Nellore Calves Research Articles

Hot Iron Branding of Beef Cattle: Process Characterization, Implications for Animal Welfare, and Its Efficiency for Cattle Individual Identification

This study aimed to characterize the hot iron branding (HIB) procedure by assessing its implications for animal welfare and its efficiency for cattle identification. The study was carried out in two stages: First, with 37 Nellore calves, by measuring the skin temperatures in the place of HIB application (ONB) and 10 cm above it (OFFB) immediately after its application and during four consecutive days, the time required for application of each HIB digit and the occurrences of rebranding; second, with two batches of cows (N = 97 and N = 94, respectively, by measuring the time spent to read cattle ID and comparing the efficiency of HIB vs. EET (electronic ear tag) and visual ear tags (VET) vs. EET. Skin temperature was significantly affected by the interaction between the place where the skin temperatures were taken (on and 10 cm above the HIB) and assessment day, with temperatures in ONB on days d0 and d2 being higher than in OFFB (p < 0.05), and 86% of the calves required at least one rebranding. EET reading was faster than HIB and VET (p < 0.001), and fewer errors were made when reading EET than HIB (1/97 vs. 17/97) and VET (2/94 vs. 12/94). We concluded that HIB potentially compromises cattle welfare and has a lower efficiency for cattle identification than EET and VET.

Analysis of the influence of the birth period on the body weight of Nelore cattle

This study aimed to present the relationship between the birth period of beef cattle and the weaning weight of Nelore calves. A total of 260,832 Nelore animals from the database of the National Association of Breeders and Researchers (ANCP) were used. Out of this total, 130,001 were males (49.84%) and 130,831 were females (50.16%) of the Nelore breed conceived via artificial insemination. The animals used were born between the years 2014 and 2017 in the Southeast and Midwest regions in different months of birth. The evaluated characteristic was the weaning weight, and the assessment of these weights was defined at 210 days (standard weaning age). It was observed that there were no significant differences (P>0.05) in weaning weight between the years of birth. However, among the birth months, significant differences (P<0.05) in weaning weight were observed, with animals born between July and October (dry season) showing higher average weights. Therefore, it was concluded that the month of birth of Nelore calves can influence the weaning weight at 210 days of age, emphasizing that the weaning month is directly related to the weight gain of the animals. Therefore, a well-defined breeding season is necessary to control the ideal months for weaning heavier animals.

Effect of Creep Feeding Supplementation on Growth Performance and Metabolic Characteristics of Nellore Heifers

The objective of this paper is to evaluate the effects of creep feeding supplementation during the preweaning phase on the growth performance and metabolic characteristics of Nellore heifers. Forty-two female Nellore calves (age = 100 ± 25 d; initial body weight (BW) = 113.4 ± 16.6 kg) were randomly assigned to the following treatments: control, where calves received mineral mix supplementation (n = 21); supplemented in creep feeding, where calves received 6 g/kg BW of a concentrate supplement (n = 21) during a period of 140 d. In the postweaning phase, all heifers received 6 g/kg BW of a concentrate supplement during a period of 210 d. Supplemented heifers had a greater average daily gain (ADG) than control heifers during the preweaning phase and, consequently, were heavier at weaning and at the end of the growing phase (p < 0.05). However, preweaning supplementation did not influence (p > 0.05) the body measurements or BW at the end of the growing period. Greater (p < 0.05) rib fat was observed in supplemented heifers. Concentrations of metabolites were not affected by preweaning supplementation (p > 0.05). Thus, supplementing heifers in the preweaning phase improved growth performance of weaning and body adiposity.

PSVI-22 Effect of Creep-Feeding on Feeding Behavior of Nellore Calves

Abstract The study aimed to evaluate the effect of creep-feeding on feeding behavior of beef calves, during nursing phase. The experiment lasted 170 days; from December/2021 to May/2022, the calves were born in September/2021 and creep-feeding supplementation started from approximately 70 days of life until weaning. The feeding behavior was evaluated twice on d 70 and d 120 post creep-feeding). The experimental design used was a randomized block [blocked by body weight (BW) of calves]. The experimental units were the paddocks (8 units per treatment, ten replicates per paddock), totalling 156 pairs cow/calf (86 pairs of male calves and 70 pairs of female calves). Two paddocks per treatment and 8 pairs per paddock were sorted for behavior analysis, totalling 32 pairs cow/calf (16 pairs of male calves and 16 pairs of female calves). The treatments consisted of creep-feeding or not creep-feeding the calves: control treatment (CONT; mineral suppement ad libitum) and creep-feeding treatment (CREEP; energetic protein supplement; 5 g/kg of BW· animal-1· /day-1). There was mineral supplement ad libitum for all the dams. The pairs cow/calf were kept in an area composed of Urochloa brizantha cv. Marandu. and idleness, suckling, grazing and creep-feeding or mineral supplementation were evaluated. The data were analyzed using the SAS PROC MIXED. There was no difference in feeding behavior of calves at 70 days of creep-feeding for idleness (P = 0.80), grazing (P = 0.59) and suckling (P = 0.30; Figure 1). Creep-feeding calves spent 14 minutes longer on supplementation than non-creep-feeding calves (P < 0.01). At 120 days of creep-feeding (180 days of age), calves that received creep feeding supplementation spent less time grazing (difference of 67 min; P < 0.01), more time on supplementation (+28 min; P < 0.01) and idleness (+42 min; P = 0.05) and similar time on suckling (P = 0.76; Figure 2).There was no difference in any of the variables at different times (P >0.08) for the dams (Figure 3). Animals in creep-feeding spend less time grazing but suckling in a similar amount of time compared with those that consumed only mineral supplement, which corroborates with the results on milk yield of dams, which were similar for both treatments.

Effects of an Appeasing Substance Application at Weaning on Growth, Stress, Behavior, and Response to Vaccination of Bos indicus Calves.

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.

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.

Nutrient intake and blood profile of Nellore calves supplemented with cellulolytic fungi from rumen

ABSTRACT This study evaluates the effects of cellulolytic fungi from rumen on the nutrient intake and blood profile of Nellore calves. A diet was formulated with 56.79% lignified hay of Urochloa brizantha and 43.21% of concentrate. Sixteen Nellore calves were evaluated in completely randomized blocks using two calf groups: four males and four females. The first group was supplemented with a culture medium containing a mixture of Aspergillus terreus (VN 15 isolate) and Trichoderma longibrachiatum (VN 20 isolate). The second group received the sterile culture medium only. Ether extract ingestion was higher in the control calves; however, the supplemented calves showed a tendency to improve feed efficiency. No significant differences were detected in the blood profiles or serum biochemistry between the calf groups. Further research analyzing different dosages, adjusting the diet protein levels, and increasing the proportion of roughage could better elucidate the interference of these fungi on the performance and blood parameters of weaned Nellore calves. Highlights Nelore calves supplemented with cellulolytic fungi showed tendency of improved feed efficiency Non-supplemented calves improved ether extract ingestion. The control group did not present differences for blood and serum biochemistry profile.

Post-weaning performance of Nellore calves subject to different weaning methods

Context Different methods of weaning have been validated to reduce the stress of calves. A novel approach has been described by ranchers whereby the zebu calves are kept in the same pasture with trainer’s cows, however, no scientific evidence is available to date. Aims This study investigated the effect of different weaning methods on the physiological responses, temperament, and post-weaning performance of calves. Methods One hundred and eighty three Nellore calves were used, including 93 males (initial bodyweight: 219.8 ± 3.25 kg (avg ± s.e.), initial age: 244 ± 14.3 days (avg ± s.e.) and 90 females (219.7 ± 3.25 kg, 246 ± 14 days (avg ± s.e.)). The calves were randomly assigned to three weaning methods: Abrupt – total separation of dam and calf; Fenceline – physical separation between dam and calf by wired fence; and Leadership – total separation between dam and calf and use of social facilitator cows. Heart rate, respiratory rate and blood samples for cortisol analysis were taken on Days 0, 1, 4, and 7 post-weaning. Temperament was assessed on Days 0, 7, and 82. Performance and body condition score (BCS) was measured at 0, 42, and 82 days post-weaning. Key results No interaction (P &gt; 0.05) between the weaning methods and sex of the calves was detected. Heart and respiratory rates were not influenced (P &gt; 0.05) by weaning methods on Days 1 and 7 post-weaning. Furthermore, females showed higher heart rate at Day 7 post-weaning (P &lt; 0.05). Weaning methods and sex of calves did not affect the cortisol levels (P &gt; 0.05). Calves on Fenceline and Leadership weaning methods had higher final bodyweight and average daily gain (ADG) from weaning until 82 days post-weaning (P &lt; 0.05) compared to the Abrupt weaning method, which had negative ADG (−26 g/day) on the first 42 days and the lowest bodyweight until 82 days post-weaning (P &lt; 0.05). Conclusions The presence of social facilitators at weaning, using dams in the Fenceline method or non-related cows in the Leadership method, ensures greater post-weaning performance. The Leadership method can be the most advantageous due to its easy handling. Implications The weaning strategies contribute to good animal performance and shorten the post-weaning and finishing phases.

Short-term protein-energy supplementation at weaning or in the transition of dry-rainy season on performance of Nellore calves kept on Mombaça or Marandu grasses

Short-term protein-energy supplementation at weaning or in the transition of dry-rainy season on performance of Nellore calves kept on Mombaça or Marandu grasses

Efficacy of prepartum vaccination against neonatal calf diarrhea in Nelore dams as a prevention measure

BackgroundNeonatal calf diarrhea (NCD) is the leading cause of calf morbidity and mortality in beef cattle. Cow’s vaccination in last stage of pregnancy is one of the most important measures to mitigate the risk of NCD outbreaks. The aim of this study was to evaluate the efficacy of prepartum single dose vaccination against NCD, especially Bovine Rotavirus type A (BoRVA) and Bovine Coronavirus (BCoV), in Nelore dams and offspring. A total of 117 pregnant cows (n = 81) and heifers (n = 36) were distributed in two groups, vaccinated (VAC: cows = 40; heifers = 19) and non-vaccinated (NVAC: cows = 41; heifers = 17). Vaccination occurred between 60 to 50 days before the expected calving date with a single dose of a water-in-oil (W/O) vaccine, and NVAC group received a dose of saline solution 0.9%. Blood samples were collected before vaccination and 30 days after to evaluate the antibody (Ab) response. Specific IgG1 Abs against BoRVA and BCoV were measured by using an Enzyme Linked Immuno Sorbent Assay (ELISA). Calves’ births were monitored, and the transference of passive immunity was evaluated. Diarrhea was monitored in the first 30 days of age, and fecal samples were collected for identification of the etiological agent.ResultsHigher titers of IgG1 Ab against BoRVA and BCoV was observed in the VAC group than NVAC group in the cow (P < 0.0001) and total dams categories (P < 0.0001). The titer of specific IgG1 Abs in the calves’ serum reflected the dams response, observing higher IgG1 Ab titers for BoRVA (P < 0.0016) and BCoV (P < 0.0095) in the offspring born to VAC cows and higher IgG1 Ab titers for BoRVA(P < 0.0171) and BCoV (P < 0.0200) in the offspring born to VAC total dams. The general incidence of diarrhea observed was 18.6% (11/59) and 29.3% (17/58) in the calves born to the VAC and NVAC group, respectively.ConclusionsPrepartum vaccination with a single dose of the vaccine tested increased the titers of IgG1 Ab against BCoV and BoRVA, and it could be used as a preventive strategy to decrease the NCD occurrence in Nelore calves.

Dynamics of the Reproductive Changes and Acquisition of Oocyte Competence in Nelore (Bos taurus indicus) Calves during the Early and Intermediate Prepubertal Periods

Simple SummaryBrazil has the largest cattle commercial herd in the world, mostly of the Nelore breed (Bos taurus indicus), and it is one of the largest in vitro bovine embryo producers. However, Nelore cows experience puberty later than taurine breeds (Bos taurus taurus), which can lead to a delay in genetic improvement. Therefore, including calves as oocyte donors for in vitro embryo production programs could be an attractive step for reducing the interval between generations, accelerating the herd’s genetic gains, and contributing to the sustainability of milk and meat production systems. Nevertheless, calves’ oocytes are reported as less competent in generating embryos and establishing pregnancies than those collected from adult females. In addition, most studies have been carried out on taurines. Thus, this study’s goal was to search for a better understanding of prepubertal Nelore females’ reproductive development, related to the performance of their oocytes in terms of in vitro production of embryos. This can provide support for making decisions on the use of this animal category as an oocyte donor and prospects for hormonal protocols or changes in the culture media for in vitro embryo production.The purpose of this study was to characterize the reproductive physiology, oocyte competence, and chromatin compaction in Nelore calves in the early-prepubertal period (EPP) and the intermediate-prepubertal period (IPP). Calves aged 2–5 (EPP) and 8–11 months old (IPP) were assigned to Trial 1 (morpho-physiological–endocrine evaluations, n = 8) or Trial 2 (oocyte donors, n = 8) vs. the respective control groups of cows (n = 8, each). All morphological endpoints, except the antral follicle count, increased from the EPP to the IPP. The EPP LH-FSH plasma concentrations were similar to cows, whereas LH was lower and FSH was higher in the IPP than in cows. . Cows produced more Grade I (12.9% vs. 4.1% and 1.7%) and fewer Grade III COC (30.1% vs. 44.5% and 49.0%) than the EPP and IPP calves, respectively. The IPP calves’ oocyte diameter was similar to those from cows but greater than those from EPP females (124.8 ± 8.5 and 126.0 ± 7.5 μm vs. 121.3 ± 7.5 μm, respectively). The expression of the chromatin compaction-related gene HDAC3 was downregulated in calves. The proportion of the blastocyst rate to the controls was lower in EPP than in IPP calves (43.7% vs. 78.7%, respectively). Progressive oocyte competence was found during the prepubertal period, which can help to decide whether to recover oocytes from calves.

Influence of Elective Cesarean Calving (with and without Dexamethasone Induction) on the Erythrogram and Iron Serum Profiles in Nellore Calves.

Simple SummaryThe use of elective cesarean section has become common practice in double muscled breeds of in vitro fertilized cattle and cloned calves, particularly before the onset of labor, when it is known that cesarean section negatively affects neonatal respiration and metabolic adaptation in humans and calves. However, there is a lack of information on the effects of cesarean section on the erythrogram of calves. The objectives of this study are to characterize the hematological profile of Nellore calves born spontaneously or by elective C-section (with or without induction with dexamethasone) and to verify the frequency of anemia in these animals. Our data indicate that in the first day of life there was a decrease in the number of red blood cells, hemoglobin rates, and values of the globular volume regardless of the type of birth; however, the recovery of these hematological values happened faster in zebu calves born spontaneously than in the group born by elective C-section (with or without induction). The results suggest that iron supplementation in the first month of life in Nellore calves that underwent cesarean section could be recommended to prevent the iron deficiency anemia observed in this study.The aim of the present study is to evaluate the erythrogram and iron serum profiles of neonatal calves born spontaneously or born by elective cesarean section with or without dexamethasone induction. The research was performed on 38 newborn Nellore calves. Three groups of calves were assigned according to the type of birth: calves born by spontaneous vaginal calving (n = 10), calves born by elective cesarean section without inducing labor (n = 14), and calves born by elective cesarean section with labor induction with dexamethasone (n = 14). Blood samples to assess red blood cell count (RBC), hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), concentration of mean corpuscular hemoglobin (MCHC), serum iron (SFe), total capacity to bind iron to transferrin (TIBIC), and transferrin saturation index (TSI) were performed at calving (0, 3, 6, and 12 h of life) and on 1, 2, 3, 5, 7, 10, 15, and 30 days of life. Regardless of the experimental group (calves born spontaneously, or born by elective cesarean section with or without dexamethasone induction), in the first day of life there was a decrease in the number of red blood cells, hemoglobin rates, and values of the globular volume. In the period of the first 10 days of life, animals from spontaneous vaginal delivery quickly recovered values of erythrocytes, hemoglobin, and packed cell volume, whereas animals born by elective C-section (induced and uninduced) did not recover as quickly in their rates of hemoglobin and packed cell volume values. In calves born by elective C-section (induced and uninduced), it was observed in their period between 10 and 30 days of life that the MCV and MCH were reduced by passing the presenting microcytic hypochromic when compared with calves obtained by spontaneous vaginal delivery. In the period between 10 and 30 days of life, the levels of SFe and TSI in animals born by elective C-section (induced and uninduced) are significantly lower. The differences in the erythrogram values between Nellore calves born spontaneously and those by elective C-section with or without induction must be considered consequent to the process of neonatal adaptation to extrauterine life. Iron supplementation in the first month of life in calves from cesarean could be recommended to prevent anemia of this iron deficiency.

Effect of injectable trace mineral at weaning on growth and physiology of Nellore calves under feed restriction

Calves are susceptible to a wide variety of stressors besides the seasoning low forage availability during their weaning phase. Thus, it is ideal if they receive adequate trace mineral supplementation during this period. This study evaluated the effect of injectable trace minerals (ITM) on performance, concentration of oxidative stress enzymes, and biochemical plasmatic parameters in Nellore calves during the weaning phase and under feed restriction. A total of 30 Nellore calves were used at the age of 7 ± 1month and 176.23 ± 21.68kg of initial body weight (BW). These animals were allocated in Urochloa decumbens pasture for 28days and transferred to Urochloa brizantha cv Marandu pasture for another 28days. The treatments were: Saline (saline solution; 0.9% NaCl) and ITM (Multimin®, providing: 15mg Cu/mL, 60mg Zn/mL, 10mg Mn/mL, and 5mg Se/mL). Both treatments were applied subcutaneously in the ratio of 1mL/45kg of BW. At the end of the experiment (d 56), animals were lighter than on d 0 in both treatments (P < 0.05). However, calves that received the ITM treatment presented lower body weight (P < 0.05) on d 56, compared to those in the control group. No significant difference (P > 0.05) was observed on the concentrations of oxidative stress enzymes. Moreover, no significant difference (P > 0.05) was observed in the plasmatic parameters; these were at normal range or slightly below the concentrations described for the species. We concluded that, in a feed restriction condition, the use of ITM in weaned calves did not improve performance, and the concentration of oxidative stress enzymes, and biochemistry variables. Therefore, we do not recommend using injectable trace minerals in the concentrations used in this study in animals under such stressful conditions.

Influence of crude protein content and flint maize processing methods on the performance of early-weaning Nellore calves

AbstractThis study aims to determine the effects of dietary crude protein (CP) content of early-weaned calves; and the influence of flint maize processing methods on intake, total tract nutrient digestibilities and performance of Nellore heifer calves. Fifteen early-weaned Nellore female calves (4 ± 0.5 months; 108 ± 13.1 kg) were used. In phase 1, animals were fed one of the following diets for 112 days: 130, 145 or 160 g CP/kg dry matter (DM). In phase 2, animals received one of the two diets for 84 days: 0.60 dry ground maize grain, 0.30 whole-plant maize silage plus 0.10 mineral-protein supplement or 0.90 snaplage plus 0.10 mineral-protein supplement. In phase 1, intake and digestibility of dietary components were not affected (P &gt; 0.05) by increasing dietary CP content. Daily total urinary nitrogen (N) and urinary urea N increased (P &lt; 0.05) in response to increasing dietary CP content. Animal performance was not affected (P &gt; 0.05) by dietary CP content. In phase 2, maize processing methods did not affect (P &gt; 0.05) intake and digestibility of dietary components as well as animal performance, carcase characteristics and carcase composition. Therefore, based on the current experimental condition, we conclude that dietary CP concentrations of 130 g/kg DM can be indicated for early-weaned Nellore calves. However, more studies are recommended to validate this result and to evaluate concentrations below 130 g CP/kg DM for early-weaned Nellore calves. Moreover, snaplage could be used as an exclusive fibre and energy source for finishing cattle in feedlot.

Factors Affecting Weight Gain in Nelore Calves from Birth to Weaning in the Bolivian Tropic

Retrospective data corresponding to the period between 2002 and 2018 were used, belonging to the Cooperativa Agropecuaria Integral San Juan de Yapacan&amp;iacute;, Santa Cruz, Bolivia. Data corresponding to 663 male and female calves born to primiparous and multiparous cows were used. The calves had 13 individual weight controls. The calves had 13 individual weight controls. Variables used: Date of birth, Calf live weight at birth in kg, Calf live weight at weaning in kg, Average daily gain in kg, Live weight of cow in kg, Number of calving of cows.&#x0D; &#x0D; The mean values and standard deviations of the weights at birth were 35.1 &amp;plusmn; 4.6 kg for males and 32.3 &amp;plusmn; 4.7 kg for females, at 240 days (weaning) the weight of the males was 229 &amp;plusmn; 35.8 kg and for females 206 &amp;plusmn; 31.5 kg. The mean values and standard deviations of the weight increases were 0.807 &amp;plusmn; 0.14 kg for males and 1.0 &amp;plusmn; 0.13 kg for females. The selected model with the regressor variables: Year, Sex of the calf, Number of calving and Live Weight at Birth, all significant (p &amp;le;0.001). No interaction was significant to be considered in the model (p&amp;ge;0.05). The live weight at birth, the sex, the years and the number of deliveries of the mothers showed in this work and for the animals analyzed to be the factors affecting the increase in live weight in the rearing stage (from birth to weaning) in Nelore calves in the Bolivian tropics.

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

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

Performance and microbiota of the digestive tract of Nellore calves supplemented with fungi isolated from bovine rumen

Background and Aim:In tropical semiarid regions, supplementation with fungi could contribute to rumen modulation, promoting greater production of fibrolytic enzymes and degradation of forage. The objective of this study was to analyze the effect of supplementation with fungi, isolated from the bovine rumen, on the performance and microbiota of the digestive tract of Nellore calves.Materials and Methods:The experiment was conducted in randomized blocks evaluating eight Nellore calves that were daily supplemented with isolates of Aspergillus terreus and Trichoderma longibrachiatum, along with eight calves that were not supplemented. After 55 days, the animals were weighed, and samples of rumen fluid and feces were collected for analysis. The characteristics that showed normal distribution were subjected to analysis of variance and compared using Tukey’s test. Whereas, the variables that did not show normal distribution were subjected to the Kruskal–Wallis test, and the frequencies of the bacterial and fungal genera were compared using the Chi-square test.Results:Supplementation with fungi promoted the reduction in ruminal pH (p<0.05). However, the final live weight; average daily weight gain; total weight gain; rumen protozoa; and the count of Enterobacteriaceae, mycelial fungi, and yeasts of ruminal fluid and feces were not influenced by supplementation (p>0.05). Moreover, the protozoa Eodinium spp. was identified only in supplemented calves (p<0.05).Conclusion:Supplementation with the fungi presented the potential for use as possible additives because it did not alter the physiological parameters of the facultative anaerobic microbiota composition in the rumen and feces. In addition, it favored the presence of the ciliate genus Eodinium. However, further studies should be performed to better define suitable dosages for supplementation.

Factors Affecting Weight Gain in Nelore Calves from Weaning to Marketing in the Bolivian Tropic Authors

The objective of the work was to evaluate the factors that affect live weight gain in the rearing stage in Nelore calves in grazing systems in the Bolivian tropics. Retrospective data corresponding to the period between 2015 and 2016 were used, corresponding to 109 weaned male calves of the Nelore breed, belonging to the Foundation Technology Center on Agriculture and Livestock in Bolivia, Santa Cruz, Bolivia. The following variables were evaluated: date of birth of the calf, live weight of the calf at birth in kg, age of the father in years, age of the mother in years, live weight of the mother in kg and live weight of the calf every 30 days until its sale slaughter in kg. The weights at birth were 38.8 ± 5 kg, at 240 days (weaning) 233.2 ± 25 kg and at 600 days (sale) 482 ± 40 kg. Live weight values ​​at 600 days according to time of birth: late 488 ± 35 kg and early 479 ± 42 kg and according to the year of birth (2015) 481 ± 42 kg and (2016) 483 ± 37 kg. There was significant interaction between the Years-Epoch and time, indicating that the average final live weight over time differs between the different Year-Epoch groups. &nbsp;In addition, the variable live weight at birth was also significant (p≤0.05). For the two years (2015 and 2016) and the 4 seasons (early and late 2015; early and late 2016), the final weight increases 2.28 kg for each unit increase in live weight at birth. The live weight at birth, the years and times were shown to be the factors affecting the increase in live weight in the rearing stage in the Bolivian tropics.

Use of Postbiotics as an Immunomodulatory of the Immune Response against Brucellosis in Nellore Calves Immunized with S 19 Vaccine

Background: Brucellosis is an important public health disease and a great problem in the cattle production.&#x0D; Objectives: The aim of this study was to evaluate the immunomodulatory efficiency of a commercial postbiotic in Nellore calves immunized with the Brucella abortus S19 vaccine.&#x0D; Methods: We used 40 calves negative for Brucella spp. organizated into four treatments during 15 days: InRum (Ingulbal Ruminant®); InPro (Ingulbal Protein®); RumPro (Ingulbal Ruminant® and Ingulbal Protein®); and Cont: control. Collections of whole blood and serum samples were performed at the beginning of the administration of postbiotic and at 15, 45, 75 and 105 days after start the experiment. At 15 days, all animals received the mandatory vaccine S19. In order to assess immunological parameters, the means of total white cells counts, total lymphocytes, monocytes and neutrophils, and total IgG antibodies were determined.&#x0D; Results: It found a significative increase (P&lt;0.05) of white cells counts and serum IgG levels in the three treatment groups throughout the experiment. Additionally, we observe a tendency not significative in a greater number of lymphocytes, monocytes and neutrophils counts in the treat calves.&#x0D; Conclusion: Our results suggest that the supplementation with postbiotic is a promising alternative to modulate both the cellular and humoral immune response of S19 vaccine against bovine brucellosis.

Short Communication: Performance of steers fed on pasture receiving different seeding rates of vetch in an integrated crop-livestock system

Aim of study: To evaluate the performance of beef calves fed black oat and Italian ryegrass pasture seeded with several different seeding rates (SR) of common vetch in a crop-livestock integrated system.Area of study: The experiment was carried out in Dois Vizinhos city, Paraná, Brazil.Material and methods: An area of 8.3 ha was used, which was divided into 11 paddocks, 0.75 ha each. Nellore calves (n = 22), 7 ± 2 months old and with initial body weight of 134 ± 27 kg were used for the tests. The experimental design was completely randomised. Vetch (Vicia sativa L., ‘Amethyst’) SR treatments included 0, 15, 30, and 45 kg ha-1, in a mixture with black oat (Avena strigosa Schreb. ‘IPR 61’ and Italian ryegrass (Lolium multiflorum Lam.) pastures.Main results: There was no effect of SR on pasture productivity parameters. The increase in vetch seed in the seed mixture resulted in an increase in crude protein and neutral detergent fibre, but decreased in vitro digestibility of vetch. However, these changes did not affect the nutritional value of the pasture. Vetch SR of 30 kg ha-1 or higher allowed greater share of the legume in the pasture, thereby enhancing greater individual animal performanceResearch highlights: Vetch SR of 30 kg ha-1 or higher allowed greater share of the legume in the pasture, thereby enhancing greater individual animal performance.