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The aim of this study was to evaluate the superestimulatory and superovulatory responses of cattle treated with corifollitropin-alpha, a long-acting human recombinant FSH (rhFSH). In the first and second experiments, we used Nelore (Bos indicus) heifers previously submitted to follicular wave suppression by active immunization against GnRH. In Experiment 1 (a dose-response study), heifers (n = 20) were randomly allocated into five groups, which received placebo (saline) or a single sc dose of 7.5, 15.0, 22.5 or 30.0 μg rhFSH. The heifers were subjected to daily ovarian scan and blood sampling during 11 days. We observed group, time, and group x time effects (P< 0.0001) for both average follicle size and circulating FSH concentrations, with a strong correlation (R = 0.82, P< 0.0001) between the area under curve (AUC) for both parameters. The peak concentration of FSH 24h after treatment and average follicle size at all timepoints, however, were similar (P> 0.05) between groups 22.5 and 30.0 μg. In Experiment 2, heifers (n = 18) were allocated into three groups, which received (0h) either placebo (control), 25 μg rhFSH or 130 mg pFSH (Folltropin). There was no difference (P> 0.05) in average follicle size at any moment, as well as in intrafollicular E2 at 120h or in plasma P4 seven days later between groups rhFSH and pFSH. In Experiment 3, cycling Nelore heifers (n = 20) were subjected to a wave synchronization protocol and superovulated (day 0) using a standard pFSH protocol (120 mg split in eight decreasing im doses) or with a single sc injection of 20 μg rhFSH. The number of follicles >7 mm on day 4 did not differ (P= 0.4370). Heifers receiving rhFSH had greater average follicle size on day 4 (P= 0.0005), ovulation rate (P< 0.0001), and number of CL (P= 0.0155), as well as a trend towards a greater number of ova (P= 0.07) and viable embryos (P= 0.0590). In Experiment 4, superovulation was induced with a single sc injection of 25 μg rhFSH in Girolando and Nelore cows and heifers (n = 20). None of the embryo yield endpoints differed between the two breeds (P> 0.05). In conclusion, cattle superstimulation and superovulation can be successfully induced with a single dose of a long-acting rhFSH (corifollitropin-alpha). • Cattle respond to superstimulation with corifollitropin-alpha in a dose-dependent manner. • Ovarian superovulation can be induced with 20–25 mcg of corifollitropin-alpha. • Corifollitropin-alpha is detected in circulating serum up to 11 days after treatment. [ABSTRACT FROM AUTHOR]

There may be an increased risk of metabolic disorders, such as rumen acidosis, in cattle fed high‐concentrate diets, particularly those from Bos taurus indicus genotypes, which have shown to be more sensitive to ruminal acidification. Therefore, this study aimed to estimate (co)variance components and identify genomic regions and pathways associated with ruminal acidosis in feedlot Nellore cattle fed high‐concentrate diets. It was utilized a dataset containing a total of 642 Nellore bulls that were genotyped from seven feedlot nutrition studies. The GGP Indicus 35k panel was used with the single step genome‐wide association study methodology in which the effects of the markers were obtained from the genomic values estimated by the GBLUP model. A bivariate model to estimate genetic correlations between the economically important traits and indicator traits for acidosis was used. The traits evaluated in this study that were nutritionally related to rumen acidosis included average daily gain (ADG), final body weight, time spent eating (TSE), time spent ruminating, rumenitis score (RUM), rumen absorptive surface area (ASA), rumen keratinized layer thickness (KER) and hot carcass weight (HCW). The identified candidate genes were mainly involved in the negative or non‐regulation of the apoptotic process, salivary secretion, and transmembrane transport. The genetic correlation between HCW and ASA was low positive (0.27 ± 0.23), and between ADG and ASA was high moderate (0.58 ± 0.59). A positive genetic correlation between RUM and all performance traits was observed, and TSE correlated negatively with HCW (−0.33 ± 0.21), ASA (−0.75 ± 0.48), and KER (−0.40 ± 0.27). The genetic association between economically important traits and indicator traits for acidosis suggested that Nellore cattle may be more sensitive to acidosis in feedlot systems. [ABSTRACT FROM AUTHOR]

The objective of this study was to verify the causes of the lower response of primiparous Bos indicus cows to the ovulation synchronization protocol. Two experiments were performed to evaluate the biochemical profile, oocyte and follicular cell quality (Experiment 1) and pregnancy (Experiment 2). In Experiment 1, suckled primiparous (n = 24) and multiparous cows (n = 24) were submitted to ovum pick up (OPU). On Day 0 (D0), all cows received 2 mg of estradiol benzoate (EB) and an intravaginal progesterone insert (P4). Five days (D5) after the first hormonal administration (EB + P4), all follicles larger than 3 mm were counted on each ovary, and ovum pick-up (OPU) was performed. On day 12 (D12), the intravaginal progesterone insert was removed, and measurement and aspiration of the largest follicle were performed. Blood samples were collected on D5 and D12 to evaluate the concentrations of glucose, cholesterol, NEFA, IGF-1 and insulin. In Experiment 2, suckled primiparous (n = 50) and multiparous (n = 50) cows were subjected to an ovulation synchronization protocol based on E2/P4 (D0: 2 mg EB plus P4 intravaginal insert; D8: 500 μg of cloprostenol, 1 mg cypionate estradiol and 300UI of eCG; D10: artificial insemination). In addition, blood samples were collected on D10 for evaluation of the same hormones and metabolites described in Experiment 1. In all studies, calves remained with the cows during the experimental period. In experiment 1, the number of oocytes grade 1 (P = 0.83), grade 2 (P = 0.23) and grade 3 (P = 0.51), total number of retrieved oocytes (P = 0.14), oocyte quality index (P = 0.93) and total viable oocytes (P = 0.38) did not differ between primiparous and multiparous cows. The number of follicles at the time of follicular aspiration (20.7 ± 1.5 vs. 18.0 ± 1.9; P = 0.05) and the diameter of the largest follicle on D12 (13.5 ± 0.6 vs. 11.4 ± 0.6; P = 0.04) were greater in multiparous cows, and the number of degenerated oocytes was greater in primiparous cows (1.9 ± 0.7 vs. 1.2 ± 0.3; P = 0.05). On D5, the concentrations of IGF-1 (P = 0.47), insulin (P = 0.08), total cholesterol (P = 0.47), NEFA (P = 0.77) and glucose (P = 0.55) in the blood and IGF-1 (P = 0.97) and insulin (P = 0.11) in the follicular fluid did not differ between parity groups. On D12, there was no difference in the concentrations of IGF-1 (P = 0.26), total cholesterol (P = 0.32), NEFAs (P = 0.31) and glucose (P = 0.93) in the blood between primiparous and multiparous cows, however, the serum insulin concentration (P = 0.04) was higher in primiparous cows. There was no correlation between serum and follicular fluid insulin concentrations (r = 0.17; P = 0.31), however, there was a low correlation between serum and follicular fluid IGF-1 concentrations (r = 0.47; P = 0.002). Quantification of transcripts did not differ between parity groups. In experiment 2, concentrations of NEFA (P = 0.12) and insulin (P = 0.16) in the blood and P/AI (P = 0.93) did not differ between parity [60 % (30/50) primiparous vs. 60 % (30/50) multiparous]. In contrast, blood concentrations of IGF-1 (P = 0.0001), total cholesterol (P = 0.005) and glucose (P = 0.01) were greater in primiparous cows. It was concluded that the oocyte quality and expression of the genes evaluated in the granulosa cells were not different between primiparous and multiparous cows. Unexpectedly, the pregnancy rate did not differ between parity. Nevertheless, the blood concentrations of IGF-1, total cholesterol and glucose were greater in primiparous cows. • The concentrations of metabolic markers and hormones were greater in primiparous cows. • Oocyte quality did not differ between primiparous and multiparous cows. • Primiparous cows had a higher number of degenerated oocytes. [ABSTRACT FROM AUTHOR]

Simple Summary: Global livestock production systems face feed availability and cost challenges, particularly for high-quality fattening beef cattle. Thus, we require research on grain-rich energy alternatives in their diets. Our study investigated the impact of substituting cassava pulp with broken rice and cassava chips in crossbred Holstein steer diets and the practical implications on the ruminant feeding system. The findings indicate that while broken rice is a superior nutrient compared to cassava pulp and chips, it significantly increased the feed costs. However, substituting cassava pulp and chips positively influenced the ensilage quality and microbial populations without adverse effects on feed intake, enteric methane emissions, and energy utilization. These results suggest that broken rice, an agro-industrial by-product, could be an efficient alternative grain-rich feed resource for ruminants. This study highlights the potential benefits of strategic feeding strategies using broken rice, particularly in tropical cattle production systems. This study evaluates the effects of substituting cassava pulp with broken rice and cassava chips in the total mixed ration silage diets of beef cattle on feed composition, ensiling quality, digestibility, and energy utilization. Fifteen Holstein Thai native crossbred (89% Bos taurus × 11% Bos indicus) steers in the fattening phase, with an average age of 2.5 ± 0.1 years and an initial body weight of 603.7 ± 14.3 kg, were used in the energy balance trial. Using a randomized complete block design with five replications, the steers received one of three treatments. The three dietary treatments included substituting cassava pulp with cassava chips and broken rice on a dry matter basis with ratios of 50:0:0, 30:20:0, or 10:20:20. The results show that broken rice is a superior nutrient source and provides greater energy balance (p < 0.01). Despite the cost implications, substituting cassava pulp and chips positively impacts the ensilage pH and reduces the acetic acid concentration (p < 0.01). There was an increase in the lactic acid bacteria count (p < 0.05) and a reduction in the rumen ammonia, propionate, and butyrate concentrations (p < 0.05) without adverse effects (p > 0.05) on digestibility, blood metabolites, or enteric methane emissions. These findings suggest that broken rice is a promising alternative grain-rich ruminant feed. Future research should explore on-farm long-term feeding and economic evaluations to provide a more comprehensive understanding of the practical implications. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to identify suitable polynomial regression for modeling the average growth trajectory and to estimate the relative development of the rib eye area, scrotal circumference, and morphometric measurements of Guzerat young bulls. Methods A total of 45 recently weaned males, aged 325.8±28.0 days and weighing 219.9±38.05 kg, were evaluated. The animals were kept on Brachiaria brizantha pastures, received multiple supplementations, and were managed under uniform conditions for 294 days, with evaluations conducted every 56 days. The average growth trajectory was adjusted using ordinary polynomials, Legendre polynomials, and quadratic B-splines. The coefficient of determination, mean absolute deviation, mean square error, the value of the restricted likelihood function, Akaike information criteria, and consistent Akaike information criteria were applied to assess the quality of the fits. For the study of allometric growth, the power model was applied. Results Ordinary polynomial and Legendre polynomial models of the fifth order provided the best fits. B-splines yielded the best fits in comparing models with the same number of parameters. Based on the restricted likelihood function, Akaike’s information criterion, and consistent Akaike’s information criterion, the B-splines model with six intervals described the growth trajectory of evaluated animals more smoothly and consistently. In the study of allometric growth, the evaluated traits exhibited negative heterogeneity (b

Objective: The aim of this study was to identify suitable polynomial regression for modeling the average growth trajectory and to estimate the relative development of the rib eye area, scrotal circumference, and morphometric measurements of Guzerat young bulls. Methods: A total of 45 recently weaned males, aged 325.8±28.0 days and weighing 219.9±38.05 kg, were evaluated. The animals were kept on Brachiaria brizantha pastures, received multiple supplementations, and were managed under uniform conditions for 294 days, with evaluations conducted every 56 days. The average growth trajectory was adjusted using ordinary polynomials, Legendre polynomials, and quadratic B-splines. The coefficient of determination, mean absolute deviation, mean square error, the value of the restricted likelihood function, Akaike information criteria, and consistent Akaike information criteria were applied to assess the quality of the fits. For the study of allometric growth, the power model was applied. Results: Ordinary polynomial and Legendre polynomial models of the fifth order provided the best fits. B-splines yielded the best fits in comparing models with the same number of parameters. Based on the restricted likelihood function, Akaike's information criterion, and consistent Akaike's information criterion, the B-splines model with six intervals described the growth trajectory of evaluated animals more smoothly and consistently. In the study of allometric growth, the evaluated traits exhibited negative heterogeneity (b<1) relative to the animals' weight (p<0.01), indicating the precocity of Guzerat cattle for weight gain on pasture. Conclusion: Complementary studies of growth trajectory and allometry can help identify when an animal's weight changes and thus assist in decision-making regarding management practices, nutritional requirements, and genetic selection strategies to optimize growth and animal performance. [ABSTRACT FROM AUTHOR]

Calving interval (CI) measures the number of days between two consecutive calves of the same cow, and previous studies based on phenotype and pedigree data reported low heritability for this trait. However, the genetic architecture of CI in the Nellore breed was not evaluated based on genomic data. Thus, this study aimed to estimate the heritability based on genomic data and carry out a genome-wide association study (GWAS) for CI in the Nellore breed, using 12,599 pedigree records, 5078 CI records, and 3818 animals genotyped with 50k SNPchip panel. Both quality control and GWAS were performed in BLUPF90 family packages, which use the single-step genomic best linear unbiased predictor (ssGBLUP) method. The average CI was 427.6 days, with a standard deviation of 106.9 and a total range of 270–730 days. The heritability estimate was 0.04 ± 0.04. The p-values of GWAS analysis resulted in a genomic inflation factor (lambda) of 1.08. The only significant SNP (rs136725686) at the genome-wide level (p-value = 1.53E-06) was located on BTA13. Other 19 SNPs were significant at the chromosome-wide level, distributed on BTA1, 2, 3, 6, 10, 13, 14, 17, 18, 22, and 26. Functional annotation analysis found thirty-six protein-coding genes, including genes related to cell cycle (RAD21 , BCAR3), oocyte function (LHX8 , CLPX , UTP23), immune system (TXK , TEC , NFATC2), endocrine function (LRRFIP2 , GPR158), estrous cycle (SLC38A7), and female fertility (CCK , LYZL4 , TRAK1 , FOXP1 , STAC). Therefore, CI is a complex trait with small heritability in Nellore cattle, and various biological processes may be involved with the genetic architecture of CI in Nellore cattle. • This is the first GWAS analysis for the calving interval in a Zebu cattle breed. • GWAS analysis found 20 SNPs associated with calving interval. • 36 protein-coding genes were found near the SNPs associated with calving interval. • Various significant SNPs are in regions where 70 QTLs were previously reported. • Various significant SNPs are in signature selection reported for cattle. [ABSTRACT FROM AUTHOR]

For decades, inbreeding in cattle has been evaluated using pedigree information. Nowadays, inbreeding coefficients can be obtained using genomic information such as runs of homozygosity (ROH). The aims of this study were to quantify ROH and heterozygosity‐rich regions (HRR) in a subpopulation of Guzerá dual‐purpose cattle, to examine ROH and HRR islands, and to compare inbreeding coefficients obtained by ROH with alternative genomic inbreeding coefficients. A subpopulation of 1733 Guzerá animals genotyped for 50k SNPs was used to obtain the ROH and HRR segments. Inbreeding coefficients by ROH (FROH), by genomic relationship matrix based on VanRaden's method 1 using reference allele frequency in the population (FGRM), by genomic relationship matrix based on VanRaden's method 1 using allele frequency fixed in 0.5 (FGRM_0.5), and by the proportion of homozygous loci (FHOM) were calculated. A total of 15,660 ROH were identified, and the chromosome with the highest number of ROH was BTA6. A total of 4843 HRRs were identified, and the chromosome with the highest number of HRRs was BTA23. No ROH and HRR islands were identified according to established criteria, but the regions closest to the definition of an island were examined from 64 to 67 Mb of BTA6, from 36 to 37 Mb of BTA2 and from 0.50 to 1.25 Mb of BTA23. The genes identified in ROH islands have previously been associated with dairy and beef traits, while genes identified on HRR islands have previously been associated with reproductive traits and disease resistance. FROH was equal to 0.095 ± 0.084, and its Spearman correlation with FGRM was low (0.44) and moderate‐high with FHOM (0.79) and with FGRM_0.5 (0.80). The inbreeding coefficients determined by ROH were higher than other cattle breeds' and higher than pedigree‐based inbreeding in the Guzerá breed obtained in previous studies. It is recommended that future studies investigate the effects of inbreeding determined by ROH on the traits under selection in the subpopulation studied. [ABSTRACT FROM AUTHOR]

This study evaluated the efficacy of the administration of different doses of equine chorionic gonadotropin (eCG; 0 IU, 200 IU, or 300 IU) at the time of the progesterone device removal in 2‐year‐old Nelore (Bos indicus) heifers synchronized for fixed‐timed artificial insemination (FTAI). On day 0 (D0), a total of 398 heifers received 2 mg of oestradiol benzoate i.m., 0.53 mg of cloprostenol i.m., and an eight‐day previously used (second use) intravaginal device containing 1 g of progesterone (P4). Eight days later (D8), simultaneous with the P4 device removal, 0.5 mg of oestradiol cypionate i.m. and 0.53 mg of cloprostenol i.m. were administered. At the same time, heifers were randomly assigned to receive one of the following treatments: G‐0 IU (n = 141; no eCG treatment), G‐200 IU (n = 132; treated with 200 IU of eCG), and G‐300 IU (n = 125; treated with 300 IU of eCG). FTAI was performed 48 h after the P4 device removal (D10). Ultrasonographic evaluations were performed at D0, D10, and D17. Heifers were scanned to measure the size of the largest follicle (LF), the presence, number, and size of the corpus luteum (CL), and the ovulation rate. Subsequently, at D40, the heifers underwent scanning to determine the pregnancy rate and identify any twin pregnancies. Additionally, at D70, scans were performed to assess pregnancy loss (PG). Data were analysed by orthogonal contrasts [C1 (eCG effect): control x (200 IU + 300 IU) and C2 (eCG dose effect): 200 IU × 300 IU]. On D0, CL presence was similar between the groups [G‐0 IU = 65.2% (92/141), G‐200 IU = 55.3% (73/132), and G‐300 IU = 63.2% (79/125); p =.16]. No interactions between the presence of CL on D0 and eCG treatment were found for any of the variables (p >.05). The diameter of the LF at FTAI (D10) was not influenced by eCG treatment (p =.22) or eCG dose (p =.18). However, treatment with eCG increased the diameter of the CL at D17 (G‐0 IU = 15.7 ± 0.3 mmb, G‐200 IU = 16.6 ± 0.2 mma, and G‐300 IU = 16.6 ± 0.3 mma; p =.001), regardless of the dose used (p =.94). The ovulation rate was higher in heifers treated with eCG [G‐0 IU = 79.4%b (112/141), G‐200 IU = 90.2%a (119/132), and G‐300 IU = 93.6%a (117/125); p =.002], but there was no effect of eCG dose (p =.36). Pregnancy per AI (P/AI) on D40 [G‐0 IU = 32.6%b (46/141), G‐200 IU = 42.4%a (56/132), and G‐300 IU = 42.4%a (53/125); P = 0.05] and D70 [G‐0 IU = 29.1%b (41/141), G‐200 IU = 40.9%a (54/132), and G‐300 IU = 40.8%a (51/125); p =.02] were higher on heifers that received eCG; however, no dose effect was observed for P/AI on D40 (p =.89) nor D70 (p =.98). Pregnancy loss between D40 and D70 tended to reduce (p =.07) in eCG‐treated heifers without dose effect (p =.91). Heifers with CL at D0 presented a greater follicle diameter (LF) on D10 (With CL = 11.2 ± 0.2 mm and Without CL = 10.2 ± 0.2 mm; p =.05), CL diameter on D17 (With CL = 15.8 ± 0.03 mm and Without CL = 11.8 ± 0.6 mm; p =.01), and ovulation rate [With CL = 95.5% (233/244) and Without CL = 74.7% (115/154); p =.01]. However, no difference in pregnancy rate at D40 (p =.52) and D70 (p =.84) was found. In conclusion, eCG treatment increases ovulation and pregnancy rates of heifers submitted to a FTAI protocol. Furthermore, eCG treatment increases the diameter of the CL after FTAI and reduces pregnancy losses. No dose effect was observed, suggesting Nelore (Bos indicus) heifers respond to 200 IU of eCG treatment for FTAI. [ABSTRACT FROM AUTHOR]

Objective 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. Methods 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. Results 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. Conclusion 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.

This study evaluates the effects of substituting cassava pulp with broken rice and cassava chips in the total mixed ration silage diets of beef cattle on feed composition, ensiling quality, digestibility, and energy utilization. Fifteen Holstein Thai native crossbred (89% Bos taurus × 11% Bos indicus) steers in the fattening phase, with an average age of 2.5 ± 0.1 years and an initial body weight of 603.7 ± 14.3 kg, were used in the energy balance trial. Using a randomized complete block design with five replications, the steers received one of three treatments. The three dietary treatments included substituting cassava pulp with cassava chips and broken rice on a dry matter basis with ratios of 50:0:0, 30:20:0, or 10:20:20. The results show that broken rice is a superior nutrient source and provides greater energy balance (p < 0.01). Despite the cost implications, substituting cassava pulp and chips positively impacts the ensilage pH and reduces the acetic acid concentration (p < 0.01). There was an increase in the lactic acid bacteria count (p < 0.05) and a reduction in the rumen ammonia, propionate, and butyrate concentrations (p < 0.05) without adverse effects (p > 0.05) on digestibility, blood metabolites, or enteric methane emissions. These findings suggest that broken rice is a promising alternative grain-rich ruminant feed. Future research should explore on-farm long-term feeding and economic evaluations to provide a more comprehensive understanding of the practical implications.

In vitro embryos production from prepubertal heifers can help contribute to breeding programs; however, strategies are necessary to increase their embryo production. The aim of this study was to investigate the effects of two nutritional plans on oocyte recovery, embryo production and growth performance of prepubertal Nelore heifers. Thirty-four Nelore heifers with age of 6.5 months were divided into two feeding treatments (NP1 and NP2). The NP1 diets served as the control and NP2 diets were formulated to contain an average of 1.22-fold more energy than NP1. After 3 months of supplementation, the animals underwent follicular aspiration (ovum pick-up, OPU) every 21 d for 3 months and embryos were produced in vitro. Wither height, chest depth, body weight and subcutaneous fat of animals were measured. The number of retrieved and viable oocytes per OPU were 1.49-fold and 1.42-fold greater in NP2 heifers (p = 0.018 and p = 0.049, respectively) than those in NP1 heifers. Heifers administered NP2 produced 29.7% blastocysts, a percentage higher than NP1 animals that produced 24.40% embryos (p < 0.05). Consequently, females in the NP2 treatment showed improved body development. These results indicate a positive effect of a higher energy diet on assisted reproduction and body development in prepubertal heifers. [ABSTRACT FROM AUTHOR]

Objective: 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. Methods: 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. Results: 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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

The effect of frame score (EC) in Brahman heifers on follicular development and body growth at puberty was evaluated. Ten prepubertal heifers were grouped according to their EC, categorized as small and large. Follicular ovarian development, ovulation, and corpus luteum formation were monitored through ultrasound. Measurements of body growth characteristics were taken every 14 days. Correlation and variance analyses were conducted using SAS (9.6) correlation and GLM procedures. The EC of large heifers was 10% higher than that of small heifers (P<0.0001). EC was significant for the total number of follicles (NTF) at puberty; small heifers had an average of 15.65 follicles versus 12.69 follicles in large heifers at puberty (P<0.0001). Furthermore, a negative correlation (P<0.0001) was observed between days to puberty and the weight of the animals and EC (-0.33 and -0.35, respectively). EC in Brahman heifers only had an effect on NTF; however, animals in each group maintained a similar EC throughout the study and were different between groups at puberty. [ABSTRACT FROM AUTHOR]

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Copyright of Akofena is the property of Universite Felix Houphouet Boigny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The sperm interacts with seminal plasma proteins during its transport through the female reproductive tract to reach the oocyte. Seminal plasma proteins have been associated as biomarkers of fertility in bovine males, while two-dimensional electrophoresis in polyacrylamide gels under denaturing conditions (2D-PAGE) is a useful technique for their separation, allowing their subsequent analysis with the aid of specialised software. Brahman bulls are known for their tolerance to tropical conditions such as low-quality pastures, high temperatures, and relative humidity as well as moderate resistance to infestations by parasites and insects. The present study describes the two-dimensional electrophoretic profiles of the seminal plasma proteins in the rainy and dry seasons, associating them with the fertility of Brahman bulls in the Colombian Orinoquía in a 90-days breeding season and a single-sire mating system (1 bull per 50 Brahman cows) with 60 consecutive days of rest. The fertility-related seminal plasma protein spots increased in the dry season. Likewise, a meaningful relationship was found between the protein spots that possibly coincide with the Binder of Sperm Proteins. It was also found that bulls with the highest percentages of pregnancy also had similarities in their 2D seminal plasma maps. We conclude that the seminal plasma protein profile of Brahman bulls raised in the Colombian low tropic changes between rainy and dry seasons, and such changes may influence the reproductive performance of those animals. [ABSTRACT FROM AUTHOR]

This study investigated the effects of substituting rice straw with cassava in total mixed ration silage on feed intake, digestibility, rumen fermentation, ruminating activity, and energy balance. An energy balance experiment was conducted to determine nutrient and energy utilization in dairy bulls. Four Holstein Friesian (HF) crossbred young bulls (93.19% HF × 6.81% Native Thai; average age of 12.08 ± 0.22 months and body weight of 266 ± 9.80 kg) were used in a 4 × 4 Latin square design with four 28-d periods. The four dietary treatments included substituting cassava with rice straw on a 50, 150, 250, and 350 g/kg dry matter basis. Increasing the amount of cassava in the diet resulted in linearly decreased rumination behaviors and enteric methane emissions (p < 0.05) but a linear increase in feed intake and digestibility, total volatile fatty acid concentration, and propionic acid: acetic acid ratio in the rumen fluid (p < 0.05), thus leading to a greater energy balance status (p < 0.01). Our results indicated that replacing cassava with rice straw from 5% to 35% in the ration of Holstein bulls resulted in a substantial reduction in physically effective fiber and chewing time but improved nutrient and energy supply. The metabolizable energy requirement for the maintenance of crossbred dairy bulls was estimated to be 599.9 kJ/kg metabolic body weight and the efficiency of metabolizable energy used for growth was 0.88. We concluded that cassava is a good energy feed resource for Holstein crossbred bulls in the tropics. [ABSTRACT FROM AUTHOR]

Simple Summary: Zebu cattle can produce food in high quantity and quality under adverse farming conditions due to their greater tolerance to heat stress and resilience to parasites compared to taurine breeds. With advances in genetic improvement programs, Gyr dairy cows currently have production rates comparable to those of some taurine herds. The present study aimed to characterize the metabolic profile (energy, protein, and mineral metabolism) of Gyr cows during the transition period, which comprises the 21 days before and after parturition. This period constitutes a fundamental phase in the life of a dairy cow, as significant hormonal and metabolic changes occur, which can predispose the cow to diseases, in addition to affecting its productive indices. This study provides relevant information by showing that high-yielding Gyr cows are metabolically balanced and less predisposed to disease during the transition period compared to taurine dairy breeds. The possibility of rearing this Zebu breed in the tropical regions of the world with excellent production rates highlights the importance of this subject. This study aimed to evaluate the effects of parity, body condition score (BCS) at calving, and milk yield on the metabolic profile of Gyr (Zebu) cows. Healthy cows in late pregnancy were grouped according to parity (primiparous, biparous, and multiparous); to BCS scale at calving (high—HBCS and normal—NBCS); and to milk yield (high—HP and moderate—MP production). BCS was assessed, and blood samples were collected on −21, −7, 0, 7, 21, and 42 days relative to parturition. The concentrations of non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), cholesterol, glucose, total protein (TP), albumin, total calcium (Ca), phosphorus (P), and magnesium (Mg); and activities of aspartate aminotransferase and gamma-glutamyltransferase were measured. Data were analyzed by two-way repeated measures ANOVA. The frequencies of high lipomobilization, subclinical ketosis, subclinical hypocalcemia (SCH), and the occurrence of diseases during early lactation were established. Regardless of grouping, NEFA, BHB, and cholesterol increased during early lactation; glucose showed higher values at calving; TP and albumin were higher at 21 and 42 DIM; and Ca, P, and Mg were lower at calving. Parity had little effect on the metabolic profile, HBCS did not differ from NBCS cows, and HP did not differ from MP cows in most metabolites. High lipomobilization in early lactation and SCH at calving were the most common imbalances but were not related to postpartum diseases. High-yielding Gyr cows have a balanced metabolic profile during the transition period, with few biologically relevant effects of parity, BCS at parturition, or milk yielded. [ABSTRACT FROM AUTHOR]

A structural variant (SV) in the agouti signaling protein gene (ASIP), namely ASIP‐SV1, has been found to strongly correlate with the darkness of hair coat in specific regions of the body of bulls from the zebu (Bos indicus) Nellore breed. Here we visually analyzed the whole‐genome sequence of zebu and taurine (Bos taurus) cattle to elucidate the extent of spread of ASIP‐SV1 in different cattle populations. Of 216 sequences analyzed, 63 zebu (45.9%) and five taurine (6.3%) animals had at least one copy of ASIP‐SV1. Four of the taurine animals presenting the SV were Romagnola cattle, a breed with history of zebu introgression. The remaining taurine animal was a Simmental, a breed frequently used in crossbreeding. These data provide evidence that ASIP‐SV1 is commonly found in zebu populations, in addition to taurine animals with zebu admixture. [ABSTRACT FROM AUTHOR]

Simple Summary: The prenatal environment can influence the postnatal performance of cattle. Especially in tropical regions, pregnant beef cows may experience nutritional restriction during gestation, which coincides with the season of poor quality and quantity of feed. Thus, it was verified that the offspring of cows subjected to a better gestation environment exhibited better productive and reproductive performances throughout their lives. In terms of genetic merit, it was found that the best animals in a restricted gestational environment are not necessarily the same in a favorable gestational environment. In other words, for each condition of the gestational environment, there are animals specifically suited to perform better. In addition, regions in the genome of these animals responsible for several traits of economic importance in cattle were identified. Thus, for a more efficient selection process, breeders must consider the effect of genotype by prenatal environment interaction and provide adequate management and nutrition care for pregnant cows. The prenatal environment is recognized as crucial for the postnatal performance in cattle. In tropical regions, pregnant beef cows commonly experience nutritional restriction during the second half of the gestation period. Thus, the present study was designed to analyze the genotype by prenatal environment interaction (G × Epn) and to identify genomic regions associated with the level and response in growth and reproduction-related traits of beef cattle to changes in the prenatal environment. A reaction norm model was applied to data from two Nelore herds using the solutions of contemporary groups for birth weight as a descriptor variable of the gestational environment quality. A better gestational environment favored weights until weaning, scrotal circumference at yearling, and days to first calving of the offspring. The G × Epn was strong enough to result in heterogeneity of variance components and genetic parameters in addition to reranking of estimated breeding values and SNPs effects. Several genomic regions associated with the level of performance and specific responses of the animals to variations in the gestational environment were revealed, which harbor QTLs and can be exploited for selection purposes. Therefore, genetic evaluation models considering G × Epn and special management and nutrition care for pregnant cows are recommended. [ABSTRACT FROM AUTHOR]

The use of sensors for livestock monitoring has grown in the last decade, motivated not only by the search for improvements in animal production and health, but also by the better use of physical, financial, and human resources in the management of livestock. Since precision livestock farming depends on technological innovation, including the use of sensors, it is essential to validate their applicability in confined animals. Therefore, the objective was to evaluate the functioning of the SCR Heatime® HR System sensor in heifers and analyze the behavioral differences of these animals in two feedlot systems (tie-stall and loose-housing). Eleven Gyr heifers of 10 months of age and an average body weight of 179 ± 26 kg were used. Animals were equipped with the SCR Heatime® HR System 7 days before the evaluations for adaptation, with the behavioral and system studies carried out during two periods each of 5 days, for 8 h a day. Five heifers were housed in tie-stall bedding and six were housed in loose-housing. After the evaluations for a period, animals have been switched systems in the following period. While the animals had the sensors attached to their bodies, behavioral evaluations were also performed visually, every 3 min by two evaluators per system. Behavior activities were characterized as standing, lying, idle standing, idle lying, ruminating standing, ruminating lying, feed, and water intake. The regression for the rumination activity recorded between the sensor and the visual assessment was significant only for loose-housing (P = 0.0002), but the Pearson correlation between both was negative and low (r = − 0.25; P = 0.0002). The sensor overestimated rumination by 27.3% in loose-housing (28 vs. 22 min/2 h) and 38.5% in tie-stall (36 vs. 26 min/2 h). Thus, when considering the different feedlot systems, validation was not possible due to the overestimation of time spent on rumination activity determined by the sensor. In the behavioral comparison between the systems by visual assessment, there was a significant difference (P < 0.05) for the behaviors of motor activity, idle lying, total idle time, and feed intake between the animals in the two housing systems. As for idle standing, ruminating standing, total rumination time, and water intake, there was no difference (P > 0.05). However, the time spent ruminating lying was greater from 10:00 to 12:00 h (43 ± 3 min/2 h) in the tie-stall, whereas in the loose-housing the animals distribute more uniformly their rumination from 08:00 to 16:00 h (26 min/2 h on average). Therefore, the use of the SCR Heatime® HR System sensor is not recommended for Gyr heifers housed in tie-stall and loose-housing systems. Regarding the daytime range of rumination and the accuracy improvements of similar sensors, it is recommended to develop them in both feedlot systems using the periods of less rumination in early morning in tie-stall and late afternoon in loose-housing. [ABSTRACT FROM AUTHOR]

In this paper a 5-year-old Brahman breed bovine is reported, which was submitted by presenting a mass in the third eyelid of the left eye which obstructed vision. Histopathological analysis of the submitted sample shows a well-differentiated squamous cell carcinoma with no evidence of lymphovascular invasion. The therapeutic management consisted of exenteration to avoid recurrences, for which the patient's evolution was satisfactory without causing problems in his productive performance. It has been described that a possible risk factor is related to permanent exposure to sunlight that affects the replication of DNA in cells and induces tumor processes. While it is true; in cattle breeding systems where females spend most of the time grazing and are exposed to ultraviolet radiation, this would explain the reason for the presentation of this neoplasm in this type of patient. In this sense, it is essential to pay attention and monitor abnormalities that may occur in cattle, whether Zebu or Taurine. [ABSTRACT FROM AUTHOR]

Background: Given the economic relevance of fertility and reproductive traits for the beef cattle industry, investigating their genetic background and developing effective breeding strategies are paramount. Considering their late and sex-dependent phenotypic expression, genomic information can contribute to speed up the rates of genetic progress per year. In this context, the main objectives of this study were to estimate variance components and genetic parameters, including heritability and genetic correlations, for fertility, female precocity, and semen production and quality (andrological attributes) traits in Nellore cattle incorporating genomic information. Results: The heritability estimates of semen quality traits were low-to-moderate, while moderate-to-high estimates were observed for semen morphological traits. The heritability of semen defects ranged from low (0.04 for minor semen defects) to moderate (0.30 for total semen defects). For seminal aspect (SMN_ASPC) and bull reproductive fitness (BULL_FIT), low (0.19) and high (0.69) heritabilities were observed, respectively. The heritability estimates for female reproductive traits ranged from 0.16 to 0.39 for rebreeding of precocious females (REBA) and probability of pregnancy at 14 months (PP14), respectively. Semen quality traits were highly genetically correlated among themselves. Moderate-to-high genetic correlations were observed between the ability to remain productive in the herd until four years of age (stayability; STAY) and the other reproductive traits, indicating that selection for female reproductive performance will indirectly contribute to increasing fertility rates. High genetic correlations between BULL_FIT and female reproductive traits related to precocity (REBA and PP14) and STAY were observed. The genetic correlations between semen quality and spermatic morphology with female reproductive traits ranged from -0.22 (REBA and scrotal circumference) to 0.48 (REBA and sperm vigor). In addition, the genetic correlations between REBA with semen quality traits ranged from -0.23 to 0.48, and with the spermatic morphology traits it ranged from -0.22 to 0.19. Conclusions: All male and female fertility and reproduction traits evaluated are heritable and can be improved through direct genetic or genomic selection. Selection for better sperm quality will positively influence the fertility and precocity of Nellore females. The findings of this study will serve as background information for designing breeding programs for genetically improving semen production and quality and reproductive performance in Nellore cattle. [ABSTRACT FROM AUTHOR]

Simple Summary: Maternal care and protective behavior have important roles in offspring survival. For Zebu dairy cattle, these maternal behaviors are even more relevant, influencing both productive performance and handler safety, as many dairy farms use cow–calf contact systems. The objectives of this study were to investigate the effects of a training protocol involving pre-calving positive tactile stimulation on the post-calving maternal care and protective behavior of primiparous Gyr cows. These cows (n = 37) were allocated into two groups: training (n = 16) and control (n = 21). Various maternal behaviors were evaluated. Calf latency to stand up, body weight, and sex influenced cow–calf interactions, whereas the training group cows touched less and spent more time not interacting with their calves. Both the training and control groups had protective dams, but a higher percentage of the trained group dams were calmer toward calf handling. We concluded that the primiparous dairy Gyr cows subjected to the pre-calving positive tactile stimulation training protocol tended to be less protective on the first handling of their calves and presented less maternal care. In dairy systems with Zebu breeds, calves are not immediately separated from their dams after calving; consequently, maternal care and protective behavior are important, influencing both productive performance and stockpeople's safety. Our objectives were to: (1) investigate the effects of a training protocol involving pre-calving positive stimulation, delivered prior to calving, on the maternal care of primiparous Gyr cows; and (2) evaluate the effects of this training protocol on maternal protective behavior towards handlers during the first calf handling. Primiparous dairy Gyr cows (n = 37) were allocated into two groups: training (n = 16) and control (n = 21). Animal behaviors were recorded in three periods: post-calving, first calf handling, and post-handling. Maternal protective behavior during calf handling was assessed from measures of aggressiveness, attention, displacement, and agitation. Calf latency to stand up (p < 0.01) and sex (p < 0.01) differed between the training and control groups. The training group had less touching (p = 0.03), more time not interacting with the calf (p = 0.03), tended to be less protective (p = 0.056), and moved less (p < 0.01) during the first handling of their calves. In conclusion, the primiparous dairy Gyr cows subjected to pre-calving training protocol displayed less maternal care and displacement during the first handling of their calves and tended to be less protective. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of hanging the carcass by the Achilles tendon (AS) versus pelvic suspension (PS) on meat quality traits. Bos indicus carcasses of two distinct biological types/sex categories comprised 10 young Brangus heifers and 10 Nellore bulls which were finished in a feedlot. Half-carcasses of each biological type/sex category were randomly hung using Achilles suspension (n = 20, AS) or pelvic suspension (n = 20, PS) for 48 h. At boning, longissimus samples were collected for evaluation by untrained consumers for tenderness, liking of flavor, juiciness and overall acceptability, after aging for 5 or 15 days. Objective samples were also tested for shear force (SF), Minolta meat colour, ultimate pH, cooking loss (CL) and purge loss (PL). There was a positive effect (p < 0.01) of PS on the sensory tenderness of Nellore bulls and Brangus heifers aged for 5 days compared to the AS method. At 15 days of aging, difference in sensory tenderness was observed (p < 0.05) in either group. Additionally, an interaction occurred between the suspension method and the aging of Nellore beef (p < 0.05) on liking of flavor, juiciness and overall acceptance, while the same effects were not observed for Brangus beef (p > 0.05). Nellore carcasses submitted to PS tended (p = 0.06) to produce more tender meat than those submitted to AS (SF = 44.62 ± 6.96 vs. 50.41 ± 8.04 N), and lower CL (p < 0.05) were found (27.7 vs. 30.9%). Carcass-suspension methods did not influence meat color, pH or PL in either group (p > 0.05). The PS contributes to improve the quality of Bos indicus bulls loins; in addition, this method allows a reduction in the aging time from 15 to 5 days, and it can be used to supply meat consumer markets which accept a certain level of eating quality. [ABSTRACT FROM AUTHOR]

Lysolecithin might increase ruminal and intestinal emulsification, leading to increased digestibility, but there is minimum information about which is the most appropriate phase to start supplementation and its impacts on feedlot performance and muscle fatty acid profile. Two experiments were conducted to evaluate the effects of phase-feeding of Lysoforte™ eXtend (LYSO). In the first experiment, 1,760 predominantly Bos indicus bullocks (initial body weight of 400 ± 0.561 kg) were allocated in a complete randomized block design. LYSO was supplemented at 1 g/1% of ether extract from the diet. Treatments were no LYSO supplementation (NON); LYSO starting during the growing period and continuing during the finishing period; LYSO starting during the finishing period (FIN); and LYSO during adaptation, growing, and finishing periods (ALL). In the second experiment, the same treatments were evaluated with 96 bullocks (64 Nellore and 32½ Nellore × ½ Angus) in a 4 × 2 factorial arrangement (treatments × genotype). For both studies, intake and average daily gain were accessed; carcass characteristics were evaluated in the first experiment, while digestibility of nutrients and profile of muscle fatty acids were measured in the second experiment. In the first experiment, LYSO increased final body weight (P < 0.022) and average daily gain (GRO and FIN; P < 0.05). In the second study, a treatment × breed × feeding phase interaction was observed with Nellore having a greater average daily gain (P < 0.05) than crossbreds in every feeding phase that LYSO was introduced to the diet. A treatment × feeding phase interaction was observed for digestibility, such that LYSO increased total dry matter (P = 0.004), crude protein (P = 0.043), and NDF (P = 0.001) digestibility during the finishing period. A treatment × breed × day classification was observed (P < 0.05). During the finishing phase, crossbreds treated with LYSO had greater DMI (P < 0.05) on very hot days than NON. Also, animals treated with LYSO presented a greater C18:3 n3 concentration (P = 0.047) in the longissimus. Overall, feeding LYSO during GRO and FIN enhanced feedlot performance and should lead to higher intakes during very hot days of the finishing feeding period.

Feed additives such as monensin (MON) and virginiamycin (VM) are widely used in feedlots diets to maximize rumen fermentation. However, the knowledge about the effects of MON and VM combinations in specifics feedlot periods and the benefits of this association are still unclear. This study aimed to evaluate the effects of withdrawal of MON when associated with VM during the adaptation and finishing periods on feedlot performance of Nellore cattle. The experiment was designed as a completely randomized block replicated six times (four animals/pen) in which 120 Nellore bulls (378.4 ± 24.4 kg) were allocated in 30 pens and fed for 112 days according to the following treatments: (T1) MON during the entire feeding period; (T2) VM during the entire feeding period; (T3) MON+VM during the adaptation period and only VM during the finishing period 1 and 2; (T4) MON+VM during the entire feeding period; (T5) MON+VM during the adaptation and finishing period 1 and only VM during the finishing period 2. After 112 days on feed, no treatment effect was observed for DMI (P ≥ 0.12). However, bulls fed T5 had greater (P = 0.05) final BW and ADG when compared to T1, T2, and T4. Cattle from T3 and T5 groups presented heavier HCW (P = 0.05) than that fed T1, T2, and T4. Nellore bulls fed T1 and T5 had lower (P < 0.01) DMI variation than those receiving T2. The withdrawal of MON when associated with VM during the final third of the feedlot period improved overall final BW, ADG, and HCW when compared to bulls fed either MON or VM, but did not positively impact feedlot performance when compared to cattle that had MON withdrawn at the end of the adaptation period.

This study investigated the effects of substituting rice straw with cassava in total mixed ration silage on feed intake, digestibility, rumen fermentation, ruminating activity, and energy balance. An energy balance experiment was conducted to determine nutrient and energy utilization in dairy bulls. Four Holstein Friesian (HF) crossbred young bulls (93.19% HF × 6.81% Native Thai; average age of 12.08 ± 0.22 months and body weight of 266 ± 9.80 kg) were used in a 4 × 4 Latin square design with four 28-d periods. The four dietary treatments included substituting cassava with rice straw on a 50, 150, 250, and 350 g/kg dry matter basis. Increasing the amount of cassava in the diet resulted in linearly decreased rumination behaviors and enteric methane emissions (p < 0.05) but a linear increase in feed intake and digestibility, total volatile fatty acid concentration, and propionic acid: acetic acid ratio in the rumen fluid (p < 0.05), thus leading to a greater energy balance status (p < 0.01). Our results indicated that replacing cassava with rice straw from 5% to 35% in the ration of Holstein bulls resulted in a substantial reduction in physically effective fiber and chewing time but improved nutrient and energy supply. The metabolizable energy requirement for the maintenance of crossbred dairy bulls was estimated to be 599.9 kJ/kg metabolic body weight and the efficiency of metabolizable energy used for growth was 0.88. We concluded that cassava is a good energy feed resource for Holstein crossbred bulls in the tropics.

This study aimed to evaluate the effects of parity, body condition score (BCS) at calving, and milk yield on the metabolic profile of Gyr (Zebu) cows. Healthy cows in late pregnancy were grouped according to parity (primiparous, biparous, and multiparous); to BCS scale at calving (high—HBCS and normal—NBCS); and to milk yield (high—HP and moderate—MP production). BCS was assessed, and blood samples were collected on −21, −7, 0, 7, 21, and 42 days relative to parturition. The concentrations of non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), cholesterol, glucose, total protein (TP), albumin, total calcium (Ca), phosphorus (P), and magnesium (Mg); and activities of aspartate aminotransferase and gamma-glutamyltransferase were measured. Data were analyzed by two-way repeated measures ANOVA. The frequencies of high lipomobilization, subclinical ketosis, subclinical hypocalcemia (SCH), and the occurrence of diseases during early lactation were established. Regardless of grouping, NEFA, BHB, and cholesterol increased during early lactation; glucose showed higher values at calving; TP and albumin were higher at 21 and 42 DIM; and Ca, P, and Mg were lower at calving. Parity had little effect on the metabolic profile, HBCS did not differ from NBCS cows, and HP did not differ from MP cows in most metabolites. High lipomobilization in early lactation and SCH at calving were the most common imbalances but were not related to postpartum diseases. High-yielding Gyr cows have a balanced metabolic profile during the transition period, with few biologically relevant effects of parity, BCS at parturition, or milk yielded.

Résumé : Dans un pays fort ancré dans la civilisation orale comme Madagascar, les objets rituels, tels que le zébu et l’alcool, sont inséparables dans le système de communication sociale. De manière intertextuelle, ils sont l’interface de l’homme dans ses discours socioreligieux ; ils sont récupérés par la littérature orale et moderne pour marquer la trace de la civilisation dans la production littéraire. L’objectif de cet article consiste à évoquer à travers le texte ethnographique et littéraire les divers enjeux du zébu et de l’alcool dans la communication intertextuelle à Madagascar. Pourquoi les Malgaches ont besoin d’interface pour bien assurer la circulation de son message lors de leur communication intertextuelle ? C’est parce qu’ils croient que dans cette communication, on a besoin d’une métaphore ou d’un symbole dans le domaine socioreligieux pour assurer sa fluidité dans divers contextes de communication. Ces objets religieux figurent dans la représentation sociale. Dans ce discours, ils se présentent sous forme de métalangage.

Objetive. To evaluate the relationship of AMH blood concentration with ovarian follicular count and in vitro embryo production in female Brahman cattle. Material and methods. To standardize the AMH quantification for Brahman donors, experiment 1 was performed, blood samples were taken from 10 heat synchronized Brahman females, in three different days of the estrous cycle, with more than 90 days postpartum and with normal reproductive evaluation. Serum concentration of AMH was determined with a commercial immunoenzymatic kit. After the technique was standardized, blood samples were taken from 100 non-synchronized Brahman oocyte donors, an ovum pick-up session was performed for in vitro embryo production and the number of follicles greater than 2 mm in the two ovaries was registered. Results. There were no differences in AMH concentration between the evaluated days of estrous cycle and a correlation of 0.82 (p<0.001) was found between antral follicle population (AFP) and AMH concentration. Serum AMH concentration ranged from 0.02 to 2.69 ng/ml in Brahman oocyte donors. Also, a correlation of 0.73 (p<0.001) between AMH and AFP and 0.54 between the AMH and the percentage of blastocysts were found in donors. Conclusions. The AMH can be used as a satisfactory endocrine marker of ovarian reserve prediction for in vitro embryo production in Brahman cattle. [ABSTRACT FROM AUTHOR]

Simple Summary: This study was conducted on eight Indian zebu breeds with an objective to reveal any cryptic genetic bottlenecks in the population. The alarming reduction in the effective population size of these breeds was the major reason for conducting this study. Genotyping of 27 FAO/ISAG-recommended microsatellite markers and further statistical analysis using allele frequency data under three different models of mutation revealed the absence of recent genetic bottlenecks in any of the populations under study. The results from the qualitative test of mode shift distortion were in accordance with the above findings. Even though the results of the present study indicated little or no critical loss of rare alleles in any of the breeds understudy, the chances of this happening cannot be completely ignored. One of the plausible explanations for this scenario could be the potential gene flow from commercial taurine cattle through indiscriminate crossbreeding in the native tract of these breeds. Thus, we here emphasize the need of further initiatives for improving selective breeding practices in order to conserve and effectively utilize the existing South Indian zebu cattle genetic diversity. During the last few decades, the effective population size of indigenous zebu cattle breeds has declined drastically, resulting in the classification of some of them into the vulnerable, endangered, or critically endangered category. Drastic reductions in the effective size of a population may result in genetic bottlenecks and can affect within-breed genetic variability and its viability. The present study was undertaken with the objective of evaluating South Indian zebu cattle populations for mutation drift equilibrium and to detect the occurrence of recent genetic bottleneck events. A total of 293 cattle from eight indigenous breeds were genotyped at 27 FAO/ISAG-recommended microsatellite marker loci. Three different statistical tests, viz., the sign test, standardized differences test, and Wilcoxon sign rank test were performed using allele frequency data to detect loci with heterozygosity excess under the infinite alleles, stepwise, and two-phase mutation models. Under the infinite alleles model, the observed number of loci with heterozygosity excess (He > Heq) ranged between 10 and 19 among the investigated cattle breeds. However, the observed heterozygosity excess was not statistically significant (p > 0.05) in any of the studied breeds. Similarly, the standardized differences test and Wilcoxon sign rank test revealed no concrete evidence for the occurrence of a recent genetic bottleneck in South Indian zebu cattle breeds. The qualitative test for mode-shift distortion revealed a normal L-shaped distribution of allele frequencies, suggesting a lack of evidence for the loss of low-frequency alleles in all the investigated South Indian zebu cattle breeds. [ABSTRACT FROM AUTHOR]

The objective of this study was to estimate (co)variances and genetic parameters and to predict genetic trends for weight at 120 (W120), 210 (W210), 365 (W365), and 450 (W450) days of age in Nelore cattle raised in the northern region of Brazil. The database comprised records of 30,387 animals born between 2000 and 2013 in the Brazilian North. Estimates were calculated by the Restricted Maximum Likelihood (REML) method, in single- and multi-trait analyses in an animal model. Heritability as obtained using single- and multi-trait models for W120 (0.22 and 0.31), W210 (0.20 and 0.34), W365 (0.51 and 0.51), and W450 (0.49 and 0.51) indicated moderate to high magnitudes, with the possibility of genetic selection and incorporation into the herd. Genetic correlations between growth traits were favorable, ranging from 0.78 to 0.96. Genetic trends for W120 and W210 varied largely, from -0.31 to 4.68 and -0.53 to 7.62 kg/year, respectively. Smaller fluctuations were observed in genetic trends for W365 and W450, which ranged from -1.08 to 10.90 and -1.29 to 12.51 kg/year, respectively. Selection for W365 and W450 proved to be the criterion of choice for Nelore herds raised in the region; however, it may compromise adult performance because of higher costs and time for production. A thorough analysis of mattings is recommended to allow the selection of earlier-developing animals.

The aim of this study was to identify the average of productive and reproductive traits in Red Sindhi females and evaluate if there is an influence of the reproductive traits on milk yield in this breed. Data related to reproductive and productive traits of 638 Sindhi breed dairy cows from North, Northeast, Midwest and Southeast regions of Brazil were provided by ABCZ. Analysis of variance followed by analysis of correlation among reproductive traits and between these and milk yield traits were used. Averages for age at first calving (AFC), calving age (CA), calving interval (CI), reproductive efficiency (RE), dry period (DP), lactation period (LP),milk yield (MY), and total milk yield (TMY) were 549.83 ± 560.47 days; 1843.53 ± 739.99 days; 533.28 ± 206.66 days; 75.46 ± 19.95%; 248.28 ± 206.66 days; 263.22 ± 63.51 days; 7.08 ± 2.78 kg of milk. day-1 and 1875.28 ± 893.36 kg of milk.lactation-1, respectively. The traits AFC, calving order (CO), CA, CI, RE and LP were separated into categories and there was no effect on MY among different categories, while the CO showed positive correlation with LP. Therefore, it can be concluded that Red Sindhi breed dairy cows showed high averages for AFC and medium averages for MY, CI and RE.

Madagascar est un pays de civilisation de zébu ; cet animal est sacré pour les Malgaches dans la mesure où ils l’utilisent comme sacrifice dans leur religion traditionnelle et pour manifester leur joie et leur affection sociale dans leur groupe ethnique respectif. L’objectif de cet article consiste à expliquer à travers la littérature malgache la manifestation de l’image de zébu dans le système de la communication horizontale et transcendante. Cet animal sacré dans la civilisation malgache est un moyen de communication dans le domaine socioéconomique dans le monde traditionnel, dans la mesure où sa possession, surtout en grand nombre est l’image de richesse et elle permet d’utiliser dans diverses activités économiques paysannes. Dans le domaine de religion, le sacrifice de zébu est comme un système d’interface dans la communication dans le monde surnaturel, la communication entre les Malgaches et Dieu créateur, la divinité de leurs ancêtres et autres divinités assimilées ; ceux qui n’ont aucun cet animal sacrificatoire sont en effet jugés les plus malheureux dans la civilisation malgache ; ils sont socialement en quelques sortes excommuniés. Cette importance de zébu n’est pas mise en indexe dans les diverses formes de production littéraire d’expression malgache ou française à travers leurs œuvres.

In dairy systems with Zebu breeds, calves are not immediately separated from their dams after calving; consequently, maternal care and protective behavior are important, influencing both productive performance and stockpeople’s safety. Our objectives were to: (1) investigate the effects of a training protocol involving pre-calving positive stimulation, delivered prior to calving, on the maternal care of primiparous Gyr cows; and (2) evaluate the effects of this training protocol on maternal protective behavior towards handlers during the first calf handling. Primiparous dairy Gyr cows (n = 37) were allocated into two groups: training (n = 16) and control (n = 21). Animal behaviors were recorded in three periods: post-calving, first calf handling, and post-handling. Maternal protective behavior during calf handling was assessed from measures of aggressiveness, attention, displacement, and agitation. Calf latency to stand up (p < 0.01) and sex (p < 0.01) differed between the training and control groups. The training group had less touching (p = 0.03), more time not interacting with the calf (p = 0.03), tended to be less protective (p = 0.056), and moved less (p < 0.01) during the first handling of their calves. In conclusion, the primiparous dairy Gyr cows subjected to pre-calving training protocol displayed less maternal care and displacement during the first handling of their calves and tended to be less protective.

This study evaluated the effects of hanging the carcass by the Achilles tendon (AS) versus pelvic suspension (PS) on meat quality traits. Bos indicus carcasses of two distinct biological types/sex categories comprised 10 young Brangus heifers and 10 Nellore bulls which were finished in a feedlot. Half-carcasses of each biological type/sex category were randomly hung using Achilles suspension (n = 20, AS) or pelvic suspension (n = 20, PS) for 48 h. At boning, longissimus samples were collected for evaluation by untrained consumers for tenderness, liking of flavor, juiciness and overall acceptability, after aging for 5 or 15 days. Objective samples were also tested for shear force (SF), Minolta meat colour, ultimate pH, cooking loss (CL) and purge loss (PL). There was a positive effect (p < 0.01) of PS on the sensory tenderness of Nellore bulls and Brangus heifers aged for 5 days compared to the AS method. At 15 days of aging, difference in sensory tenderness was observed (p < 0.05) in either group. Additionally, an interaction occurred between the suspension method and the aging of Nellore beef (p < 0.05) on liking of flavor, juiciness and overall acceptance, while the same effects were not observed for Brangus beef (p > 0.05). Nellore carcasses submitted to PS tended (p = 0.06) to produce more tender meat than those submitted to AS (SF = 44.62 ± 6.96 vs. 50.41 ± 8.04 N), and lower CL (p < 0.05) were found (27.7 vs. 30.9%). Carcass-suspension methods did not influence meat color, pH or PL in either group (p > 0.05). The PS contributes to improve the quality of Bos indicus bulls loins; in addition, this method allows a reduction in the aging time from 15 to 5 days, and it can be used to supply meat consumer markets which accept a certain level of eating quality.

The incidence of sub‐fertility is higher in crossbred bulls compared to zebu bulls. In the present study, we analysed the metabolomic profile of seminal plasma from crossbred and zebu bulls and uncovered differentially expressed metabolites between these two breeds. Using a high‐throughput LC‐MS/MS‐based approach, we identified 990 and 1,002 metabolites in crossbred and zebu bull seminal plasma respectively. After excluding the exogenous metabolites, we found that 50 and 68 putative metabolites were unique to crossbred and zebu bull seminal plasma, respectively, whilst 87 metabolites were common to both. After data normalisation, 63 metabolites were found to be dysregulated between crossbred and zebu bull seminal plasma. Observed pathways included Linoleic acid metabolism (observed metabolite was phosphatidylcholine) in crossbred bull seminal plasma whereas inositol phosphate metabolism (observed metabolites were phosphatidylinositol‐3,4,5‐trisphosphate/inositol 1,3,4,5,6‐pentakisphosphate/myo‐inositol hexakisphosphate) was observed in zebu bull seminal plasma. Abundance of Tetradecanoyl‐CoA was significantly higher, whilst abundance of Taurine was significantly lower in crossbred bull seminal plasma. In conclusion, the present study established the seminal plasma metabolomic profile in crossbred and zebu bulls and suggest that increased lipid peroxidation coupled with low concentrations of antioxidants in seminal plasma might be associated with high incidence of sub‐fertility in crossbred bulls. [ABSTRACT FROM AUTHOR]

Abstract The aim was to evaluate the association between growth, carcass and visual scores traits with precocious calving in Nellore cattle. Birth weight (BW), weight at 120, 210, 365 and 450 days of age, pre and post-weaning average daily gain, rib eye area, backfat thickness (BF), rump fat thickness and visual scores obtained at 18 months were used for the analysis. Records from 700 females born between 2009 and 2015, exposed to mating starting at 11 months of age were analyzed. Discriminant analyzes were performed with the software Statistica. BW and BF showed the highest (P>0.01) discrimination value for early heifer pregnancy (EP). Extreme intrauterine growth retardation can result in slower growth, which reflects in the worst reproductive performance, confirmed by the variation in BW between precocious and conventional heifers. The results also demonstrate that the level of body fat affects begin of puberty. Bone structure, musculature, depth, tail insertion and rump scores presented the highest discrimination value for EP. These traits can be used as selection tools to improve sexual precocity in female Nellore cattle. The results obtained in this study would support farmers to guide the heifer management and decisions in order to enhance the EP.

Objective: The aim of this study was to identify suitable polynomial regression for modeling the average growth trajectory and to estimate the relative development of the rib eye area, scrotal circumference, and morphometric measurements of Guzerat young bulls., Methods: A total of 45 recently weaned males, aged 325.8±28.0 days and weighing 219.9±38.05 kg, were evaluated. The animals were kept on Brachiaria brizantha pastures, received multiple supplementations, and were managed under uniform conditions for 294 days, with evaluations conducted every 56 days. The average growth trajectory was adjusted using ordinary polynomials, Legendre polynomials, and quadratic B-splines. The coefficient of determination, mean absolute deviation, mean square error, the value of the restricted likelihood function, Akaike information criteria, and consistent Akaike information criteria were applied to assess the quality of the fits. For the study of allometric growth, the power model was applied., Results: Ordinary polynomial and Legendre polynomial models of the fifth order provided the best fits. B-splines yielded the best fits in comparing models with the same number of parameters. Based on the restricted likelihood function, Akaike's information criterion, and consistent Akaike's information criterion, the B-splines model with six intervals described the growth trajectory of evaluated animals more smoothly and consistently. In the study of allometric growth, the evaluated traits exhibited negative heterogeneity (b<1) relative to the animals' weight (p<0.01), indicating the precocity of Guzerat cattle for weight gain on pasture., Conclusion: Complementary studies of growth trajectory and allometry can help identify when an animal's weight changes and thus assist in decision-making regarding management practices, nutritional requirements, and genetic selection strategies to optimize growth and animal performance.

L’étude a eu pour objectif d’évaluer deux protocoles de synchronisation des chaleurs à base de prostaglandine F2α (alfaprostol 2 mg), l’un court à injection unique et insémination artificielle (IA) sur chaleurs observées, l’autre long à double injection à 11 jours d’intervalle et IA à temps fixe 80 heures après la seconde injection. Elle a porté sur 72 vaches et 12 génisses de race Goudali, toutes cyclées. Les semences utilisées ont été celles des taureaux Bruns Suisses, Aubracs et Gascons. Le taux d’induction des chaleurs a été de 100 %, avec un délai de 2 à 11 jours postinjection pour la venue des chaleurs en protocole court. Après un minimum de 60 jours post-IA, une palpation transrectale a été effectuée, ainsi qu’un suivi des gravidités jusqu’aux vêlages. Les taux de gravidité, d’avortement et de vêlage ont été respectivement de 17,8 %, 13,3 % et 15,4, soit respectivement pour les protocoles court et long 30,8 %, 16,6 % et 25,6 %, et 6,7 %, 0 % et 6,6 % (p < 0,05). La durée moyenne de gravidité a été de 290 ± 4,5 jours, soit respectivement pour les protocoles court et long 290 ± 4,5 jours et 289,7 ± 5,8 jours (p = 0,181). Le poids moyen des veaux à la naissance a été de 22,9 ±1,4 kg, soit respectivement pour les protocoles court et long 22,9 ± 1,6 kg et 23,0 ± 1,0 kg (p = 0,319). La sex-ratio (% de mâles par rapport à la population totale) a été de 69,2 % (p = 0,6). Les animaux présentant une durée post-partum entre 5 et 10 mois, dont l’IA avait été pratiquée dans le corps de l’utérus et entre 16 et 17 heures après la détection des chaleurs, ont présenté une meilleure fertilité (p < 0,05).

During the last few decades, the effective population size of indigenous zebu cattle breeds has declined drastically, resulting in the classification of some of them into the vulnerable, endangered, or critically endangered category. Drastic reductions in the effective size of a population may result in genetic bottlenecks and can affect within-breed genetic variability and its viability. The present study was undertaken with the objective of evaluating South Indian zebu cattle populations for mutation drift equilibrium and to detect the occurrence of recent genetic bottleneck events. A total of 293 cattle from eight indigenous breeds were genotyped at 27 FAO/ISAG-recommended microsatellite marker loci. Three different statistical tests, viz., the sign test, standardized differences test, and Wilcoxon sign rank test were performed using allele frequency data to detect loci with heterozygosity excess under the infinite alleles, stepwise, and two-phase mutation models. Under the infinite alleles model, the observed number of loci with heterozygosity excess (He > Heq) ranged between 10 and 19 among the investigated cattle breeds. However, the observed heterozygosity excess was not statistically significant (p > 0.05) in any of the studied breeds. Similarly, the standardized differences test and Wilcoxon sign rank test revealed no concrete evidence for the occurrence of a recent genetic bottleneck in South Indian zebu cattle breeds. The qualitative test for mode-shift distortion revealed a normal L-shaped distribution of allele frequencies, suggesting a lack of evidence for the loss of low-frequency alleles in all the investigated South Indian zebu cattle breeds.

• Number of dams with phenotypic records influenced genetic parameter estimates. • Direct heritability estimates remained stable across different data structures. • Covariance between direct and maternal effects was sensitive to data structure. • Maternal records influenced genetic associations, impacting multiple traits. The number of dams with their own phenotypic records is crucial for estimating the genetic correlation between direct and maternal effects in beef cattle. In this study, using multi-trait analyzes, we assessed the impact of varying the percentage of dams with own records (0, 20, 35, 50, and 70 %) on genetic parameter estimates in Nelore beef cattle. The analyzes focused on key traits in the selection index: weaning weight (WW), post-weaning weight gain (PWG), scrotal circumference, and muscling score. Direct heritability estimates remained relatively stable across data structures, while maternal heritability and the covariance between direct and maternal effects showed important variations. The genetic correlation between direct and maternal effects of WW linearly shifted from negative in D0 (−0.20) to positive in D70 (0.31), emphasizing the impact of increasing the number of dams with own records. Maternal phenotypic records influenced genetic associations between traits, notably WW and PWG (0.13 in D0 and 0.36 in D70). These findings highlight that changes in data structure can impact the estimation of genetic parameters for multiple traits. The study underscores the importance of robust data structures, maternal phenotypic records (>35 %), and complete pedigree information to obtain reliable estimates of genetic parameters in beef cattle. [ABSTRACT FROM AUTHOR]

Technological devices are increasingly present in livestock activities, such as identifying the reproductive status of cows. For this, predictive models must be accurate and usable in the productive context. The aims of this study were to evaluate estrus-associated changes in reticulo-rumen temperature (RRT) and activity (ACT) in Dairy Gyr heifers provided by reticulo-rumen boluses and to test the ability of different models for estrus prediction. The RRT and ACT of 45 heifers submitted to estrus synchronization were recorded using reticulo-rumen boluses. The means of RRT and ACT at different time intervals were compared between the day before and the day of estrus manifestation. An analysis of variance of RRT and ACT was performed using mixed models. A second approach employed logistic regression, random forest, and linear discriminant analysis models using RRT, ACT, time of day, and the temperature-humidity index (THI) as predictors. There was an increase in RRT and ACT at estrus (p < 0.05) compared to the same period on the day before and on the day after estrus. The random forest model provided the best performance values with a sensitivity of 51.69% and specificity of 93.1%. The present results suggest that RRT and ACT contribute to the identification of estrus in Dairy Gyr heifers.

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 < 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 < 0.01) compared with control, and additionally produced more hydrogen (P < 0.01) vs control. There were significant reductions in the measured methane yield in relation to DMI (CH4: DMI, P < 0.01) and methane intensity (CH4/ADG, P < 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 < 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. [ABSTRACT FROM AUTHOR]

Climate drying could have transformed ecosystems in southern Madagascar during recent millennia by contributing to the extinction of endemic megafauna. However, the extent of regional aridification during the past 2000 years is poorly known, as are the responses of endemic animals and economically important livestock to drying. We inferred ~1600 years of climate change around Lake Ranobe, SW Madagascar, using oxygen isotope analyses of monospecific freshwater ostracods (Bradleystrandesia cf. fuscata) and elemental analyses of lake core sediment. We inferred past changes in habitat and diet of introduced and extinct endemic megaherbivores using bone collagen stable isotope and 14C datasets (n = 63). Extinct pygmy hippos and multiple giant lemur species disappeared from the vicinity of Ranobe during a dry interval ~1000–700 cal yr BP, but the simultaneous appearance of introduced cattle, high charcoal concentrations, and other evidence of human activity confound inference of drought-driven extirpations. Unlike the endemic megafauna, relatively low collagen stable nitrogen isotope values among cattle suggest they survived dry intervals by exploiting patches of wet habitat. Although megafaunal extirpations coincided with drought in SW Madagascar, coupled data from bone and lake sediments do not support the hypothesis that extinct megafauna populations collapsed solely because of drought. Given that the reliance of livestock on mesic patches will become more important in the face of projected climate drying, we argue that sustainable conservation of spiny forests in SW Madagascar should support local livelihoods by ensuring that zebu have access to mesic habitat. Additionally, the current interactions between pastoralism and riparian habitats should be studied to help conserve the island’s biodiversity.