Henrique Jorge Fernandes

This study evaluated the effects of protein supplementation with monensin or different inclusion levels of a phytogenic feed additive (PHYT) on performance, feeding behavior, serum protein profile, ruminal parameters, digestibility and nitrogen metabolism of grazing Nellore young bulls. Two simultaneous experiments were conducted. In Experiment 1, 120 Nellore young bulls (289 ± 17.5kg) were assigned to a completely randomized design with six treatments: Control, without additives; Mon, with monensin adjusted weekly to provide 150 mg/animal/day; and four PHYT levels adjusted weekly to provide 0.20, 0.40, 0.60, or 0.80 g/animal/day. In Experiment 2, five rumen-cannulated bulls (568 ± 46kg) were used in a 5 x 5 Latin square design to assess digestive and ruminal parameters. In Experiment 1, animals receiving 0.60 g/day of the PHYT had greater final body weight and average daily gain compared to Control and Mon animals (P < 0.05). Mon reduced supplement intake and altered supplement-feeding behavior (P < 0.05). Mon increased alpha-1-acid glycoprotein, whereas 0.60 and 0.80 g/day of the PHYT increased transferrin, IgA, and IgG concentrations (P < 0.05), suggesting a serum profile more favorable to iron homeostasis and humoral immunity. In Experiment 2, PHYT supplementation generally maintained digestive and ruminal responses, although 0.40 g/day affected crude protein digestibility and 0.20 g/day increased microbial nitrogen production (P < 0.05). Overall, PHYT supplementation at 0.60 g/day improved performance and promoted a favorable serum protein profile associated with immune competence and iron homeostasis, supporting its use as an alternative to antibiotic feed additives in grazing beef cattle.

This study aimed to identify factors and technologies that could enhance the pregnancy rate of “Nellored” females by evaluating the animal category, number of progesterone-releasing intravaginal device (DP4) uses and day of its removal, equine chorionic gonadotropin (eCG) dosage, time of fixed-time artificial insemination (FTAI), melengestrol acetate (MGA®) supplementation (before FTAI in heifers and after artificial insemination in cows), vaccination against reproductive diseases, body condition score (BCS, on a 1–5 scale), month of last calving before FTAI, and estrus expression intensity. Data from 15,618 FTAI procedures conducted across three breeding seasons (October to February of 2016/2017, 2017/2018, and 2018/2019), were evaluated. Multiparous cows showed higher pregnancy rates (45%), compared with primiparous cows (39%) and heifers (29%) (p < 0.05). Pregnancy rates decreased with lower estrus expression scores (51% for score 3, 36% for score 2 and 27% for score 1). The month of last calving before FTAI, period of the day when FTAI was performed, DP4 removal day and vaccination against reproductive diseases did not affect pregnancy rates (p > 0.05). MGA® supplementation before FTAI increased pregnancy rates in heifers from 19 to 34% (p < 0.05). The use of DP4 affected pregnancy rates (p < 0.05); however, its reuse did not have a negative impact. Higher pregnancy rates for FTAI protocols were observed in multiparous cows, animals with high estrus intensity, and a BCS of 2.5 to 3.0. Administering at least 200 IU eCG and supplementing heifers with MGA® through 26th to 13th days before FTAI is recommended.

This experiment evaluated the effects of bovine appeasing substance (BAS) administration at feedlot entry on growth, temperament, inflammation, response to vaccination, behavior, carcass characteristics, and meat quality of beef heifers. Thirty heifers were weaned and assigned to (d 0): (1) BAS (n = 15; SecureCattle; IRSEA Group) or (2) Saline (n = 15). On d 0, heifers were also vaccinated against respiratory diseases and slaughtered on d 150. Administering BAS increased (p = 0.05) average daily gain from d 6 to 45, reduced (p ≤ 0.03) plasma ceruloplasmin and serum cortisol concentrations on d 15 and 45 and increased (p = 0.03) the response to vaccination. Additionally, BAS reduced (p < 0.01) the entry scores on d 6, 15, and 45 and reduced (p = 0.05) exit scores on d 2, 6, and 15. The BAS increased (p ≤ 0.04) walking, drinking, and eating time, and tended (p ≤ 0.10) to increase lying and ruminating time. Lastly, BAS tended (p ≤ 0.10) to increase the myofibrillar fragmentation index and reduce the thiobarbituric acid reactive substance concentration in meat. Thus, BAS administration increased growth, reduced stress, and inflammation, and improved immune responses, behavior, and meat quality of heifers.

The objective of this study was to identify parameters, before the start of the breeding season, that affect the conception rate of precocious Nelore heifers through ultrasonographic ovarian evaluation and evaluation of weight and body condition score (BCS). A total of 407 heifers aged 404±69 days (≈14 months old), weighing 267.1±31.2 kg, and with mean BCS of 3.1±0.5, were used. Heifers were subjected to hormone treatment to induce cyclicity and, 30 days later, to a fixed-time artificial insemination (FTAI) [...] ABSTRACT The objective of this study was to identify parameters, before the start of the breeding season, that affect the conception rate of precocious Nelore heifers through ultrasonographic ovarian evaluation and evaluation of weight and body condition score (BCS). A total of 407 heifers aged 404±69 days (≈14 months old), weighing 267.1±31.2 kg, and with mean BCS of 3.1±0.5, were used. Heifers were subjected to hormone treatment to induce cyclicity and, 30 days later, to a fixed-time artificial insemination (FTAI)

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 < 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 < 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 > 0.05) and increased ADGs and ADGf (compared with CON and MON; P < 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.

Our objective was to evaluate the effect of a phytogenic additive in protein supplement for grazing Nellore young bulls on serum protein profile. One hundred and fourteen animals (iBW, n = 114; 273 ± 4.46 kg) were allocated for 152 days in six pastures of Brachiaria brizantha cv. Marandu (̴7 ha each), and randomly distributed in six treatments with or without additives on protein supplement (30% crude protein). Treatments were: 1) Negative Control (CON), with no additive; 2) Positive Control, with 15 ppm of Monensin (MON); 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 was offered ad libitum. Additives dosages were adjusted weekly to achieve the targeted dose/animal. Blood samples were collected in the last day and analyzed for positive acute phase proteins (increases with the inflammation response), haptoglobin (HAP) and glycoprotein (GLY); negative acute phase protein (decreases with the inflammation), transferrin (TRA); and Immunoglobulins A and G. Data were analyzed using SAS PROC GLIMMIX. Significance of 5% was adopted. Contrasts of use of Monensin, use of Digestarom, type of additive, and linear and quadratic effects of Digestarom were evaluated. Compared with MON, Digestarom decreased (P < 0.05) HAP (124 vs. 76.2 mg/dL) and GLY (1,361 vs. 85.6 mg/dL). TRA increased (P < 0.05) with Digestarom (310 and 307 mg/dL for D0.6 and D0.8, vs. 204 and 177 mg/dL for CON and MON). Digestarom increased (P < 0.05) immunoglobulins A (193, 218 and 225 mg/dL for D0.4, D0.6 and D0.8) and G (1.5 g/dL for D0.4, D0.6 and D0.8) compared with CON (IgA 146 mg/dL and IgG 0.9 g/dL) and MON (IgA 93 mg/dL and IgG 0.3 g/dL). Digestarom levels also showed a quadratic effect on TRA (including 165 and 245 mg/dL for D0.2 and D0.4) and on IgA and IgG (including 124 mg/dL and 0.8 g/dL for D0.2). Overall serum protein responses of the animals receiving Digestarom (reduced haptoglobin and glycoprotein, and graeter transferrin, IgA and IgG) demonstrates that these animals had improved immune responses and could be better able to respond to infectious and stress challenges.

An analog of a bovine-appeasing substance (BAS) was previously demonstrated to have calming effects, and it could be an alternative to alleviate the stress caused by weaning. Thus, the objective of this study was to evaluate the effects of BAS administration at weaning on growth, stress, behavior, and response to vaccination of Nellore calves. Eighty-six Nellore calves (40 females and 46 males) were abruptly weaned and randomly assigned into 1 of 2 treatments: (1) saline solution (0.9% NaCl; n = 43) and (2) BAS (Secure Catte, IRSEA Group, Quartier Salignan, France; n = 43). The solutions were topically applied (5 mL/calf) to the nuchal skin area of each animal. On d 0, before treatment application, calves were vaccinated against infectious bovine rhinotracheitis (IBR), parainfluenza-3 (PI₃) virus, and bovine viral diarrhea virus types 1 and 2 (BVDV-1 and 2). Calves from each treatment were kept in different pastures for 15 d (time of BAS action) and then moved to a single pasture. Body weight (BW), blood samples, and temperament in the chute (entry score, chute score, and exit score) were collected on d 0, 3, 8, 15, 51, and 100, and behavior on pasture on d 1, 2, 4, 5, 6, 7, and 9. Calves assigned to BAS vs. Saline treatment tended to have greater BW on d 15 (p = 0.10), tended to have lower entry scores on d 8 and 51 (p = 0.10), and chute scores on d 8 (p = 0.07), and had lower exit scores on d 8 (p = 0.02). Calves assigned to BAS vs. Saline treatment also had greater time grazing on d 7 and 9 (p < 0.01), eating concentrate on d 2, 5, and 6 (p = 0.05), walking on d 1, 2, 5, and 9 (p < 0.01), standing and ruminating on d 2, 7 and 9 (p < 0.01), and playing on d 2, 4, 6, 7, and 9 (p < 0.01). Furthermore, they had lower time lying on 1 and 2 (p < 0.01), standing on d 5 and 9 (p < 0.01), and vocalizing on d 1 and 2 (p < 0.01). Calves assigned to BAS vs. Saline treatment had greater serum titter concentrations of PI₃ t on d 15 and 51 (p = 0.05) and BVDV-1 on d 51 (p = 0.02). However, they had lower serum concentrations of cortisol on d 3 (p = 0.03). BAS administration did not affect (p ≥ 0.12) the serum titer concentration of IBR and BVDV-2 titers or the plasma concentration of haptoglobin and ceruloplasmin. The BAS administration improved BW, reduced temperament and serum cortisol concentration, and improved behavior and response to vaccination.

The aim is to evaluate the factors that affect the response to technical assistance in beef cattle farms. Data were collected from 19 rural properties with the main economic activity focused on beef cattle, assisted by the technical and managerial program (ATER). The information was got from technical visits and structured interviews for 24 months. To assess the impact of the application of technological innovations on assisted properties, we analyzed the participation of the owner in technological training and implementation of other technology besides pasture reform; productivity, profitability, and production increment were determined in the period before and after the ATER. The producers technological training could not increase (P>0.05) productivity. The best responses (P0.05) of the owners qualification and the percentage of degraded area. We can conclude that pasture reform should not be used as the only technological innovation at the beginning of the technical assistance process in beef cattle. An economic occupancy rate of the property close to 60% of the total area allows for a greater response to technological advances.

This study evaluated the structure of swards planted with Urochloa brizantha cv. BRS Paiaguas and BRS Piata under the eucalyptus shading system, fertilized via foliar at the beginning of the dry and rainy seasons. The experiment followed a randomized block design with a 4×2×2 (4 leaf fertilizer levels × 2 systems × 2 seasons) factorial arrangement. The results were analyzed using the GLIMMIX PROC of SAS University while means were compared by the T-test at 5%. Foliar fertilizer had a significant (P≤0.05) effect on cv. BRS Paiaguas stem mass under shading while the 3 and 6 L/ha levels produced the lowest (P≤0.05) masses. The forage and root masses were not significantly affected (P≥0.05) by the systems and seasons whereas the dead material mass was not influenced by the seasons. The shading system resulted in (P≤0.05) significantly lower dead material mass for both cultivars and higher (P≤0.05) leaf and stem masses for the cv. BRS Piata. In the rainy season, leaf and stem masses were greater (P≤0.05). Foliar fertilization up to 6 L/ha favored the stem control in cv. BRS Paiaguas under shading. The resulting masses of forage, dead material, and root allow concluding that the cultivars adapted well to the shading and dry season.