Live Weight Gain Research Articles

The use of the complex drug "Optibak®-F" in feeding young ferrets

The use of probiotics and symbiotics allows you to normalize the work of the gastrointestinal tract, normalize the microflora, increase immunity, prevent infectious diseases, and increase the safety of livestock. The aim of the research was to study the effect of complex application preparation "OptiBak®-F" in diets on the growth of young ferrets during the growing period. The experiment was carried out on slaughtered young ferrets of pearl type at the ferret farm FSUE "Russian Sable" of Moscow region. It was found that daily introduction of "OptiBak®-F" preparation into ferrets' feed in July-September in the amount of 0,05-0,06 g per head per day increases live weight gain of young animals in a month by 137,2 g (p<0,05) in comparison with animals of the control group. The similar tendency was maintained three weeks after completion of the preparation introduction into the general ration: at the end of September the live weight of young animals was significantly higher by 138.7 g (p<0.05) and was 2003.0 g against 1864.3 g in the control. High safety of young animals was recorded in both groups. Average daily feed intake in the groups was 225 g per head. During the experiment period when "OptiBak®-F" was used, absolute live weight gain of young ferrets in the experimental group was higher than in the control by 109.7 g (795.5 g vs. 685,8 g), relative - by 4.5% (49.6% vs. 45.1%), while feed costs in physical weight per unit of live weight gain decreased by 13.7%, and in terms of feed cost - by 11.0%, taking into account the cost of the preparation.

Meat and fat qualities of pigs of different breeds

Objective. Study of meat and fat qualities of pigs of different genotypes. The research was conducted on young large white and Poltava meat breeds. Methods. General scientific, interdisciplinary, analytical, zootechnical, physical and chemical. During the fattening period, such indicators as live weight gain and feed consumption per unit of gain, the age of reaching live weight of 100 kg are taken into account. The content of meat, fat and bones in the carcasses, as well as the chemical composition and physical properties of the meat were determined. Results. Observations showed that the average daily increase in the live weight of animals of large white breed during fattening was 690 g, the payment of fodder was 4.22 fodder. unit Young animals reached a live weight of 100 kg in 182 days. Animals of the Poltava meat breed, respectively, 720 g of average daily gain, 3.95 feed. unit and the time to reach a live weight of 100 kg - 170 days. Pigs of the Poltava meat breed surpassed the young of the large white breed in terms of carcass length (by 6.3 cm, or 7.2 %), the weight of the rear third of the half carcass (by 0.75 kg, or 6.6 %) and had thinner (by 5 mm, or 15 %) spigot, evenly distributed along the entire length of the half-carcass. This, in turn, led to a higher yield of the most nutritionally valuable parts ofpork (bone, loin, brisket). The meat of animals of the Poltava meat breed was a little more tender, since it took 35 % less effort to cut its standard sample than the meat of pigs of the large white breed. The meat of pigs of a large white breed was characterized by less boiling and more intensive coloring. The most pronounced were interbreed differences in the chemical composition of pork dishes prepared in different ways. Boiled large white pork contained more moisture (by 3.65 %) and fat (by 4.15 %), but less protein (by 1.1 %). The same pattern was observed in the chemical composition of fried pork. Conclusions. The obtained research results allow us to state that the fleshiness of pig carcasses is a breed, hereditarily determined trait that can be improved by breeding methods. Feeding and housing conditions also affect the productive qualities of pigs, however, their different genotypes react differently and to different degrees to the influence of environmental factors. Keywords: breed, live weight, pork, half carcass length, meat quality, tenderness, chemical composition.

The effect of birth type and gender on growth performance, live weight gain, growth pattern modeling, and survival rate in Anatolian Merino lambs

In this study, the aim was to determine the effect of birth type and gender on growth performance, live weight gain, growth modeling, and survival rate in Anatolian Merino lambs. Growth performance was determined in 28 singletons (14 females/14 males), 80 twins (38 females/42 males), and 54 triplets (22 females/32 males) lambs in the study. The body weight of the lambs was measured on the day of birth (day 0), and at 10, 20, 30, 45, and 60 days of age. Birth type was effective on growth performance in Anatolian Merino lambs (P

Effectiveness of integrated use of non-conventional additives in the feeding of young cattle

It is known that eff ective feed additives include pine fl our, zeolites and mineral salts. The purpose of the work was to investigate the eff ectiveness of the integrated inclusion of local non-conventional feed additives in the rations of young cattle of Simmental breed under the conditions of the Republic of Sakha (Yakutia). Scientifi c and production evaluation of the results obtained was carried out under the conditions of the Lonkur peasant farm in the Suntar district of Western Yakutia. The scientifi c and production experiment was carried out in accordance with generally accepted methodological recommendations in the fi eld of feeding of farm animals. It was found during the experiment that the integrated inclusion of non- conventional feed additives in the rations of young cattle of Simmental breed contributed to an increase in the weight growth rate of animals in the experimental group to 610 g/day (versus 560 g/day in the control group). As a result, the live weight of the animals in the experimental group was 386.8 kg, and in the control group it was 375.7 kg or the absolute gain in live weight was 128.1 and 117.6 kg, respectively, for the groups. Due to the additional gain in live weight in the experimental group (525 kg), an economic eff ect was obtained in it, which amounted to 152.25 thousand rubles or 14.5 rubles per day for 1 head. It was found as a result of experiment that in the experimental group the level of profitability was 8.21 %, while in the control group it was only 1.77 %. We note that scientific and production testing confirmed the trend that we had previously established in scientific and economic experiments. Thus, the research base was updated in terms of economic indicators with the use of experimental non-conventional feed additives when rearing of young cattle, which shows the promise and practical feasibility of their use under the conditions of Western Yakutia.

Replacing soybean meal with lesser mealworm Alphitobius diaperinus improves broiler productive performances, haematology, intestinal morphology and meat quality

Abstract Insects are becoming more popular as a soybean meal substitute because they can be raised sustainably on food and feed residues, which improves farming efficiency, sustainability, and animal welfare. In the current study, we replaced 4, 8 and 12% SBM with lesser mealworm Alphitobius diaperinus (Coleoptera: Tenebrionidae) larvae and determined its effects on productive performances, blood parameters, gut morphometry and meat quality of the broiler chickens. We also compared commercially available black soldier fly Hermetia illucens (Diptera: Stratiomyidae) larvae. A total of 350 one-day-old broiler chicks (Ross 308) were randomly assigned to seven isocaloric and isonitrogenous diets (5 pens/treatment and 10 birds/pen). The results found that 12% A. diaperinus and H. illucens diets significantly () increased the live weight (LW) and average daily weight gain (ADG) while improving feed conversion ratio (FCR) in the broilers. Daily feed intake (DFI) did not show a significant difference () among all the dietary treatments. Haematology and serum biochemistry traits were significantly () improved except MCHC, monocytes, Eosinophils (EO), albumin and creatinine. The 12% A. diaperinus and H. illucens diets showed the highest villus height (Vh) and the lowest crypt depth than other diets. The meat quality traits were statistically () improved except meat pH, drip loss and shear force (). The results of the study highlight the importance of substituting SBM up to 12% with either A. diaperinus or H. illucens larvae, which improves the productive performances, blood parameters, gut morphometry and meat quality of broilers and thus can be incorporated as an alternative protein source in poultry feed.

Formic acid as an antibiotic alternative in broiler diets: effects on growth, carcass characteristics, blood chemistry, and intestinal microbial load

This study explored the ability of formic acid (FA) to replace antibiotics in broiler chicken diets. It examined how FA affected the chickens' growth, carcass characteristics, blood chemistry, and gut bacteria. The experiment randomly assigned 300 one-day-old (Ross 308) broiler chicks to 5 groups, each divided into 6 replicates with 10 unsexed chicks. The following were the treatments: 1st group, negative control (NC): only received a basal diet; 2nd group, positive control (PC): received a basal diet supplemented with 0.5 grams of Colistin antibiotic per kilogram of diet; 3rd, 4th, and 5th groups (FA2, FA4, and FA6) these groups received a basal diet along with formic acid added at increasing levels: 2, 4, and 6 Cm3 per kilogram of diet, respectively. Results found no significant differences in live body weight (LBW) or body weight gain (BWG) between treatment groups, except for LBW at one week and BWG at 0 to 1 and 4 to 5 wk of age. No significant variations were found in feed intake (FI) and feed conversion ratio (FCR) among the treatment groups, excluding FI and FCR at 1 to 2 wk of age. The treatments significantly impacted carcass traits, dressing percentage, breast meat, thigh meat, spleen, giblets, blood levels of urea, creatinine, total protein, globulin, and albumin, as well as the activity of enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in chicks fed different diets compared to control groups. The addition of FA to the diet significantly impacted antioxidant levels. Also, the FA2 group had the highest total bacterial count (TBC). However, the FA6 group was the opposite; it had the lowest levels of harmful bacteria, such as E. coli and Coliform. Supplementing broiler diets with formic acid improves blood parameters, antioxidant activity, and gut bacteria counts, with 4.0 cm³ formic acid/kg diet supplementation promoting optimal broiler health and product quality.

Loss-of-function G6PD variant moderated high-fat diet-induced obesity, adipocyte hypertrophy, and fatty liver in male rats

Obesity is a major risk factor for liver and cardiovascular diseases. However, obesity-driven mechanisms that contribute to the pathogenesis of multiple organ diseases are still obscure and treatment is inadequate. We hypothesized that increased glucose-6-phosphate dehydrogenase (G6PD), the key rate-limiting enzyme in the pentose shunt, is critical in evoking metabolic reprogramming in multiple organs and is a significant contributor to the pathogenesis of liver and cardiovascular diseases. G6PD is induced by carbohydrate-rich diet and insulin. Long-term (8 months) high-fat diet (HFD) feeding increased body weight and elicited metabolic reprogramming in visceral fat, liver, and aorta, of the wild-type rats. In addition, HFD increased inflammatory chemokines in visceral fat. Interestingly, CRISPR-edited loss-of-function Mediterranean G6PD variant (G6PDS188F) rats, which mimic human polymorphism, moderated HFD-induced weight gain and metabolic reprogramming in visceral fat, liver, and aorta. The G6PDS188F variant prevented HFD-induced CCL7 and adipocyte hypertrophy. Furthermore, the G6PDS188F variant increased Magel2 – a gene encoding circadian clock-related protein that suppresses obesity associated with Prader-Willi syndrome – and reduced HFD-induced non-alcoholic fatty liver. Additionally, the G6PDS188F variant reduced aging-induced aortic stiffening. Our findings suggest G6PD is a regulator of HFD-induced obesity, adipocyte hypertrophy, and fatty liver.

Engraftment Syndrome in Autologous Hematopoietic Stem Cell Transplant Patients: Incidence, Associated Risk Factors, Features, and Outcomes.

BACKGROUND Autologous stem cell transplantation (ASCT) is the standard treatment for multiple myeloma (MM) and refractory/relapsed (R/R) lymphoma patients. Engraftment syndrome (ES) is a non-infectious febrile syndrome during ASCT. This study focused on the incidence, risk factors, manifestations, and outcomes of patients with ES receiving ASCT. MATERIAL AND METHODS This retrospective cohort study included MM and R/R lymphoma patients who underwent ASCT at Chiang Mai University Hospital from January 2014 to September 2020. ES was diagnosed by the consensus of independent reviewers based on clinical manifestations, laboratory, and radiological findings. RESULTS We included 124 patients, of whom 67 (54.1%) had lymphoma. The mean age was 48.0±12.3 years. The incidence of ES was 36.3%. The ES group had a significantly higher proportion of patients with fever, elevated liver enzymes, elevated bilirubin, hypoalbuminemia, and weight gain compared to the non-ES group. TNC more than 10×10⁸ cells/kg was an independent risk factor for ES (odds ratio 2.94 with a 95% confidence interval of 1.15-7.50, P=0.024). ES was associated with longer length of stay (22.5±8.2 vs 16.9±6.4 days, P<0.001) but was not associated with overall survival (OS). CONCLUSIONS The incidence of ES in this cohort was 36.3%. Features observed in ES patients were fever, elevated liver enzymes, elevated bilirubin, and hypoalbuminemia. TNC of more than 10×10⁸ cells/kg was an independent risk factor. ES was associated with longer length of stay but not survival outcomes.

Behavioural response to gastrointestinal parasites of yearling dairy calves at pasture

ABSTRACT Aims To investigate the association between gastrointestinal parasites (GIP) and animal behaviour in dairy calves under New Zealand pastoral conditions, using animal-mounted, accelerometer-based sensors. Methods Thirty-six, 5–6-month-old, Friesian-Jersey, heifer calves fitted with animal activity sensors to track behaviour were randomly allocated to one of two treatment groups. Half the animals were challenged with an oral dose of 20,000 larvae of Ostertagia ostertagi and Cooperia oncophera once a week for 3 weeks and half were unchallenged. Five weeks after the last dose, seven infected and nine uninfected animals were treated with an oral anthelmintic (AHC) and data collected for a further week. Accelerometer data were classified into minutes per day eating, ruminating, in moderate–high activity or in low activity. Live weight and faecal egg counts (FEC) were recorded weekly over the study period. All animals co-grazed a newly sown pasture not previously grazed by ruminants and were moved every week to fresh grazing. Treatment status was blinded to those managing the animals which were otherwise treated identically. Results Complete behavioural records were available from 30/36 calves, (13 challenged and 17 unchallenged). Before treatment with AHC, FEC increased in infected and un-treated calves over the study, while uninfected animals maintained a near zero FEC. There was no difference in live weight gain between the two groups over the study period. Bayesian, multinomial regression predicted differences in animal behaviour between infected and uninfected animals that were not treated with AHC over the 7 weeks following initial infection. Parasitised calves not treated with AHC were less active and spent up to 6 (95% highest density interval (HDI) = 1–11) minutes/day less in low level activity and up to 15 (95% HDI = 7–20) minutes/day less in moderate to high level activity. They ruminated up to 9 (95% HDI = 2–15) minutes/day more and ate up to 10 (95% HDI = 2–19) minutes/day more than control calves that were not treated with AHC. The effect of AHC on time spent in each behaviour differed between infected and uninfected calves and increased the coefficient of dispersion of the behavioural data. Conclusions and clinical relevance Small differences in animal behaviour can be measured in calves with GIP. However, to use this to target treatment, further validation studies are required to confirm the accuracy of behavioural classification and understand the complex drivers of animal behaviour in a dynamic and variable pasture-parasite–host environment.

Liver Metabolomics Analysis Revealing Key Metabolites Associated with Different Stages of Nonalcoholic Fatty Liver Disease in Hamsters.

Nonalcoholic fatty liver disease (NAFLD) is not only the top cause of liver diseases but also a hepatic-correlated metabolic syndrome. This study performed untargeted metabolomics analysis of NAFLD hamsters to identify the key metabolites to discriminate different stages of NAFLD. Hamsters were fed a high-fat diet (HFD) to establish the NAFLD model with different stages (six weeks named as the NAFLD1 group and twelve weeks as the NAFLD2 group, respectively). Those liver samples were analyzed by untargeted metabolomics (UM) analysis to investigate metabolic changes and metabolites to discriminate different stages of NAFLD. The significant liver weight gain in NAFLD hamsters was observed, accompanied by significantly increased levels of serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Moreover, the levels of TG, LDL-C, ALT, and AST were significantly higher in the NAFLD2 group than in the NAFLD1 group. The UM analysis also revealed the metabolic changes; 27 differently expressed metabolites were detected between the NAFLD2 and NAFLD1 groups. More importantly, the levels of N-methylalanine, allantoin, glucose, and glutamylvaline were found to be significantly different between any two groups (control, NAFLD2 and NAFLD1). Receiver operating characteristic curve (ROC) curve results also showed that these four metabolites are able to distinguish control, NAFLD1 and NAFLD2 groups. This study indicated that the process of NAFLD in hamsters is accompanied by different metabolite changes, and these key differently expressed metabolites may be valuable diagnostic biomarkers and responses to therapeutic interventions.

Urea-molasses block supplementation on nutrients digestibility of Yankasa rams fed maize stover

Sixty (60) days of feeding trial was conducted to determine the nutrients digestibility of Yankasa rams fed maize Stover as basal diet, seven (7) days adaptation period for twelve growing Yankasa rams aged between 9-12 months was carried out and were subjected to four (4) dietary treatments with three (3) replicates in a completely randomized design (CRD). The four treatments were, T1 (Maize Stover only (control), T2 (molasses 36%, rice offal 43%, urea 5%, cement 7% salt 9% and basal diet)), T3 (molasses 26%, rice offal 43%, urea 15%, cement 9% salt 7% and basal diet) and T4 ( Molasses 40%, rice offal 39%, urea 10%, cement 4% salt 7% and basal diet), to determine feed intake, growth rate, rumen Nitrogen-ammonia (NH3-N) content and PH, the results of dry matter digestibility ranges from 11.22%-67.01%, crude protein digestibility ranges from 78.96–91.97%, fat digestibility ranges from 96.22–97.23%, crude fibre digestibility ranged from 10.32–28.39%, ash was from 51.66–59.56%. The result shows higher concentration of Ammonia (mg/mol) in T4 (19.97mg/100ml), and the lowest was recorded in T1 (14.95mg/100ml). The rumen pH as observed in all the treatments were within the range of 7.15-8.00 with T4 as the highest and T2 having the lowest, these results showed no significant difference at (P&gt;0.05) between the treatments groups. The study revealed that rams in treatment (T2) generally gave a significant difference (P&lt;0.05) higher performance in terms of dry matter intake and live weight gain. From the results obtained in this study, urea-molasses treatment of maize stover improved crude protein contents and digestibility, consequently, an economic decision had been proved in the used of urea-molasses treated maize stover as an animal feed which improved the nitrogen (protein) contents of the treated Stover, energy and soluble carbohydrate. The use of urea-molasses treatment is safe, economical, socially acceptable, and environmentally friendly and can be applied easily on the farm with high probability of being adopted by farmers.

The carbon footprint of livestock farms under conventional management and silvopastoral systems in Jalisco, Chiapas, and Campeche (Mexico)

Livestock production is one of the most important agricultural sources of greenhouses gasses (GHG). Transforming the livestock sector is a critical task to mitigate the effects of climate change, and the implementation of silvopastoral systems (SPS) may be a way to do so. Carbon footprint (CF) estimation was carried out for 131 conventional livestock farms (CONF) and SPS farms (SPSF) selected in the states of Jalisco, Chiapas and Campeche (Mexico). GHG emissions were estimated based on interviews with the farmers and farm monitoring to collect information about management, milk production and the live weight gain (LWG) of calves (for meat production) using national emission factors. Emissions from animals, fossil fuels, electricity and nitrogen fertilizers were estimated using Tier I and II criteria. Land use distribution was recorded for each farm, and their carbon fixation in total biomass and soils was estimated using studies from tropical Latin America. CF was estimated for area and for production of milk and the LWG of calves. SPSF had lower GHG emissions, higher carbon fixation rates and a better CF than CONF (5.7 vs. 8.0 t CO2e/ha/year; 6.9 vs. 5.5 t C/ha/year and − 5.0 vs. −2.9 t CO2e/ha/year, respectively). The CF of milk production and calf LWG were − 68.6 to −4.6 kg CO2e/kg and − 3.2 to −0.1 t CO2e/kg, respectively. Our results highlight the importance of implementing SPS to mitigate climate change in livestock production, given its contribution to GHG emissions and the importance of capturing atmospheric carbon in biomass and soils. National and regional policies should focus on promoting implementing SPS as an active and effective strategy for improving CF in livestock farms.

Studying the efficiency of Gaprin application in sterlet farming

In the course of the experiment, the influence of new feed additives created on the basis of Gaprin and representing biomass of inactivated cell culture of non-pathogenic methane-oxidizing yeasts or bacteria on sturgeon fish productivity indicators was studied. The research was carried out in the Krasnodar Territory on sterlet fingerlings. The experiment lasted for 60 days. According to the scheme of the experiment, the 1st (control) group of fish received complete feeds without additives, i.e. containing 100.0% fish meal. In group 2 feeding, 50.0% fishmeal was replaced with 50.0% Gaprin. Group 3 diet contained 25.0% fishmeal and 75.0% Gaprin. In the feed for group 4, fish meal and Gaprin were in the ratio of 75/25%. In Group 5, fish meal was completely replaced by Gaprin, in this case the amount of additive was 10.5 kg. Sterlet fingerlings from Group 6 received feed with 10.0% Gaprin. The initial live weight in all groups was similar at 30 g. However, the inclusion of Gaprin in the diet by reducing the amount of fish meal contributed to an increase in the final live weight of sterlets in the experimental groups by 4.4–19.4% compared to the control. The exceptions were groups 5 and 6, which received 100.0 and 90.0% Gaprin instead of fishmeal. Final live weight in these groups was lower by 2.3 and 0.9%, respectively. Feed costs per 1 kg of live weight gain in the groups with partial or complete replacement of fish meal were lower relative to the 1st group (from 7.0 to 17.9%,).Inclusion of Gaprin in complete feeds contributed to the increase in profit from 553.00 to 1785.00 rubles.

Calf Management: Individual or Paired Housing Affects Dairy Calf Health and Welfare.

Previous research has indicated that preweaned dairy calves reared in pairs compared with individually have improved performance and indicators of animal welfare. One hundred and thirty Holstein female calves completed the trial, with eighty-five being allocated to paired housing and forty-five calves being allocated to individual housing. Daily live weight gain (DLWG), treatments and mortality were recorded throughout the preweaning period. Salivary cortisol, latency to feed and latency to approach a novel object were assessed at batching. There were no significant differences in DLWG, mortality and disease treatments between the average of the pair and the individually housed calves, although the pair-reared calves were quicker to approach the milk feed after batching and interacted more quickly with a novel object. The heaviest born calves within the pair had the highest DLWG from birth to weaning, with a higher percentage of calves approaching the novel object, compared with the lightest born calf within the pair. This study shows that calves within a pair may have significantly different performance and welfare during the preweaning period, with the heavier calf outperforming and displaying less fear and more exploratory behaviour than the lighter calf within a pair.

The Impact of Abrupt and Fenceline-Weaning Methods on Cattle Stress Response, Live Weight Gain, and Behaviour.

The impact of abrupt (AB) and fenceline (FL) weaning methods on cattle stress response, live weight gain, and behaviour were determined across 14 days. Thirty-two cow-calf pairs were fitted with ear tag sensors (to continuously record behaviour) and allocated to two weaning treatments. After separation, FL calves were maintained in a pen adjacent to the FL cow paddock. The AB calves were transported to a pen removing all contact with the cows. After 7 d, FL cows were transported away from all calf pens. Body weights and salivary samples were collected for all animals on experimental days 0, 7, and 14. Fenceline-weaned calves had a greater duration of rest and rumination with reduced high activity across the first 3 days after separation as compared to abruptly weaned calves in line with the greater occurrences of pacing observed for AB calves. Fenceline-separated cows had greater levels of rest across the first 7 days but similar levels of rumination compared to abruptly separated cows. Fenceline-separated cow activity levels tended to be greater and eating levels were similar across the first three days. Body weight (BW) and cortisol concentrations were similar for AB and FL cattle, but FL cows had lower overall weight gain than the abrupt cows likely due to reduced eating time on days four to seven. Together, these results suggest that calves be fenceline-weaned for three days followed by total separation.

The use of improved premix recipes in rations of cattle

Complete balanced feeding of farm animals cannot be organized without the use of various balancing additives, in particular premixes. It is important to note that the greatest eff ect from the use of premixes is observed when their recipes are developed taking into account specifi c feeding and housing conditions. The purpose of this work was to study the eff ectiveness of using improved premix recipes based on an analysis of the actual nutritional value of feed in the rations of lactating cows and calves. During the research, two experiments were carried out. The experiments were carried out at the Staraya Chigla livestock complex in the Anninsky district of the Voronezh region. In the experiment on cows, 20 animals were selected, which were divided into two groups (control and experimental) of 10 heads in each using the method of analogue pairs. In an experiment to study the eff ectiveness of the premix in feeding of young animals, two groups of calves of 12 heads in each were similarly formed. Animals of the control groups received farm rations with the premix developed without taking into account the analysis of the nutritional value of the rations. In the experimental groups, cows and calves received new and improved premixes developed based on these specific feeding conditions. The use of the premix with an improved recipe in the rations of cows made it possible to increase the average daily milk yield by 5,61 %, the fat content by 0,05 abs.% and the protein content in milk by 0,15 abs.%. At the same time, there was an increase in the level of digestibility of dry matter by 1,25 abs.%, organic matter by 1,07 abs.%, crude protein by 1,56 abs.%, crude fat by 1,63 abs.%, crude fi ber by 1,08 abs.%, nitrogen-free extractive substances by 1,87 abs.%. Calculation of feed intake for the synthesis of 1 kg of milk showed that they were lower in the experimental group by 0,31 MJ of net lactation energy and 2,97 g of digestible protein. Positive results were also obtained in experiments on calves. The use of the premix developed on the basis of the actual nutritional value of feed and rations, made it possible to increase the live weight of heifers at 12 months of age by 5,04 %, the average daily gain in live weight during the experimental period by 5,74 %, the relative gain by 1,91 abs.%.

Рост и развитие бычков лимузинской породы различных генотипов в постнатальном онтогенезе

The purpose of research is to study the growth and development of Limousin bulls of various genotypes in postnatal ontogenesis. Objectives: to study of weight growth, absolute, average daily gains in live weight and relative growth rate of young animals by age periods and for the entire period of growing and fattening; to study of the linear growth of bulls in postnatal ontogenesis based on the dynamics of body measurements and body composition indices. The objects of the study are bulls of the Limousin breed of various genotypes obtained from the mating of cows of French, Australian and local selection with bulls of local reproduction. The scientific and economic experiment was carried out in 2021–2022 at LLC Meat Union of Bashkir Producers, located in the Kuyurgazinsky District of the Republic of Bashkortostan. Indicators of live weight dynamics, live weight gain, relative growth rate, body measurements and body composition indices in the age aspect were studied. Research of the weight growth of young animals of various genotypes made it possible to identify significant differences in terms of absolute and average daily gain in live weight for the entire period of growing and fattening between bulls of the 1st and 2nd experimental groups, respectively, by 32.5 kg and 59.7 g (in both cases – by 6.2 %). The highest values of measurements, indicating the formation of meat qualities and body shape, were noted in bulls of the 1st group compared with peers of the 2nd and 3rd experimental groups. Breeding animals for a long period under different housing and feeding technologies influences the characteristics of the growth and development of the descendants of local reproduction of Limousin breed cattle.

Monitoring the live weight of Hereford breeding cattle under pasture conditions

Assessing the growth potential and sustainability of breeding stock productivity makes it possible to predict effective herd management, including the duration of use of cows, significantly affecting the potential economic efficiency of raising young animals. The object of the study was data on live weight and average daily gain of Hereford cows and heifers. An assessment was made of Hereford cows’ live weight and growth rate and replacement young cattle of different years of birth, bred under conditions of year-round keeping on pasture. Assessing the growth potential of animals forming a herd for more than 15 years allows us to evaluate the trends that have led to current productivity. Keeping animals on pasture all year round, on the one hand, allows for the formation of animal resistance to environmental conditions; on the other hand, there is a tendency for the year of birth to influence the productive performance of animals, especially at the stage of raising them as replacement young animals. Still, these differences are smoothed out in the future, which today allows us to have a herd equalized by live weight. A significant influence of cows ’ birth year on their growth rates has been established. The study aimed to assess the live weight and growth rate of Hereford cows and young animals from the breeding herd, born in different years. The study’s objectives included evaluating the final weight of animals in the herd and assessing their live weight and average daily gain at the selection stage at the age of 15 months.

The effect of increasing proportion mixed vegetable wastes in combination with corn stover as a basal diet on intake, digestion, liveweight gain and income over feed cost of Bali bulls supplemented with rice bran

The effect of increasing proportion mixed vegetable wastes in combination with corn stover as a basal diet on intake, digestion, liveweight gain and income over feed cost of Bali bulls supplemented with rice bran

Defining a Haplotype Encompassing the LCORL-NCAPG Locus Associated with Increased Lean Growth in Beef Cattle.

Numerous studies have shown genetic variation at the LCORL-NCAPG locus is strongly associated with growth traits in beef cattle. However, a causative molecular variant has yet to be identified. To define all possible candidate variants, 34 Charolais-sired calves were whole-genome sequenced, including 17 homozygous for a long-range haplotype associated with increased growth (QQ) and 17 homozygous for potential ancestral haplotypes for this region (qq). The Q haplotype was refined to an 814 kb region between chr6:37,199,897-38,014,080 and contained 218 variants not found in qq individuals. These variants include an insertion in an intron of NCAPG, a previously documented mutation in NCAPG (rs109570900), two coding sequence mutations in LCORL (rs109696064 and rs384548488), and 15 variants located within ATAC peaks that were predicted to affect transcription factor binding. Notably, rs384548488 is a frameshift variant likely resulting in loss of function for long isoforms of LCORL. To test the association of the coding sequence variants of LCORL with phenotype, 405 cattle from five populations were genotyped. The two variants were in complete linkage disequilibrium. Statistical analysis of the three populations that contained QQ animals revealed significant (p < 0.05) associations with genotype and birth weight, live weight, carcass weight, hip height, and average daily gain. These findings affirm the link between this locus and growth in beef cattle and describe DNA variants that define the haplotype. However, further studies will be required to define the true causative mutation.