Young Bulls Research Articles

The impact of bull breeding management on reproductive function (review)

Providing the population with quality food products is currently relevant. High-tech production of meat and dairy products requires breeding animals with high genetic potential. The main role is given to bull sires, since they are responsible for the constant reproduction of the breeding stock, which depends on the non-stop renovation of the herd with high breeding value’s calves. Management of growing and breeding of young bulls can directly affect the reproductive function of sires and the physiological health. The article provides analytical data based on literary sources containing research by various authors on this topic, and reviews methods and technologies for keeping breeding bulls on various farms in the Russia and abroad. Currently, there is a many problems of getting high-quality breeding young bulls to an artificial insemination center. Currently, there are problems with obtaining high-quality breeding bulls of the enterprise. There are animals with abnormal development of the musculoskeletal system, joints, hooves, with signs of osteomalacia, etc. Such animals require additional costs for veterinary and breeding services. The quality of the sperm products they produce often does not comply with state normative. The reason is related either to the choice of maintenance technology or feeding technology. It is necessary to competently organize management, breeding and veterinary work in farms that are purposefully engaged in breeding young animals.

The effect of the carcass fat thickness on the qualitative technological and sensory attributes of beef

The established correlations between subcutaneous fat thickness and the quality attributes of carcasses and beef are relevant for producers and the processing industry. The purpose of the study is to establish the characteristics of slaughter, chemical composition, sensory physical, and technological properties of beef made of young bulls belonging to the Ukrainian black-and-white dairy breed aged 18 to 24 months, depending on the thickness of the fat on the carcass. The colour of muscle and adipose tissue, the conformation of carcasses, the development of subcutaneous fat, marbling, chemical composition, and sensory attributes of beef and broth made of it were determined in the context of different fat thicknesses on the carcass. With an increase in the thickness of subcutaneous fat, the fleshiness (conformation) of carcasses increases by 55.2% (P>0.95), the cover of carcasses with fat increases by 43.5 (P>0.99), and muscle penetration improves by 45.8% (P>0.95). With the thickening of subcutaneous fat from 0.5 to 1.1 cm or more, there is a tendency of tendons and ligaments in carcasses to increase by 53.6%, with adipose tissue increasing by 25.6%, points for the juiciness of boiled beef increasing by 20.8%, its tenderness increasing by 12.5%, and the reduction in the m. longissimus dorsi 'loin eye' area increased by 7.3%, marbling increased by 19.0%, reduction of moisture content in meat increased by 27.8%, and its boiling properties increased by 7.9%. With an increase in the thickness of subcutaneous fat in beef, there was a tendency for the reduction of its acidity (pH), the amount of dry matter, the total content of fat and minerals, deterioration of taste, aroma, residue after chewing boiled meat, flavour, and aroma, concentration, and transparency of broth made of it. The practical significance of these studies is to obtain knowledge that allows the assessment of the quality characteristics of carcasses and beef by the thickness of subcutaneous fat for their further use by producers and processing industries.

Impact of live yeast and selenium supplementation on blood metabolites and rumen pH of young bulls after long-transport to the fattening unit

Impact of live yeast and selenium supplementation on blood metabolites and rumen pH of young bulls after long-transport to the fattening unit

Productivity and economic performance of Nellore young bulls fed diets with increasing fiber content.

Adequate neutral detergent insoluble fiber (NDF) content in the total diet can improve intake efficiency, prevent rumen disorders, and enhance the health and performance of feedlot-finished beef cattle. We hypothesized that an increase in dietary fiber levels would decrease the productive performance but increase the economic performance of young bulls in confinement. Thus, it was aimed to evaluate the effect of increasing fiber levels on feed intake, wastage, and productive and economic performance of Nellore young bulls finished in confinement. We used 20 Nellore cattle, non-castrated males, 30 months old, and average body weight (BW) of 416.35 ± 2.2kg distributed in a completely randomized design, kept in individual stalls. Animals were divided into four treatments consisting of four levels of neutral detergent insoluble fiber (NDF) (25%, 30%, 35%, and 40% NDF) in total DM. Nutrient intake, feed conversion, feed waste, body weight (BW) at slaughter, total weight gain (TWG), average daily gain (ADG), hot carcass weight (HCW), and carcass yield (CR) were evaluated. In addition, economic parameters (revenue, food expenses, and gross margin) were calculated and compared. The dry matter (DMI), organic matter (OMI), crude protein (CPI), and ether extract (EEI) intakes showed quadratic behavior. The DMI maximum estimated was 28.5% NDF in the diet. The NDF and ADF intakes showed a positive linear effect and the starch intake had a negative linear effect. There was a significant positive linear effect (P < 0.05) for the variables total mixed ration (TMR) offered and daily and total RTM intake. Minimum RTM wastage was estimated with a diet containing 30% NDF. The maximum points for BW at slaughter, HCW, and ADG were 29.9%; 29.6%, and 25% NDF, respectively. The costs of concentrate and silage showed a positive linear behavior, as did the ADG costs and the carcass equivalent cost (P < 0.05). The maximum point of the revenue estimate (US$/animal) was 29.9% of NDF, 26.1% of NDF for the total expenditure on food (US$/animal), and 32.5% of NDF for the gross margin (U$/animal). In conclusion, the animals fed a 30% NDF diet showed the best performance and economics, in addition to less food waste. We recommend 25 to 32.5% of NDF in the diet to obtain maximum productive and economic performance when finishing Nellore young bulls in confinement.

Assessment of inbreeding coefficients and inbreeding depression on complex traits from genomic and pedigree data in Nelore cattle.

Nelore cattle play a key role in tropical production systems due to their resilience to harsh conditions, such as heat stress and seasonally poor nutrition. Monitoring their genetic diversity is essential to manage the negative impacts of inbreeding. Traditionally, inbreeding and inbreeding depression are assessed by pedigree-based coefficients (F), but recently, genetic markers have been preferred for their precision in capturing the inbreeding level and identifying animals at risk of reduced productive and reproductive performance. Hence, we compared the inbreeding and inbreeding depression for productive and reproductive performance traits in Nelore cattle using different inbreeding coefficient estimation methods from pedigree information (FPed), the genomic relationship matrix (FGRM), runs of homozygosity (FROH) of different lengths (> 1Mb (genome), between 1 and 2Mb - FROH 1-2; 2-4 Mb FROH 2-4 or > 8 Mb FROH >8) and excess homozygosity (FSNP). The correlation between FPed and FROH was lower when the latter was based on shorter segments (r = 0.15 with FROH 1-2, r = 0.20 with FROH 2-4 and r = 0.28 with FROH 4-8). Meanwhile, the FPed had a moderate correlation withFSNP (r = 0.47) and high correlation withFROH >8 (r = 0.58)and FROH-genome (r = 0.60). The FROH-genome was highly correlated with inbreeding based on FROH>8 (r = 0.93) and FSNP (r = 0.88). The FGRM exhibited a high correlation with FROH-genome (r = 0.55)and FROH >8 (r = 0.51) and a lower correlation with other inbreeding estimators varying from 0.30 for FROH 2-4 to 0.37 for FROH 1-2. Increased levels of inbreeding had a negative impact on the productive and reproductive performance of Nelore cattle. The unfavorable inbreeding effect on productive and reproductive traitsranged from 0.12 to 0.51 for FPed, 0.19-0.59 for FGRM, 0.21-0.58 for FROH-genome, and 0.19-0.54 for FSNP per 1% of inbreeding scaled on the percentage of the mean. When scaling the linear regression coefficients on the standard deviation, the unfavorable inbreeding effect varied from 0.43 to 1.56% for FPed, 0.49-1.97% for FGRM, 0.34-2.2% for FROH-genome, and 0.50-1.62% for FSNP per 1% of inbreeding.The impact of the homozygous segments on reproductive and performance traits varied based on the chromosomes. This shows that specific homozygous chromosome segments can be signs of positive selection due to their beneficial effects on the traits. The low correlation observed between FPed and genomic-based inbreeding estimates suggests that the presence of animals with one unknown parent (sire or dam) in the pedigree does not account for ancient inbreeding. The ROH hotspots surround genes related to reproduction, growth, meat quality, and adaptation to environmental stress. Inbreeding depression has adverse effects on productive and reproductive traits in Nelore cattle, particularly on age at puberty in young bulls and heifer calving at 30 months, as well as on scrotal circumference and body weight when scaled on the standard deviation of the trait.

Supplementation with 25-hydroxicolecalciferol increases the nutritional efficiency and carcass growth of grazing Nellore young bulls

We aimed to evaluate the effect of 25-OH Vit D3 (Hy-D, DSM, Brazil) supplementation on the performance, body measures, and carcass characteristics of growing and finishing grazing Nellore young bulls. Two experiments were conducted. In Experiment 1, 150 animals (body weight (BW) of 350 ± 23kg) were separated into 6 treatment groups: protein supplement (PS); protein supplement with monensin (PS+Mon); protein supplement with 25-OH Vit D3 (PS+Vit D3); protein supplement with monensin and 25-OH Vit D3 (PS+Mon+Vit D3); protein-energetic supplement (PE); protein-energetic supplement with 25-OH Vit D3 (PE+Vit D3). In Experiment 2, 240 animals with an initial BW of 390 ± 16kg were separated into the same protein-energetic supplement treatment groups used in Experiment 1 with or without 25-OH Vit D3 (two treatments). Animals in the different treatments of Experiment 1 had similar ADG and final BW values (P > 0.05), except for those that received monensin in PS, which showed lower ADG (P < 0.05). The addition of monensin to the PS inhibited increases in the body measures (P < 0.05) except for the height at withers (P > 0.05). Animals that received PE+Vit D3 showed greater increases in rib width (P < 0.05). In Experiment 2, animals that received 25-OH Vit D3 were 8.0kg heavier than the animals that did not receive this supplement (P < 0.05). The results show that supplementation with 25-OH Vit D3 is a promising and effective method of improving carcass weight and yield in finishing beef cattle during grazing.

Genetic Variations in the NRF2 Microsatellite Contribute to the Regulation of Bovine Sperm-Borne Antioxidant Capacity.

Nuclear factor (erythroid-derived 2)-like 2 (NRF2) is a transcription factor protein-coding gene, considered a master regulator of the cellular stress response. The genetic variations of the NRF2 could influence its transcriptional profile and, subsequently, the stress resilience in all cell types, including sperm cells. Therefore, the sperm-borne antioxidants abundance in association with the genetic variation of a GCC microsatellite located at the 5' upstream region of the NRF2 gene was investigated in young (n = 8) and old (n = 8) Holstein bulls' sperm cells at different seasons. The sperm DNA was sequenced using Sanger sequencing, while- the sperm-borne mRNA analysis was carried out using the synthesized cDNA and qPCR. The data were statistically analyzed using GraphPad Prism 10.0.2 software. The results showed that two bulls had a heterozygous genotype of eight and nine GCC repeats, while biallelic of eight, nine, and fifteen repeats were identified in two, ten, and two bulls, respectively. The computational in silico analysis revealed that the NRF2 upstream sequence with 15, 9, and 8 GCC repeats bound with 725, 709, and 707 DNA-binding transcription factor proteins, respectively. Lower quality of sperm DNA was detected in the spring season compared to other seasons and in young bulls compared to old ones, particularly in the summer and autumn seasons. The mRNA expression analysis revealed that the PRDX1 gene was the abundant transcript among the studied sperm-borne antioxidants and was significantly determined in old bulls' spermatozoa. Moreover, two transcripts of the NRF2 gene and antioxidant (SOD1, CAT, GPX1, TXN1, NQO1) genes displayed differential expression patterns between the age groups across seasons in an antioxidant-dependent manner. The bulls with a heterozygous GCC sequence exhibited elevated sperm-borne mRNA levels of NRF2 and PRDX1 transcripts. Taken together, the findings suggest that the NRF2-GCC microsatellite may contribute to the transcription regulation of NRF2 transcripts and their subsequent downstream antioxidants in bovine sperm cells.

PSVI-18 Association between residual feed intake and reproductive-related traits in young bulls

Abstract Enhancement of feed efficiency (FE) along with reproductive performance is critical to maximize profitability of beef production systems. Residual feed intake (RFI) is a measure of FE, assessing differences between expected and actual feed intake. Published data suggest a negative impact of RFI on reproductive performance. The objective of this experiment was to establish the relationship between RFI and reproductive parameters related with puberty in young bulls. Growing, Brangus bulls (n = 58; 10 to 12 mo of age) were tested for FE over 56 d and ranked as low RFI (LRFI) and high RFI (HRFI). Scrotal circumference (SC) was measured at the greatest diameter of the testicles by the same operator using a scrotal measuring tape, and semen samples were collected by electroejaculation at the beginning and at the end of the test. Fresh semen was visually evaluated (VE) for visual motility (VM), morphology [major defects (MAD)], minor defects (MID), total defects (TD)], plasma membrane integrity (PMI) via Eosin-nigrosin stain and sperm concentration (Con). Sperm kinematics were objectively determined simultaneously via computer-assisted sperm analysis (CASA-IVOS II System, Hamilton Thorne, Beverly, MA) within 6 h of collection in a medium designed specifically for holding sperm. Statistical analysis included repeated measures to assess interactions between Group (LRFI, HRFI) and Time (0 and 56 d of RFI measurement). Results are presented as mean ± SEM in Table 1. The main effect of Group did not affect CASA derived traits, while MAD and TD were affected among VE traits. A Time effect was observed in the amplitude of lateral head displacement (ALH), beat cross frequency (BCF), curvilinear velocity (VCL) and linearity (LIN). A tendency was indicated for total motility (TM), and average path velocity (VAP) among CASA derived traits, while all VE traits were affected by Time except for visual motility (VM). Finally, an interaction effect (Group x Time) was observed in LIN and plasma membrane integrity (PMI). In conclusion, age at puberty as determined by VM, Con, and SC (Group: P = 0.12, Day: P &amp;lt; 0.001, Group x Day: P = 0.79) was not associated with RFI. Overall, fertility-related measurements were not influenced by RFI, with time emerging as the primary influencing factor across evaluated parameters. Evaluation of reproductive parameters following d 56 FE testing may be a useful determinant for identifying differences in seminal characteristics of young bulls.

PSV-15 Evaluating the relationship between subcutaneous backfat thickness and sperm morphology in young beef bulls

Abstract Literature indicates that high-energy diets can lead to reductions in both sperm motility and morphology in bulls. This study aimed to investigate the relationship between individual variation in subcutaneous backfat thickness (SCBF) and sperm morphology in young beef bulls exposed to the same diet. We hypothesized that bulls with excessive subcutaneous fat thickness have increased sperm morphology defects compared with bulls with adequate subcutaneous backfat thickness. Historical data collected from yearling Bos taurus beef bulls (n = 557) enrolled in a bull development program were used in an observational retrospective cohort study to test this hypothesis. Over the course of 5 yr, bulls in two locations were developed according to industry standard practices, and performance was evaluated over 84 d with a 21-d adaptation period. At the end of the performance evaluation period, a carcass ultrasound was performed to evaluate ribeye area, SCBF, and intramuscular fat. Furthermore, breeding soundness examinations (BSE) were performed according to the Society of Theriogenology guidelines within 40 d after carcass ultrasonography. Bulls that failed the BSE for reasons unrelated to semen quality were excluded from this study. Within each year, bulls were ranked based on SCBF and classified as top 10% (TOP; n = 55), middle 80% (MID; n = 446), and bottom 10% (BTM;n = 56) for SCBF. Initial body weight (BW) was greater (P &amp;lt; 0.01) in TOP bulls compared with MID and BTM (Table 1). Off-test BW was also greater in TOP compared with MID and BTM bulls (P &amp;lt; 0.01). In contrast, average daily gain and scrotal circumference did not differ between experimental groups (P = 0.35 and P = 0.65, respectively). TOP bulls had greater (P &amp;lt; 0.01) SCBF compared with MID and BTM, and MID bulls had greater (P &amp;lt; 0.01) SCBF compared with BTM bulls. Similar results were observed for intramuscular fat (P &amp;lt; 0.01) and ribeye area (P &amp;lt; 0.01). Percentage of normal sperm cells was greater in both BTM and MID bulls compared with TOP bulls (P &amp;lt; 0.01). Additionally, percentage of primary abnormalities tended (P = 0.07) to be greater in TOP bulls compared with BTM and MID. There were no differences in the percentage of secondary abnormalities between experimental groups (P = 0.45). There was a tendency (P = 0.07) for a greater percentage of TOP bulls to fail the BSE compared with MID and BTM bulls. Moreover, there was a positive linear relationship (P = 0.01) between SCBF and the probability of failing the BSE. In summary, elevated SCBF in bulls exposed to the same diet was associated with an increase in sperm morphological abnormalities and tended to increase the percentage of bulls failing the BSE.

PSIV-12 Effects of creep-feeding supplementation on growth performance during the rearing and finishing phases of grazing Nellore young bulls

Abstract The study aimed to evaluate the effect of creep-feeding on growth performance of beef young bulls (n = 40) when they were subjected to an intensive rearing and finishing system. The experiment lasted 325 d, from May/2022 to April/2023, the calves were born in September/2021 and creep-feeding supplementation lasted 170 d, from December/2021 to May/2022. The experimental design used was a randomized block [blocked by body weight (BW) of calves in the beginning of supplementation]. The experimental units were the paddocks (4 paddocks per treatment, and 5 animals per paddock). The treatments consisted of supplementation on creep-feeding system or not during the nursing phase: control (mineral supplement ad libitum) and creep-feeding treatment (energetic protein supplement, 5 g/kg BWּ animal-1ּ d-1). After weaning, all the bulls were managed similarly with an energetic protein supplement (10 g/ kg BWּ animal-1ּ d-1) during the grazing intensive rearing phase, and 15 gּ/kg BWּ animal-1ּ d-1during the grazing intensive finishing phase) until slaughter. The bulls were allocated to grazing area of Urochloa brizantha cv. Marandu. The data were analyzed using the MIXED procedures of SAS (SAS Institute Inc., Cary, NC, USA, version 9.4). The bulls subjected to creep-feeding system had greater BW at beginning of rearing phase (+14 kg) and beginning of rainy season (+18 kg; P = 0.03; Figure 1). At beginning of finishing phase and slaughter, the bulls had the same BW (P ≥ 0.71; Table 1). The back and rump fat thickness measures showed tendency to be different between the treatments (P ≤ 0.10), where creep-fed animals were greater. Probably, creep-fed bulls slowed down their BW gain during the rainy season on rearing and finishing phases, due to presenting a change in the gain composition. Creep-feeding may have influenced the puberty of these bulls, and caused them to begin deposition of fat earlier than those that did not receive creep-feeding. Thus, the animal tends to balance BW with changes in the gain composition, and the percentage of muscle tissue tends to reduce, while the proportion of fat tends to increase. Creep-feeding supplementation increased the animals weaning weight by 14 kg but, it was not able to influence the slaughter weight due to changes in the gain composition.

125 Could yeast derivatives change beef cattle water intake in different scenarios?

Abstract Adequate water intake is linked to greater dry matter intake, heat loss, and productivity. To measure the water intake of beef cattle reared in groups, two experiments were carried out in Brazil (South East/Middle East) using water throughs coupled with scales (Intergado, Betim, Brazil) and RFID individual identification systems, allowing the recording of individual water intake of animals. In experiment 1, young bulls (n = 96; 105 d on feed - feedlot) were randomly assigned to four treatments: 1) Control, no yeast derivative; 2) AY – 7 g·animal⁻¹·d⁻¹, Autolyzed Yeast grown on sugarcane molasses (RumenYeast, ICC, Brazil); 3) YM – 3 g·animal⁻¹·d⁻¹, yeast rich in soluble Yeast Metabolites; 4) YB – 5 g·animal⁻¹·d⁻¹, Yeast Blend (live Yeast plus autolyzed Yeast). Diets (adaptation, growing, and finishing) x treatments were treated as fixed effects on the complete randomized design. In experiment 2, backgrounding bull calves (n = 32) reared on grazing and 710 g/d of protein supplements (90 d) were randomly assigned to two treatments: 1) Control, no yeast derivative; 2) AY – 7 g·animal⁻¹·d⁻¹, Autolyzed Yeast (RumenYeast), the means were subjected to ANOVA analyses. In both experiments, additives were inserted into the diet (mineral premix or supplement), animals were the experimental unit, and differences were declared significant at P &amp;lt; 0.05. Yeast derivatives increased (P &amp;lt; 0.05) water intake in both experiments (Figure 1). The average increment in water intake (L·animal⁻¹·d⁻¹ was 13.9%. Interestingly, the increment in relation to control was noted for all yeast derivatives and scenarios covered by the experiments (feedlot adaptation diet, feedlot growing diet, feedlot finishing diet, and grazing system). Until now, there seems to be no literature explanation for our findings. However, these results could help to explain the positive effects of yeast derivatives on rumen pH, protein microbial flow, and thermal stress since greater water intake increases the passage rate of rumen fluid and body heat loss. Statistical correlations may not be understood as a cause-consequence link. However, when dealing with a new question, correlations may give us a path to go on and investigate. Malheiros et al. (2023) noted a negative correlation between water intake and rumen dimethylamine. Autolyzed yeast can strongly decrease the concentration of rumen methylamines in cows facing subacute acidosis (Humer et al., 2018). Niacin metabolism should also be investigated since its supplementation enhances cows’ blood niacin levels and water intake. Yeast derivatives are rich in niacin, and autolyzed yeast supplementation can increase blood niacin and body heat loss during summer (Dias et al., 2018), probably increasing water need. In conclusion, yeast derivatives increased the water intake of beef cattle, and this finding adds to the understanding of how yeast derivatives supplementation benefits ruminants.

26 Trace minerals to improve bull fertility

Abstract Bull fertility is paramount for reproductive success in cow-calf production systems and there are a variety of factors that influence bull fertility. Trace mineral requirements and recommendations have been established for growing and finishing steers, as well as lactating and pregnant cows, yet no specific requirements have been established for young or mature beef bulls. Nonetheless, trace minerals have been shown to have an important role in sexual maturation and semen quality of ruminants. Research performed in rams indicates that zinc deficiency results in reduced testicular development, decreased testicular concentrations of testosterone, and impaired development of seminiferous tubules. Deficiency of Zn has also been reported to negatively impact male fertility in humans, where men diagnosed with infertility responded positively to Zn supplementation. In growing bulls, diets with greater concentrations of organic forms of Zn, Cu, and Mn, tended to result in earlier attainment of puberty compared with control diets containing inorganic minerals. Furthermore, greater liver concentrations of Zn have been negatively correlated with sperm acrosomal damage in growing bulls, based on flow cytometry analyses. More recent research indicates that the use of hydroxichloride-based trace minerals results in greater liver concentrations of Zn and Cu compared with sulfate sources. While evidence indicates that trace mineral status has an important role in bull fertility, further research is required to better understand the contributions of trace minerals to semen quality. In addition, investigating the impact of trace mineral sources with greater bioavailability on semen quality may result in the development of practical recommendations that optimize bull fertility.

The Overall Situation of the Livestock and Evaluation of the Quantity of Beef Production in Batna City (Algeria)

Background: This study aims to determine the evolution of beef production during the last five years (2019-2023) in Batna city (Algeria) Methods: For the realization of this work we carried out an investigation at the municipal slaughterhouse of the city. During this investigation, we also took slaughter data. These include the weight of the carcasses and the classification of the slaughterhouse according to the categories of animals slaughtered. Moreover, a study was conducted to gather data from the Directorate of Agricultural Services (DSA) and the Ministry of Agriculture and Rural Development (MADR) regarding the number of cow herds in the studied city. The goal of this strategy is to comprehend the general state of the city’s livestock, including those destined for fattening and slaughter. Result: The animals intended for slaughter are mainly male cattle; of the young bulls and calves, the females admitted are cull dairy cows ( greater than 8 years). The results of this investigation showed that the beef production has experienced a remarkable drop from 1262560 kg in 2019 to 473430 kg in 2022, a slight change observed in 2023 but which still remains weak.

PSXIII-29 How does the combination of 3-nitrooxypropanol with feed additives affect the performance, carcass characteristics, and meat quality of feedlot young Nellore bulls?

PSXIII-29 How does the combination of 3-nitrooxypropanol with feed additives affect the performance, carcass characteristics, and meat quality of feedlot young Nellore bulls?

PSVI-21 Long-term effects of weaning and feeding strategies during early life on performance of young bulls

PSVI-21 Long-term effects of weaning and feeding strategies during early life on performance of young bulls

Accelerometers-based position and time interval comparisons for predicting the behaviors of young bulls housed in a feedlot system

Animal behavior monitoring is an important tool for animal production. This behavior monitoring strategy can indicate the well-being and health of animals, which can lead to better productive performance. This study aimed to assess the most effective accelerometer attachment position (on either the halter or a neck collar) and data transmission time intervals (ranging from 6 to 600 s) for predicting behavioral patterns, including water and food intake frequencies, as well as other activities in young beef cattle bulls within a feedlot system. A range of machine learning algorithms were applied to satisfy the aims of the study, including the random forest, support vector machine, multilayer perceptron, and naive Bayes classifier algorithms. All studied models produced high performance metrics (above 0.90) when using both attachment positions, except for the models built using the naive Bayes classifier. Therefore, coupling accelerometers with collars is a more viable alternative for use on animals, as doing so is easier than applying accelerometers to halters. Utilizing a dataset with more observations (i.e., shorter time intervals) did not result in considerable improvements in the performance metrics of the trained models. Therefore, using datasets with fewer observations is more advantageous, as it can lead to decreased computational and temporal demands for model training, in addition to saving the battery of the device considered in this study.

Metabolic profile of Charolais young bulls transported over long-distance

Long-distance transport can cause stress to beef cattle impairing health and growth performances. This study aimed to deepen the knowledge of the effects of long-distance transport on young bulls’ metabolic profile to identify reliable blood parameters for monitoring their health and welfare. Eighty Charolais young bulls, transported for 12 hours to the final fattening unit, were weighed and blood sampled at three time intervals: before leaving the commingling centre (day −1), upon arrival at the fattening unit (day 0), and 7 days post-arrival (day 7). These bulls were part of a larger study aimed at testing whether the animals have some benefit from the supplementation of live yeast and selenium through slow-release rumen boluses that were administered to half of them before departure from France (‘Yeast’ vs ‘Control’ group). The effect of the supplementation on the parameters considered in this study was included in the statistical analysis to account for the structure of the experimental design. Transport affected the initial body weight of the animals, which dropped on day 0 and it was not fully recovered on day 7. Most plasma traits of protein, energy, hepato-muscle, and mineral profiles were affected by transport. Cortisol was also assessed and peaked at day 0. The footprint of the long-distance transport on bulls’ metabolic profile indicated a combination of stress, energy deficit, and muscle damage, with a certain degree of dehydration and liver impairment. Plasma traits measured on day −1 highlighted that stressful conditions and physiological responses of the bulls to recover homeostasis already started during the commingling phase before departure. No effect of supplementation was detected, except for higher selenium plasma level in Yeast bulls at day 7. Among blood parameters, non-esterified fatty acids, total protein, cortisol, glucose, and iron were those responsible for most of the variation in metabolic profile of bulls undergoing long journey. Therefore, these traits might be used as major biomarkers to assess stress in transported beef cattle, helping to identify critical situations for which proper mitigating actions should be taken. The outcomes of this study suggested that preventive measures against transport stress in beef cattle should start at the commingling of the animals in the collection centers, thus before departure.

Effects of condensed tannin-enriched alternative energy feedstuff supplementation on performance, nitrogen utilization, and rumen microbial diversity in grazing beef cattle

This study aims to investigate the effects of alternative energy feedstuff supplementation containing condensed tannin (CT) on palisade grass pastures, focusing on intake, nutrient digestibility, animal performance, ruminal and blood parameters, nitrogen use efficiency (NUE), and its impacts on the ruminal bacterial community in backgrounding Nellore young bulls. Two experiments were conducted simultaneously. Animal performance was evaluated in Experiment 1. The experimental design was a completely randomized block; ninety Nellore bulls (Bos taurus indicus) with an average initial body weight (BW) of approximately 240 ± 5 kg were used (64 as testers and 26 as regulators). The feed intake, digestibility of dry matter and nutrients, ruminal parameters, NUE, and the impact on the ruminal bacterial community were evaluated in Experiment 2. The experimental design was a 4 × 4 double Latin square involving eight Nellore bulls with an average initial BW of 290 ± 8 kg, all of which were cannulated in the rumen. The treatments consisted of energy supplementation at 0.3 % of BW with peanut skin (PS), 0.3 % of BW with sorghum grain (SG), 0.3 % of BW with soybean hulls (SHs), and a control treatment with a supply of mineral salt ad libitum. The total digestible nutrient intake was lower in animals that received only mineral supplements (p < 0.005). The dry matter (DM) intake decreased with treatment PS, while the DM and nutrient digestibility increased (p < 0.005). There was a reduction in ruminal ammonia nitrogen and an improvement in NUE in the PS treatment (p < 0.005). However, the bacterial and Archaea populations were unaffected (p = 0.619). Individual animal performance and gain per kg were increased in the treatment with supplements containing or without CT compared to the mineral supplement (p < 0.001). The NUE improved in treatments PS, SG, and SH (p < 0.01). Feedstuff supplementation using no edible foods by products containing CTs is an effective alternative energy source for Nellore bulls grazing on palisade grass during the rainy season. Additionally, it can be used to mitigate the environmental impacts of N excretion.

Evaluation of Body Measurements of Limousin Young Bulls by Principal Component Analysis

The aim of this study was to analyse how body measurements, live weight and age in young Limousin bulls are interrelated, and what ratio of the phenotype variance can be explained by a group of them, so what traits should be considered in early selection. Body measures of 8-9 months old Limousin young bulls (n=610) in two consecutive years from 32 Hungarian farms were registered, and their covariance structure was studied by principal component analysis. Two components were defined, explaining 71.58% of the total variance. The first component was composed of live weight and body measures; the second component contained age. Live weight, withers’ height and hip height measures had highly definitive effect in the first component. Length of back, width at shoulders, and width at hip bone measurements had lower, but still significant effects. Eigenvalue of the first component had been very high, with 58.36% eigenvalue variance. Only effect of age proved to be highly significant in the second component, with an eigenvalue variance 13.22%. As age contributes less, if correction is needed for transforming results of individuals comparable, then it is advised to be based on live weight. Registered body measurements could be considered together in selection decisions, not needless to take all separately.

Traits of Mortadella from Meat of Different Commercial Categories of Indigenous Dairy Cattle.

The rising interest in healthier meat options prompted the exploration of alternatives to traditional pork-based products, incorporating meat from different livestock species, feeding regimens, and functional ingredients. This study investigates the production of healthier meat products by examining the physicochemical traits, fatty acid profile, and sensory properties of mortadella made with Cinisara meat of four young bulls and four adult cows, and four females of the Nebrodi Black Pig. All the animals were fed principally on natural resources. Nutritional analysis revealed different levels of moisture, protein, fat, and ash in raw materials, with pistachios contributing to a healthy fatty acid profile rich in monounsaturated and polyunsaturated fatty acids. Formulations using cow meat exhibited higher fat content and caloric value, resulting in sensory attributes such as more intense color, improved fat cube adhesion, and pronounced odors compared to young bull and control mortadella. Fatty acid analysis demonstrated distinctive profiles influenced by the meat type used and, as expected, bovine products showed higher contents of rumenic and other conjugated linoleic acids. Pork mortadella displayed greater ω6 and ω3 values, with a healthier ω6/ω3 ratio comparable to those found in cow products. Young bull mortadella showed the worse atherogenic and thrombogenic indices. The findings underscore the impact of raw materials on the nutritional and sensory attributes of mortadella, emphasizing the necessity for interventions to enhance fatty acid composition in processed meat products.