Search Results (38)

Weaning is challenging for dairy calves, frequently resulting in digestive issues. This highlights the importance of implementing appropriate nutritional strategies to enhance gut health and support optimal growth. Postbiotics is a promising alternative to traditional probiotics, conferring health benefits without the risks associated with live bacteria. This study aimed to investigate the effect of dietary supplementation with a postbiotic from dead-cell Limosilactobacillus ingluviei C37 (postbiotic LIC37) on blood biochemical parameters and jejunal epithelium transcriptomic profiles in calves. Fourteen Holstein bull calves were randomly allocated into two groups (n = 7). The control group (CON) received a basic diet, while the postbiotic group (DCLI) was supplemented with 1 g/d of postbiotic LIC37 for 90 days. Blood samples were collected on days 76, 83, and 90, respectively. The jejunal epithelial tissue was obtained from four randomly selected calves per group at day 90 for transcriptome analysis. The results showed that postbiotic LIC37 supplementation reduced globulin, total protein, neutrophil (Neu) levels, and neutrophil-to-lymphocyte ratio (NLR) levels in the DCLI group (p < 0.05). Transcriptomic analysis identified 76 differentially expressed genes (DEGs), with significant upregulation of genes involved in fatty acid metabolism (FABP1), intestinal barrier function (B4GALNT2), and detoxification (GSTA1), alongside downregulation of immune response regulation (FCRLA, FCRL4). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses highlighted enrichment in pathways related to glutathione metabolism, drug metabolism, and vitamin digestion, indicating that postbiotic supplementation improved detoxification, oxidative stress defense, and nutrient absorption in calves. This study provides novel insights into the molecular mechanisms underlying the benefits of postbiotic LIC37 and supports its potential as a sustainable alternative to probiotics in calf nutrition. Full article

Fifty high-risk bull calves were used in a completely randomized design (ten calves/treatment) to evaluate the optimal period of calcium propionate (CaPr) supplementation following arrival into the feedlot. The variables evaluated were the growth performance, dietary energetics, body fat reserves, serum metabolites, and economic return at day 56 of arrival. Calves, which were weighed at the moment of reception (156.2 ± 1.57 kg off-truck body weight, BW), were received with a 50:50 forage-to-concentrate ratio diet and clean water. At 12 h from reception, they were housed in individual pens during a 56 d feeding period and assigned to treatments consisting of a daily supplementation of a commercial product (Propical^® Dresen Química, SAPI de CV., Mexico City, Mexico) that provided 19 g CaPr/calf for 0, 14, 28, 42, or 56 d following arrival into the feedlot. Compared with the other treatments, the calves receiving CaPr during the initial 42 d had a greater average daily weight gain (p ≤ 0.035) without affecting the dry matter intake (p ≥ 0.24). Thus, the gain efficiency (p ≤ 0.050) and dietary energy utilization were improved (p ≤ 0.046). Rib fat thickness (p ≥ 0.090) and Longissimus lumborum muscle area (p ≥ 0.112) were not affected by the CaPr supplementation, whereas calves showed the greatest values (p ≤ 0.038) to the rump back fat thickness at 42 and 56 days of CaPr supplementation. With the exception of the total albumin (being maximal at day 56 (p ≤ 0.024)) and total cholesterol (which, compared to the controls, was maximal at 28 and 42 d; p = 0.030), the serum metabolic profiles were not affected by the treatments. Using the profit estimated for the control group as a baseline, supplementing CaPr for 42 d yielded a greater net income (USD 34.84 more/calf). CaPr supplementation for more or less than 42 d showed a very similar profit (~USD 6.80/calf). Because the cost of gain was very similar for these treatments and the controls (USD 1.42 vs. 1.46/kg), the positive difference in profit was mediated mainly by an increase in income selling (+USD 13.02/calf) for the CaPr calves. Based on the performance, serum metabolites, and profit, it is concluded that the optimal duration of supplemental CaPr is 42 d. Offering 19 g CaPr during this period enhanced the growth performance, dietary energy, and economic returns. Full article

Animal density is a grazing management decision implemented by managers that may reduce animal diet quality. Over three years, we collected herd-level cattle samples with varying animal numbers and densities across C₃ grass–legume meadows near Powell, WY, USA. Paddocks ranged in size from 3 to 72 ha, cattle groups ranged from 80 to 370 animals, animal units (AUs; defined as heifers = 0.8, cow–calf pairs = 1.3, and bulls = 1.6) ranged from 52 to 248.6, animal density ranged from 1.5 to 30.3 animals/ha, and AU density ranged from 0.9 to 19.8 AUs/ha. Near-infrared reflectance spectroscopy of fecal samples (f.NIRS) was used to estimate crude protein (CP), digestible organic matter (DOM), and the DOM:CP ratio. Structural equation modeling (SEM) that mediated time (i.e., Day of Year) rendered all animal number or density variables as significant predictors for CP and DOM (negative estimates) and for DOM:CP (positive estimate), indicating that congregating animals in larger groups and/or greater densities, even in meadows with high-quality forage species, may reduce post-ingestive diet quality estimates by −1.2% and −2.0 for CP and DOM for every +100 animals or for every +10 animals per hectare. Livestock managers could potentially override this negative effect by adjusting when animals are congregated at higher densities. Full article

Background: Oxidative stress in the testicles of male livestock can cause reduced fertility. Melatonin is a natural product with antioxidant effects, but its specific antioxidant mechanism is still unclear. This study used calf testicular Sertoli cells as materials to explore the mechanism by which melatonin alleviates the oxidative stress of Sertoli cells, laying a foundation for improving the fertility of bulls. Methods: The optimal treatment concentrations of H₂O₂ and melatonin (MLT) were screened out using a CCK8 kit and MDA kit. Then, the cells were divided into four groups for treatment: control group, H₂O₂ treatment group, MLT treatment group, and H₂O₂ and MLT co-treatment group, then the MDA, ROS, GSH, and SOD contents were detected. Real-time quantitative PCR analysis and Western blot analysis were used to detect genes and proteins related to the Nrf2-Keap1 pathway. Immunofluorescence staining was used to analyze changes in Nrf2. Results: Research results show that the MDA content of cells in the group treated with H₂O₂ and MLT combined was significantly lower than that in the group treated with H₂O₂ alone, but there was no difference from the control group. Compared with the control group, the ROS level of cells in the H₂O₂-treated group significantly increased, and the content of GSH and SOD significantly decreased. Compared with the H₂O₂-treated group, the ROS level of cells in the H₂O₂ and MLT co-treated group significantly decreased, and the content of GSH and SOD increased significantly, but no difference from the control group. Similarly, MTL can alleviate the changes in cellular Nrf2, Keap1, HO-1, and NQO1 expression caused by H₂O₂. Conclusions: Melatonin activates the Nrf2-Keap1 signaling pathway in Sertoli cells, elevating the expression of HO-1 and NQO1, and thereby exerting its antioxidant capabilities. Full article

This study investigates morbidity, mortality, and weight gain in pre-weaned female dairy calves, which pose economic and animal welfare challenges for farms, particularly in family-run operations in southern Brazil. We aimed to identify the rates and factors associated with these outcomes in Alto Uruguai, Rio Grande do Sul, Brazil, tracking 547 calves from 70 farms across 27 municipalities from July 2015 to September 2016. We assessed calf-rearing practices, nutrition, health, and the environment using farmer questionnaires, direct observations, and systematic weight and health monitoring of female calves from birth to weaning. The association between predictors and perinatal mortality (stillbirths and deaths within 24 h), postnatal mortality (deaths from 25 h after birth to weaning), calf morbidity, and weight gain was analysed through regression models. The participating farms had 25 (9–70) (median and range) lactating cows and produced 411 (96–1631) L/d of milk (median and range). Total mortality rate was 6.8% (median 0, range 0–50%/range), of which 2.4% (median 0, range 0–50%/range) was perinatal and 4.5% (median 0, range 0–40%/range) postnatal. Average morbidity was one case for every five calves born alive (106/538), 83% of which were reported as diarrhoea cases. Weight gain was 570 ± 212 g/d (mean and standard deviation). The postnatal mortality rate was highest in the first few weeks of life and among calves with at least one case of diarrhoea. Younger and winter/spring-born calves became sick more frequently. The calves of purebred bulls, fed with cow’s milk, which received at least 4 L of milk and 0.5 kg of feed daily, had greater weight gain. The calf mortality rate was at the lower end of the range reported in international research. The main disease affecting calves was diarrhoea, and weight gain was insufficient for calves to double their weight by the time they were weaned. The results of the present study suggest that the quality of the management adopted in calf rearing in many of the family-run dairy farms of southern Brazil may be compromising the welfare, health, performance, and survival of the calves and possibly the productivity of dairy herds. Full article

This study investigated the factors influencing gestation length in a herd of Wagyu cattle in Rio Grande do Sul, Brazil. Fifty-five multiparous purebred Wagyu cows underwent a Fixed-Time Artificial Insemination (FTAI) protocol using semen from a bull randomly selected from five bulls representing three distinct genetic lines. Following birth, we recorded the calves’ gender, weight, and gestation length. The ANOVA test was employed to assess genetic effects on calf weight and gestation length, with significance set at p < 0.05. The 55 inseminations resulted in 52 births, comprising 34 females and 18 males. The average calf weight was 25.9 kg, with 25.2 kg for females and 27.2 kg for males (p = 0.38). No significant effect was observed for birth weight concerning the sire’s genetic line (p = 0.42), although there was a trend towards an effect from the maternal grandfather (p = 0.09). The mean duration of pregnancy was 283.8 ± 5.91 days, with no significant effect of gender on gestation length (p = 0.6). However, when evaluating the genetic influences on gestation length, we observed significant effects from the sire’s genetic line (p < 0.0001) and the maternal grandfather (p < 0.0001). Notably, longer pregnancies resulted in heavier calves (p < 0.0001). This is the first study to identify the effects of Wagyu breed lines on pregnancy length. Full article

Genetic disorders are caused by a hereditary change in the structure of DNA that may hurt the health and life of animals. Several recessive haplotypes and a few causative mutations are known in Holstein Friesian cattle: CDH (Holstein cholesterol deficiency), haplotypes with a homozygous deficiency in Holstein (HH1, HH3, HH4, HH5, HH6, HH7), BLAD (bovine leukocyte adhesion deficiency), DUMPS (deficiency of uridine monophosphate synthase), FXI (factor XI deficiency), HHM (mule foot, syndactyly), and BC (citrullinaemia). From a breeding point of view, these genetic diseases have highly negative effects and are a significant problem for breeders, exposing them to economic losses and hurting animal welfare. This study aimed to characterize the Polish population of Holstein Friesian dairy cattle, considering the carrier status of twelve selected genetic defects. This study was based on genotype data collected from 78,884 cows and 691 bulls of the Holstein Friesian variety. The studies were performed using Illumina Infinium microarrays. Among both bulls and cows, the highest numbers of carriers were detected for HH5 (appropriately 6.7% and 5.4%). The lowest numbers of carriers were detected for DUMPS, factor XI, and HHM. The study revealed one calf suffering from cholesterol deficiency. Full article

Objectives: Various measures have been attempted to prevent infectious diseases in calves, such as environmental improvement and vaccine administration. Probiotics are commonly used to improve the body condition of newborn calves and prevent disease. In our previous research, Lactiplantibacillus plantarum RGU-LP1 (LP1) suppressed the expression of inflammatory cytokines in PBMCs of cattle fed it in the diet. In this study, we evaluated the effect of LP1 on the weights and number of treatments of the calves. Methods: Twenty-six one-week-old Holstein bull calves were divided into two groups (thirteen each), the LP1 group (LP1-treated) and the CN group (no LP1 fed), and tested as follows. The LP1 group was fed lyophilized LP1 (10⁹ CFU/head/day) in milk replacer for 40 days. The CN group was fed the same diet only. Calves were followed for 63 days. The average treatment costs for the LP1 during the period were recorded. Feces and blood were collected from each calf during this period. Feces were examined for gut microbiota, and blood for immune assay and cytokine gene expression. Results: The LP1-treated group showed a decrease in disease incidence and an increase in body weights compared to controls. The average treatment cost during the observation period was significantly reduced compared to the CN group. The expression of TGFβ and IL10, inhibitory cytokines of inflammation, was significantly increased. The simultaneous expression of this set of inhibitory molecules resulted in low serum IL1β levels during the growth period. Conclusions: The Th1-type cytokine IFNγ was also significantly increased in LP1-treated calves. By reducing the amount of disease treatments and increasing dairy gain, LP1 is effective in preventing infectious diseases in calves. In addition, the increase in IFNγ by LP1 indicates improved Th1-type immunity in calves. These results show that LP1 has effects on the regulated inflammatory response and growth of calves. Full article

Mycoplasma bovis is a globally significant pathogen of cattle associated with a wide range of clinical syndromes, including respiratory disease, mastitis, arthritis, otitis, and reproductive failure. Since its detection in Ireland in 1994, M. bovis has become a significant contributor to morbidity and mortality in Irish cattle. This study aimed to investigate herd-level risk factors associated with M. bovis seropositivity in replacement dairy heifers, using data from 105 Irish dairy herds. Ten heifers per herd were sampled on three occasions: spring 2018, spring 2019, and autumn 2019. Seropositivity was evaluated using two thresholds: ≥1 positive heifer (Model ≥ 1POS) and ≥3 positive heifers (Model ≥ 3POS). M. bovis seropositivity varied over time, with at least one positive heifer in 50.4% (95% confidence interval (CI): 40.5–60.3) of herds in spring 2018, 35.2% (95% CI: 26.2–45.1) in spring 2019, and 45.7% (95% CI: 36.0–55.7) in autumn 2019. Herds with three or more positive heifers increased from 31.4% (95%CI: 22.7–41.2) in spring 2018 to 42.9% (95% CI: 33.2–52.9) by autumn 2019. Risk factors for M. bovis seropositivity included the purchase of cattle, which significantly raised the odds of seropositivity across multiple visit periods (Model ≥ 1POS: Odds ratio (OR) 3.84, p = 0.02; Model ≥ 3POS: OR 3.69, p = 0.02). Managing more than three land parcels, housing heifer calves separately from bull calves, and sharing airspace between calves and older animals also increased seropositivity risks. Conversely, more colostrum feeds reduced the risk of seropositivity (Model ≥ 1POS: OR 0.81, p = 0.05), while colostrum quality assessment and feeding waste milk showed a trend toward increased risk. These findings suggest the importance of robust biosecurity measures, including limiting cattle purchases, improving calf management, and enhancing colostrum feeding practices, to control the spread of M. bovis. This study provides valuable insights into the epidemiology of M. bovis in Irish dairy herds, emphasising the need for targeted biosecurity and surveillance to safeguard herd productivity. Full article

The aim of this study was to examine the impact of daily calcium propionate (CaPr) supplementation (0 or 20 g/calf) on growth performance, dietary energetics, body fat reserves, serum metabolites, and hematological responses in high-risk beef calves fed diets with varying (50, 60, or 70%) concentrate (CON) levels. In addition, a cost/income analysis of CaPr supplementation was carried out. Forty-eight crossbred bull calves (152.8 ± 1.56 kg body weight and 5.5 months of age) were involved in a fully randomized experimental design employing a 2 × 3 factorial arrangement of treatments. Calves were allocated (n = 8 per treatment) to individual pens (3.14 × 5.25 m) and were subjected to one of the following treatments during 42 d: No CaPr supplementation in diets containing 50, 60, or 70% CON (NoCaPr + 50, NoCaPr + 60, NoCaPr + 70, respectively) or daily CaPr supplementation dosed at 20 g/calf in diets containing 50, 60, or 70% CON (20CaPr + 50, 20CaPr + 60, 20CaPr + 70, respectively). Non-supplemented calves exhibited decreased dry matter intake (DMI) with increasing CON levels in their diets, while CaPr-supplemented calves displayed the opposite effect (interaction, p = 0.04). In calves fed a lower-CON diet (50%), those supplemented with CaPr showed greater average daily gain (ADG, 20.2%, p = 0.05) and lower DMI (2.2%, p = 0.03), resulting in improved ADG/DMI ratio, dietary energy, and energy retention (24.6, 14.4, and 18%, p < 0.05). These effects diminished when calves received diets with 60 or 70% CON but led to a 14.2% increase in rump fat thickness (p = 0.04). Only in non-supplemented CaPr calves, increasing the level of CON from 50 to 70% in the diet increased ADG (21.2%), decreased DMI (2.2%), and improved the ADG/DMI ratio (22.7%), with no impact on dietary net energy utilization. Non-supplemented calves exhibited an increase in lymphocytes as CON levels rose in their diets, whereas CaPr-supplemented calves showed the opposite effect (interaction, p = 0.05). Supplementation of CaPr decreased total protein (TP, p = 0.03) and albumin (ALB, p < 0.01) serum concentrations, with lower concentrations observed in 20CaPr + 50. CaPr supplementation reduced (p = 0.01) total cholesterol (TCHO) levels. An interaction between CaPr and CON level (p = 0.02) was observed since TCHO levels remained consistently low at higher CON levels. Glucose was decreased with increasing levels of CON (p = 0.02) but not (p = 0.85) for CaPr-supplemented calves. NoCaPr + 50 and NoCaPr + 70 increased (p = 0.05) ALB concentration. Gamma glutamyltransferase levels increased (p = 0.05) with increasing CON levels irrespective of CaPr supplementation. Comparing the profit within the same CON level in the diet, CaPr treatments yielded higher income, with the largest difference in profit observed when CaPr was supplemented at 50% CON level (USD 29 more/calf). In conclusion, CaPr supplementation proves to be an effective strategy for enhancing growth performance and dietary energy among high-risk beef calves, resulting in greater economic returns. The groups that received CaPr demonstrated superior profitability, particularly in calves fed diets with lower CON levels. Under the conditions in which this experiment was carried out, the optimal response occurred when the low-CON diet (50%) was supplemented with CaPr. Full article

Low birth weight (BW) calves exhibit higher mortality rates, reduced body weights at parturition, lower first-lactation milk yields, and longer parturition to first insemination intervals. In human medicine, small for gestational age (SGA) births are associated with increased perinatal morbidity and long-term metabolic risks. This study aimed to define SGA in Holstein Friesian (HF) calves, evaluate their body measurements and proportions, and identify its prenatal risk factors. Four linear regression models were built with weight as a function for gestation length for bull and heifer calves born from nulli- or multiparous dams. Calves with a BW below the 10th percentile were classified as SGA. Differences in body measurements were analyzed using ANOVA, and logistic regression models identified prenatal risk factors to be born SGA. Gestation length, calf sex, and dam parity were crucial variables in defining SGA. SGA calves had significantly smaller body measurements (p < 0.001) and larger body proportions (p < 0.001) compared to average and large calves. For nulliparous dams, a higher 2nd trimester temperature–humidity index (p = 0.032) and older age at parturition (>26 months, p = 0.026) significantly increased the birth of SGA calves. For multiparous dams, both low (<5800 kg, p = 0.049) and high (6700–8600 kg, p = 0.027) milk yields during gestation lead to more SGA births, although very high-yielding dams (>8600 kg) did not birth more SGA calves. This study establishes SGA in HF calves, suggests SGA calves are asymmetrical with evidence of “brain sparing”, and highlights the impact of prenatal factors on calf size at birth. Further research is needed to determine the long-term effects of being born SGA on growth, reproductive performance, and productivity. Full article

In this study, we have included the water footprint (WF) in the process of optimizing animal feed rations. The global footprint of cattle production accounts for the largest share (33%) of the global water footprint of livestock production. Using two homogeneous groups of Limousine × Podolian young bulls, two different diets were compared: corn silage feeding (CSF), with a corn silage-based diet; and triticale silage feeding (TSF), with a triticale silage-based diet. Silage constituted about 41% and 46% of the feed composition (for CSF and TSF, respectively). Diets were characterised by the same energy and protein content. Despite the lower WF in the TSF group than in the CSF group (7726 vs. 8571 L/day/calf respectively), no significant differences were found in animal performances (i.e., daily weight gain and final weight), feed conversion or income over feed costs. These results show that simple production decisions can have a significant impact on water resource. Therefore, the use of triticale silage should be further promoted, especially in world regions with limited water resources where low WF feed formulation is more strategic than elsewhere. Full article

This study utilized fifty bull calves of the Continental × British crossbreed, with an average body weight of 147.0 ± 1.67 kg (BW), in a completely randomized design. The objective was to examine the impact of varying levels and duration of calcium propionate (CaPr) supplementation on the growth performance, body fat reserves, serum metabolites, and hemogram of high-risk newly received stocker calves. These calves were individually housed and fed a received diet for 56 d. The calves received the following treatments: (1) no CaPr (CTL), (2) 20 g CaPr/calf/d, (3) 40 g CaPr/calf/d, (4) 60 g CaPr/calf/d, and (5) 80 g CaPr/calf/d at 14, 28, 42, and 56 d after their arrival. Supplementing with 20 g CaPr from 28 to 56 d after arrival increased average daily gain (ADG) and BW (p < 0.05), and DMI was not affected (p > 0.05). This was reflected at 28 d with increases (p < 0.05) in the ADG/DMI ratio and longissimus muscle area (LMA), and at 56 d in back fat thickness (BFT) and fat thickness at the rump (FTR). Also, with 20 g, blood urea nitrogen decreased (p < 0.05), and increases were observed in the activity of gamma glutamyltransferase, monocytes (quadratic trend, p < 0.07), and granulocytes % (quadratic effect, p < 0.03). However, as the level of CaPr increased during the first 14 d after arrival, daily water intake, creatinine, total cholesterol, mean corpuscular hemoglobin concentration (linear effect, p < 0.05), globulin, calcium, and mean corpuscular volume (linear trend, p = 0.08) increased, while alkaline phosphatase (linear trend, p = 0.07) and lymphocytes (linear effect, p = 0.05) decreased. Finally, the different levels of CaPr supplementation did not produce any significant effects or differences (p > 0.05) in the remaining serum metabolites and hemogram (p > 0.05). Ultimately, the inclusion of 20 g CaPr/calf/d in the diet for 28 d in newly received stocker calves increased ADG, ADG/DMI ratio, and LMA. If extended to 42 or 56 d, the increases in ADG persisted, but there was also a rise in body fat reserves (BFT and FTR) at the expense of a reduction in the ADG/DMI ratio. Furthermore, the different supplementation levels did not impact the reference range for most serum metabolites or the health of stocker calves. Full article

This study assessed the impact of different calf rearing systems on calf health, behavior, meat quality, and oxidative stability. The study involved two groups of bull calves: conventionally penned calves (control, fed with use of automatic feeders) and calves reared alongside foster cows (experimental). The presence of foster cows was found to have a significant positive influence on calf health. Calves raised with foster cows experienced lower rates of diarrhea, delayed instances of coughing, and a reduced occurrence of rhinitis compared to conventionally reared calves. Behavioral observations revealed differences in sucking and licking behaviors between the two groups. Calves with foster cows displayed more consistent patterns of these behaviors, while conventionally reared calves exhibited greater variability. Additionally, the experimental group consistently achieved higher daily weight gains, suggesting the potential for larger and more valuable carcasses at slaughter. Importantly, there were no significant differences in the quality of veal between the two rearing groups. This included fatty acid composition, color attributes, and myoglobin levels, indicating consistent meat quality. In summary, this research highlights the advantages of rearing systems that prioritize calf health and behavior, emphasizing maternal care and natural behaviors. Such systems hold promise for improving calf welfare and enhancing the sustainability of the meat production industry. The integration of foster cows into dairy farming practices emerges as a practical and effective approach, particularly for the rearing of bull calves. Full article

The objective of this study was to evaluate the impact of cows’ calving ages and newborn calf body weight on the pre-weaning growth rates of calves under the farming conditions of a northeastern European country. The females were purebred Charolais cows that calved between 2019 and 2022. A total of 130 calves (bulls = 76; heifers = 54) were observed during the evaluation. The investigation showed that, based on gender, bulls had a 4.28% higher birth weight than heifers (p < 0.05). The gender of the calves affected their weight, indicating that newborns bulls were significantly heavier. Calf gender affected calf growing performance. Male calves’ weight gain was higher than that of females in the time before weaning (210 days). The highest gain of bulls was observed from 211 days to 365 days after birth. The average daily weight of male calves during this period was 6.16% (p < 0.001) higher compared to the period up to 210 days after birth. Heifers had a higher daily weight in the period up to 210 days after birth, and the daily weight gain was 12.9% (p < 0.001) higher in this period compared to the period from 211 to 365 days after birth. We observed a higher weight gain in calves from mothers with a higher number of calvings. Being born from cows with four or more calvings had a significant effect on the weight gain of calves in the period up to 210 days (p < 0.05). In the period up to 210 days, the weight gain of calves born from cows with two calvings was the lowest and was 9.79% lower compared to calves born from cows with four and more calvings (p < 0.05). The best weights were obtained from calves born in the spring and autumn seasons. Calves born in spring, summer, and autumn differed in weight by 0.37 kg. The calves of cows that were inseminated in the autumn season had the highest gain in the period up to 210 days and also from 210 to 365 days (p < 0.05). In our study, significantly higher average birth weight of calves was detected in autumn compared to summer and winter (p < 0.05). Also, the highest gain was found from 211 to 365 days after birth in the summer season, but the difference was only 1.47% (p < 0.05). Full article