concentrate.

A meta-analytic study was conducted to develop and evaluate models for the prediction of pasture dry matter intake (DMIpasture) by beef cattle in tropical conditions. 804 individual observations of DMIpasture were used, taken from 23 studies through analysis of mixed models, including the study as a random effect. To evaluate the accuracy and precision of the new models proposed as well as for the models of Azevedo et al., (2016) and Minson and McDonald (1987), an independent databank with 87 means from treatments of 21 experiments (n = 888 animals) was used. Three prediction models were adjusted: Model I (Animal Information), Model II (Animal Information + Supplement) and Model III (Animal Information + Supplement + Pasture). The proposed models presented similarity for the average square root of the prediction error. The inclusion of the predictive variables for supplementation (supplement dry matter intake - DMIsupplement - % of the body weight and crude protein intake through supplement) with the variables for the animal (BW0,75 and average daily gain) and of the pasture (% of crude protein) in Model III improves accuracy and precision and provides higher determination and correlation coefficients, and agreement than the other proposed models. Similarly, it was found to be more accurate and precise than the equations of Azevedo et al., (2016) and Minson and McDonald (1987), which presented lower precision and accuracy than the proposed models. The DMIpasture for beef cattle in tropical conditions is more accurate and precise when the information for the animal, supplement and pasture is included.

This study aimed to evaluate the effect of probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079) supplementation during feedlot adaptation period on performance of Nellore bulls. One-hundred ninety-eight Nellore bulls were used in a completely randomized block design, divided in 22 pens (9 animals/pen). Treatments were: CON – adaptation diet and finishing diet comprised of basal diet (with 28 ppm of monensin); and SCB – same diets as for the previous treatment with monensin plus probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079, ProTernative® 20; Lallemand Animal Nutrition at a dose of 1.0 x 10e10 cfu/animal/d) supplementation. Supplementation was offered for the first 42 days (21 days in the step-up phase and 21 days in the finishing diet with 900 g concentrate/kg DM), then both treatments were fed the same basal diet for another 76d, reaching 118 days in total. Pen was considered the experimental unit and data were analyzed using the MIXED procedure of SAS with Tukey test at 5% significance level. Final carcass weight was 1.69% greater for animals fed SCB (283.8 vs. 288.7 kg, P = 0.04). Total carcass weight gain (111.0 vs. 114.8 kg) and daily carcass weight gain (0.924 vs. 0.956 kg) tended (P = 0.06) to increase by 3.46% in SCB-fed animals compared to the CON ones. Gain yield (P = 0.39), biological efficiency (P = 0.35) and carcass yield (P = 0.71) did not differ between treatments. Probiotic supplementation with live yeast during the first 42 days in feedlot helped Nellore bulls optimize early on growth performance with an interesting carry-over effect on carcass gain through the total feedlot time.

The objective of this study was to determine the correlation between ingestive behaviour, apparent digestibility and residual feed intake (RFI) of finishing Nellore bulls fed a high concentrate diet. One hundred and twenty Nellore bulls, housed in individual pens, were evaluated in individual performance tests. The animals were fed a high concentrate diet (23:77roughage/concentrate ratio). The animals were classified as: low RFI, medium RFI, and high RFI. Data from ten animals from each group was used. Faecal production and nutrient digestibility were calculated using indigestible neutral detergent fiber as an internal marker. The feeding behaviour was evaluated over twenty-four hours by direct observation every five minutes. The most efficient animals (low RFI, 8.58 kg DM/day) consumed 27.62% less feed than the least efficient animals (high RFI, 10.95 kg DM/day). Animals with medium efficiency (mean RFI, 9.49 kg DM/day) consumed 15.39% less than high RFI. Nutrient digestibility coefficients were similar except for ether extract (P0.05). Animals spent, on average, three hours twenty-eight minutes feeding, seven hours thirty-two minutes ruminating and thirteen hours forty minutes in idle time. In the present study, ingestive behaviour and dry matter digestibility were not responsible for between-animal variation in residual feed intake in Nellore bulls fed a high concentrate diet.

Two experiments were conducted to evaluate the effects of feed additives [monensin (MON); 30 mg/kg of dry matter (DM), and virginiamycin (VM); 25 mg/kg DM] and grain adaptation programs [adding roughage (ROU; sugarcane bagasse) or not (NO-ROU) during the 20-d adaptation period] on performance, carcass characteristics, and nutrient digestibility of Bos indicus cattle fed finishing diets containing 85% whole shelled corn and 15% of a pelleted protein-mineral-vitamin supplement. In Exp.1, 105 Nellore bulls [initial body weight (BW) = 368 ± 25 kg] were used in a complete randomized block design with a 2 × 2 factorial arrangement of treatments, consisting of two feed additives (MON and VM) associated with two adaptation programs (ROU or NO-ROU during the 20-d adaptation period). Effects of feed additives × adaptation programs were not detected (P ≥ 0.13). Feed additives did not affect dry matter intake (DMI), average daily gain (ADG), and feed efficiency (G:F) during the 20-d adaptation period (P ≥ 0.35). During the total feeding period (105 d), feeding MON decreased DMI (P ≤ 0.03) compared to VM. Adding sugarcane bagasse to finishing diets during the 20-d adaptation period (ROU) increased ADG (P = 0.05) and G:F (P = 0.03), and tended to increase BW (P = 0.09) compared to NO-ROU. In Exp. 2, 10 ruminally cannulated Nellore steers (BW = 268 ± 38 kg) were used in a completely randomized design to evaluate the effects of the two feed additives used in the Exp. 1 (MON and VM; 5 steers/treatment) on DMI, total apparent digestibility of nutrients, and ruminal fermentation characteristics. No differences in DMI, total tract apparent digestibility of nutrients, and ruminal fermentation characteristics were observed between MON and VM (P ≥ 0.32). An effect of sampling day (P < 0.001) was observed for ruminal pH, which was greater on day 0 compared to day 7, 14, and 21 of the experimental period (P ≤ 0.05). In summary, supplementing monensin and virginiamycin for finishing Nellore bulls fed whole shelled corn diets, resulted in similar growth performance and carcass characteristics. Including sugarcane bagasse to adapt finishing bulls to no-roughage diets containing whole shelled corn is an alternative to increase growth performance.

This study aimed to evaluate the effect of probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079) supplementation during feedlot adaptation period on performance of Nellore bulls. One-hundred ninety-eight Nellore bulls were used in a completely randomized block design, divided in 22 pens (9 animals/pen). Treatments were: CON – adaptation diet and finishing diet comprised of basal diet (with 28 ppm of monensin); and SCB – same diets as for the previous treatment with monensin plus probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079, ProTernative® 20; Lallemand Animal Nutrition at a dose of 1.0 x 10e10 cfu/animal/d) supplementation. Supplementation was offered for the first 42 days (21 days in the step-up phase and 21 days in the finishing diet with 900 g concentrate/kg DM), then both treatments were fed the same basal diet for another 76d, reaching 118 days in total. Pen was considered the experimental unit. Growth data were analyzed using the MIXED procedure of SAS with Tukey test at 5% significance level, and a linear regression analysis was performed for the dry matter intake (DMI) data. During the first 42 days, average DMI did not differ; however, bulls fed SCB plateaued the curve of at 9.17 kg DMI/d earlier (39 days, R2 = 0.97) than those fed CON (43 days; R2 = 0.96) diets. Final body weight (509.5 vs. 518.0 kg, P = 0.02), total body weight gain (163.7 vs. 170.3 kg, P = 0.01) and average body weight daily gain (1.366 vs. 1.420 kg, P = 0.01) were greater for SCB-fed bulls. Feed efficiency of SCB-supplemented bulls was 8.05% greater than CON (P = 0.04). Probiotic supplementation with live yeast Saccharomyces cerevisiae boulardii CNCM I-1079 during the first 42 days in feedlot contributes to reaching the plateau of DMI curve earlier and improving overall performance of Nellore bulls during the total period.

The objective of this work was to evaluate the potential of livestock intensification in Brazil. Beef cattle stocking rates were estimated according to agricultural census data on livestock production in Brazilian municipalities. Pasture carrying capacity was obtained by combining moderate resolution imaging spectroradiometer (Modis) images of gross primary productivity and data on dry matter demand per animal unit (AU). Cattle stocking rate for Brazil, in 2014/2015, was 0.97 AU ha-1, and the carrying capacity was 3.60 AU ha-1; therefore, there is an average livestock intensification potential of 2.63 AU ha-1. The highest average intensification potential was observed for the Southern region (3.62 AU ha-1), and the lowest for the Northern (2.13 AU ha-1) and Northeastern regions (2.22 AU ha-1). It is possible to estimate cattle stocking rate, pasture carrying capacity, and potential of livestock intensification by integrating data on agricultural census and remote sensing.

This study evaluated the effects of monensin source on performance and carcass characteristics of Nellore bulls offered a high-concentrate diet during the finishing phase. On d 0 of the study, 240 Nellore bulls (initial BW = 363.2 ± 40.9 kg) were ranked and blocked according to initial BW, whereas within blocks animals were allotted into pens and randomly assigned into 1 of 3 treatments: 1) no ionophore feeding (CONT), 2) CONT diet plus 28 ppm (mg/kg DM) of monensin sodium-A (Rumensin ™ -200; Elanco Animal Health), and 3) CONT diet plus 28 ppm monensin sodium-B (generic). The experimental period lasted 104 d and was divided into a 21-d adaptation period and an 83-d finishing phase. During the adaptation phase, both monensin sources increased (P ≤ 0.01) BW change, ADG, and F:G ratio, reducing the DMI variation (P = 0.02). When the entire experimental period was evaluated, no treatment effects were detected (P ≥ 0.26) on final BW, BW change, total DMI, DMI as % BW, and ADG. Nonetheless, DMI variation was reduced as monensin was included in the diet (P = 0.01) and, as expected, only MON-A improved the efficiency of the animals by reducing the F:G ratio (P = 0.05) compared with CONT and by reducing (P = 0.05) the biological efficiency when compared with the MON-B group. Additionally, carcass ADG tended (P = 0.10) to be greater for MON-A compared with MON-B, no other differences in the carcass characteristics were observed (P ≥ 0.53). In summary, monensin feeding reduced DMI variation in the feedlot, but the source of monensin is important for the feedlot scenario, given that only MON-A significantly benefited the performance during the finishing phase of Nellore bulls offered a high-concentrate diet.

Arachis pintoi, commonly known as forage peanut, is a leguminous plant with good forage yield and nutritional quality adapted to the Brazilian environmental conditions and used in grass/legume pastures or preserved as silage or hay. In this study, we evaluated the nutritional value and dry matter losses of silages produced with different proportions of forage peanutcv. BRS Mandobi and elephant grass. Five levels of substitution of elephant grass (0, 25, 50, 75, and 100%, fresh matter basis) for the legume were tested in a completely randomized design with four replicates. The fiber components of the silages, except lignin, decreased with higher levels of forage peanut. Crude protein content and in vitro dry matter digestibility presented maximum values of 16.9% and 62.5%, increasing by 0.07 and 0.15 units with every 1% of the legume added to the silage, respectively. Silage pH rose from 3.8 to 5.4, although gas and effluent losses had estimated reductions of 0.01 and 0.66 units for each additional unit of the legume. Silages composed of elephant grass and more than 50% forage peanut improve the nutritional value of the feed and increase dry matter recovery of the ensiled forage mass. Silages with these proportions of forage peanut have high protein and low fiber contents.

This study addressed the dose-response effect of an encapsulated nitrate product (ENP) replacing soybean meal (SBM) in the finishing period (87-d) of feedlot bulls. One hundred twenty Nellore bulls (340 ± 28 kg of body weight, BW; mean ± SD) were allotted to 20 outdoor pens (6 animals/pen) and assigned to a randomized complete block design with 5 blocks based on initial BW and 4 dietary treatments: SBM, as control; ENP-10, 10 g ENP/kg dry matter (DM; 6.5 g NO3−/kg DM); ENP-20, 20 g ENP/kg DM (13 g NO3−/kg DM); and ENP-30, 30 g ENP/kg DM (19.5 g NO3−/kg DM). Finishing diets (90:10 concentrate to roughage ratio) were formulated to provide similar amounts of nutrients. Animals were gradually and simultaneously adapted over 14 d to ENP and concentrate. Dry matter intake (DMI) reduced linearly (from 9.6 to 8.4 kg/d; P = 0.02) with ENP inclusion. Final BW, average daily gain (ADG), carcass ADG, hot carcass weight, dressing percentage, and fat thickness were not affected (P ≥ 0.12) by treatments. There was a quadratic trend for increased carcass gain:feed (0.121, 0.130, 0.128, 0.127, respectively; P = 0.07). Nitrate concentration in meat increased linearly (3.48, 2.73, 3.98, 6.59 mg NaNO3/kg meat; P = 0.02) with ENP addition, although nitrite was not detected. Time spent eating (min/d) was similar (P ≥ 0.16) among treatments, whereas a linear increase (P = 0.02) was observed for time spent eating per unit of DMI when ENP was fed. There was a trend (P = 0.07) for a quadratic effect in ruminating time per unit of DMI according to ENP increments. Blood methemoglobin before morning feeding increased linearly (P

Two experiments were designed to evaluate the effects of monensin, virginiamycin, and flavomycin on growth performance, carcass characteristics, apparent total tract nutrient digestibility, and rumen fermentation of zebu cattle fed a no-roughage finishing diet (whole shelled corn [WSC] based). In Exp. 1, 100 crossbred bulls (; 392 kg [SD 46.8] average initial BW) were blocked by initial BW in a 101-d feedlot trial. Five treatments were evaluated using 4 pens per treatment (5 bulls/pen): monensin at 30 mg/kg DM, virginiamycin at 25 mg/kg DM, monensin at 20 mg/kg DM plus virginiamycin at 25 mg/kg DM, flavomycin at 4.4 mg/kg DM, and monensin at 20 mg/kg DM plus flavomycin at 2.2 mg/kg DM. There were no differences in growth performance (final BW, ADG, DMI, and G:F; ≥ 0.527) and carcass characteristics (HCW, dressing percent, and 12th-rib fat; ≥ 0.235) among treatments. In Exp. 2, 7 ruminally fistulated steers were used in a 7 × 7 Latin square design to evaluate the 5 treatments of Exp. 1 and 2 additional treatments: monensin at 30 mg/kg DM plus virginiamycin at 25 mg/kg DM and monensin at 20 mg/kg DM plus flavomycin at 4.4 mg/kg DM. Experimental periods were 14 d in length (9 d of adaptation and 5 d of measurements). Apparent total tract DM, OM, CP, and NDF digestibilities were similar among treatments ( ≥ 0.224). There was no treatment effect ( ≥ 0.253) in rumen fermentation responses (ruminal pH, rumen ammonia nitrogen, VFA, and number of protozoa). In conclusion, no evidence of benefits to cattle fed a no-roughage WSC-based diet was found to support the use of monensin combined with virginiamycin or flavomycin in the doses tested herein.

This study analyzed the productive strategies and technology of beef producers in the Vermelho basin in Goiás, Brazil. The data were used to develop a technological index, applicable to the local beef production systems. The data were obtained using questionnaires. A set of 60 properties was selected to provide a representative sample of the relief and soil quality within the study area. The data were analyzed using multiple correspondence, cluster analysis, and beta regression procedures. The variables that most contributed to the definition of the technological level were identified. The variables and production units each formed three clusters, corresponding to three levels of technology: low, mid, and high. The data were used to calculate a predictive index for the analysis and mapping of the technology used in the study area. High cattle densities were found in systems with low technology, indicating low productivity and profitability, and reduced environmental sustainability.

This study evaluated the effects of the encapsulated calcium ammonium nitrate as a partial substitute for soybean meals in the concentrate on performance and rate consumption of Nellore young bulls under grazing conditions, supplemented during the growing phase. Sixty-four Nellore young bulls (initial BW = 246.69 ± 7.43 kg) where allotted into 16 paddocks of 1.0 ha each of Urochloa brizantha, randomly assigned into one of two treatments: (CTL) supplement with 22% CP, without nitrate inclusion and; (ENP): supplement with 22% CP, with a inclusion of 50 g of encapsulated calcium ammonium nitrate to each 100 kg of body weight. The experimental period lasted 84 d, during the dry-rainy transition season. Animals were supplemented with 1.0% of BW, once a day (at 1000 h). Supplementation disappearance rate were evaluated the during continuous 24h after feeding, with intervals of 3 hours. For performance evaluation, animals were weighted every 28 days. Data were analyzed as a completely randomized design, using ANOVA (α = 0.05). There were no differences in ADG (1,039 vs 1,012 kg, P < 0.4468), G:F (0.299 vs 0.331, P < 0.1435) and final BW (336.44 vs 329.86 kg, P < 0.2063). The treatments affected the rate of supplementation disappearance (P < 0.0001). Control animals consumed all supplement offered 9h after fed. On the other hand, animals from the nitrate supplementation consumed only 54.65% in the same period. The nitrate decreased the overall supplement intake (P < 0.0011) with CTL consumed 2.844 kg, while ENP consumed 2.492 kg. The inclusion of 50 g of encapsulated calcium ammonium nitrate to each 100 kg of body weight in the supplement of growing cattle under grazing conditions, on dry-rainy transition season decreases DMI and the rate of supplemental disappearance, however, this not affected the performance.

The aim of this trial was to evaluate the effect of encapsulated calcium ammonium nitrate as a partial substitute for soybean meals in the concentrate dry matter intake, average daily gain and feed efficiency of Nellore young bulls under grazing conditions, during the dry season. Sixty-four weaned Nellore (initial BW = 177.46±3.77 kg and 9 mo old) were used in a completely randomized assay. The study lasted 84 days on the dry season. Animals were allotted into 16 paddocks of 1.0 ha each of Urochloa brizantha, randomly assigned into one of two treatments: (CTL) supplement with 25% CP, without nitrate inclusion and; (ENP): supplement with 25% CP, with a inclusion of 50 g of encapsulated calcium ammonium nitrate to each 100 kg of body weight. Animals were fed with concentrate at 1.0% of body weight. Concentrate offered was monitored daily as well as his refusals were collected and weighed to determine daily concentrate dry matter intake (DMI) and feed efficiency (F:G). Animals were weighed every 28 d for calculating average daily gain (ADG). Data were analyzed as a completely randomized design, using ANOVA (α = 0.05). No effects of treatments (P > 0.3487) were observed for final BW (246.69 kg). The same for concentrate dry matter intake (P > 0.0550). Animals consumed 2.34 kg of supplement per day. The average daily gain (0.832 kg, P > 0.2649) and feed efficiency (0.356 kg, P > 0.7315) were not affected by the inclusion of nitrate. The inclusion of encapsulated calcium ammonium nitrate in supplement to Nellore young bulls under grazing conditions during the growing phase did not affect the performance.

The objective was to evaluate the effects of Bacillus toyonensis on performance, carcass traits and its influence on ruminal and intestinal mucosa development of Nellore bulls fed tropical grass pasture on dry season supplemented with concentrate at 2.0% BW for 133 d. Four animals were slaughtered at the beginning of the experiment so that the initial carcass yield could be estimated. Eighty Nellore bulls (initial BW 354.02 ± 3.38 kg) were blocked according to body weight and assigned to one of two treatments: concentrate with Bacillus toyonensis (animals fed 1.6 x 109 UFC/day) or without (control group). Then, the remaining animals were allocated in 16 paddocks of Urochloa brizantha with 1.0 ha each (eight paddocks/treatment and five animals/paddock). At the end of the trial, bulls were slaughtered and carcass traits such as HCW, dressing percentage, 12th-rib fat thickness, carcass gain and carcass ADG were obtained. Tissue from the ventral sac and jejunum were collected and fixed in buffered formalin for evaluation of rumen papillae and intestine villi morphology. Data were analyzed using the GLM procedure of SAS. Paddock was the experimental unit for all analyses. Results indicated there were no significant difference (P > 0.05) between treatments for final BW (528.2 kg), ADG (1.333 kg) and G:F (0.165). No significant differences were detected between treatments for HCW (299.8 kg), dressing percentage (56.82%), and carcass ADG (0.885 kg). Conversely, control group showed a significant (P < 0.025) higher 12th-rib fat thickness (4.06 vs 2.97 mm). No significant effect on the development of the ruminal and intestinal epithelium was observed with the use of probiotic. Probiotic based on Bacillus toyonensis did not improve growth performance and carcass characteristics on finishing Nellore bulls fed tropical grass pasture on dry season.

In this trial, 120 Nellore young bulls of ± 386kg kg initial weight were used to evaluate the effect of different sources of crude protein on the feedlot performance (finishing phase) and carcass characteristics. Animals were maintained in fifteen pens for 105 days. Animals were individually weighed and blocked by initial body weight. Pens within a block were randomly assigned to one of three treatments: (D14) Control diet including 14% of crude protein (CP) on dry matter; (D12) Inclusion of 12.5% CP/dry matter and (D11), inclusion of 11% of CP/dry matter. Feed offered was monitored daily as well as feed refusals were collected and weighed to determine the DMI and feed efficiency (F:G). Animals were weighed every 28 d after 16 h feed withdrawal for calculating ADG. The D14 and D12 treatments increased the final weight (P = 0.008) when compared to D11 (564.13; 550.96 and 529.73 kg, respectively). The D14 treatment increased the ADG (1.69 kg; P = 0.002) when compared to D12 (1.54 kg) and D11 animals (1.35 kg). The same was observed for DMI (P = 0.001) (10.40kg, 9.77kg e 8.68kg, respectively) and % BW (P = 0.001), when D14 had the greatest value (2.2%), and D11 the worst (1.90%). There were no effect of the treatments for F:G (P = 0.202). Hot carcass weight was increased by the D14 treatment (P = 0.006) (311.97kg; 300.55 and 289.30kg, respectively). However, the cooling losses were not affected (P = 0.0843), as well as were observed for dressing (P = 0.089). Nevertheless, the carcass daily gain was improved by the D14 (P = 0.02), with animals increasing 1.13 kg/d; D12 with 1.01kg/d and D11, 0.91 kg. In conclusion, the sources of crude protein can affect the feedlot cattle performance, in agreement with the Brazilian Nellore requirement program (Br-Corte). However, in this trial, diets with 14% of CP improved the animal’s performance.

This study was undertaken to examine production performance, pasture and milk intakes and nutrient digestibility in heifers supplemented with different levels of energy in a creep-feeding system on Urochloa decumbens Stapf pastures during the rainy-dry transition season. Fifty-one heifers with predominant Nellore genetic composition (average initial age and weight: 120 days and 133.4 ± 3.12 kg) and their respective dams were used in an evaluation of production performance, intake, and diet digestibility. Four treatments were evaluated, namely, MM - mineral mixture; T250 - 0.250 kg of supplement per head per day; T500 - 0.500 kg of supplement per head per day; and T750 - 0.750 kg of supplement per head per day, totaling three groups with 13 animals each and one group with 12 animals. All supplements were balanced to provide 100 g of CP animal-1 day-1. LIPE® and chromium oxide were used as external markers to estimate fecal excretion and individual DM and supplement intakes, respectively, whereas iNDF was used as an internal marker for pasture DM intake. Production performance did not differ between the supplemented and unsupplemented animals. Total DM intake and pasture DM intake were higher in the group supplemented with concentrate, and the same was observed for the digestibility of DM and NDFap consumed by the animals. The average cow milk yield was 5.33 kg/day, with average protein and fat contents of 3.51% and 4.85%, respectively. In conclusion, compared to the use of mineral mixture only, multiple supplementation at different levels containing 100 g of CP does not significantly improve performance in lactating beef heifers grazing on Urochloa decumbens Stapf and supplemented during the rainy-dry transition season.

This study was designed to evaluate the effects of different supplementation plans on the nutrient intake, apparent total-tract digestibility, grazing behavior, growth performance, and carcass characteristics of beef cattle under grazing conditions from ages 4 to 18 months old. The beef calves grazed Brachiaria decumbens in four seasons: rainy-dry transition, dry, dry-rainy transition, and rainy. Forty-four animals (11 per treatment) were randomly assigned to one of four nutritional plans of supplementation defined by the quantity of supplement offered: control, low, medium, and high supplementation. There was no difference (P > 0.10) in dry matter intake (DMI). However, animals receiving medium and high supplementation had decreased (P < 0.10) forage dry matter intake (FDMI) compared with those under non- and low supplementation. The DMI and FDMI were lower (P < 0.10) in the dry season. During the rainy season, the grazing time decreased (P < 0.10) for animals receiving supplementation compared with non-supplemented ones, but was similar between medium and high supplementation. The performance and carcass characteristics were greater (P < 0.10) for high and medium supplementation compared with low and control. In conclusion, increasing the supplementation plans for beef cattle in tropical pastures increases the nutrient intake but decreases FDMI. The performance also increases with the supplementation plan; however, the growth rate is affected by the grazing season.

The objective of this study was to estimate requirements of energy, protein and macrominerals of young Nellore/Holstein crossbreds bulls supplemented on pastures of Brachiaria decumbens Stapf. Thirty-five young bulls, at 8.53±0.18 months of age and with initial body weight of 230.6±6.1 kg were used. Ten animals were slaughtered as reference, in different weight range, and the other animals were slaughtered at the end of the experimental period. For estimate of net energy requirements for weight, a regression equation between log of retained energy (RE) and log of empty body weight gain (EBWG) was constructed. Net requirements of Ca, P, Mg, Na and K were determined by the equation Y' = a.b.Xb-1, in which a and b represent the intercept and the coefficient of equation of prediction of macrominerals in body content, respectively. Requirements of metabolizable energy for maintenance (MEm) were obtained from retained energy in function of metabolizable energy intake (MEI). The requirements of MEm of Nellore/Holstein crossbreds young bulls on pasture was 125 kcal/EBW0.75/day. The efficiency of ME utilization for maintenance (k) of grazing Nellore/Holstein crossbred young mbulls was 0.58 and 0.24 for gain. The total metabolizable protein requirements for an animal with 400 kg and with average daily gain of 1.0 kg, were 638.36 g/day. The dietetic requirements of Ca and P for an animal with 400 kg BW were 0.49 and 0.21% of DM, respectively. Daily metabolizable energy requirement for maintenance of grazing Nellore/Holstein crossbred young bulls was 11.6% greater than the values found for cattle in feedlot in Brazil (112 kcal/kg EBW0.75).

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:07:52Z No. of bitstreams: 1 S1516-35982012000200023.pdf: 46654 bytes, checksum: 30965eba025aed84fff84c6dd7ef8ce0 (MD5) Made available in DSpace on 2013-08-22T19:07:53Z (GMT). No. of bitstreams: 1 S1516-35982012000200023.pdf: 46654 bytes, checksum: 30965eba025aed84fff84c6dd7ef8ce0 (MD5) Previous issue date: 2012-02-01 Made available in DSpace on 2013-09-30T20:12:37Z (GMT). No. of bitstreams: 2 S1516-35982012000200023.pdf: 46654 bytes, checksum: 30965eba025aed84fff84c6dd7ef8ce0 (MD5) S1516-35982012000200023.pdf.txt: 26582 bytes, checksum: 58a4225e0eb7844e6898ca66458e29f7 (MD5) Previous issue date: 2012-02-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:18:22Z No. of bitstreams: 2 S1516-35982012000200023.pdf: 46654 bytes, checksum: 30965eba025aed84fff84c6dd7ef8ce0 (MD5) S1516-35982012000200023.pdf.txt: 26582 bytes, checksum: 58a4225e0eb7844e6898ca66458e29f7 (MD5) Made available in DSpace on 2014-05-20T15:18:22Z (GMT). No. of bitstreams: 2 S1516-35982012000200023.pdf: 46654 bytes, checksum: 30965eba025aed84fff84c6dd7ef8ce0 (MD5) S1516-35982012000200023.pdf.txt: 26582 bytes, checksum: 58a4225e0eb7844e6898ca66458e29f7 (MD5) Previous issue date: 2012-02-01 The objective of this study was to determine requirements of calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K) and sodium (Na) for grazing zebu bovines. The experiment area was composed of Brachiaria decumbens paddocks. Twenty-seven non-castrated animals, with initial live weight of 311.0 kg and at an average age of 14 months were used. Three animals were slaughtered, after adaptation period, so they were used as control for estimates of empty body weight and initial body composition of animals in the experiment. Out of the 24 remaining animals, four were sent to the maintenance group with restrict grazing time to limit energy intake close to the maintenance level. The other 20 animals were distributed in four treatments: mineral mixture, self-control intake and three-times-a-week-offer frequency (offered on Mondays, Wednesdays and Fridays) and daily. Concentrations of all studied macro elements in empty body and empty body gain decreased as live weight increased. The ratios obtained for g Ca/100 g of retained protein and g P/100 g of retained protein were 9.18 and 4.72, respectively. Total dietary requirement of calcium was lower than the one recommended by NRC (2000), but P requirement was very close to that. UFMT ICAA UFV DZO UNESP UNESP

This trial was conducted to evaluate the quantitative carcass traits of Nellore, F1 Simmental × Nellore and F1 Angus × Nellore steers fed at maintenance level or ad libitum with 1% and 2% of the body weight in concentrate. The animals were allotted to the treatments in a completely randomized experimental design, in a 3 × 3 factorial arrangement. The animals fed the ad libitum diet with more concentrate had greater cold carcass weight, cold carcass yield and longissimus muscle area/100 kg of cold carcass weight when compared with animals fed the diet with low concentrate allowance. There was no difference between the ad libitum diets for all of the carcass cuts yields, except for top sirloin. Crossbred animals had cold carcass yield larger than the Nellore animals. F1 Angus × Nellore animals had greater rib fat thickness and smaller longissimus muscle area/100 kg than the F1 Simmental × Nellore cattle. The yield of commercial carcass cuts was not influenced by genetic group, except for the shoulder clod yield, which was smaller in crossbred animals compared with Nellore animals. The longissimus muscle area, rib fat thickness and rump fat, taken by ultrasound were influenced by the body weight of the animals. Crossbred animals fed diets with higher concentrate level produce carcasses most suitable for the requirements of the market.

Objetivou-se avaliar suplementos formulados com diferentes fontes de proteína, no período das águas, sobre o desempenho produtivo de novilhas de corte em recria. Para avaliar o desempenho produtivo, 20 novilhas mestiças Holandês x Zebu e aneloradas, com peso corporal médio de 234 kg e idade aproximada de 14 meses, foram distribuídas em cinco piquetes de B. decumbens Stapf de 2,5 ha cada, em delineamento inteiramente casualizado, com cinco tratamentos e quatro repetições. Os suplementos foram à base de farelo de soja (FS), farelo de algodão 38% PB (FA38), farelo de glúten de milho 60% PB (GM) e farelo de trigo + ureia (FT), além de um tratamento-testemunha, constituído apenas de mistura mineral (MM). A quantidade diária de suplemento foi fixada para fornecer aproximadamente 180 g de PB dia-1, sendo 0,450; 0,550; 0,350 e 0,450 kg animal-1 dia-1, respectivamente, para os tratamentos FS, FA38, GM e FT. Os animais foram pesados a cada 28 dias e rotacionados entre os piquetes a cada sete dias. Os animais submetidos ao tratamento FT apresentaram ganhos médios diários (GMD) superiores (p < 0,10) àqueles recebendo o tratamento MM (0,839 X 0,666 kg dia-1). Recomenda-se o fornecimento de 500 g de suplemento que contém ureia, farelo de trigo e minerais para novilhas em recria, quando se deseja obter ganhos de peso moderados, em torno de 850 g dia-1.This paper aimed to evaluate the supplements formulated from different sources of protein during the rainy season over the productive performance of beef heifers during breeding. In order to evaluate productive performance, 20 Holstein x Zebu crossbred heifers, with average body weight of 234 kg and approximate age of 14 months, were divided into five paddocks of B. decumbens Stapf of 2.5 ha each, in a completely randomized design with five treatments and four repetitions. The supplements were based on soybean meal (FS); cottonseed meal (FA) 38% crude protein (CP) (FA 38); corn gluten meal 60% CP (GM) and wheat bran + urea (FTU); and a treatment witness, composed of mineral mix (MM) only. The daily amount of supplement was established for providing about 180 g of CP day-1; that is, 0.450, 0.550, 0.350 and 0.450 kg animal-1 day-1, respectivelly, for the treatments with FS, FA38, GM and FTU. The animals were weighted every 28 days and rotated among the paddocks every 7 days. The ones which were submitted to the FTU treatment showed higher average daily gains (ADG) (p < 0.10) than those which received a MM treatment (0.839 X 0.666 kg day-1). The 500 g supply of supplement containing urea, FTU and minerals for heifers during breeding is recommended when intending to get moderate weight gain - around 850 g day-1.

The study assessed performance, microbial protein synthesis, intake and digestibility of nutrients by beef heifers receiving levels of multiple supplements or nitrogen salt, in a self-controlled intake, on pasture, during the dry season. Thirty-five beef heifers, from 6 to 9 months of age and average initial body weight of 203.4 + 4.5 kg, were used. Study factors were: control - mineral mixture; nitrogen salt - 50% of urea + mineral mixture, at proportion of 1:1, and 50% of corn (75% of crude protein); levels of multiple supplementation - multiple supplements with different percentages of intake controller mixture (urea + mineral mixture, at the proportion of 1:1), corn and soybean meal (45% of crude protein). Supplement consumptions observed were: 115, 173, 572 and 1214 g/animal/day for animals fed on nitrogen salt, low, medium and high levels of multiple supplement, respectively. Supplemented animals had greater average daily gain, evidencing the positive linear effect of the levels of multiple supplementation on average daily gain. Overall, there were no significant differences between average daily gain of animals fed on multiple supplements or nitrogen salt. Supplementation increased the intake and digestibility of nutrients, except for digestibility of neutral detergent fiber, although the intake of digested neutral detergent fiber increased. Supplementation increased the production of microbial nitrogen as well as nitrogen losses in urine, although the quantity of nitrogen assimilated by bacteria, proportionally to intake, was higher. Supplementation improves nutritional parameters and weight gain.

Objetivou-se avaliar o desempenho produtivo, o consumo e a digestibilidade aparente na recria de novilhas de corte em pastagem de Brachiaria decumbens Stapf, sob suplementação com fontes de energia amilácea ou fibrosa durante o período da seca. Foram utilizadas 40 novilhas (20 da raça Nelore e 20 mestiças), recém-desmamadas, com 8,5 meses de idade e peso inicial de 197,9 ± 3,74 kg. Foram formulados dois suplementos: o primeiro à base de fubá de milho e farelo de soja (rico em amido) e o segundo, à base de farelo de trigo (rico em fibra), que foram ofertados nas quantidades de 0,5 ou 1,0 kg/animal/dia, em comparação à oferta de apenas mistura mineral (controle). Os animais foram distribuídos segundo delineamento de blocos completos casualizados em esquema fatorial 2 × 2 + 1, com duas fontes de energia e dois níveis de suplementação mais o controle; o grupo genético foi adotado como medida de controle local. O ganho médio diário de peso foi maior nos animais sob suplementação que naqueles que receberam apenas mistura mineral (0,198 vs 0,077 kg/animal/dia). Além disso, o desempenho dos animais sob suplementação com fonte amilácea de energia foi maior em relação aos daqueles que receberam suplemento à base de farelo de trigo (0,232 vs 0,163 kg/animal/dia). O consumo de matéria seca de pasto foi menor no grupo que recebeu o maior nível de suplementação. A suplementação de novilhas de corte sob pastejo durante o período da seca possibilita aumentar o desempenho produtivo. Em comparação ao farelo de trigo, a utilização da mistura milho/farelo de soja como base da mistura múltipla melhora o desempenho produtivo das novilhas. This experiment aimed at evaluating the productive performance, intake and the apparent digestibility in the raising of beef heifers on Brachiaria decumbens Stapf. pastures under supplementation with starch or fibrous energy sources during the dry season. It was used 40 newly weaned heifers (20 Nellore and 20 crossbreed), at 8.5 months of age and 197.9 ± 3.74 kg initial weight. Two supplements were formulated: the first was corn meal- and soybean meal-based diet (high in starch) and the second was based on wheat meal (high in fiber), which were given at the quantities of 0.5 or 1.0 kg/animal/day, compared to the offer of only mineral mixture (control). The animals were distributed according to a complete randomized block design in a 2 × 2 + 1 factorial arrangement with two sources of energy and two levels of supplementation plus the control treatment; the genetic group was used as a measure of local control. The average daily weight gain was higher for the animals under supplementation than those fed only mineral mixture (0.198 vs. 0.077 kg/animal/day). Moreover, performance of the animals under supplementation with starch energy source was higher than those fed wheat meal-based supplement (0.232 vs. 0.163 kg/animal/day). The intake of pasture dry matter was lower for the group given the highest supplementation level. The supplementation of beef heifers under pasture makes it possible to improve the productive performance. Compared to wheat meal, the use of the corn/soybean mixture meal as the basis of multiple mixture improves the productive performance of the heifers.

The objective of this work was to determine macromineral requirements by Zebu steers grazing Brachiaria decumbens supplemented with concentrate. It was used 24 non-castrated steers, at an average age of 7 months and at initial average weight 180 kg. Eight control animals were slaughtered for determining initial body composition. The 16 remaining animals were divided in four four-animal plots, in a complete random design. Each plot received mineral mixture or supplements at the levels 0.75; 1.50 or 2.25 kg/animal/day. The right half-carcass of eight animals, two per group, was dissected in muscle, fat and bones and all body constituents were weighted for determination of empty body weight and body composition. Net requirements of calcium and phosphorus for an animal at 400 kg body weight were 11.13 g and 5.40 g, respectively. To estimate dietary requirements of maintenance and after, sum them to dietary requirements for gain in order to obtain total dietary requirements, it was adopted endogenous losses and bioavailability present in literature for each mineral macroelement. Total dietary requirement for calcium, phosphorus, magnesium, sodium and potassium for a 400-kg BW animal with 1.0-kg daily weight gain were 34.59; 17.36; 7.82; 5.19 and 41.11 g/day, respectively. Macromineral requirements by beef cattle under pasture supplementation are similar to those recommended by BR-Corte for beef cattle in feedlots. Objetivou-se determinar as exigências de macrominerais de novilhos zebuínos em pastagem de Brachiaria decumbens suplementada com concentrado. Foram utilizados 24 novilhos, não-castrados, com idade e pesos médio iniciais de 7 meses e 180 kg. Foram abatidos oito animais-referência para determinação da composição corporal inicial. Os 16 animais restantes foram divididos em quatro lotes de quatro animais, em delineamento inteiramente casualizado. Cada lote recebeu mistura mineral ou suplementos nos níveis de 0,75; 1,50 ou 2,25 kg/animal/dia. A meia-carcaça direita de oito animais, dois por grupo, foi dissecada em músculo, gordura e ossos e todos os constituintes do corpo foram pesados para determinação do peso de corpo vazio e da composição corporal. As exigências líquidas de cálcio e fósforo para um animal de 400 kg de peso corporal foram, respectivamente, 11,13 g e 5,40 g. Para estimar as exigências dietéticas de mantença e, posteriormente, somá-las às exigências dietéticas para ganho, no intuito de se obter as exigências dietéticas totais, foram adotadas as perdas endógenas e a biodisponibilidade presentes na literatura para cada macroelemento mineral. As exigências dietéticas totais de cálcio, fósforo, magnesium, sódio e potássio para um animal de 400 kg de PC com ganho diário de 1,0 kg foram, respectivamente, 34,59; 17,36; 7,82; 5,19 e 41,11 g/dia. As exigências em macrominerais de bovinos de corte sob suplementação a pasto são semelhantes às recomendadas pelo BR-Corte para bovinos de corte em confinamento.

Avaliaram-se o desempenho produtivo, o consumo e a digestibilidade em bezerros Nelore em fase de amamentação em pastagem de Brachiaria decumbens suplementada com diferentes fontes de energia. A área foi dividida em cinco piquetes de 6,8 ha, com disponibilidade média de matéria seca e matéria seca potencialmente digestível de 4,10 e 2,38 t/ha, respectivamente. Foram utilizados 45 bezerros Nelore, com peso e idade iniciais de 96,0 ± 11,0 kg e 101 ± 12 dias, em delineamento inteiramente casualizado, em arranjo fatorial 5 × 2 (cinco suplementos e dois sexos). Os suplementos foram: MM - mistura mineral (controle); GM - farelo de soja (FS) + grão de milho triturado (GM) e mistura mineral; FTGM - farelo de soja + farelo de trigo + grão de milho triturado e mistura mineral; FA - farelo de soja + farelo de arroz e mistura mineral; GMS - farelo de soja + grão de milho triturado + grão de sorgo triturados e mistura mineral, fornecidos diariamente na quantidade de 60 g/animal para o grupo controle e 500 g/animal para os demais suplementos. Os animais que receberam suplemento múltiplo com milho e sorgo como fonte de energia proporcionaram ganho diário médio adicional de 100 g/animal (16,39%) em comparação à mistura mineral. O uso do suplemento múltiplo à base de grão de milho como fonte de energia reduziu o consumo de matéria seca, matéria orgânica de pasto e fibra em detergente neutro em relação às fontes energéticas farelo de arroz e à combinação de milho com sorgo. A suplementação com as fontes de energia, sobretudo as combinações de farelo de trigo e milho ou de milho e sorgo, podem proporcionar ganhos adicionais em animais em creep-feeding. A suplementação múltipla aumenta o consumo de pasto quando se utilizam grão de milho e sorgo combinados como fonte de energia. The performance, intake and digestibility were evaluated in Nellore beef calves supplemented with different energy sources in Brachiaria decumbens pasture were evaluated. The area was divided into five 6.8 ha paddocks with an availability of dry matter and potentially digestible dry matter of 4.10 and 2.38 t/ha, respectively. Forty-five animals with 96.0 ± 11.0 kg initial weight and 101 ± 12 days of age were allotted to a completely randomized experimental design, as a 5 × 2 factorial (five supplements and two sex). The following supplements were evaluated: mineral mix (MM), control group; soybean meal (SM) + ground corn grain (GCG) and mineral mix; soybean meal + wheat meal + ground corn grain and mineral mix; soybean meal + rice meal and mineral mix; soybean meal + ground sorghum grain + ground corn grain and mineral mix; supplied daily at the amount of 60 g/animal for the control group and 500 g for the other diets, respectively. There was statistical significance for the animals that received supplementation with ground corn grain and ground sorghum grain that showed an additional average daily gain of 100 g (16.39%) higher than the animals that received only mineral mix. The use of multiple supplements based on ground sorghum grain and corn grain increased dry matter intake and forage organic matter more than the diet with ground corn grain. The supplementation with energy sources with ground sorghum grain and corn grain can provide additional average daily gain and increase in forage intake, in animals in creep-feeding.