Weight Of Bulls Research Articles

The yield of adipose tissue and by-products in the course of the slaughter of inbred and outbred bulls of the Ukrainian beef breed

The research focuses on analysing and generalising the distribution of internal adipose tissue and organs that are not part of the carcasses of inbred and outbred bulls of the Ukrainian beef breed. Animal stock inbreeding was determined based on five breeding records according to Wright’s method modified by Kyslovskyi. Two experimental groups of 5 bulls were formed. The average inbreeding coefficient for inbred bulls was 3.43%. Animals were bred up to 18 months of age. Following slaughter, the mass and the yield of the head, liver, lungs, heart, kidneys, and brain were determined, and 4 types of fat were separated and weighed: perirenal, from the stomach, intestines, and pericardial. Inbred animals are more prone to the accretion of internal adipose tissue. Inbred bulls have 1.8 points more of it. Fat is more intensely accumulated around inbred bulls' multichambered stomachs and kidneys. Intensive fat accumulation was observed around the hearts and intestines of outbred bulls. Adipose tissue around the heart and intestines is more variable in inbred and outbred animals – from the forestomach and kidneys. The weight of inbred bulls’ liver is less by 22.4%, kidneys – by 62.5%, heart – by 11.1%, and head – by 23.8% compared to outbred ones. The weight of their lungs is more by 10.5%. At the same time, inbred bulls tend to have brain weight gain of 12.5% and testicles – by 8.3%. Thus, inbreeding application in Ukrainian beef breeds with a small population size affects the growth of internal organs and the intensity of accumulation and distribution of interior fat. Due to more intensive accumulation of internal adipose tissue, inbred bulls have increased expenditure of forage energy for its formation. They are characterized by an increased yield of low-value raw fat, making them less efficient than outbred bulls for beef production.

Effects of Different Prenatal Nutrition Strategies on the Liver Metabolome of Bulls and Its Correlation with Body and Liver Weight.

This study investigated the effect of prenatal nutrition on liver metabolome and on body (BW) and liver weight (LW) of Nellore bulls at slaughter. Three treatments were applied in 126 cows during pregnancy: NP—control (mineral supplementation); PP—protein-energy supplementation in the third trimester; and FP—protein-energy supplementation during the entire pregnancy. Offspring BW and LW were evaluated, and a targeted metabolomics analysis was performed on their livers (n = 18, 22.5 ± 1 months of age). Data were submitted to principal component analysis (PCA), analysis of variance (ANOVA), enrichment analysis, and Pearson’s correlation analysis. The phenotypes did not show differences between treatments (p > 0.05). Metabolites PCA showed an overlap of treatment clusters in the analysis. We found significant metabolites in ANOVA (p ≤ 0.05; Glycine, Hydroxytetradecadienylcarnitine, Aminoadipic acid and Carnosine). Enrichment analysis revealed some biological processes (Histidine metabolism, beta-Alanine metabolism, and Lysine degradation). Pearson’s correlation analysis showed 29 significant correlated metabolites with BW and 1 metabolite correlated with LW. In summary, prenatal nutrition did not show effects on the phenotypes evaluated, but affected some metabolites and biological pathways, mainly related to oxidative metabolism. In addition, BW seems to influence the hepatic metabolome more than LW, due to the amount and magnitude of correlations found.

Efficiency of nutritional use feed substances of ruminal breeds of ruminants in the conditions of the Bukovina region

The proposed article explores the effectiveness of using nutrients of forages of Bugayets of various breeds of cattle in the conditions of the Carpathian region of Bukovina. In the studies carried out, it was proved that the first three months, the daily weight gain of young animals in the control group was 661 g, the second – by 13.8 %, and the third – by 22.6 % were less with a likely difference with the control. The absolute gains in the first three months were 60.8; 52.5 and 47.1 kg, respectively, while in the subsequent period (from 3 to 6 months of age) they were high in animals of the second group (92.4 kg), which 9.7 kg (11.7 %) more than the third group and 5.2 kg (5.9 %) more than the first. According to the research results, it can be seen that the milk period of animals hornless beef simmental cattle gave 804 g daily gain, first-generation hybrids – by 2.2 %, and young animals ¾-blood chunks of simmental cattle – by 12.2 % less with a probable difference with control. So the absolute gains were 148.0; 144.9 and 129.8 kg, respectively (P > 0.95). Studies have found that from 15 to 18 months of age the absolute gains in live weight of bulls in the first group were 111.7 kg, in the second – by 7.6 kg (6.8 %) were greater, in the third – by 4.0 kg (3.6 %) less. At the end of the fattening period in all groups of animals, the average daily gains were above 1000 g. As a result, the live weight of bulls of the first group at 18 months of age was 483.3 kg, the second – 461.9 and the third – 447.8 (P > 0.95) kg. The coefficient of variability was high among animals of the Simmental hornless beef cattle breed (7.58 %), and the lowest among ¾-blooded simmental crosses (4.28 %). It was found that the efficiency of raising gobies of different breeds was that the profitability in the sale of young animals in the control group was 16.68 %, the second and third experimental groups – less by 5.01 and 8.42 %, respectively.

The Utilization of Fermented Rice Straw Ammoniation Feed (Amofer ) to Increase Body weight Gain of Bali bull in Batu Kuta Lombok Barat

The utilization of rice straw waste as fermented ammonia (Amofer) for cattle farming was done in Desa Batu Kuta Kecamatan Narmada Kabupaten Lombok Barat from April-September 2021 with aims to introduce Amofer feed technology to increase body weight of bulls. The research procedures that have been carried out includes: 1). Amofer feed manufacture by adding ammonia in rice straw (Ammonia Straw), and 2). Amofer feeding management. This study was used 15 Bali bulls with 225 kg – 250 kg of body weights. There are three (3) treatments of Amofer feeding management, namely: R0 = Farmer's treatment (straw+concentrate); R1 = Forage 30% (15% elephant grass + 15% gamal grass) + 69 % Amofer feed + 1 % Concentrate (corn + bran); R2 = Forage 70% (35% elephant grass + 35% gamal grass) + 29 % Amofer feed + 1 % Concentrate (corn + bran). Parameters measured were feed consumption (FC) and daily body weight gain (DBWG). The results showed that the highest of FC was found on Bali bull with R-2 treatment (14.42 kg/each/day), and the highest of DBWG was shown by Bali bull whith R-2 treatment (0.66 kg/each/day). It is concluded, the Amofer feed formula in R2 treatment was more efficiently applied to ruminants with the aim of fattening cattle.

ANALIZA I PORÓWNANIE PARAMETRÓW UŻYTKOWOŚCI MIĘSNEJ BUHAJÓW RASY LIMOUSIN POCHODZENIA POLSKIEGO I FRANCUSKIEGO

The study covered bulls of the Limousine meat breed, whose parents were of Polish and French origin, kept on farms in Poland. This study aimed to assess whether individuals of Polish origin cover their genetic potential compared to bulls of French origin. These studies were carried out under the program of the Ministry of Science and Higher Education "Implementation Doctorate" DWD3 / 53/2019 in cooperation with the Polish Association of Beef Cattle Breeders and Producers in 2019-2022. The research material consisted of 925 bulls, 447 by French father and 478 by Polish father. Among breeders of Polish origin, special attention was paid to the fact that parents of French origin did not appear in the pedigrees in the previous two generations. The following factors were taken into account in the comparative analysis: the country of origin of the bull's father, the country of origin of the bull's mother, body weight after calving (kg), body weight at 210 and 420 days of life (kg) and gains (g) in this period, standardized weight in 210 and 420 days (kg), as well as the height at withers (cm), chest circumference (cm), ultrasound measurement of the longest back muscle (cm3), muscle index, development index, collective evaluation index, calibre, muscle and bone share, functional features and state. The individual calendar months were taken into account as the calving period. Statistical analysis was performed by multivariate ANOVA using SPSS.23 software. A significant influence of the father's origin on the vital parameters of bulls was shown. After the birth of a Polish father, the mean body weight of bulls was 39.08 kg and was lower by 0.95 kg (p ≥ 0.01) than males of French origin. Bodyweight, daily gains, standardized body weight in the 210th and 420th day of life, height at the withers, chest circumference, ultrasound measurement of the longest back muscle, meatiness index, development index, and aggregate evaluation index spoke in favour of bulls of French origin. However, there were no significant differences in maternal origin, size, muscle and bone proportion, functional components, and condition.

Method for elimination of D-vitamin deficiency of fatting bulls in stress conditions of industrial complex

The development of stress-induced disorders in fattening bulls under industrial technology exacerbates vitamin and mineral deficiency. Effective and environmentally friendly to increase the level of missing vitamins are preparations of natural origin. One of them is melange, which includes egg white and yolk. The creation of melange is due to more convenient storage and transportation in comparison with whole eggs. The melange contains a large amount of protein, polyunsaturated fatty acids, as well as a vitamin-mineral complex, its characteristic feature is the stability of biologically active properties during freezing or melting. The energy value of melange is 157.00 kilocalories per 100 g of the product, which are made up of calories obtained from proteins - 12.70 g, fats - 11.50 g and carbohydrates - 0.70 g. The content of vitamin D3 in melange was studied. The studies were carried out at OOO IL Test-Pushchino on a Shimadzu LCMS-8060 liquid chromatography-mass spectrometer. A high content of vitamin D3 in melange was found, equal to 3617 µg/kg. The object of research were bulls of black-and-white breed aged from 6 to 12 months. The experiment was carried out on two groups of animals, 15 heads each. All bulls received the same basic diet. The calves of group I were the control and received only the main diet, the bulls of the experimental group received, in addition to the main feed ration, a composition representing a mixture of the following composition: egg powder (at a dose of 100 g) per head; urea (at a dose of 15 g) per head and Miarom P (at a dose of 20 g) per head by mixing with the feed mixture for 30 days. A positive dynamics of vitamin D3 was established when using the proposed composition: from the initial values equal to 20.05 ?g/kg, the vitamin content reaches 50 ?g per kg by the 30th day of the experiment.Starting from the 10th day of the experiment, the calcium content reaches 2.57 mmol/L and by the end of the experiment it is 2.64 mmol/L, which tends to the middle of the reference values (2.06-3.16).A similar trend is observed in the dynamics of the phosphorus content in the blood of bulls, already from the 10th day the phosphorus concentration approaches the highest limit of the reference values (1.13-2.91 mmol/L) and is equal to 2.80 mmol/L, and by the 30th day reaches 2.81 mmol / L. Throughout the experiment, the increase in live weight of bulls of both groups (experimental and control) was determined, the results showed that the bulls that were fed most intensively grew using the "Method of increasing the average daily gain of bulls aged 6 months and over" (patent No. 2751221), according to which bulls in addition to the main diet received egg powder at a dose of 100 g per head; urea at a dose of 15 g per head and Miarom P at a dose of 20 g per head by mixing with the feed mixture for 30 days. The weight of bulls in the experimental group after 30 days of feeding was higher by an average of 6 kg (163.0 kg versus 157.0 kg in the control). At the same time, an increase in average daily gains in bulls by 11% was found, which allows us to recommend the use of the proposed composition for bulls with D-vitamin deficiency.

ЭФФЕКТИВНОСТЬ ИСПОЛЬЗОВАНИЯ АДАПТОГЕНОВ РАЗЛИЧНОГО ПРОИСХОЖДЕНИЯ НА МЯСНУЮ ПРОДУКТИВНОСТЬ КРУПНОГО РОГАТОГО СКОТА

The article is devoted to determining the feasibility and effectiveness of the use of adaptogens of plant and animal origin in the feeding of cattle. A scientific and economic experiment was carried out on bulls of the Kazakh white-headed breed, in the diet of which they were introduced in the form of tinctures (at the rate of 0.01 ml of tincture per 1 kg of body weight) adaptogen levzeya (for animals of the II experimental group), drone homogenate (III experimental group) and pantocrine (experimental group IV), while the animals of group I were assigned to the control group and did not receive supplements. The effectiveness of the use of the tested components was determined according to the weight growth of bulls, the morphological and biochemical composition of blood, and the chemical composition of beef. The results of assessing the live weight of bulls by age periods indicate that young animals consuming a plant adaptogen exceeded control peers by 18 months of age by 18.60 kg (3.72%); animal origin – by 28.50 kg (5.71%; Р ≤ 0.05) and 21.00 kg (4.21%). In all animals participating in the experiment, the blood parameters were within the physiological norms, but with a slight increase towards the upper normative limits in the experimental samples. There is an improvement in the qualitative composition of the final livestock products. Thus, the indicator of the biological usefulness of beef was higher in samples taken from experimental animals by 0.18–0.36 units. (P ≤ 0.05). The greatest nutritional, biological and energy value was characterized by milk obtained from cows, in the diet of which drone homogenate was introduced. Thus, the results of comprehensive studies indicate the effectiveness of introducing adaptogens of both plant and animal nature into the diet, but the best effect was obtained from the use of drone homogenate.

Economic efficiency of using high energy of bulls’ growth

The article presents the results of research on the comparative assessment of the growth, development and meat productivity of calves and castrates of Kalmyk and Simmental breeds under the same conditions of feeding and maintenance and identification of ways to increase the profitability of beef production by using the physiological state of young animals. The experimental young animals received the same amount of feed by volume and the composition of the diet was the same. As a result of the conducted studies, it was found that the live weight of bulls of both breeds with their intensive cultivation exceeded the mass of castrates in all age periods. After weaning, there was no significant difference in the live weight of calves of the Kalmyk and Simmental breeds, which had a live weight of 255.6 and 253.9 kg, respectively, and by the age of 15.5 months, many bulls of both breeds reached from 500 to 520 kg. Castrates of both breeds grew less intensively. However, in the final period of fattening, they gave a high average daily increase (more than a kilogram). The Kalmyk castrati were less demanding of coarse feeds and used them better. According to the indicators of the control slaughter, it can be noted that the mass of carcasses of bulls of both breeds is the same, and castrates had such a mass of carcasses only at the age of 18 months. At the same time, the carcass mass of castrates of the Simmental breed was 7.6 kg lower than the carcass mass of Kalmyk castrates. Bulls and castrates of both breeds gave an exceptionally high slaughter yield. At the same time, animals of the Kalmyk breed have a higher slaughter yield due to the large accumulation of internal fat. An analysis of the data on the efficiency of beef production when selling one head of bulls at 15-16 months of age compared with castrates shows that the level of profitability per sold head is higher for both breeds by 1.8 and 4.3%, respectively. Thus, due to the peculiarities of the hormonal status of bulls, compared with castrates, they have an increased ability to grow, protein synthesis and reduced fat formation. However, castrates can also be grown extensively and for a longer time in less favorable conditions and receive high-quality beef, steers – only intensively and for a limited period (up to 16-18 months).

The effects of differing nutritional levels and body condition score on scrotal circumference, motility, and morphology of bovine sperm.

Bulls often experience various levels of nutrient availability throughout the year. Nutritional management is a critical factor on overall ejaculate composition and the ability to get females pregnant. We hypothesized that differing nutritional levels and body condition score (BCS) affect reproductive fertility parameters in bulls. Mature Angus bulls (n = 11) were individually housed and randomly assigned to one of two dietary regimens: 1) over-fed (n = 5) or 2) restricted (n = 6). Bulls were fed the same ration at different volumes to achieve desired effects resulting in eight individual treatments: gain to an over-fed body condition score ([BCS]; GO), gain after nutrient restriction (GR), loss after an over-fed BCS (LO), loss from nutrient restriction (LR), maintenance at ideal adiposity (BCS = 6) after overfeeding (IMO), maintenance at ideal adiposity after nutrient restriction (IMR), maintenance at an over-fed BCS (BCS = 8; MO), and maintenance at a restricted BCS (BCS = 4; MR). Body weight (BW) and BCS were recorded every 2 wk to monitor bull weight and BCS changes. Scrotal circumference was measured every 28 d. Body fat and sperm motility and morphology were evaluated every 84 d. Scrotal circumference, motility, and morphology were normalized to the initial value of each bull. Thus, allowing the individual bull to serve as a control. Statistical analyses were conducted with PROC GLIMMIX of SAS as a complete randomized design to determine if treatment influenced BW, BCS, scrotal circumference, motility, morphology, and adipose thickness. Scrotal circumference (P < 0.001) had the least amount of deviation from initial during the LR (0.29 ± 0.44) treatment and the greatest during the MO (3.06 ± 0.44), LO (2.28 ± 0.44), MR (2.43 ± 0.44), GR (3.03 ± 0.44), and IMR (2.91 ± 0.44) treatments. Sperm motility was not affected by nutritional treatments (P = 0.55). Both head and total defects of sperm differed (P = 0.02) due to nutritional treatments. Increased head abnormalities occurred during the LO (37.60 ± 8.61) treatment, with no differences between the other treatments. Total defects increased during the LO (43.80 ± 9.55) treatment with similar increases in bulls during the GR (29.40 ± 9.55) and IMR (35.60 ± 9.55) treatments. In conclusion, male fertility was impacted when a deviation from a BCS of 6 occurred which could be detrimental to reproductive and beef production efficiency.

Phenotypic characterisation of Alambadi cattle—An unexplored indigenous population of south India

Alambadi is one of the draught cattle of south India, distributed unevenly in the hilly tracts of Dharmapuri and Krishnagiri districts of Tamil Nadu and bordering Karnataka, with varying densities. It is a medium-sized animal, with the typical coat colour of iron-grey and distribution of white patches around eyes, above muzzle. The horns were cylindrical, slate-coloured, sloping backwards, spreading sideways and upwards, with a slightly forward slope at the upper half of the horns and ending with a pointed tip. The overall means for body length, chest girth and height at withers of adult bulls, bullocks and cows were 122.96±2.37, 145.50±2.97 and 120.63±1.35; 133.96±2.18,168.15±2.20 and 134.41±2.30; and 127.52±0.47, 152.08±0.48 and 121.39±0.30 cm respectively. The average body weight of adult bulls, bullocks and cows were estimated as 293.96, 376.73 and 312.09 kg respectively. The means for daily partial milk yield, lactation length and estimated lactation milk yield were 2.60±0.01 kg, 171.16 days and 432.30 kg respectively. The overall mean fat, SNF, protein and total solids contents in raw milk were 3.58±0.13, 8.46±0.60, 3.22±0.05 and 12.01±0.13% respectively. The average age at first oestrus, age at first calving and calving interval of Alambadi cows were 3.33±0.07, 4.46±0.08 and 1.47±0.06 years, respectively. The population of Alambadi cattle (5,273) is categorized as ‘not at risk’.

Use of body measurements to predict live body weight of Simmental bull in Lembang Artificial Insemination Center, West Java

This research aimed to evaluate the use of body measurements (chest girth (CG), body length (BL), and shoulder height (SH)) to predict live body weight (BW) of Simmental bulls in Lembang Artificial Insemination Center, West Java. This research was carried out in December 2019 using a survey method of which all Simmental bulls aged 1—12 years were used in this study. Data were analyzed using simple and multiple correlations and regression models using the R program. Pearson correlation analysis was used to analyze correlation between BW and body measurements, while to find the fittest and more parsimonious regression model we used determination coefficient (R2) and stepwise regression analysis as criteria of selection. The results showed that the average of BW, CG, BL, and SH were 814.54 ± 144.18 kg, 215.72 ± 16.50 cm, 170.13 ± 17.09 cm, and 142.79 ± 11.01 cm, respectively. The results of this study also indicated that CG, BL, and SH positively and significantly correlated with BW, with correlation value of 0.90, 0.85, and 0.79, respectively. Combination of CG, BL, and SH produced the highest correlations value (r = 0.92) with the fittest regression model for predicting BW, namely BW=-888.64 + 4.21*CG + 2.83*BL + 2.20*SH, with R2 of 0.86.

Influence of methods of selection of parents by the index of similarity of antigens in blood groups on weight and linear growth of bulls

In solving the problem of qualitative improvement of meat breeds, an important place is occupied by the improvement of methods of practical use of existing methods of selection of parental pairs using histocompatibility antigens, polymorphic proteins and blood group systems. The purpose of the work is to determine the effect of homogeneous and heterogeneous selection of parental pairs by blood group factors on the weight and linear growth of Ukrainian beef bulls. Ukrainian meat breed is bred using four breeds and is characterised by high variability in polymorphic traits. The type of selection of parents was determined by the index of antigenic similarity (ras) of antigens of the B blood group system of cattle. To calculate the index of antigenic similarity of parents, the formula of D.A. Zhivotovskiy and A.M. Mashurov was used. The selection was considered homogeneous if the parents’ ras ≥ 0.268, and heterogeneous if ras ≤ 0.267. It is proved that bulls that come from parents with higher ras prevail in the test by average daily gain and have a higher live weight. For ras in parents over 0.268, animals tend to improve growth rate by 8 months of age. This trend continues after weaning. Bulls sired by parents with ras up to 0.267 have better average daily gains in the period from 15 to 18 months, which indicates their lower precocity. According to the index of antigenic similarity of parents over 0.268, animals are better in terms of meat forms at the age of 15 and 18 months. At 15 months of age, bulls obtained from homogeneous selection for ras have smaller height measurements, the better developed front part of the body in terms of chest width and depth, and longer torso and hindquarters. Homogeneous selection of parental pairs according to the index of similarity of antigens of the B blood group system improves the weight growth and expressiveness of meat forms in bulls of the Ukrainian beef breed

Acclimatization and productive qualities of American origin Aberdeen-Angus cattle pastured at the submontane area of the Northern Caucasus

Beef production remains one of the most difficult and time-consuming sectors in cattle breeding. The purpose of this work was to establish the productivity and acclimatization abilities of the Aberdeen-Angus breed of American selection to the natural and climatic conditions of Karachay-Cherkessia Republic. The experimental research was performed in Hummer Company LLC of Ust-Dzhegutinsky District of Karachaevo-Cherkessia Republic, Russian Federation. The object of the study was livestock of Aberdeen-Angus breed imported from the USA (Dodge City, Kansas). The research was conducted by setting up the scientific and technical experiments, summarizing and analyzing the data of the zootechnical registration. To study the specific features of acclimatization and adaptation of animals, five experimental groups with 20 heads each were organized. The groups were formed of daughters of bulls Gar New Design 5050 (I group); Three Trees Prime Cut 0145 (II group); Boyd Poundmaker 21 (III group); Woodhill Foresight (IV group); Vermilion Nebraska M404 (V group). It was found that the Aberdeen-Angus cattle of the American selection showed rather high adaptation potential, which resulted in quick acclimatization to the changed environmental conditions and adaptation to the conditions of housing and feeding. The animals had a high thermal stability index ranging from 58.1 to 74.3, with the highest thermal stability indices of 70.8 and 74.3, respectively, of Gar New Design 5050 and Vermilion Nebraska M404 bull calves. The best adaptation coefficient indices were also obtained for calves of Gar New Design 5050 and Vermilion Nebraska M404 bulls. The descendants of all five breeds have high stress resistance values and are characterized by optimal reactions to pain irritation. In terms of natural resistance the daughter of bulls Gar New Design 5050 and Vermilion Nebraska M404 were superior to their peers. The structure of the hair cover of cows in groups I and V was the most adapted to environmental changes. During the period of sucking the bulls born from cows of I and V groups had significantly higher average daily gain in live weight, which allowed at the age of 6 months to have a live weight of bulls of 201.0 and 203.5 kg respectively.

Optimal model for weaning-weight of Bunaji Bulls at NAPRI Farm, Shika, Nigeria

Empirical models have over the years been commonly established by animal research centers for the study of weight-age profiles in order to understand the metabolic processes of growth. They provide efficient parameter estimates for mature weight and rate of maturing, but were found to consistently either over-or-under estimate the mature weight. estimate the mature weight. They also perform poorly in predicting weight in early life or beyond the range of input data. At the National Animal Production Research Institute (NAPRI) farm, Shika, Brody was established as the model that provides efficient parameter estimates of weight-age profiles for Bunaji bulls. However, a major drawback of the model is its consistent underestimation of weight prior to six months of age, leading to poor prediction of weaning weight. To address this shortcoming, we propose in this article a joint mean-covariance model that provide optimal parameter estimates for the weaning weight of Bunaji bulls

Maternal heat stress reduces body and organ growth in calves: Relationship to immune status

Late-gestation heat stress of dairy cows reduces fetal growth and influences postnatal performance and immune status of the offspring. Our first objective was to evaluate the effect of in utero heat stress on overall fetal and organ growth, particularly organs associated with immune function. The second objective was to examine the cellular mechanism of altered passive immunity in neonatal bull calves after in utero heat stress. Specifically, we examined the rate of apoptosis of intestinal cells early in life, as it is associated with gut closure. Dams were dried off approximately 45 d before expected calving and randomly assigned to 1 of 2 treatments: heat stress (HT) or cooling (CL). During the dry period all cows were housed under shade in a freestall barn, where the pen for CL cows was equipped with active cooling, including water soakers and fans, whereas the pen for HT cows had no soakers or fans. Using rectal temperature and respiration rate as indicators, heat stress was severe. Average rectal temperature in HT cows was 39.3°C compared with 39.0°C in CL cows, and HT cows had a respiration rate of 66.7 breaths/min compared with 43.2 breaths/min for CL cows. Bull calves (n = 30) were immediately separated from their dams at birth, weighed, and then killed before colostrum feeding (n = 5/treatment; d 0) or at 1 or 2 d of age following colostrum feeding (n = 5/treatment per day). After slaughter, the small intestine was removed and weighed, and samples from the jejunum were fixed for immunohistochemistry. Birth weight of bulls from HT dams was 1.1 kg lower than that of bulls from CL dams. Thymus, spleen, and heart weights of HT bulls were lower relative to those of CL bulls, whereas liver weight of HT bulls tended to be lower relative to that of CL bulls. Jejunal cell apoptosis decreased with age in both HT and CL calves after birth, mirroring gut closure. However, in utero heat stress increased the apoptotic rate in the jejunum, particularly at birth. We conclude that the chronic exposure to heat strain of HT compared with CL dams in late gestation significantly affected fetal growth and immune tissue development, which may be associated with reduced immune function in early life. Also, late-gestation heat stress increased calves' intestinal apoptosis in the first 2 d of life, which might explain the decreased IgG uptake and limited passive immune competence observed in previous studies.

Use Effect of Unconventional Feed and Mineral Additives on Animal and Poultry Productivity

The possibilities of increasing productivity of animals and poultry by using an additive containing selenium, rapeseed cake and complex mineral additive have been studied. An addition of the preparation “Kartsesel” in mixed fodder promoted the increase in digestibility of nutrients, the increase in erythrocytes, hemoglobin in blood, output of conditioned youngsters, profitability of production. Conditioned young growth was obtained more by 19-22 %. Inclusion in mixed fodder at cultivation of goose rapeseed presscake of Siberian selection positively affected the increase of live weight, yield of gutted carcass. Goose of the first experimental group surpassed the control group by live weight by 3.4%, and the second experimental group by 6.1%. Output of gutted carcass of goose receiving rapeseed meal and rapeseed meal in combination with rapeseed oil is 286.13 g and 388.48 g more. Complex mineral additive in the diet of bulls contributed to the increase of live weight of bulls in 15 months of age, slaughter output, profitability of production and improvement of meat quality. The live weight of the control group of bulls not receiving the feed additive made 459.50 kg, and the experimental group made 11.00 kg more. At the same time the level of profitability of production on steers of the experimental group receiving a mineral additive amounted to 13.77% instead of 10.24% in the control group.

Reproductive functions of cows and heifers of the Aberdeen-Angus Breed according to the calving season

This paper presents indicators of reproductive functions of cows and heifers of the Aberdeen-Angus breed depending on the calving season in one of the farms of the Central Federal district of Russia. 1.729 calves were received, including calving of cows with twins, or 0.6%. Calves are produced in spring, summer and autumn in 2019. In the summer, the highest number of complex calving (8.0%), abortions and stillbirths (5.8%) was observed. In summer, heifers have more difficulty calving than in spring. Animals calve more easily and with fewer abortions and stillbirths in the autumn months. Quantity of abortions and stillbirths in this period were 0.9%, it is significantly less than the average for the year. Young bulls birth weight did not affect the further increase in live weight until 5 months of age. The live weight of bulls in summer and autumn is higher than those born in spring; it was found (p≤0.001). We recommend to strengthen control over feeding and body condition of cows and heifers with calving summer time and to provide them shelter from the heat. Calving of cows in the spring, autumn, and heifer only in the spring are the most prosperous.

Effect of Season and Year of Birth on Pubertal Age, Body Weight and Scrotal Circumference of Kankrej Bulls at First Semen Collection

Data on 26 bulls of Kankrej cattle (birth date from 2006 to 2017) inducted at a semen station from 2010 to 2020 were analyzed to study the effects of season and year of birth on age, body weight and scrotal circumference of bull at first semen collection. The overall least-squares means for age, body weight, and scrotal circumference of bulls at first semen collection were 1122.36 ± 86.9 days, 537.69 ± 10.51 kg and 30.86 ± 1.60 cm. Non-genetic factors like season and year of birth did not contribute significantly (p&gt;0.05) to these parameters’ variations. Results of the study revealed well adaptation of Kankrej cattle breed to seasonal changes and farm management took care of yearly variation in such a way that age, body weight and scrotal circumference of Kankrej bulls at first semen collection did not vary significantly.

The effect of vitamin-mineral premix on the dynamics of live weight and slaughter indices of bull calves of the Kazakh white-headed breed

The dynamics of live weight and slaughter indicators of Kazakh white-headed bulls were studied when the vitamin and mineral premix was introduced into the diet. Animals that were fed with a premix in a concentration of 1% along with the main diet exceeded their peers in live weight at the age of eight months by 4.38 kg (2.03 %), and at 18 months, at the end of the experiment, by 20.4 kg (3.89%). Control slaughters showed that the slaughter weight of the bulls of the experimental group was better than the control by 25.27 kg (7.64 %), and the superiority in slaughter yield was 2.49 %.

Does bull temperament impact growth performance and semen quality?

The aim of this study was to evaluate the influence of temperament on body weight and reproductive performance of Nelore bulls. Temperament of 24 young bulls was assessed by chute score (CS) and flight speed (FS). Based on the results of two consecutive evaluations (M1 and M2), bulls were divided into two groups according to their CS: Reactive (n = 12) and Calm (n = 12). Blood samples were collected from both groups for testosterone and cortisol analysis once a month for 4 months. Similarly, over 4 months semen was collected along with scrotal and ocular globe thermography for further analysis, and body weight (BW) was recorded. Reactive bulls showed greater CS (P<0.0001) and FS (P<0.01) and lower BW (P<0.01) than Calm bulls. Cortisol concentrations in serum were reduced in the Calm group (P<0.05), but serum testosterone concentrations did not differ between groups with distinct behaviour. The scrotal thermography on Reactive bulls presented greater temperature at the caudal pole of testicle (P<0.05). However, semen quality (volume, kinetics, morphology and concentration) did not differ between the two groups. The results of this study demonstrated that bulls with reactive temperament were affected on their cortisol concentrations leading to loss of body weight and greater testicles temperature. The temperament of Nelore bulls had no impact on testosterone concentrations or fresh semen quality, even with increased serum cortisol and scrotal temperature.