Live Weight Gain Research Articles

Productivity of young pigs in rearing when the use of feed additives ActivSorbent and PolyActiv as feed adsorbents of mycotoxins

Intensification of pig farming is directly related to the need to provide pig-producing farms with their own feed. Modern conditions of industrial pig farming impose increased requirements on the organization of complete feeding of pigs based on the use of high-quality feed, feed and biologically active additives. The purpose of the research was to study the productivity of young pigs during rearing when use feed additives ActiveSorben and PolyActive adsorbents of mycotoxins in feed. Research to identify the optimal dosage of mycotoxin adsorbents of feed ActiveSorbent and PolyActive and their effect on the metabolism and productive indicators of young pigs was carried out on fi rst-generation hybrid piglets (Large White × Landrace) during rearing, in the production conditions of the pig-breeding complex of Tavla LLC in the Kochkurovsky district of the Republic of Mordovia with a capacity of 12,000 heads per year. It has been found according to the results of industrial testing of the feed mycotoxin adsorbents ActiveSorbent and PolyActive that their use in doses of 1.750 kg/t of compound feed reduced the costs of producing 1 kg of live weight gain by 10.31 and 8.51 rubles, respectively. The level of profi tability in the experimental groups increased compared to the control group when using the additive ActiveSorbent by 18.93 abs.% and PolyActive by 15.24 abs.%. Thus, the inclusion of feed additives ActiveSorbent and PolyActive of feed mycotoxin adsorbents in the diet of rearing piglets under industrial pig farming conditions when recalculated for the resulting products contributes to increased productivity, reduced cost of production and an increase in the level of production profitability.

Experimental immunotherapy of association infections of the gastrointestinal tract of newborn calves using yolk melange enriched with specific Y class immunoglobulins

Mass gastrointestinal diseases of newborn calves manifested by symptoms of diarrhea are caused by various etiological factors and most often occur in the form of mixed infections. Mixed infections have a more severe diarrhea than mono-infections. The economic consequences of such infections due to the high prevalence, frequent mortality and loss of productivity during further exploitation of the animal can be significant. The most common causative agents of gastrointestinal diseases of newborn calves of viral etiology is rotavirus and coronavirus infections. Mixed (viral-bacterial) infection can lead to 100% mortality of the diseased calves. Specific vaccination of springer cows against gastrointestinal pathogens in calves, which is performed to increase the number of pathogen-specific immunoglobulins in the colostrum at calf birth, and ingestion of colostrum by the calves during the first 4 hours of life are the most important strategies to prevent severe diarrhea. But as practice shows, this is not always enough. The purpose of this work was to study the effectiveness of immunoprophylaxis of associative infections of the gastrointestinal tract of newborn calves with the use of melange prepared from chicken eggs previously immunized with the vaccine "Rotagal" (Pharmagal-BIO s.r.o., Slovakia), used for the prevention of colibacillosis, rotavirus and coronavirus infections of cattle. As a result of the study, it was established that the addition of yolk melange rich in specific immunoglobulins of Y class to the colostrum in the first hours of life of the calves has a pronounced prophylactic effect, facilitates the course of the infectious process in case of the disease, saves costs for the treatment of sick animals, increases survival rate, contributes to the acceleration of live weight gain. The use of an immunobiological preparation based on transovarial immunoglobulins has a positive effect on the indicators of nonspecific resistance of newborn calves compared to the calves with early postnatal disease and antibiotic treatment.

Combined sulforaphane and β-sitosterol mitigate olanzapine-induced metabolic disorders in rats: Insights on FOXO, PI3K/AKT, JAK/STAT3, and MAPK signaling pathways

One of the best antipsychotics for treating schizophrenia and bipolar disorders is olanzapine (OLA). However, its use is restricted owing to unfavorable adverse effects as liver damage, dyslipidemia, and weight gain. The primary objective of the present investigation was to examine the signaling mechanisms that underlie the metabolic disruption generated by OLA. Besides, the potential protective effect of sulforaphane (SFN) and β-sitosterol (βSS) against obesity and metabolic toxicity induced by OLA were inspected as well. A total of five groups of male Wistar rats were established, including the control, OLA, SFN+OLA, βSS+OLA, and the combination + OLA groups. Hepatic histopathology, biochemical analyses, ultimate body weights, liver function, oxidative stress, and pro-inflammatory cytokines were evaluated. In addition to the relative expression of FOXO, the signaling pathways for PI3K/AKT, JAK/STAT3, and MAPK were assessed as well. All biochemical and hepatic histopathological abnormalities caused by OLA were alleviated by SFN and/or βSS. A substantial decrease in systolic blood pressure (SBP), proinflammatory cytokines, serum lipid profile parameters, hepatic MDA, TBIL, AST, and ALT were reduced through SFN or/and βSS. To sum up, the detrimental effects of OLA are mediated by alterations in the Akt/FOXO3a/ATG12, Ras/SOS2/Raf-1/MEK/ERK1/2, and Smad3,4/TGF-β signaling pathways. The administration of SFN and/or βSS has the potential to mitigate the metabolic deficit, biochemical imbalances, hepatic histological abnormalities, and the overall unfavorable consequences induced by OLA by modulating the abovementioned signaling pathways.

Эффективность использования новой кормовой добавки на основе органических кислот при выращивании цыплят-бройлеров

Purpose. Studying the effectiveness of using feed additive "Aciform" when included in the diet of broiler chickens. Materials and Methods. The objects of research were broiler chickens of Cobb-500 cross and feed additive "Aciform". The experiment was carried out in the conditions of the farm of Krest'yanskiy Dvor LLC (Volgograd region). Three groups (two experimental and control) were formed, 140 animals each. The poultry in the control group received feed that did not contain the studied feed additive. Norm for adding additive was 1 kg per 1 ton of feed in the 1st experimental group and 2 kg per 1 ton of feed in the 2nd experimental group. The duration of feeding is from 14 days to 42 days of age. During the experiment, the safety of poultry, the percentage of mortality and pecking, as well as the dynamics of live weight gain and the occurrence of possible side effects when using the feed additive were monitored using standard scientific research methods (zootechnical, mathematical) and certified laboratory equipment. Results. The use of new feed additive "Aciform" in feeding broiler chickens from 14 to 42 days of age at an input rate of 1 and 2 kg per 1 ton of feed had a positive effect on the increase in live weight of chickens. The chickens of experimental groups (1 and 2) exceeded poultry of control group in terms of the average daily gain in live weight by 1.0 and 2.9% (P≤0.05) for the entire experimental period, in terms of absolute increase on the 42nd day of growing – by 1.0 and 2.1%. The incidence of pecking in poultry of experimental groups (1 and 2) was 2.9 and 1.8%, and in the control group – 2.1%. In the groups of broiler chickens that received the test additive as part of the diet (1st and 2nd experimental), there were fewer dead poultry by 2.9 and 3.4%, and the survival rate was higher by 2.9 and 3.8% than in control group. Conclusion. The inclusion of new feed additive "Aciform" in the diet of broiler chickens had a positive effect on the safety, growth rate and productive qualities of the poultry.

PERFORMANCE OF SOKOTO RED GOAT FED UREA TREATED GROUNDNUT (ARACHIS HYPOGAEA) SHELL

The study that assessed the impact of treatment of groundnut shell on performance, nutrient digestibility, and nitrogen utilization by Sokoto red goats was carried out at Professor Lawal Abdu Saulawa Livestock Teaching and Research Farm, Federal University Dustin-Ma, Katsina State. Fifteen growing male goats used for the experiment were allotted to three treatments at five for each treatment in a Completely Randomized Design (CRD) with each one serving as a replicate. The experiment comprised of three treatments namely T1, T2 and T3 at inclusion levels of urea treated GNS at 0%, 10% and 20% respectively. The feeding trial was carried out for 84 days. Growth, digestibility, and nitrogen utilization parameters were measured. The proximate analysis revealed slight increase in crude protein while crude fibre decreased with increased level of inclusion of GNS. Lignin composition also slightly reduced from 11.90% in T1 to 10.90% (T3). There were significant differences (P<0.05) in weight gain per day, daily feed intake and feed efficiency. Average daily weight gain (75g/day) and feed efficiency (0.15) were higher in treatment T3 than those of other treatments but with lower average dry matter intake (490.83g/day). The nitrogen intake, faecal nitrogen, urine nitrogen, nitrogen absorbed, nitrogen balance, and nitrogen retained were significantly different (P<0.05) across the treatments. Treatment T3 which contained 20% inclusion level of UGNS was the best among all the diets because it contained 86.90% CPD, 95.66% EED, 92.76%, CFD 17.45%, 14.27 g/day nitrogen balance and 81.82% nitrogen retention. The feed cost per kg liveweight gain was significantly less (P<0.05) in treatment T3. The conclusion of the study was that treatment T3, which contained 20% urea treated GNS performed better than others.

Effect of a silvopastoral system with Leucaena diversifolia on enteric methane emissions, animal performance, and meat fatty acid profile of beef steers

AbstractThe aim of this research was to evaluate dietary inclusion of Leucaena diversifolia into a grass monoculture (GM) diet and its influence on enteric methane emissions, animal live weight gain and meat fatty acid content of steers. Two GM diets comprised Urochloa hybrid cv. Cayman or U. brizantha cv. Toledo; silvopastoral (SPS) mixed diets included an association of either grass with L. diversifolia in a 74:26 (grass:legume) planting ratio. The experiment was conducted over 16 months with 14 Brahman x Angus crossbred steers (374±7.5 kg body weight), divided into two diet groups. Steers were weighed periodically during the experiment, and methane emissions were quantified with the polytunnel technique. The meat quality and fatty acid profile were measured after slaughtering the steers. Energy density, total and digestible dry matter intake and crude protein were higher in steers fed SPS than GM (P≤0.05). At the end of the experiment, animals from SPS weighed on average 63 kg more than animals offered GM (535 vs. 472 kg; P=0.025). Net methane emitted by steers offered SPS was 142 g per day, this is equivalent to 15% less than emissions from animals that were offered GM (168 g; P=0.007). The meat fatty acid profile was similar between diets, except for cervoniv-DHA and omega-6: omega-3 ratio, which were higher in steers consuming GM diet (P≤0.05). The results of this study suggest that the inclusion of L. diversifolia improves nutrient intake, increases animal productivity, reduces daily enteric methane emission, and decreases the omega-6: omega-3 ratio in meat.

Orange (Citrus sinensis) essential oil inclusion in high-energy diets for feedlot lambs: productivity, eating behavior, carcass characteristics, rumen morphometry, and fatty acid profile of the meat

This study evaluated the effect of different orange essential oil (OEO) inclusion rates on live weight gain, eating behavior, carcass characteristics, morphology of the ruminal epithelium, and fatty acid profile in the meat of feedlot lambs. Forty uncastrated Dorper × Santa Inês ram lambs with an initial average body weight of 21.8 ± 4.7 kg and average age of 86 ± 15 days were allocated to one of five dietary treatments in a randomized complete block design. Dietary treatments consisted of a 90:10 concentrate-to-forage ratio total mixed ration supplemented as follows: 1. non-additive supplementation (Control), and 2. additive supplementation with 100, 500, and 1000 mg OEO/kg diet DM (OEO100, OEO500, and OEO1000) or with 25 mg sodium monensin/kg diet DM (MON). The feeding lasted 84 d. Supplementation with OEO increased linearly dry matter intake (DMI), growth rate and feed efficiency (FE). Because of the linear increases in growth rate and the efficiency of energy utilization of the diet, lambs receiving OEO exhibited a greater (increasing linear effect) hot carcass weight (HCW), Longissimus muscle area (LMA), subcutaneous fat thickness (SFT), and body wall thickness (BWT) than lambs fed with Control. Lambs fed MON had lower DMI, growth rate and FE than Control and OEO. Compared to Control and OEO supplemented, lambs that received MON showed lower HCW, LMA, SFT, and BWT. Lambs fed with MON had lower oocyst counts than lambs fed with all other treatments. Lambs fed with MON spent more time eating and ruminating, with higher chewing rates than lambs fed all other diets. Rumen morphometry was unaffected by dietary treatment. The OEO supplementation increased the sum of monounsaturated fatty acids, improved the human health promotion index (HP index), and reduced the thrombogenicity index in the meat relative to lambs fed the MON treatment. Under the conditions in which the experiment was conducted, the inclusion of up to 1000 g/kg diet DM in high-energy finishing diets promotes DMI and improved growth performance and FE. Improvements in the carcass (HCW, LMA, and BTF) with OEO supplementation were mainly due to improvements in growth rate rather than effects on gain composition. Based on growth performance and carcass characteristics, OEO was a superior feed additive to sodium monensin. The OEO supplementation has a discreet effect on the fatty acid profile of the meat, but it is sufficient to improve the HP index. These findings highlight its potential as an effective additive for enhancing lamb productivity.

МОРФОГЕНЕЗ ЯИЧНИКОВ ЦЫПЛЯТ-БРОЙЛЕРОВ ПРИ ИСПОЛЬЗОВАНИИ КОРМОВОЙ ДОБАВКИ «ЯНТАРНЫЙ ХОЛОДОК»

The aim of research is to study the development of structural and functional features of the reproductive system of broiler chickens using the feed additive Yantarnyj holodok. Research was conducted on broiler chickens of the Ross-308 cross under experimental conditions, while for the experiment, control and experimental groups of 30 heads each were created, starting from the day-old age, broiler chickens of the control group received tap water from vacuum drinkers without adding a feed additive, and chickens of the experimental group were given the feed additive Yantarnyj holodok daily in a dose of 1.5 l / t with drin¬king water until the end of growing. As a main diet, broiler chickens of both groups received compound feed of Ptitsefabrika Artemovskaya LLC. The use of the feed additive Yantarnyj holodok had a positive effect on the live weight gain, which by the end of the experiment was 2,938.10 ± 405.34 g, which was 1.9 % higher than the average value in the control group. 100 % survival of broiler chickens in the experimental group was established. Histological studies revealed the process of gradual improvement of the ovary structure, the formation of its cortical and cerebral zones. At the age of 10 days, the histological structure of the ovary was not formed and represented only the protein coat, and the internal part was represented by chaotically scattered follicles, among which follicles in the pertification state were found. By the 20th day, the cortical and medullar zones of the ovary could be seen. By the 35th day, the formation of egg-bearing mounds with a zone of formed follicles of varying degrees of maturity is observed, but complete maturation of follicles with a formed egg cell was not detected in the studied individuals. The medullar zone of the ovary is rich in blood vessels of different calibers, that is, the vascularization of the ovary of chickens of this age is significantly developed.

Scientific basis for intelligent of production processes in cattle breeding

Increasing the productivity of livestock and veterinary specialists is an integral part of intensifying the production of animal husbandry products. The solution of multifaceted problems is ensured by the organization of their work. For example, the intelligent of production processes in livestock breeding lies in the fact that the use of innovative technologies, the rate of which on average in the industry reaches 46 %. So far, involves the use of electronic telecommunication devices, which had currently better meet the requirements for the maintenance and operation of breeding animals than traditional standards using analog-digital forms of equipment and document fl ow. The purpose of the research was to study the eff ectiveness of using innovative equipment in terms of time spent on implementing animal science accounting and obtaining animal husbandry products when breeding animals using telecommunication devices for recording technical and technological processes through the integration of data collection terminals using RFID (radio frequency identifi cation) and scanners that allow reading electronic ear (UHF) tags, boluses, electronic chips compared to traditional equipment that is still used in livestock enterprises. It has been established that the use of innovative technologies in animal husbandry meets the requirements of breeding pedigree animals better than using previous standards, i.e. using analog-electronic forms of equipment. Thus, innovative technologies make production processes shorter in time by 16.3 %, and more economical. Analysis of the results of the growth rate of off spring of individual sires using traditional standard technologies showed the loss of working time 10.3 times greater than when using innovations. With traditional breeding technologies, losses in the average daily gain in live weight of young and adult animals by 17.5 and 30.0 %, respectively, were noted. Losses in average daily gain in live weight were noted by 1.1–1.2 times greater when using traditional technologies of registration, identifi cation and control than when using innovations. Therefore, it is necessary to organize professional communication with colleagues in the information fi eld to participate in breeding pedigree livestock in cattle breeding.

Infl uence of biologically active additive on meat productivity of pigs

In order to improve the digestibility and assimilation of nutrients in feed by animals, biologically active additives have recently been used in practice. The purpose of the research was to study the infl uence of a biologically active additive on the meat productivity of pigs. The research was carried out at the Agrofi rma Ariant LLC in the Emanzhelinsky district one of the largest pig-breeding complexes in the Chelyabinsk region for the production of pork on an industrial basis. The data on the use of the probiotic Bifi dumbacterin in the diet of fattening pigs have been presented in the article. The probiotic feed additive was given to animals in the amount of 0.05 and 0.10 g/head/day. It was found that the absolute gain in live weight of young pigs in the control group during the experimental period was 69.60 kg, in the 1st experimental group it was 74.16 kg, which was by 4.56 kg more, and in the 2nd experimental group it was 76.56 kg, which was by 6.96 kg more. The average daily live weight gain of animals in the 1st and 2nd experimental groups was higher than in the control by 6.55 and 10.00 %, respectively. The use of a biologically active additive in addition to the main diet had a positive eff ect on the formation of meat productivity of fattened young pigs in the experimental groups. The pigs of the 1st and 2nd experimental groups exceeded the control group in slaughter weight by 5.35 and 7.81 %, respectively, in hot carcass weight by 5.13 and 7.39 %, in slaughter yield by 0.5 and 0.7 abs.%. Economic effi ciency in monetary terms was higher in the experimental groups. The use of Bifidumbacterin in feeding of young pigs made it possible to reduce the prime-cost of 1 centner of live weight gain by 294.14–423.17 rubles and increase the level of profitability of pork production by 7.26–10.74 abs.%.

Infl uence of various methods of rearing on the productivity and quality of meat of broiler chickens

Housing poultry by using intensive rearing methods often leads to stress, metabolic disorders in its body, and reduced productivity and meat quality. Therefore, along with traditional technologies, free-range technology of housing of meat chickens has recently attracted increasing interest. The purpose of the work was to study the infl uence of various rearing methods on the productivity and meat quality of meat chickens, as well as to provide an experimental justifi cation for rational rearing periods and stocking density of chickens in free-range conditions. The productivity, meat qualities, and meat quality of chickens of the new domestic cross Smena 9 were studied under free-range conditions in comparison with cage and floor poultry rearing methods. The rational rearing period and stocking density of meat chickens using free-range areas, as well as the animal science and economic effi ciency of free-range rearing of meat chickens of the cross Smena 9 were determined. The highest average live weight of the cross Smena 9 chickens was achieved with the free-range technology of rearing at the age of 56 days and amounted to 3960.3 g, which was by 3.02 and 3.36 % higher compared to cage and fl oor keeping of the chickens. Feed costs per 1 kg of live weight gain in chickens reared to the age of 56 days were 9.21 % lower compared to chickens reared to the age of 63 days. When fattening chickens to 56 days, the highest yield of edible parts in the carcass was obtained 82.60 %, including muscles 64.95 % and higher taste qualities of poultry meat. When rearing chickens at a stocking density of 12 and 11 heads/m2, the live weight of the chickens was 5.52 (p ≤ 0.05) and 5.61 % (p ≤ 0.05) higher, compared to chickens reared at a stocking density of 15 heads/m2. According to animal science indicators and economic efficiency, the best chickens were reared at a stocking density of 12 heads/m2, and as a result, the highest productivity index was obtained 359.3 units.

Weight and linear growth of steers of Aubrac breed when using the feed additive Hendrix C for cattle

One of the main factors, which influence on the intensity of growth and fattening of steers are adequate feeding. In this regard, the study of the effect of the feed additive Hendrix C for cattle on the steers of Aubrac breed has scientific and practical interest. In order to carry out a scientific and economic experiment on steers of Aubrac breed aged from 7 to 18 months, two groups were formed. The control group received a commercial feeding ration, the experimental group received the ration with a reduced content of digestible protein due to a decrease in the rapeseed presscake in the ration. The steers received the missing amount of digestible protein due to the feed additive Hendrix C for cattle. This made it possible to obtain steers with a higher live weight for rearing and fattening. Thus, the significunt difference in live weight by the end of the experiment between the experimental and control groups was 51.5 kg or 9.6 % (P > 0.999). The average daily live weight gain for the age period from 9 to 18 months in the experimental group of steers was 1033 g, which exceeded the same indicator for the control group steers by 150 g or 17.0 % (P > 0.999). In terms of height measurements, the experimental group of steers showed an advantage in all age periods. It should be noted that the steers that received the feed additive were characterized by better development of the rear part of the body, which was shown by the hip width and half-girth measurements. Thus, the feed additive Hendrix C for cattle can be recommended for fattening of steers of Aubrac breed.

Use of non-alkaloid lupine grain of the variety Deko in compound feed for young laying hens

The purpose of the research was to study the use of alkaloid-free lupine grain of the variety Deco in compound feed for young laying hens of the cross Hisex Brown. The studies were carried out under the conditions of enterprises of the Volgograd region on poultry of the highly productive egg-laying сross Hisex Brown. The nutritional value of lupine with diff erent levels of its introduction into compound feed recipes instead of full-fat soy for young egg-laying hens was assessed. The positive eff ect of lupine use on such important animal science and physiological indicators as digestibility and assimilation of nutrients in diets, live weight of young hens, hematological indicators of experimental chickens, and economic eficiency was substantiated. Thus, the digestibility coefficient of dry matter of feed in the control group was 70.96 %, in the 1st experimental group it was 71.87 %, which was by 0.91 abs.% more than in the control group; in the 2nd experimental group it was 72.23 %, which was also higher than the control by 1.27 abs.% and in the 3rd experimental group the studied indicator was 72.07 % and was higher than the control group by 1.11 abs.%. The indicators of total and average daily live weight gain in the experimental groups were higher than in the control group. Thus, in the 1st experimental group these indicators were higher in comparison with the control by 12.5 g and 0.11 g (0.95 %). In the 2nd experimental group these indicators were higher than in the control group by 29.31 g and 0.25 g (2.23 %) and in the 3rd group by 18.38 g and 0.15 g (1.4 %), respectively. The economic efficiency in terms of cost indicators of compound feed for poultry in the control and experimental groups was within the following limits: in the 1st experimental group 857.5 rubles, in the 2nd experimental group 1286.25 rubles, and in the 3rd experimental group 1715.0 rubles.

Visual and chemical stimuli from live prey affect feed intake, weight gain, and growth of juvenile Florida pompano (Trachinotus carolinus)

Visual and chemical stimuli from live prey affect feed intake, weight gain, and growth of juvenile Florida pompano (Trachinotus carolinus)

Carbon footprint of mixed farming crop-livestock rotational-based grazing beef systems using long term experimental data

In the context of ever-growing demand for food and associated concerns regarding the environmental impacts of high-input agricultural systems, there is growing interest in mixed farm enterprises to deliver greater sustainability compared with mono-enterprise production systems. However, assessments of such systems are complex and require high-resolution data to determine the true value and interconnectivity across enterprises. Given the scarcity of information on mixed crop–livestock systems and the difficulties of its analysis, we perform life cycle assessment using temporally high-resolution data (2019–2022) from a long-term experiment in South America to evaluate the ‘cradle-to-farmgate exit’ greenhouse gas emissions intensities of four rotational crop–livestock systems. Systems evaluated were continuous cropping: 2 years of continuous cropping; short rotation: 2-year continuous cropping plus 2-year pasture; long rotation: 2-year continuous cropping followed by 4-year pasture; and forage rotation: continuous pasture. Emissions intensities for beef throughput were reported as kilograms of carbon dioxide equivalents (CO2-eq) per kilogram of liveweight gain (LWG) using the Intergovernmental Panel for Climate Change’s Sixth Assessment Report (AR6 2021) CO2 characterisation factors. Point estimate results were found to be 11.3, 11.8, 11.8 and 16.4 kg CO2-eq/kg/LWG for continuous cropping, short rotation, long rotation and forage rotation, respectively. Emission averages arising from crops, which were separated from animal-based emissions using economic allocation, were 1.23, 0.53 and 0.52 kg CO2-eq/kg for soybean, wheat and oat, respectively. The inclusion of soil organic carbon stock changes had notable effects on reducing each system’s emissions: by 22.4%, 19.2%, 25.3% and 42.1% under continuous cropping, short rotation, long rotation and forage rotation, respectively, when soil organic carbon was included. Given there are few life cycle assessment studies available on such mixed-enterprise ‘semi-circular’ systems, particularly with novel primary data, this study adds critical knowledge to agri-food-related sustainability literature by addressing environmental issues in complex production systems compared to extant and broad coverage of mono-enterprise systems.

Influence of growth intensity of black and white dairy cattle on their reproduction and productivity under free housing

Targeted and economically justified livestock breeding, considering the biological characteristics of growing animals, is a key issue in dairy farming. One of the insufficiently studied aspects of livestock breeding is the period of animal development from the first insemination to the first lactation, which affects their safety, productivity, and reproductive capacity. The study was conducted at the breeding station of the Ukrainian black-and-white dairy breed of the state enterprise "Kutuzivka" in Kharkiv district, Kharkiv region, Ukraine. Animals born in different years differed in growth intensity, reproductive performance, and productivity. At the same time, there was a tendency for the milk yield of first-born heifers to improve with an increase in live weight gain from insemination to the first lactation. According to the results of the correlation analysis, this weight gain had a significant relationship with age and live weight at first insemination, milk yield for 90 days, milk yield for 150 days, milk yield for 305 days of lactation, and live weight at first lactation. The survival rate of all first-born heifers with a weight gain of more than 146 kg was 16–21% higher compared to animals with a lower weight gain. Also, such animals had the highest milk yields for all lactation periods. Their advantage in milk yield was 234 kg for the first 90 days of lactation, 331–381 kg for 150 days of lactation, and 573–675 kg for 305 days of lactation. Groups of animals with different live weight gain after the first insemination also had significant differences in the duration of the service period and the number of stillborn calves. The results of the study concluded that the animals with the highest gain were significantly younger and had a higher live weight at insemination as well as the highest live weight in the first lactation. The early maturation of replacement heifers will contribute to the intensive reproduction of the herd, which will increase the profitability of the dairy industry. Further research is needed to determine the effect of growth intensity on the reproductive performance of second and subsequent lactation cows and calf safety.

ЭФФЕКТИВНОСТЬ БИОКОНВЕРСИИ ПИТАТЕЛЬНЫХ ВЕЩЕСТВ И ЭНЕРГИИ КОРМА В МЯСНУЮ ПРОДУКЦИЮ БАРАНЧИКАМИ РАЗНОГО ГЕНОТИПА

The purpose of the study is to determine the influence of the genotype of rams on the efficiency of transformation of protein and energy of the feed ration by purebred young animals of the Romanov breed (Group I), its crosses with the Edilbaevskaya breed of the first generation 1/2 Romanovskaya × 1/2 Edilbay (II group) and the second generation 1/4 Romanovskaya × 1/4 Edilbay – ( Group III) in food protein and energy of meat products. Crossbreeds of groups II and III were distinguished by less crude protein consumption per 1 kg of live weight gain than peers of group I – by 15.9 (1.62 %) and 33.5 g (3.48 %) and energy by 3.64 (4.23 %) and 4.89 mJ (5.77 %). An advantage was noted for crosses of groups II and III in terms of the weight of edible parts of the carcass, which amounted to 5.05 (36.89 %) and 6.79 kg (49.60 %). Purebred rams of group I were inferior to crossbred young animals of groups II and III in terms of protein content in the edible part of the carcass by 0.86 (31.62 %) and 1.15 kg (42.28 %), respectively, extractable fat – by 0.82 (66.13 %) and 1.25 kg (100.8 %), energy – by 46.54 (49.01 %) and 68.30 mJ (71.93 %). All this determined the advantage of crossbred rams of groups II and III in terms of the yield of nutrients, edible parts of the carcass and energy per 1 kg of pre-slaughter live weight. For protein, this advantage was 2.49 (3.53 %) and 4.32 g (6.12 %), extractable fat – 9.86 (30.65 %) and 16.01 g (49.77 %), energy – 0.59 (23.98 %) and 0.70 mJ (28.45 %). The advantage of crossbred young animals of groups II and III in terms of the protein bioconversion coefficient was established, which was 0.26 and 0.65 % for protein, 0.21 and 0.40 % for energy, respectively. The leading position in all indicators was noted for crossbreeds of the second generation of group III.

39 Effects of feeding sun-dried bovine rumen contents on growth and carcass quality of New Zealand White rabbits

This research study aimed to investigate the impact of sun-dried bovine rumen contents (SDBRC) on the growth and linear body measurements of New Zealand White rabbits. The experimental rabbits (n=12) were selected from four New Zealand White bucks and subsequently allocated into three distinct treatments, each with specific dietary compositions. The control group was provided with a standard diet of rabbit pellets, while the experimental groups received rabbit pellets supplemented with 30% (Treatment A) and 40% (Treatment B) of SDBRC. All animals were subjected to consistent and meticulous livestock management practices throughout the 12-week experimental period. There were no significant differences in the growth of rabbits given rabbit pellets and 30% SDBRC. However, the live weight gain and final weights of rabbits on 40% SDBRC inclusion were significantly lower than the 30% SDBRC inclusion and the control (P<0.05). Parameters, such as total feed intake, feed conversion ratio, and dressing percentage were not significantly different (P>0.05). The linear body measurements (heart girth, body length, and abdominal circumference), were not significantly (P>0.05) influenced by dietary variations. Carcass weight for the rabbits on 40% SDBRC inclusion was significantly lower than for rabbits on the control and 30% SBDRC inclusion diets (p=0.001). Other carcass parameters such as meat colour and pH exhibited no significant differences across all three treatments (p>0.05). These findings highlight the promising potential of incorporating SDBRC into rabbit diets, particularly up to 30%, without compromising growth performance and carcass characteristic.

Investigation of Some Environmental Factors on Reproductive Characteristics, Milk Traits and Kleiber Ratios of Kilis Goats Reared in the Fertile Crescent of Türkiye

This study was carried out to determine the effect of environmental factors on some yield traits in Kilis goats. For this purpose, 6000 heads of Kilis goats each year, and a total of 30000 goats and kids born from them for 5 years, were the subject of the research. Milk control in goats was calculated by the ICAR-AT method. At the end of the study, Average birth weight was 3.56 kg, weaning weight was 15.06 kg and daily live weight gain was 191.64 g in kids. KR value found to be 23.6±0.03 in kids. Lactation milk yield in mothers was determined as 367.64 kg. As a result, it was determined that environmental factors were effective on the reproductive parameters and milk yield characteristics of Kilis goats and the developmental characteristics of kids. The crucial determination of these factors in the breeding of this breed will increase the accuracy of selection. In addition, the success will also be increased by starting the transition from the traditional breeding approach to the genomic breeding method and by combining these two strategies.

Effect of supplementation of berseem hay meal as replacer of mustard cake protein on nutrient intake, utilization and growth performance in Jalauni lambs

Berseem (Trifolium alexandrinum) hay meal (BHM) as a replacement for mustard cake (MSC) in the ration of growing Jalauni lambs was studied. About 15 Jalauni male lambs (23.25 ± 1.2 kg) were randomly distributed into three groups of five each in an experiment based on a randomized block design and were randomly assigned to one of the three dietary treatments. The animals were fed control concentrate mixture (GI) or concentrate mixtures in which 60% N of mustard cake was replaced with BHM containing 0.75% NPN (GII) or 1.0% NPN (GIII) making them iso-nitrogenous and iso-caloric. Gram straw (GS) was offered ad libitum to all the animals. Total dry matter intake (DMI) was comparable among the groups. Digestibility of nutrients, namely DM, organic matter (OM), and neutral detergent fiber (NDF) were non-significantly different among the groups. However, crude protein (CP) digestibility was higher in GI or GII than GIII. Rumen fermentation was not affected due to the incorporation of BHM as a replacer of mustard cake in the diet. N balance was also comparable. However, N retention as % of N absorbed was significantly (p <0.05) lower in GIII as compared to GI or GII. Nutrient content in terms of TDN or ME was similar among the experimental diets. However, DCP% was higher in GI or GII than GIII. Cost per kg live weight gain was significantly (p <0.05) lower in BHM-incorporated diets (GII or GIII) than in the control diet (GI). It was concluded that BHM can be incorporated into the diet of growing Jalauni lambs as a replacer of mustard cake for economical livestock production.