Nellore Bulls Research Articles

Andrological Points Classification (CAP) Nelore Bulls (Bos Taurus Indicus) of Different Ages, Kept in Reproduction Central

The objective of this study was to evaluate the reproductive potential of Nellore bulls at different ages, using the Andrological Points Classification system andto analyze the physical and morphological characteristics of the semen, when submitted to the cryopreservation protocol. Thus, 15 Nellore bulls were evaluated, divided into three groups according to age. The first group consisted of bulls aged ≤ 4 years, the second group of bulls aged 5 ≥ to ≤ 7 years, and the third group of bulls aged 8 ≥ to ≤ 10 years. From the evaluations performed, biometrics testicular and semen morphology, were relevant to determine the andrological classification by points (CAP index). For this purpose, the semen was collected using the electroejaculation method. And the results were expressed as mean and standard deviation.

Metabolomics Changes in Meat and Subcutaneous Fat of Male Cattle Submitted to Fetal Programming.

This study investigated changes in meat and subcutaneous fat metabolomes and possible metabolic pathways related to prenatal nutrition in beef cattle. For this purpose, 18 Nellore bulls were used for meat sampling and 15 for fat sampling. The nutritional treatments during the gestation were: NP-not programmed or control, without protein-energy supplementation; PP-partially programmed, with protein-energy supplementation (0.3% of body weight (BW)) only in the final third of pregnancy; and FP-full programming, with protein-energy supplementation (0.3% of BW) during the entire pregnancy. The meat and fat samples were collected individually 24 h after slaughter, and the metabolites were extracted using a combination of chemical reagents and mechanical processes and subsequently quantified using liquid chromatography or flow injection coupled to mass spectrometry. The data obtained were submitted to principal component analysis (PCA), analysis of variance (ANOVA), and functional enrichment analysis, with a significance level of 5%. The PCA showed an overlap between the treatments for both meat and fat. In meat, 25 metabolites were statistically different between treatments (p ≤ 0.05), belonging to four classes (glycerophospholipids, amino acids, sphingolipids, and biogenic amine). In fat, 10 significant metabolites (p ≤ 0.05) were obtained in two classes (phosphatidylcholine and lysophosphatidylcholine). The functional enrichment analysis showed alterations in the aminoacyl-tRNA pathway in meat (p = 0.030); however, there was no pathway enriched for fat. Fetal programming influenced the meat and fat metabolomes and the aminoacyl-tRNA metabolic pathway, which is an important candidate for the biological process linked to meat quality and related to fetal programming in beef cattle.

Farm-Scale Effectiveness of Feed Additives Supplied through a Mineral Mix for Beef Cattle Grazing Tropical Pastures

The effectiveness of feed additives delivered through free-choice mineral mixtures (MMs) to grazing cattle remains unclear. Two farm-scale and one in vitro experiment (Exp.) were conducted to investigate the effects of salinomycin and virginiamycin, delivered through an MM, on growing bulls grazing tropical pastures. In Exp. 1, 316 zebu (Bos indicus) Nellore bulls (225 ± 26.7 kg liveweight (LW)) were randomly allocated to four treatments: (1) MM no additives (CON), (2) MM with salinomycin at 1950 mg/kg (SLI), (3) MM with salinomycin at 780 mg/kg (SHI), and (4) MM with virginiamycin at 1950 mg/kg (VGN). Over 123 days, these bulls grazed tropical grasses on pastures of guinea grass, palisade grass, or Bermuda grass. No significant treatment effects were observed for oocyst eggs or ruminal parameters. Bulls fed VGN had higher average daily gain (ADG) compared to CON (p = 0.02) and SLI (p = 0.03) but similar compared to SHI (p = 0.07). In Exp. 2, 308 zebu cross bulls (237 ± 23.0 kg LW) grazed Bermuda grass paddocks and were allocated into two treatments: (1) MM with no additives (CON) and (2) MM containing virginiamycin at 2522 mg/kg (VGN). Cattle fed VGN had a significantly higher ADG (p = 0.007). Exp. 3 tested salinomycin’s effectiveness in vitro at different exposure times to MM, revealing no impact of exposure time on short-chain fatty acid production. In conclusion, virginiamycin delivered through free-choice MM can increase grazing beef bulls’ ADG by 12% compared with CON, with no clear link to rumen fermentation or coccidiostat effects.

166 Assessment of testicular echotexture in Nelore bulls: implications for puberty evaluation

166 Assessment of testicular echotexture in Nelore bulls: implications for puberty evaluation

Fetal Programming and Its Effects on Meat Quality of Nellore Bulls.

This work aimed to evaluate the effects of prenatal nutritional stimulation at different pregnancy stages on carcass traits and meat quality in bovine progeny. For this purpose, 63 Nellore bulls, born from cows submitted to three nutritional plans, were used: not programmed (NP), which did not receive protein supplementation; partially programmed (PP), which had protein-energy supplementation (0.3% of mean body weight of each batch) only in the final third of pregnancy; and full programming (FP), which received supplementation (0.3% of mean body weight of each batch) throughout pregnancy. The averages of parameters were submitted to the ANOVA, and the supplementation periods, which were different when p value < 0.05, were compared. Carcass weights and rib eye area (REA) did not differ between treatments (p > 0.05), but subcutaneous fat thickness (SFT) showed a tendency (p = 0.08) between groups. For lipids and marbling, no differences were found (p > 0.05). In the analyses of maturation time and shelf life, no difference was observed between treatments. However, there was a tendency between treatments at 14 days of maturation time for cooking loss (CL) (p = 0.08). Treatments did not affect shear force in the progenies (p > 0.05). Fetal programming had no effect on the meat quality of Nellore bulls.

PSXII-23 Performance of Nellore Bulls Fed Snaplage in Fishing Diets

Abstract The aim of this study was to investigate the influence of snaplage on fecal characteristics, feeding behavior, and performance in fishing bulls. Seventy-two single-sourced Nellore bulls (initial shrunk BW = 400 ± 27.4 kg) were randomly assigned to 1 of 3 treatments (3 bulls per pen; 8 pen replicates per treatment). Treatments consisted of finishing diets with the following sources of fiber and energy: 1) corn silage, reconstituted corn grain silage, and dry-ground corn (CONTROL), 2) snaplage (inclusion of 65% of DM) and dry-ground corn (SNAP65), and 3) snaplage only (inclusion of 85% of DM; SNAP85). All diets contained the same inclusion of soybean meal, cotton meal, urea, and mineral mix. Diets were formulated using NASEM (2016) to provide an ADG of 1.8 kg/d. Bulls were adapted to the finishing diets over a 15-d period and fed for a total of 86 d. Fecal samples were collected on d 42, 65, and 73. Feeding behavior was assessed on d 51 and 69. Statistical analysis of experimental data was performed using the MIXED procedure of SAS 9.4. An α of 0.05 determined significance and an α of 0.06 to 0.10 was considered a tendency. No differences were obtained for initial BW, G:F, hot carcass, and dressing. SNAP85 had a greater intake, followed by SNAP65 and CONTROL diets (P = 0.02). There was a tendency of greater ADG and final BW (P = 0.07 and 0.08, respectively) for SNAP65 diets (2.0 kg/d and 572 kg), followed by SNAP85 (1.95 kg/d and 567 kg) and CONTROL (1.85 kg/d and 558 kg). A tendency (P = 0.07) was also observed for greater ribeye area in bulls consuming SNAP65 (85 cm2), followed by CONTROL (81 cm2), and SNAP85 (77 cm2). Bulls consuming SNAP65 and SNAP85 spent more time chewing (on average, 249 min/d) than those consuming CONTROL diets (177 min/d; P = 0.01). Regarding fecal characteristics, pH and fecal starch were greater for SNAP85 (P = 0.01 for both variables). Overall, snaplage is a suitable ingredient for high-starch diets for providing energy and physically effective fiber. The inclusion of 65% of snaplage and 20% of dry-ground corn (DM basis) showed a slight superior performance in Nellore bulls.

PSXII-18 The Probiotic Containing Bacillus Licheniformis and Bacillus Subtilis Improves Feed Efficiency in Beef Cattle

Abstract The aim of this study was to investigate the effects of a probiotic containing B. licheniformis and B. subtilis on fecal characteristics, blood parameters, and performance in feedlot cattle. One hundred and forty-four single-sourced Angus x Nellore bulls (initial shrunk BW = 401 ± 45.5 kg) were randomly assigned to 1 of 2 treatments (4 bulls per pen; 18 pen replicates per treatment). Treatments consisted of a finishing diet containing no probiotic (CONTROL) or a diet with 2 g of probiotic/bull/d (PROB). The probiotic was composed of B. licheniformis CH200 and B. subtilis CH201 (3.2 x 109 CFU/g; BOVACILLUS). The diet was formulated using NASEM (2016) to provide an ADG of 1.9 kg/d (23% of corn silage, 65% of ground corn, 8% of soybean meal, 1% of urea, and 3% of mineral mix; DM basis). Bulls were adapted to the finishing diet over a 15-d period and fed for a total of 84 d. Fecal samples were collected on d 33 and 63. Blood samples were collected on the day of shipping to slaughter. Statistical analysis of experimental data was performed using the MIXED procedure of SAS 9.4. An α of 0.05 determined significance and an α of 0.06 to 0.10 was considered a tendency. No differences were obtained for initial BW, final BW, ADG, hot carcass, and dressing. Dry matter intake was reduced by 4% (P = 0.002) and G:F was increased by 6.3% (P = 0.036) in bulls consuming PROB diet. Regarding blood parameters, no differences were observed for glucose, haptoglobin, and LBP. There was a tendency of greater plasma urea (P = 0.09) in bulls consuming CONTROL diets. Fecal characteristics (DM, starch, N, pH, and scoring) were not different between treatments. Overall, dietary supplementation with B. licheniformis and B. subtilis improves feed efficiency in feedlot cattle.

PSX-25 The Fecal Metabolome Differs Between Nelore Bulls Fed Pre- and Post-Feedlot Diets: Initial Results

Abstract The objective of this study was to evaluate the fecal metabolome of Nelore bulls (Bos taurus indicus) fed pre- and post-feedlot diets. In pre-feedlot, 21 animals belonging to the Nelore Qualitas breeding program aged 666 ± 68 days old, and 534.5 ± 34.2 kg of body weight were allocated to one pen for 15 days. The pre-feedlot diet contained corn silage (80%) and sugarcane bagasse (20%). Next, the bulls (546.0 ± 41.2 kg of body weight) were submitted into a finishing stage in feedlot for 56 days. During the post-feedlot diet contained wet grain corn (44.6%), corn silage (27.6%), citrus pulp (11.9%), peanut bran (8%), sugarcane bagasse (4.9%), premix (1.8%) and urea (1.2%) twice a day with ad libitum access in Intergado electronic troughs (Intergado Ltda., Contagem, Minas Gerais, Brazil). Pre- and post-feedlot fecal samples were collected directly from the rectal ampulla of each bovine and stored in a -80°C freezer for metabolomic assays by Nuclear Magnetic Resonance analysis (1H NMR). The metabolites were identified, quantified and data processing using the Chenomx NMR Suite 8.6 (Chenomx Inc., Edmonton, AB, Canada) and MetaboAnalyst 5.0 (http://www.metaboanalyst.ca). We identified and quantified 57 and 55 metabolites in the fecal samples of the bulls fed pre- and post-feedlot diet, respectively. We observed that 39 metabolites differed (P &amp;lt; 0.05) between pre- and post-feedlot diet. The 2-phenylpropionate, caprylate, fumarate, deaminotyrosine, gamma-glutamyl phenylalanine, NADH, thymidine and pantothenate were observed only in the pre-feedlot diet. However, acetamide, 2-oxoglutarate, uracil, xanthine, trimethylamine and demethyl sulfone were consumed exclusively post-feedlot diet. Our multivariate analyses demonstrated that the fecal metabolite profiles of the Nelore bulls fed pre- and post-feedlot diet were different. The first two components of principal component analysis (PCA) explained 86.1% of the total data variance (PC1 = 77.6%; PC2 = 8.5%). Likewise, the partial least squares discriminant analysis (PLS-DA) explained 85.5% of the data variance with the first two components (component 1 (74.4%) vs. component 2 (8.1%)). Three fecal metabolites (acetate, butyrate, and propionate) with variable importance in the projection (VIP scores over 1.0; P&amp;lt;0.05) were greater in animals fed post-feedlot diet. Additionally, metabolome profile offers information on the main metabolic pathways, and five pathways were identified as different (P&amp;lt;0.05 and impact &amp;gt;2) in the fecal samples that bulls fed pre and post feedlot diets: pyruvate metabolism (bta00620); glycine, serine and threonine metabolism (bta00260); synthesis and degradation of ketone bodies (bta00088); histidine metabolism (bta00340) and biosynthesis of phenylalanine, tyrosine and tryptophan (bta00400). Our results suggest that pre- and post-feedlot diets modify the fecal metabolome profile of Nelore bulls. In addition, further studies about metabolic effects of diets are required for a better understanding of these influence on Nelore bulls.

PSXIV-3 3-Nitrooxypropanol Dosages to Reduce Methane Emission By Feedlot Beef Cattle

Abstract Our objective was to evaluate the effects of 3-nitrooxypropanol (3-NOP, Bovaer, DSM Nutritional Products) at different levels in feedlot beef cattle diets on productive performance, biological efficiency, and methane (CH4) emissions. Thirty Nellore bulls (iBW, 407 ± 6 kg) were randomly assigned to three treatments with ten replicates (animal) per treatment. The animals were fed a high-concentrate feedlot diet for 87 days, according to the three treatments: 1) 0, Control (no addition of 3-NOP); 2) Bovaer75 (75 mg/kg DM of 3-NOP), 3) Bovaer100 (100 mg/kg DM of 3-NOP,). Gas emissions (CH4 and H2) were evaluated individually using the GreenFeed unit (C-Lock, USA), while the variables of dry matter intake (DMI) were evaluated using digital feeders (Intergado System, Brazil). Body weights of yearling bulls were recorded after 16-h fasting at the beginning and end of the experiment. Data were submitted to be analyzed using PROC MIXED from SAS 9.4, evaluated by orthogonal contrasts, with a significance level of 5%. Initial BW was used as a covariate when significant to adjust the statistic model. No differences on DMI (kg/d and %BW, P = 0.323) were observed between control animals and those fed with Bovaer. Animals fed with Bovaer75 had greater ADG than control and Bovaer100, (1.73 vs. 1.63 and 1.60 kg/d; P = 0.038 and P = 0.025, respectively) and better biological efficiency than control (⁓127.0 vs 135.3 kg DMI/15 kg carcass produced, P &amp;lt; 0.023). A similar result was observed for carcass gain, in which animals supplemented with Bovaer 75 had greater gains than the control. Animals fed 75 and 100 mg/kg DM of Bovaer emitted respectively 33.7% and 42.7% less methane per se (g/d, P &amp;lt; 0.01) compared with control, and additionally produced more hydrogen (P &amp;lt; 0.01) vs control. There were significant reductions in the measured methane yield in relation to DMI (CH4: DMI, P &amp;lt; 0.01) and methane intensity (CH4/ADG, P &amp;lt; 0.01) for animals fed the two levels of Bovaer, in comparison with the control, as well as a significant difference in the reduction of CH4 in relation to the biological efficiency for the animals fed with Bovaer (P &amp;lt; 0.01). We conclude that feeding Bovaer consistently reduces methane emission from feedlot cattle, in which the reduction intensity increased over the dosages evaluated in the current study.

343 Combination of Feed Additives to Reduce Methane Emissions and Increase Performance By Feedlot Cattle

Abstract Our objective was to evaluate the effects of 3-Nitrooxypropanol (3-NOP) associated with different feed additives on performance, carcass characteristics and enteric methane (CH4) emissions. Twenty-seven Nellore bulls (initial BW, 410 ± 6 kg) were randomly allocated to three treatments with nine replicates per treatment (animal as experimental unit). The animals were fed a high-concentrate feedlot diet (R:C, 10:90) for 102 days, according with the following three treatments: 1) Control (CTRL): Sodium Monensin (26 mg/kg DM); 2) BOV: Control + 3-NOP (Bovaer;100 mg/kg DM); 3) BOVPERF (Bovaer Performance pack): Control + 3-NOP (100 mg/kg DM) + Essential oils (Crina Ruminants, 100 mg/kg DM) + 25-OH-Vitamin D3 (Hy-D, 0.10 mg/kg DM) + carbo-amino-phospho-chelate of chromium and zinc (0.4 and 60 mg/kg of DM, respectively). The gases emissions (CH4 and H2) and DMI variables were assessed individually, by using the GreenFeed and Intergado electronic system placed in the feedlot pen, respectively. The BW of Yearling bulls were recorded at the beginning and final of the experiment after 16-h fasting (Table). Data were analyzed by ANOVA using the PROC MIXED of SAS 9.4, in which means comparison were evaluated by Tukey test at P &amp;lt; 0.05. Feeding BOVPERF increased DM intake during adaptation period (P = 0.04), and over the total period (P &amp;lt; 0.01) compared with control with no difference on feed efficiency (P =0.61). There was no difference (P &amp;gt; 0.05) on DMI between CTRL and BOV. Animals fed BOVPERF had greater HCW (+13 kg, P = 0.04) and greater carcass ADG (+120 g/d, P = 0.04) compared with CTRL. Animals fed BOV and BOVPERF emitted 39% less CH4 (P &amp;lt; 0.01) and produced 292% more H2 (P &amp;lt; 0.01) compared with CTRL. In addition, there were significant reductions in methane intensity, as measured by the ratios CH4/kg DM (-42%; P &amp;lt; 0.01), and CH4/kg carcass ADG (-41.13%; P &amp;lt; 0.01) for animals fed with BOV and BOVPERF compared with CTRL. We conclude that feeding Bovaer performance pack reduces methane emissions and increases carcass production in feedlot beef cattle.

PSX-27 The Impact of Feeding Young Nellore Bulls with a Low Concentrate Diet for Different Periods Followed By a High Concentrate Diet on Dry Matter Intake and Performance

Abstract In Brazil, it is common practice to feed young bulls a low-concentrate diet (LCD) after weaning, followed by a high-concentrate diet (HCD) during the finishing phase to optimize animal growth while reducing the cost of concentrated feed. By restricting the concentrate intake during the early phase, the animals can potentially adapt better to a high-energy diet during the finishing phase, leading to improved performance. Thus, the objective of this study was to evaluate the impact of different LCD feeding periods after weaning, followed by feeding a HCD, on dry matter intake (DMI), average daily gain (ADG), feed efficiency (G:F), and final body weight (BW) of young Nellore bulls. Thirty-two young Nellore bulls (average initial BW = 265 ± 5 kg; age = 7 ± 1 mo) were used in a completely randomized design into four groups (n = 8/group) and assigned to receive one of 4 treatments containing different periods of LCD. The LCD consisted of 800 g/kg of forage sorghum silage and 200 g/kg of concentrate, while the HCD contained 200 g/kg of corn silage and 800 g/kg of concentrate. The diets were formulated according to BR-CORTE (2016) to achieve ADG of 0.6 kg/day and 1.2 kg/day for the LCD and HCD, respectively. The experiment lasted 154 days (14 days for adaptation to the HCD). The LCD and HCD feeding periods respectively were 0 and 140 (T0), 28 and 112 (T28), 56 and 84 (T56), and 84 and 56 (T84) days. All animals were fed ad libitum in an electronic feeder (INTERGADO, Intergado Ltd., Contagem, MG, Brazil), and individual daily feed intake was recorded. The bulls were weighed at the beginning and the end of the LCD and HCD feeding periods after undergoing 16 h of fasting to measure BW and ADG of both periods. Data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) assuming the significance level of 0.05. There was no evidence that different LCD feeding periods impacted DMI (P = 0.99), ADG (P = 0.59), or G:F (P = 0.48) during the LCD feeding period. The DMI during the HCD feeding period of T0 did not differ from the others, the T28 was not significantly different from the T84, and the T56 treatment was greater than T28 and T84 (P &amp;lt; 0.05). No significant difference was found between the treatments for ADG (P = 0.09) and G:F (P = 0.98) during the HCD feeding period. The T0 had the heaviest final BW, while there was no difference between the T28 and T56 groups, and the T84 group had the lightest final BW(P &amp;lt; 0.01). Given that the final BW was heavier for T0, it may be inferred that there are no benefits to using LCD feeding periods.

PSVI-24 A Phytogenic Feed Additive Improves Performance By Nellore Growing Bulls Grazing on Tropical Pastures

Abstract Our objective was to evaluate the effect of including a phytogenic additive in protein supplement on performance of grazing Nellore bulls during growing phase in the rainy season. One hundred and fourteen animals (iBW, 273 ± 4.46 kg) were allocated for 152 days in six paddocks of Brachiaria brizantha cv. Marandu (~7 ha each), with automatic feeders and scales (in drinkers, Intergado, Brazil); and randomly distributed in six treatments fed on protein supplement (30% Crude protein): 1) Negative Control (CON), with no additive; 2) Monensin (MON; positive control, 15 ppm) 3) Digestarom (DSM Nutritional Products) at 0.2 g· animal-1· /day-1 (D0.2); 4) Digestarom at 0.4 g· animal-1· /day-1 (D0.4); 5) Digestarom at 0.6 g· animal-1· /day-1 (D0.6) and 6) Digestarom at 0.8 g· animal-1· /day-1 (D0.8). Supplement offered and additives inclusion were adjusted weekly, based on the intake of the previous week. Supplement intake (SI, measured by the automatic feeders) and Average Daily Gain (ADGs; measured subtracting final and initial fast BW, divided by 152 days; and ADGf; measured by the automatic scales) were evaluated during this study. Data were analyzed by SAS PROC GLIMMIX and significance of 5% was adopted. Means of Digestarom levels were compared with the CON and MON, and of the MON was compared with the CON using a Dunnett test. MON reduced (P &amp;lt; 0.05) SI (175 g/d) compared with CON (433 g/d) and all Digestarom levels (423, 303, 468 and 332 g/d respectively). D0.4 and D0.8 also reduced SI when compared with CON. The ADGs and the ADGf of animals on D0.6 (927 and 1.262 g/d) were greater (P &amp;lt; 0.05) compared with CON (0.860 and 1.127 g/d) and MON (0.840 and 1.114 g/d). The other levels of Digestarom [D0.2 (0.886 and 1.107 g/d), D0.4 (0.823 and 1.054 g/d), and D0.8 (0.853 and 1.071 g/d)] did not differ from CON and MON. D0.6 did not reduce SI (compared with CON; P &amp;gt; 0.05) and increased ADGs and ADGf (compared with CON and MON; P &amp;lt; 0.05). Feeding Digestarom at the dose of 0.6 g· animal-1· /day-1 may increase BW gain of grazing growing bulls during rainy season.

PSVI-3 Effects of Different Concentrate Inclusion Levels in Diets Containing Agri002E Sorghum Silage on Intake and Digestibility in Growing Nellore Bulls

Abstract The sorghum hybrid, AGRI002E, sorghum was developed for high dry matter (DM) production per area. However, there are no reports in the literature evaluating the use of this silage with different inclusion levels of concentration on the ingestive and digestive variables of beef cattle. Therefore, this study aimed to access the effects of different concentrate levels in diets containing AGRI002E sorghum silage (SS) on feed intake, ruminal and apparent total tract digestibilities of organic matter (OM), neutral detergent fiber corrected for contaminant ash and protein (apNDF), and starch. Nellore rumen-cannulated bulls (n = 5; BW = 242 ± 5 kg) were used in a 5×5 Latin square design. The experimental treatments consisted of five concentrate levels (0, 200, 400, 600, and 800 g of concentrate/kg of diet DM) in SS-based diets. The concentrates used in the experimental diets were based on corn, soybean meal, sulfated urea, virginiamycin, and mineral supplement. The diets were formulated to provide approximately 120 g of crude protein per kg dietary DM. In the 0% concentrate diet, the protein level was adjusted with sulfated urea. All diets contained the same amount of virginiamycin and mineral supplement. Each experimental period lasted 24 d, with 17 d adaptation, 4 d of total feces collection, and 3 d collection to obtain omasal flow using a double marker technique (indigestible NDF and Co-EDTA). Data were analyzed using MIXED-SAS. Starch and OM intake linearly increased (P &amp;lt; 0.001) with increasing concentrate inclusion. Intake of apNDF decreased linearly (P = 0.018) and tended to be quadratically influenced (P = 0.022) with increasing concentrate inclusion (Table 1). Ruminal digestibility of OM increased linearly (P &amp;lt; 0.001) with increasing concentrate inclusion. Starch ruminal digestibility decreased linearly (P = 0.003) and tended to be influenced quadratically (P = 0.0015) with increasing concentrate inclusion. Ruminal digestibility of apNDF tended to decrease linearly (P = 0.057) with increasing concentrate inclusion. Total apparent digestibility of OM increased linearly (P &amp;lt; 0.001) and apNDF and starch total apparent digestibility decreased linearly (P ≤ 0.002) with increasing concentrate inclusion. Increasing inclusion of concentrate in AGRI002E sorghum silage-based diets increased OM and starch intake, and ruminal and total apparent OM digestibility and decreased apNDF intake and ruminal and apNDF and starch total apparent digestibility.

Ruminal and feces metabolites associated with feed efficiency, water intake and methane emission in Nelore bulls

The objectives of this study were twofold: (1) to identify potential differences in the ruminal and fecal metabolite profiles of Nelore bulls under different nutritional interventions; and (2) to identify metabolites associated with cattle sustainability related-traits. We used different nutritional interventions in the feedlot: conventional (Conv; n = 26), and by-product (ByPr, n = 26). Thirty-eight ruminal fluid and 27 fecal metabolites were significantly different (P < 0.05) between the ByPr and Conv groups. Individual dry matter intake (DMI), residual feed intake (RFI), observed water intake (OWI), predicted water intake (WI), and residual water intake (RWI) phenotypes were lower (P < 0.05) in the Conv group, while the ByPr group exhibited lower methane emission (ME) (P < 0.05). Ruminal fluid dimethylamine was significantly associated (P < 0.05) with DMI, RFI, FE (feed efficiency), OWI and WI. Aspartate was associated (P < 0.05) with DMI, RFI, FE and WI. Fecal C22:1n9 was significantly associated with OWI and RWI (P < 0.05). Fatty acid C14:0 and hypoxanthine were significantly associated with DMI and RFI (P < 0.05). The results demonstrated that different nutritional interventions alter ruminal and fecal metabolites and provided new insights into the relationship of these metabolites with feed efficiency and water intake traits in Nelore bulls.

Relative Abundance of Spermadhesin-1 in the Seminal Plasma of Young Nellore Bulls Is in Agreement with Reproductive Parameters.

This study aimed to evaluate the proteomic profile of seminal plasma from young Nellore bulls. We used 20 bulls aged between 19.8 and 22.7 months, divided into two groups according to the results of the Breeding Soundness Evaluation (BSE): approved (FIT n = 10) and not approved (UNFIT n = 10). The scrotal perimeter was measured and a semen collection was performed through electroejaculation. The percentage of sperm motility, mass motility, and sperm vigor were calculated using conventional microscopy, and the percentage of sperm abnormalities was calculated using phase-contrast microscopy of all ejaculates. Seminal plasma was separated from spermatozoa using centrifugation and processed for proteomic analysis by LC-MS/MS. Seminal plasma proteins were identified using MASCOT Daemon software v.2.4.0 and label-free quantification analysis was carried out by SCAFFOLD Q+ software v.4.0 using the Exponentially Modified Protein Abundance Index (emPAI) method. Functional classification of proteins was performed based on their genetic ontology terms using KOG. Functional cluster analysis was performed on DAVID. There were no differences in scrotal perimeter and physical semen characteristics between FIT and UNFIT groups of bulls. The percentage of sperm abnormalities was higher (p < 0.05) in the UNFIT group of bulls. A total of 297 proteins were identified for the two groups. There were a total of 11 differentially abundant proteins (p < 0.05), two of them more abundant in FIT bulls (Spermadhesin-1 and Ig gamma-1 chain C region) and nine in UNFIT bulls (Vasoactive intestinal peptide, Metalloproteinase inhibitor 2, Ig lambda-1 chain C regions, Protein FAM3C, Hemoglobin beta, Seminal ribonuclease, Spermadhesin 2, Seminal plasma protein BSP-30kDa, and Spermadhesin Z13). Spermadhesin-1 was the protein with the highest relative abundance (36.7%) in the seminal plasma among all bulls, corresponding to 47.7% for the FIT bulls and 25,7% for the UNFIT bulls. Posttranslational modification, protein turnover, and chaperones were the functional categories with the highest number of classified proteins. Protein functional annotation clusters were related to Phospholipid efflux, ATP binding, and chaperonin-containing T-complex. The differentially abundant proteins in the group of FIT bulls were related to sperm capacitation and protection against reactive species of oxygen. In contrast, differentially expressed proteins in the group of UNFIT bulls were related to motility inhibition, intramembrane cholesterol removal and oxidative stress. In conclusion, the proteomic profile of the seminal plasma of FIT bulls presents proteins with participation in several biological processes favorable to fertilization, while the proteins of the seminal plasma of UNFIT bulls indicate a series of alterations that can compromise the fertilizing capacity of the spermatozoa. In addition, the relative abundance of spermadhesin-1 found in the seminal plasma of young Nellore bulls could be studied as a reproductive parameter for selection.

Characteristics of intramuscular collagen in calf-fed Nellore bulls and steers throughout the finishing phase

This study evaluated collagen solubility and gene expression of biomarkers for intramuscular collagen (IMCT) deposition and remodeling in the Longissimus muscle of bulls and steers through the finishing phase. Thirty-six Nellore calves were used (18 bulls and 18 steers), and six of each sexual condition were randomly assigned to be harvested at 0, 100, or 200 days on feed (DOF) to evaluate collagen characteristics in different time points throughout the finishing phase. Bulls showed a greater collagen solubility than steers (P = 0.03). The gene expression of fibrogenic markers (TGFβ1, COL1A1, and COL3A1) and IMCT remodeling mediators (MMPII, TIMPII, and LOX) were not affected by sexual condition or DOF (P > 0.05). Our data indicate that young Nellore bulls have a higher percentage of soluble intramuscular collagen, possibly due to higher collagen remodeling associated with a faster growth rate and muscle hypertrophy. Moreover, castration and DOF did not modify mRNA levels of fibrogenic and collagen remodeling markers.

Oxidative stress associated with proteomic and fatty acid profiles of sperm from Nellore bulls at rest†.

Sexual rest is a transient condition, which compromises conception rates, characterized by large volumes of ejaculate with high percentages of dead sperm observed in bulls. The biochemical mechanisms leading to this ejaculate pattern are not fully understood. Six adult resting Nellore bulls were submitted to Breeding Soundness Evaluation by four consecutive semen collections through the electroejaculation method during a 30min period. Each ejaculate had its semen phenotypic parameters; morphology and physical aspects were evaluated. To assess enzymatic activity (superoxide dismutase, catalase, and glutathione S-transferase), lipid peroxidation (concentrations of malondialdehyde and nitric oxide), fatty acid, and proteomic profile aliquots of spermatozoa from the first and fourth ejaculates were used. All sperm parameters differed between the first and fourth ejaculates. Spermatozoa from the first ejaculate showed lower enzymatic activity and a higher concentration of lipid peroxidation markers. Among the 19 identified fatty acids, 52.7% are polyunsaturated. Relative abundance analysis showed that C12:0 and C18:0 fatty acids differed between the first and fourth ejaculates, being the fourth ejaculate richer in spermatozoa. The proteomics analysis identified a total of 974 proteins in both sample groups (first and fourth ejaculates). The majority of identified proteins are related to cellular processes and signaling. Quantitative proteomics showed 36 differentially abundant proteins, 6 up-regulated proteins in the first ejaculate, and 30 up-regulated proteins in the fourth ejaculate. Spermatozoa from bulls at sexual rest have less antioxidant capacity, causing changes in their fatty acid composition and protein profile, which generates the observed sperm pattern and lower fertilization capacity.

Iodixanol supplementation in freezing extender improves the antioxidant capacity of semen.

The aim of this study was to evaluate the effect of supplementing bovine semen freezing extender with different concentrations of iodixanol on post-thaw sperm characteristics. Six ejaculates of three Nellore bulls were pooled and diluted in commercial extender (BotuBov®) and then divided into 4 groups: control group (without adding iodixanol); groups G1.5, G3, or G6 according to the concentration of iodixanol solution (RedCushion®). After dilution, the samples were cooled and frozen. Post-thaw semen evaluation included sperm motility by CASA immediately after thawing and after 60 min of incubation at 37°C, flow cytometry analysis for integrity of plasma and acrosomal membranes, membrane destabilization and translocation of phosphatidylserine, mitochondrial membrane potential, and formation of intracellular anion superoxide ( ), hydrogen peroxide (H2 O2 ), and membrane lipid peroxidation. The group G6 presented significantly higher (p < .05) total and progressive motility, percentage of plasma and acrosomal membrane integrity, and H2 O2 than control and group G1.5. Furthermore, group G6 showed lower (p < .05) lipid peroxidation than control. In addition, regardless of the concentration used, the percentage of spermatozoa without phosphatidylserine translocation was higher (p < .05) in all iodixanol supplemented groups. In conclusion, iodixanol supplementation preserved the motility and integrity of sperm membranes during cryopreservation and protected against lipid peroxidation.

Three environmental dimensions of beef cattle in tropical feedlot: Water, nutrients and land

This study aims to evaluate water, land, and nutrient efficiencies in a tropical beef feedlot system by providing artificial shading and considering local conditions and feed cultivation. The study was conducted at the Experimental Feedlot of Embrapa Southeast Livestock in Brazil. Forty-eight Nellore bulls were divided into two groups, with one group having shade (GS) and the other without shade (GWS). The animals' body weights, water intake, and dry matter intake were recorded. The water footprint was calculated using a product-focused assessment, considering water consumed in feed production and animal drinking. The nutrient balance and land footprint were also assessed. To both treatments, the crop scenario with soybean and corn first crop produced in Maringa resulted in the lowest water and land footprint values. Corn was the main contributor to green water consumption. The efficiency in water use for corn decreased between the first and second crops. The water footprint of soybean meal varied between production locations. GWS had slightly higher average blue water consumption than GS. In terms of nutrient balance, the GS treatment exhibited lower nitrogen and phosphorus balance values, indicating higher efficiency in the use of these elements. The provision of artificial shading was found to reduce the water footprint and improve nutrient use efficiency. The location of grain production and the timing of corn planting were identified as key factors influencing water and land footprint values.

Does vitamin blends supplementation affect the animal performance, carcass traits, and nutrient digestibility of young Nellore finishing bulls?

This study was realized to evaluate the effects of supplementation with blends of water and fat-soluble vitamins on animal performance and carcass traits of young Nellore bulls. Forty-three Nellore bulls, with an initial weight of 261±27.3 kg and a mean age of 8±1.0 months, were used. Five animals were slaughtered at the beginning of the experiment (reference group), to determine the initial empty body weight of the bulls that remained in the experiment. The remaining 38 bulls were fed ad libitum and distributed in a completely randomized design in a 2×2 factorial scheme, with or without supplementation of water-soluble (B-blend+ or B-blend-) and fat-soluble (ADE+ or ADE-) vitamin blends. Diets were isonitrogenous (120 g of crude protein/kg dry matter [DM] of total mixed ration) and consisted of a roughage:concentrate rate of 30:70 based on total DM of diet. The experiment lasted 170 days, with 30 days of adaptation and 140 days for data collection. At the beginning and end of the experimental period, the bulls were weighed to determine the average daily gain. To estimate the apparent digestibility of nutrients and microbial efficiency, spot collections of feces and urine were performed for five consecutive days. DM, ashes, organic matter, crude protein, ethereal extract, neutral detergent fiber corrected for residual ash and residual nitrogenous, and N intake and apparent digestibility were not influenced by vitamin supplementation, but total digestible nutrients intake and non-fibrous carbohydrates digestibility were influenced by B complex vitamin supplementation. Nitrogen balance, microbial efficiency, and performance data were not influenced (p>0.05) by vitamin supplementation. Vitamin supplementation (a blend of water-soluble and fat-soluble vitamins or their combinations) does not influence the animal performance and carcass traits of young Nellore bulls.