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This field observational study describes the seasonal pattern of small lungworm infections under different grazing managements from August 2018 to March 2019. Live weight, lungworm and gastrointestinal nematode infection, as well as pasture type grazed and snail density, were measured at 5 farm visits. Across all visits and mobs, about one quarter to one half of sheep were positive for small lungworm, although prevalence was as low as 0% and as high as 78%. The density of the intermediate host molluscs was greater than 1600 snails/m2 in irrigated perennial lucerne pasture when it was grazed ('Pasture A'), but was low (<300) in non‐irrigated perennial pasture ('Pasture B') and non‐irrigated forage crop ('Pasture C'). Overall, non‐infected lambs had a similar live weight compared with the small lungworm infected lambs (mean difference −0.6 kg; 95% CI −1.6 to 0.2; P = 0.1). The odds ratio of small lungworm infection associated with a twofold increase in worm egg count was 1.7 (95% CI 1.1 to 2.7; P = 0.02). Rather than a distinct seasonal pattern of infection, we found that small lungworm can occur throughout the year, with prevalence most influenced by pasture type (irrigated vs dryland), grazing management and the population density of the intermediate hosts. Importantly, this study suggested that small lungworm infection did not reduce lamb live weights. It reinforced that to improve sheep productivity, well‐established determinants of production, such as correct grazing management to optimise pasture quality and strategies to reduce infections with gastrointestinal nematodes, should be the priority of farm managers. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the effect of body condition score (BCS) at lambing over the resumption of ovarian and estrous postpartum activity in lactating Pelibuey ewes. Twenty ewes were assigned to two groups, according to the BCS at lambing: Low BCS (LBC, n = 10) and High BCS (HBC, n = 10). Ovarian and estrous activities were daily monitored from day 3 postpartum until the first estrous or 90 days postpartum. Continuous variables were analyzed using Student´s t test and binary responses with the exact Fisher test. No significant effect of BCS at lambing on ewes in estrous, lambing to first estrous interval, estrous length, and estrous cycle length, preovulatory follicles at estrous, the maximum follicular diameter at estrous day or ovulation rate was observed. However, the lambing to first preovulatory follicle interval was shorter in the HBC group (HBC = 6.2 ± 2.6 vs LBC = 10.8 ± 4.5 d; P < 0.05). The lambing to first corpus luteum intervals were similar between groups, but without estrous expression. The function of the first corpus luteum postpartum was similar in both groups. BCS at lambing did not affect the resumption of ovarian and estrous activity postpartum in lactating Pelibuey ewes. [ABSTRACT FROM AUTHOR]

Subject of a scientific experiment were 16 male lambs of the Ile de France breed, divided into 2 groups of 8, with different types of birth, fattened for a period of 60 days. The aim of the experiment was to study the growth and fattening abilities of lambs with different types of birth. Live weight was recorded at birth, at 60, at 75, at 90, at 105 days and pre-slaughter live weight at 120 days. The average daily gain by groups and subperiods was calculated. The quantities of feed consumed and the residual quantities were reported daily. The data were processed by the methods of variation statistics with Data Analysis, EXCEL, 2016 by Microsoft. It was found that male twin lambs of the Ile de France breed started the experiment with 12.81% lower average live weight, but in 60 days achieved 8.74% significantly higher absolute gain of 25.312 kg, compared to the group of singles - 23.100 kg. The twins achieved a 7.42% higher average daily gain of 0.445 g compared to singles for the entire experimental period. The twin lambs achieved 1 kg increase with lower consumption, respectively by 5.57% of dry matter, 6.36% of energy and crude protein by 7.18% of the group of singles, which shows better feed utilization and the indication of compensatory growth in lambs born as twins. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the weight development of sheep from the Bulgarian Dairy Synthetic Population, with a genetic component of the breeds East Friesian, Lacaune and Chios. Analyzed were 903 pedigrees and a total of 2180 records for live weight at weaning, at 9, 18 and 36 months of age of ewes reared at the Agricultural Institute – Shumen. An animal model was used to achieve this goal. The established average values were 27.973 kg at weaning, 49.608 kg at 9 months, 66.574 kg at 18 months and 71.482 kg at 36 months. The variation of the symptom decreased with increasing age from 16% at weaning to 6% at 36 months of age. Genetic assessments of individual generations and the phenotypic realization of the trait did not follow a clear tendency to increase or decrease live weight. In purebred animals, a close to the general average additive and a weak negative non-additive effect was found for all ages. The values of the additive and non-additive effect in the genetic groups with a component of 12.5% of the East Friesian breed, the Lacaune breed for the first generation and the Chios breed for the first and subsequent generations were predominantly positive. [ABSTRACT FROM AUTHOR]

The impact of age, live weight, and growth rate of the bulls of Ukrainian breeds on the area of "muscle eye" (crosssection of m. longissimus dorsi when the carcass is divided into front and rear between the 12th and 13th ribs) was studied. The correlation between the size of the "muscle eye" and the carcass's characteristics and the meat's qualitative indicators was also determined. The research was conducted on the bulls of Ukrainian black-and-white dairy (UBWDB) and Ukrainian meat (UMB) breeds. Living animals "muscle eye" area was determined with the ultrasonic analyser Emperor 860, after slaughter. It was found that UMB bulls have the area of "muscle eye" twice as big as their UBWDB peers. The "muscle eye" area increases when growing the cattle to 400 - 450 kg. In the future, it will be practically independent of the age and weight of the animals and remains stable. An increase in the average daily gains within the breed leads to an increase in the "muscle eye" area. The area of "muscle eye" has a weak negative connection (r = -0.193) with meat tenderness and dry matter content (r = -0.345) and a positive one with slaughter weight (r = 0.614) and slaughter yield (r = 0.653). Of the three parameters (length, depth, and area) of "muscle eye", the greatest impact on the technological properties of meat has depth. Its increase has a negative connection with meat tenderness (r = -0.810) and moisture (r = -0.474), but it has a positive impact on the moisture retention capacity (r = 0.338) and weight of weighed portion after heat treatment. The obtained results can be used to clarify the optimal growing parameters of the bulls of Ukrainian black-and-white dairy and meat breeds for meat and determine the optimal age and live weight of the cattle slaughter. [ABSTRACT FROM AUTHOR]

This study was carried out for the purpose of determination of some growth and development characteristics in the period between birth and twelve months of age in Yerli Kara cattle. The animal material of the study was composed of 104 Yerli Kara calves located in Ankara province. In the study, live weight, withers height, rump height, chest girth, body length, chest depth and front wrist girth values at birth were found as 14.85 kg, 58.00 cm, 60.10 cm, 54.41 cm, 49.36 cm, 24.25 cm and 7.40 cm respectively. The same values at the age of three months were found as 49.37 kg, 73.95 cm, 76.84 cm, 83.45 cm, 79.14 cm, 35.45 cm and 9.46 cm respectively. Values at the age of six months in these calves were detected as 81.22 kg, 87.29 cm, 90.35 cm, 99.36 cm, 92.93 cm, 42.79 cm and 10.58 cm respectively. Values at the age of twelve-month were determined as 97.29 kg, 92.15 cm, 95.55 cm, 106.22 cm, 98.07 cm, 45.26 cm and 10.74 cm in the same order. Average daily gains values were found 0.360 kg in the period between birth and 3 months of age, 0.333 kg from 3 to 6 months, and 0.102 kg from 6 to 12 months. The results showed that the body measurements of animals in this study are generally lower than the values reported in literature. Therefore, a selection program considering this fact will be useful for the development of native Yerli Kara cattle maintained at the farm operations of Ankara province. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the effect of replacing maize meal with Sorghum vulgare meal, a high-tannin sorghum meal, in fattening diets on bodyweight and methane emissions by yearling male Pedi goats. A total of 12 yearling male Pedi goats with an average initial liveweight of 14 ± 1 kg were randomly assigned to a complete randomized design with four treatments, which were formulated such that 0%, 10%, 20% and 30% of the maize meal was replaced with Sorghum vulgare meal. The experiment was conducted over 28 days, with 21 days adaptation, followed by seven days for sample collection. Replacing maize meal with sorghum did not produce detectable (P >0.05) effects on bodyweight and live weight gain. The various replacement levels of sorghum meal had no detectable effects on the blood cell profile of Pedi goats either. However, they reduced methane emission and improved feed conversion ratio (P <0.05), which allowed for an approximation of the feed required by growing goats. These findings may assist farmers in selecting and utilizing the right feeds to maximize profitability in the small-stock farming sector. [ABSTRACT FROM AUTHOR]

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mustafa Kemal University Journal of Agricultural Sciences / Mustafa Kemal Üniversitesi Tarım Bilimleri Dergisi is the property of Mustafa Kemal University, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents the results of a study of the milk productivity of Holstein cows in the dynamics of lactations, correlation between the level of milk yield, fat content, and the amount of milk fat, live weight and milk ratio. The studies were carried out in the herd of the breeding farm of SLL (Society of limited liability), „Doksancom" on Holstein cows in the dynamics of 4 lactations. A comparative analysis of the yield of cows in the dynamics of lactations showed that during the second lactation, milk productivity was 934 kg of milk, the third - 959 kg of milk, the fourth - 1527 kg of milk more than in the first lactation, the difference being significant at P <0.01, P <0.05 and P <0.001, respectively. The lactation curve of all analyzed cows of the Holstein breed of the herd of SLL „Doksancom" changed with a certain regularity and had a leveled character, characterized by a high stable type. The relationship between milk yield and the percentage of fat in milk of cows of first-fourth lactation was in negative correlation from weak (-0.187, second lactation), moderate (-0.338 - -0.486, first-fourth lactation) to noticeable (-0.557, third lactation). A negative correlation in the entire analyzed animal population was found between milk ratio and live weight, ranging from mild -0.018 to moderate - 0.334. This will allow further selection of highly productive cows in the herd with an optimal live weight for the Holstein breed. [ABSTRACT FROM AUTHOR]

The publication is devoted to the study of morpho-biological and productivity traits in cross-bred lambs of F1 ♀Tsigai x ♂Assaf, F2 ♀ (♀Tsigai x ♂Assaf) x ♂Assaf and F1 ♀Karakul x ♂Assaf. After weaning from their mothers, three groups formed from 5 heads of ram lambs and 5 heads of ewe lambs, obtained after cross breeding, were supplied for two months for control rearing. At the end of the experiment were taken body measurements and body indices were calculated concerning their live weight gain and average daily weight gain. A control slaughter of 5 male lambs from each group was carried out. The measurements of carcasses were taken and their indices were calculated. The carcass cutting with boning of the right half-carcasses were carried out with the aim to calculate the ratio of meat content and to obtain an average sample of meat in order to study its chemical composition. During the control rearing period, the gross weight gain of the ram lambs in F2 ♀ (♀Tsigai x ♂Assaf ) x ♂Assaf was 9.90 kg, which is higher compared to F1 ♀Tsigai x ♂Assaf ram lambs by 0.96 kg and in comparison to F1 ♀Karakul x ♂Assaf by 0.12 kg. The slaughter yield in F2 ♀ (♀Tsigai x ♂Assaf ) x ♂Assaf was 48.97%, which is higher compared to F1 ♀Tsigai x ♂Assaf ram lambs by 1.73% and in F1 ♀Karakul x ♂Assaf by 1.29%. The meat ratio in F1 ♀Tsigai x ♂Assaf is 2.97, which means, there is 2.97 kg of meat per 1 kilogram of bones. In crossbreeds F2 ♀ (♀Tsigai x ♂Assaf) x ♂ Assaf it was 2.71, which is 0.26 less and in F1 ♀Karakul x ♂Assaf it is also 0.43 less compared to F1 ♀Tsigai x ♂Assaf. According to the chemical composition of meat, the highest indicator for fat is in F1 ♀Tsigai x ♂Assaf with 10.17%. For the protein and collagen the highest indicator is in F2 ♀ (♀Tsigai x ♂Assaf) x ♂ Assaf, with respectively, 18.61 and 0.99%. [ABSTRACT FROM AUTHOR]

The aim of the study was to establish the influence of genealogical line on the level of productive traits live weight, prolificacy and wool production in ewes of the Thracian merino breed, raised at the Agricultural Institute - Stara Zagora. The object of analysis were 4 genealogical lines - Line 40, Line 8031, Line 764 and Line 84, as the total number of ewes included in the research was 210, born in the period 2013-2018. Productive performance including live weight (at birth, at weaning, 9 and 18 months of age, 2.5, 3.5, 4.5 and 5.5 years), prolificacy (number of lambs born per ewe from I to IV lambing) and wool traits (wool production, staple length, wool yield and pure fiber of different ages) were studied according to the individual line. Data on productivity were based on performed controls and processed using variation statistics and Excel program. Some genetic diversity was found in the live weight of ewes and significant differences between the ages of 9 months and 2.5 years. Linear differentiation for wool production was available only at 18 months of age. For the other traits - prolificacy, staple length, wool yield and pure fiber, no significant differences were found between the genealogical lines. Due to the extremely limited population of the Thracian merino breed and the purposeful selection in the breeding flock of the Agricultural Institute - Stara Zagora, the genetic diversity was very limited. This requires the introduction of blood plasma from other fine-fleece breeds in order to eliminate inbreeding effect and increase genetic diversity, ensuring the preservation of the breed and increase genetic progress. [ABSTRACT FROM AUTHOR]

Subject of the study were 15 female and 15 male lambs from the Karnobat local sheep breed. The aim of the experiment was to monitor the weight development of offspring with different types of birth in the period before weaning. The study was conducted in 2020 with a flock owned by the Institute of Agriculture – Karnobat. There were 4 groups of lambs, equaled in type of birth (singles, twins), sex (female, male), age and live weight. The live weight trait was recorded at birth, at 10, at 30, at 70 and at 90 days. A total of 150 measurements of the live weight of the lambs were made, on the basis of which the average daily gain was calculated by periods for both sexes and for different types of birth. The data were processed by the method of variation statistics with the software MINITAB 16. It was found that the Karnobat local sheep breed is characterized by a good growth intensity of the offspring until weaning. Female lambs reached an average of 28.557 kg, and males respectively 30.233 kg at 90 days. The average daily gain ranged from 0.233 kg to 0.312 kg for female lambs and from 0.255 kg to 0.347 kg for male lambs. The highest growth was achieved by lambs of both sexes in the period 30 − 70 days. Lambs born as singles had a higher average live weight and daily gain until weaning, but with age the differences decrease, which shows good compensatory growth abilities of the twin lambs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

It has been highlighted the data of researches as for the influence of natural and climatic zones of Ukraine on display of economically useful signs of the most numerous cattle in the country like Ukrainian black-spotted dairy breed. It was the grounds to assert the efficiency of resources use in those conditions to which they are most adapted and have genetically determined potential. It was found that cowsof lactation breeding herds in the Forest-steppe zone produced 7344 kg of milk, which is 242 kg and 1125 kg more than in the Steppe and Polissya regions due to significant variation of the characteristic within each climatic zone (Cv = 11.6– 27,5%). The Polissya zone, where the animals' yieldwere 5764 kg, while in other climates 6982–6992 kg, does not contribute to the high productivity of the first lactation cows. It is proved that the duration of the service period in cows of three natural and climatic zones of Ukraine varied from 106 days in Polissya to 126 days – Forest-steppe, but it did not agree with the output of calves per 100 cows, which in 81 Polissya amounted to 82 and Forest-steppe – 79. The heifers of the Steppe zone are inseminated with live weight of 391 kg at the age of 477 days, and the Forest-steppe and Polissya with slightly less 385 kg and 387 kg, respectively, at the age of 493 days and 517 days. There is no significant difference in live weight at the ages of 6, 12 and 18 months between heifers of different natural and climatic zones of Ukraine, but the degree of development of the trait after 6 months was slightly better in cattle of the Steppe zone. A positive correlation was found between milk yield of first lactation cows of all natural climatic zones and their live weight at 6, 12 and 18 months of age, as well as negative calf age at first insemination (-0.587 ... -0.810) with significant correlation from the cattle of the Steppe zone. A high correlation coefficient (+0.703) was found in cows between live weight of heifers at first insemination and first lactation in the Polissya region.

ABSTRACT Meat productivity and quality of beef are determined by a number of factors, including pedigree traits of animals. Meat productivity is closely related to the biological patterns of their growth and development. Considering the patterns that affect meat productivity enables effective growing and fattening of livestock and obtaining commercially viable beef. To predict economically useful traits in beef cattle breeding, interior indicators can be used, as they reflect the metabolic picture of the animal’s body. The research studies in physiology and biochemistry of livestock aimed at revealing the persistent mechanisms of a growing animal organism make them relevant. The article identifies a correlation between the interior indicators and the fattening indicators of three experimental groups of steers. The main forecasting factors of meat productivity indicators have been substantiated. Regression coefficients have been found and show how much the live weight varies depending on the determining factors. Meat productivity predicting procedures have been modeled with respect to the protein content in blood serum.

The productivity of cows with the first calving depending on live weight and average daily gains of heifers during rearing studied. The data of animals of Ukrainian Black-and- White dairy breed of Kyiv factory type used for the research. Every three months, from birth to 18 months of age, heifers were determined live weight and average daily gain. According to the indicators of weight growth, the heifers divided into 5 groups of the standard deviation principle from the mean. In animals included in these groups studied the performance of the first lactation. It found that obtaining a live weight of 3-month-old heifers over 127 kg can significantly reduce the age of the first calving. The advantage over animals belonging to the groups with less weight is 2.7-3.5 months. Increasing the live weight of heifers at 12 and 15 months also allows reducing the age of the first calving. Moderate (less than 722 g per day) growth of heifers at the age of 6-9 months also has a positive effect on the reduction of the age of the first calving. The weight of newborns heifers during lactation was associated with first calving cow’s milk yield. Heifers born with the lowest live weight (less than 28 kg) had after the first calving milk yield per lactation 145… 1956 kg more than in other groups. The live weight of 3-month-old heifers is of the greatest importance for the formation of high milk productivity of cows. Obtaining live weight of heifers of this age 117-127 kg with an average daily gain of 902-1037 g provided in first the lactation the largest milk yield with an advantage over animals of other groups up to 3119 kg. In older age periods, the influence of growing heifers on the formation of milk productivity is less pronounced, and the optimal live weight and growth rate was at the level of the average size of the herd. The research results can used to optimize the growth plans of heifers and their selection

The aim of the research was to study meat and slaughter indicators, which allow to judge the qualitative characteristics of animal productivity, quantity and quality of final products in bulls of Ukrainian black-spotted dairy breed and crossbreeds F1 1/2 Ukrainian black-spotted and 1/2 Swiss dairy breeds at 18 months of age. The results of scientific and economic experiment on comparative study of meat and butchering slaughter indicators of pure bred young cattle of Ukrainian blackspotted dairy breed and crossbreeds F1 ½ of Ukrainian black-spotted and ½ of Swiss dairy breeds are presented. It was found that the addition of blood of the Swiss breed had a positive effect on the better productivity of local animals in different periods of cultivation in comparison with purebred animals. According to slaughter yield, local bulls outnumbered purebred counterparts by 0.8%. The boning of the diverting weir of the experimental animals made it possible to establish the ratio of pulp, bones, cartilage, tendons and ligaments. In terms of muscle yield, local animals of the experimental group had a significant advantage over control counterparts by 2.8%

The duration of productive use is a complex integral feature and is determined by both genetic and paratypical factors. This feature should ensure maximum milk productivity of animals, economic efficiency of dairy farms and generally limit the cost of raising and keeping cows. Research conducted in the experimental farms of state enterprises “Kutuzovka”, Kharkov district of Kharkov region using cow’s Ukrainian black-and-white dairy breed (4038 cows). We studied the duration of productive use of cows divided into gradations according to the conditional bloodline for the Holstein breed, depending on the weight in the control age periods of cultivation (at birth, at 6, 12 and 18 months). The maximum value of the duration of productive use was recorded in the group of cows with a share of conditional blood for the Holstein breed up to 30% inclusive (the average duration of productive use is 2.77 lactations). The highest indicator of the duration of productive use of the studied animals was 4.09 lactations. Among cows with a share of conditional blood for the Holstein breed up to 30% longer produced those born with a weight of more than 40 kg (4.09 lactations), at 6 months of age weighed 100-149 kg, at 12 months – 200-249 kg, at 18 months of age – 350-399 kg. Among animals with a share of bloodline of 31-60 %, those that had a weight at the age of 6 months produced the longest: 155- 190 kg (3.17 lactations), at 12 months – 250-299 kg (2.98 lactations), at 18 months – 350-399 kg (3.06 lactations). In the most numerous gradation with the share of bloodline for the Holstein breed 61-90 %, the longest productive use was characterized by animals born with a weight of 30-39 kg (2.12 lactation), at 6 months of age they weighed more than 200 kg (3.29 lactation), at 12 months-300-349 kg (3.40 lactation), at 18 months – 400-449 kg (2.82 lactation). The average duration of productive use of cows of this grade is quite low – in the range of 2.82-3.29 lactations. The highest degree of influence on the duration of productive use in this gradation of animals was recorded by the live weight factor at 6 months of age (η2 = 10.8). Comparative assessment of the cows gradation with a share of conditional blood for the Holstein breed of 91 % or more found that the longest productive use was characterized by cows that had a live weight at birth of 30-39 kg (1.93 lactation), in 6 months – 155-199 kg (2.73 lactation), in 12 months – 250-299 kg (2.87 lactation) and in 18 months – 350-399 kg (2.62 lactation). The degree of influence of live weight at this age on the duration of productive use of cows is insignificant, except for live weight at 6 months of age (η2 = 11.8)

The objective of the study is to determine, whether the growth retardations of replacement cows are admissible, and in which periods of culture they most significantly affect the further productivity of the cows. The subject of the analysis was the number of animals who at the age of 15 months had the live weight no less than 300 kg (which complied with the breed standard or was inferior to the requirements for 10 % maximum). The animals were divided into 5 groups. The first group included the animals with growth retardation before the age of 3 months. The second one – at the age of 3-6 months; the third one – 6-9 months and the fourth one – 9-12 months. The fifth one was the control group, without growth retardation. The growth retardation referred to the live weight reduction at the end of the period in comparison with its beginning or the average daily weight gain less than 500 g. The authors measured the live weight, first lactation productivity and the lifetime productivity of the animals. It has been established that the growth retardation of the heifers before the age of 3 months negatively affected the growth rate in the following three-month period. They can completely compensate the growth retardation only at the age of 18 months. The other group animals compensated the live weight retardation in comparison with the control group by the age of 15 months. The firstlings which had the growth retardation at the age of 0-3 and 3-6 months, has the highest milk productivity. The same trend was observed in milk fat and protein output and the age of the first calving. However, in the growth retardation group the livability of firstlings, the number of lactations and the productive live was worse. The lifelong milk yield in the growth retardation group was 15-37 % lower than in the control group. Growth retardation at the age of 6-9 months negatively affected the higher lactation productivity. The highest daily milk yield in this group of cows was lower in the control group by 14 % (p < 0.05). Therefore, growth retardation had no negative effect on the milk yield of the firstlings, but resulted in lower survival of the animals, shortened the productive life and lifetime yield. The later the growths retardation occurs, the sooner the heifers can compensate it and the lower is its effect on the lifetime productivity of the cows. In view of the reduction of lifetime productivity, it is purposeful to draft out the animals with the growth retardation

According to the current norms (DSTD-AIC-04.05.) the density of keeping chickens in cages should be 22–25 hens/m2 , which corresponds to their provision with an area in the range of 400–450 cm2 /hen. This level of housing density does not coincide with the slightly more comfortable (13–20 hens/m2, or 490–750 cm2 /hen) established in the United States and EU countries for chickens of modern egg crosses (Council DirecƟve 1999/74/EC). Therefore, it is important to study the egg producƟvity of chickens of industrial flocks in 6–15-Ɵer cages baƩeries at a density in accordance with domesƟc and European standards. In the condiƟons of the modern industrial poultry complex in a comparaƟve aspect two variants of the maintenance of laying hens in cages of 12-Ɵer baƩeries are invesƟgated. The first variant of keeping provided laying of laying hens in cages according to the European norms – 14 hens/m2 (726 cm2 /hen), and the second – 25 hens/m2 (402 cm2 /hen) that corresponded to domesƟc norms. It was found that the maintenance of laying hens of modern high-performance cross for 44 weeks (unƟl reaching 62 weeks of age) in cages of 12-Ɵer baƩeries in density in accordance with the requirements of domesƟc standards (22–25 hens/m2, or 400–450 cm2 /hen) provides 32265 edible eggs (2023 kg of egg mass) from 1 m2 of poultry area, which is 1.8 Ɵmes more than the density required by European standards (13–20 hens/m2 , or 490–750 cm2/hen). In addiƟon, 85.2 million eggs were obtained from hens kept in 12-Ɵered cage baƩeries of a poultry house with an area of 2640 m2 in terms of density in accordance with domesƟc norms that is 37.6 million eggs more than from their counterparts, retained by European standards. It has been proved that the density of keeping industrial chickens in cages of 1–3-Ɵer baƩeries provided by domesƟc norms should be extended to the baƩeries of new 12-Ɵer structures

An actual problem today is the utilization of waste products of the processing industry by feeding them to animals in order to obtain valuable animal protein. With this aim, a scientific and economic experiment was conducted to determine the productivity effect of table poultry young quails feeding with distillers dried grain (DDGS) in the composition of feed in the amount of 5–20 % per the productivity and chemical composition of their meat. At the beginning of the experiment, the daily young quails of the Pharaoh breed were divided into 5 groups according to the principle of analogues where the 1st one was the control and the 2nd–5th were the experimental ones. In the compound feed of animals of the 1st control group the distillers dried grain (DDGS) was absent. Animals of the 2nd experimental group consumed compound feed with a content of 5 % distillers dried grain (DDGS), the 3rd experimental group – 10 %, the 4th experimental group - 15% and the 5th experimental group – 20 % of the specified feed. The article presents the results of a scientific and economic trial to determine the effect of feeding 5–20 % of distillers dried grain (DDGS) to young broiler quail in the composition of compound feeds on the productivity and chemical composition of their meat. It is proved that the highest productivity of quail is achieved by consuming 10% of distillers dried grain (DDGS) in the compound feed. The doses of DDGS by 5 and 15 % also has a positive effect on the live weight of quails. However, analysis of the chemical and amino acid composition of the meat has shown that already at the content of 10 % of DDGS in the compound feed in the quail meat a decrease in protein and an increase in the proportion of fat. It is worth noting the constant level of raw ash in the meat of quails of all groups. Increasing the distillers dried grain with solubles (DDGS) content of the compound feed also contributes to the reduction of some essential amino acids. However, changes in the chemical and amino acid composition of quail meat during distillers dried grain (DDGS) feeding were not statistically significant. Thus, the optimal content of distillers dried grain (DDGS) in the feed of table poultry quails can be considered as 5–10 %

The article presents material on the effect of the amino acids lysine and methionine in pig diets. Studies have been carried out to increase the live weight of animals, depending on the content of these amino acids in the diet when fattening up to 100 and 120 kg. Presented research results obtained during testing in certified and accredited laboratories. When growing gilts to live weight from 30 to 50 kg, a deficiency in the level of lysine was found, which reaches up to 29.6%, and methionine with cystine up to 23.1%. When growing animals from 81 to 120 kg of live weight, the lysine deficiency is 14.9%, and methionine with cystine is 8,8%. This necessitated balancing the diet of animals to the required level of amino acid content. The most effective on the growth and development of animals, as well as on indicators of pork quality, was the introduction of feed lysine in combination with methionine in pig diets.

The unprofitableness in the industry of beef cattle husbandry is associated with the death of newborn calves during the colostral period (calves have insufficient immune protection, which can be obtained only with timely use of colostrum) due to imperfection in the housing technology or its individual elements. We have been conducted two experiments: the first one – on calves and cows of the second calving, and the second - on calves and cows of the third calving and older. At revealing of a problematic cow–calf pair (cow’s refusal of the calf or calf’s refusal to consume colostrum) in 2017 and 2018, a new technological housing element was introduced in the experimental groups of animals – transfer of the problematic cow–calf pair to a separate correction section, for common housing to stimulate cow’s maternal instincts or the calf’s eating behavior. According to the data of the first part of our experiment, it was found that the number of problem calves received from cows of the second calving in first group was 2 calves, in second and third group – 1 calf each, respectively. The live weight of problem calves at birth between the three groups was not significant. According to this indicator, calves from the first group had lower live weight by 1.5 kg compared to animals from the second group and by 1 kg compared to animals from the third group. The problem calves, which were transferred together with the cows to separate correction sections, reached the highest live weight when weaned, compared with animals kept under traditional farming technology, the preference was 63.3 kg and 64.8 kg, respectively. In general, in the experimental group, which included the problem calves, the calves’ live weight at weaning showed a significant difference between animals of first and third groups which amounted to 6.2 kg (P > 0.95). According to data from the second part of the experiment, which was carried out on cows of third calving and older cows with offsprings, three problem calves were identified in each group. With a slight difference in the live weight of problem calves at birth, the advantage in this indicator during weaning was in animals of the second and third groups, which were transferred to separate correction sections, which amounted to 62.0 kg and 63.5 kg. Overall, a significant difference of 3.1 kg (P > 0.95) was revealed in weight during the weaning between first and third groups of calves. It was found that at transference of problem “cow-calf” pair into a separate correction section the survival rate of problem calves increased from 33–50 % to 67–100 %. Thus, by transference of problem cow–calf pairs into separate correction sections during the colostral period with year-round free-range housing, it is possible to increase the survival rate of problem calves and ensure their full-value growth.

This article describes the beneficial economic characteristics-productivity, exterior characteristics and growth and development of offspring of fleshy-woolly sheep of Uzbekistan in different breeding periods. In terms of wool yield, fleshy-woolly ewes outperformed native breed ewes. In this case, the amount of wool at shearing is 1.26 kg (49.6%), the weight of wool after washing is 0.97 kg (67.8%), and the length of wool is 2.13 cm (19.2%) higher. Lambs obtained from ewes in the experimental groups were determined at birth, 30 days, and 3 months of age. Ewes inseminated early from September 1 to September 20 had higher live weight, body size and wool productivity than those inseminated later, from October 20 to November 10. At the same time, it made it possible to introduce artificial insemination of fleshy-woolly ewes with frozen seeds of rams belonging to the global semi-soft woolly gene pool in the meat-wool direction. The live weight of lambs obtained from them was higher by at birth - 0.4 kg (9.3%), at 10 days - 0.5 kg (6.8%) and at 3 months - 0.4 kg (1.3%) compared to the live weight of lambs obtained from natural insemination of fleshy-woolly ewes with rams.

The milk yield of Bushuev cattle bred in the extremely hot climate of Syrdarya region was 2742 kg in the first lactation, 3412 kg in the second lactation, and 3597 kg in the third lactation. According to the herd with high milk productivity in 4-6 months, in the III-lactation, 700 kg more milk was milked from dairy cattle than in the I and II-lactation. It was observed that the coefficient of milk production of cattle increases with the increase of lactation periods. The difference between them was 100-200 kg. The results of the analysis showed that the highest live weight was observed in the III-lactation group of cattle and was 468 kg. According to the results of the inspection carried out on the farm, the fat content of the milk of the cattle in the herd was 3.9-4.1%. The average fat content of milk was 113.4 -164.7 kg. Feed consumption of 1 liter of milk obtained from Bushuev dairy cattle was equal to 1.15 feed units. The average amount of milk milked from one head of cattle in the farm was 3572 kg. The unit of feed consumed during lactation was 4107 kg.

The article presents and summarizes the results of many years of research on the influence of the quality and the level of protein in diets on the growth rate of bull-calves. The studies found that improving the quality of protein in the diets of fattening bull-calves of dairy breeds at different growth periods due to a decrease in protein disintegration in the rumen by 2.5-6.9% contributed to an increase in the average daily gain in live weight of young animals by 2.5-16.4%. An increase in the protein level in the diets of intensively fed calves of Holstein and Aberdeen Angus breeds aged from 3 to 12 months by 1.5 times was due to increased feeding of concentrates significantly increased the average daily gain in live weight of young animals by 47 and 30%, respectively.

It is proved that the use of zeolite in pig breeding as mineral additives in comparison with the use of polysols contributes to an increase in the control slaughter of pigs: slaughter yield, carcass slaughter weight, yield of pure meat, reduce fat in the carcass. The inclusion of zeolite in the diet of pregnant sows stimulates growth and fetal development. Pigs grow faster after birth and reach maturity more quickly.

Copyright of Journal of Tropical Animal & Veterinary Sciences / Jurnal Ilmu Peternakan dan Veteriner Tropis is the property of Fakultas Peternakan Universitas Papua and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study aimed to analyze the live weight (LW) and some body measurements to estimate the LW of lambs in five different meat-type sheep breeds reared in the same flock under intensive conditions. A total of 202 head of lambs, including both genders of Kivircik (K), Bandirma (B), Karacabey Merino (KM), Hampshire Down x Merino crossbreed (HM), and Ramlic (R), were conducted in this study. Birth weights ranged between 3.94-5.07 kg in those breeds and were affected significantly by breed and birth types (P<0.001). The effect of sex was clearly seen with the weaning period; males lambs were 2.61 kg heavier than female lambs (P<0.001). The importance of breed differences on chest circumference (CC) increased as the lambs grew older. On the other hand, sex had a significant effect on all body measurements at the pre- and post-weaning period (P<0.01 and P<0.001); however, did not on body length (BL) at the pre-weaning period (P>0.05). In contrast, the importance of birth type on BL and CC decreased as the lambs grew older (P>0.05). The results of regressing LW and body measurements show that LW was very highly (P<0.001) correlated with body measurements (r=0.682-0.892). The highest correlations were observed between LW and CC (r=0.802-0.892) in B, KM, and R lambs. These results suggest that using body measurements as a correction factor has a great benefit in those breeds, such as withers height and CC are used to estimate LW in KM and R lambs, effectively. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Buffalo is an emerging species after cattle though they have some phenotypic difference. To assess differentiation between species based on body measurements a factorial experiment (2 species × 3 ages) of CRD conducted in Bangladesh. Live weight of buffalo (464.2 kg) differed (P < 0.001) with cattle (388.5 kg) and it increased (P < 0.001) with the increase of age. A significant difference (P < 0.01) was observed in the case of body condition score (BCS). The skin of buffalo was found thicker (P < 0.001) than cattle. Nine of the body measurements of buffalo (heart girth (HG), barrel (Ba), horn length (HL), horn circumference (HC), thigh circumference (ThC), hind shank circumference (HsC), fore shank circumference (FsC), hook to hook distance (HHD), and pin to pin distance (PPD) were higher (P < 0.001) than cattle. Wither height (WH), muzzle (Mz), tail circumference (TC), and hook to pin distance (HPD) differed (P < 0.01) between the species. Hip height (HH) differed significantly (P < 0.05). All the body parameters and skin thickness showed age effects. Live weights of the two species had a strong correlation with HG and Ba (0.79 and 0.74, respectively). HG showed strong correlation with Ba, HC, HsC and HHD (0.84, 0.72, 0.73 and 0.78, respectively). The correlation coefficient between WH and HH were 0.84, and HsC and FsC was 0.78. HL had strong correlation with HC, FsC and HHD (0.88, 0.71 and 0.79, respectively). So, various phenotypic traits were responsible for the change of other traits positively. [ABSTRACT FROM AUTHOR]

Subject of the study were 330 sheep of the Karnobat Fine-Fleece Breed, born in the period 2013−2018, ownership of the Institute of Agriculture - Karnobat. The aim of the current study was to establish the influence of inbreeding on the productivity in Karnobat Fine-Fleece sheep breed. The main productive traits of 186 outbred and 144 inbred animals were controlled: live weight at weaning, at 1.5 and at 2.5 years; wool yield; staple length; clean wool yield and clean fibre at 1.5 and at 2.5 years. The inbreeding degree was calculated by Wright's formula. The data were processed by the methods of variation statistics. It was found that the inbreeding degree at a level above 6.9% had a negative effect on live weight, wool yield, staple length and the amount of clean fibre for the two studied ages.The clean wool yield at 1.5 years did not depend on the level of inbreeding, but at 2.5 years the outbred animals showed a 14% higher clean wool yield than sheep with inbreeding over 12%. Inbreeding should be applied carefully in purebred breeding without raising the level to a degree that adversely affects the main productive traits of the population. Subject of the study were 330 sheep of the Karnobat Fine-Fleece Breed, born in the period 2013−2018, ownership of the Institute of Agriculture - Karnobat. The aim of the current study was to establish the influence of inbreeding on the productivity in Karnobat Fine-Fleece sheep breed. The main productive traits of 186 outbred and 144 inbred animals were controlled: live weight at weaning, at 1.5 and at 2.5 years; wool yield; staple length; clean wool yield and clean fibre at 1.5 and at 2.5 years. The inbreeding degree was calculated by Wright's formula. The data were processed by the methods of variation statistics. It was found that the inbreeding degree at a level above 6.9% had a negative effect on live weight, wool yield, staple length and the amount of clean fibre for the two studied ages.The clean wool yield at 1.5 years did not depend on the level of inbreeding, but at 2.5 years the outbred animals showed a 14% higher clean wool yield than sheep with inbreeding over 12%. Inbreeding should be applied carefully in purebred breeding without raising the level to a degree that adversely affects the main productive traits of the population. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the effect of the type of birth on the weight development of Ile de France lambs. The study was carried out with 472 Ile de France lambs (230 female and 242 male) with different birth type (single, twins, triplets and more) from the herd of Institute of Animal Science − Kostinbrod for the period 2016−2020. The live weight at birth, at 10 days, 30 days and 70 days were measured. The average daily weight gain between 10 and 30th days and 30th and 70th day was determined. The data were statistically evaluated. The effect of the type of birth on the examined traits was determined through one way ANOVA using Data Analysis statistical package of Excel 2016, Microsoft. Significant effect of the birth type on the live weight was observed in the female (P<0.001) and male lambs (P<0.01, P<0.001) on all the studied ages (at birth, at 10, 30 and 70 days of age). The effect of type of birth on the average daily gain between 10 and 30 th day and in the female animals (P<0.001) and a lack of such in the male lambs on the weight gain between 10-30th days and between 30-70 days in both male and female lambs. [ABSTRACT FROM AUTHOR]

The article presents the results of studies of milk productivity of Holstein cows in the dynamics of lactation, correlations between the level of milk yield, fat content, amount of milk fat, and live weight. The research was carried out in the herd of the breeding farm of Society of limited liability "Doksancom", on Holstein cows in the dynamics of lactation, as well as first-calf heifers of various origins. For each subsequent lactation, the milk yield of cows in the herd of Society of limited liability "Doksancom" increases. It was established that milk productivity for the second lactation was by 1468 kg of milk, for the third - 1215 kg of milk, for the fourth-sixth lactation - 1199 kg of milk more than for the first lactation, the difference is significant at P<0.001, P<0.001 and P<0.01 respectively. Comparative analysis of the milk yield of first-calf heifers raised in various farms showed that first-calf cows raised in the herd of Society of limited liability "Doksancom" had the highest productivity - 9518 kg of milk, which is by 925 kg more than first-calf cows purchased from the breeding farm of Joint-Stock Company "Aydyn", the difference is significant (P<0.05) and per 1200 kg - first-calf cows imported from Holland (P <0.01). The relationship between milk yield and the percentage of fat in milk of cows was in a negative correlation from weak -0.154 (IV-VI lactation) to moderate -0.409 - -0.449, II and III lactation, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Harran University Journal of the Faculty of Veterinary Medicine / Harran Üniversitesi Veteriner Fakültesi Dergisi is the property of Harran University, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of the present study was to determine the effect of the marketing year on the fertility of sheep and birth weight of lambs of Staroplaninski Tsigai and Karakachanska breeds. It was conducted with 310 ewes of Staroplaninski Tsigai and 442 Karakachanska in 2019, 2020 and 2021, and their lambs of which 316 Tsigai and 447 Karakachanska. The animals were raised in the Experimental Base of RIMSA − Troyan and fed according to the norms with free access to water. Biological fertility was established as the ratio of the number of live-born, stillborn and aborted lambs compared to the number of ewes. The live weight of lambs at birth was controlled by weighing (up to 24 hours after lambing) to the nearest 0.1 kg. The information was processed by the methods of variation statistics, through the ANOVA model of one-way analysis of variance and through Student's t-test, with the statistical package Data Analysis, Excel 2016, Microsoft. A reliable effect of the marketing year on the fertility of Tsigai (F=5.002***) and lack of one in the Karakachanska was established. There is a proven high effect (P<0.001) of the year on live birth weight of lambs in both studied breeds. [ABSTRACT FROM AUTHOR]

The aim of the present study was to establish live weight, Body condition score (BCS), body dimensions and phenotypic correlations between them in young female breeding animals of Bulgarian dairy synthetic population (BDSP). The object of research were 137 ewe lambs of the flock, bred at the Agricultural Institute in Stara Zagora for a period of 3 years. Live weight of animals and body dimensions were performed at 6, 9 and 18 months of age and Body condition score was assessed. In addition, the phenotypic dependences between indicators were calculated. The data were processed with Statistica software product. Based on the obtained results, it could be summarized that the live weight and bone system of the animals increased more intensively in the period from 6 to 9 months of age, which was accompanied by an increase in BCS. During the next period (after 9 months of age) there was a certain slowdown in the growth rate and a decrease in BCS, but an increase in live weight. The values of the two indicators at the age of 18 months however showed that the physiological condition of the animals was suitable for their inclusion in the breeding process. The highest values of phenotypic correlations were found between live weight, BCS and body dimensions at 6 months of age. At the next two ages (9 and 18 months), these dependencies declined. Live weight, body length, chest depth and croup width maintained a high level of correlation with the body volume. The highest phenotypic correlations between BCS and other indicators were established in animals at 6 months and the lowest ones at 9 months of age [ABSTRACT FROM AUTHOR]

Objective: To estimate the lactation curve and milk production of Pelibuey ewes and their relationship with preweaning growth rate of the lambs. Design/methodology/approach: Forty-five Pelibuey ewes were milked during 70 days in Montecillo, Mexico, in 2018, to estimate the daily and total milk production. The lactation curve was fitted with the incomplete gamma function. In addition, the effects of type of birth and ewe weight at milking on milk production were analyzed, and correlations were calculated between ewe milk production and growth rate of the lambs, per week and for the entire lactation. Results: A "typical" lactation curve was found, average ewe milk production for the whole lactation, weighted for the number of lambs suckling, was 131±8 L, with 444±24 g d-1. Ewe weight at milking had an effect (p<0.01) on milk production. Positive correlations were found (p<0.05) between ewe milk production and preweaning growth rate of the lambs. Study Limitations/Implications: There is a strong dependency of the lambs on the milk production of the Pelibuey ewe, a factor of great relevance so that lambs can gain body weight and survive during lactation. Findings/Conclusions: Pelibuey ewes produce less milk than dairy ewes. Therefore, lambs should be weaned at a maximum of 10 weeks of lactation. [ABSTRACT FROM AUTHOR]

We studied the efficiency of the ProStor synbiotic for increasing the growth rate and viability of young chickens and enhancing their natural resistance, livability, and productivity during the adult stage. The homogeneity of young chickens that were reared to replace the adult ones and received the synbiotic with fodder (0.5 kg per 1 t of fodder) during 140 days of rearing was 90.3%, thereby exceeding the value of the same parameter in the control group by 3.2%. The livability of young chickens during the rearing period was 2.67% higher in the experimental group than in the control group, which caused a reduction in the fodder costs and an increase in the yield of young chickens by the time of transfer to adult livestock at the age of 20 weeks. The administration of the ProStor synbiotic in the same concentration to broiler parent stocks with 10-day courses in different biological cycles of egg laying increased the egg production per laying hen by 5.3%, hatching egg yield by 3.6%, and hatched chick yield by 2.1% in the experimental group compared with the control group. Based on the results of the study, it was concluded that the ProStor synbiotic can serve as an adequate replacement for in-feed antibiotics in poultry diets.

The technical conversion factor (TCF) is a survey-based estimate of the percentage of carcass weight obtained per unit of live weight. Practitioners and researchers have used it to predict the corresponding price ratio (PR). We use both in-sample regressions and out-of-sample forecasting analysis to test the validity of this approach in case of predicting the price effects of processing livestock in Europe. By regressing the PR on the inverse value of the corresponding TCF for a large panel of European countries and animal types, we find a significant positive relation between these variables, which also has economic value in terms of improving out-of-sample forecasting precision. This result is shown to be robust to animal type, year, and country fixed effects. The TCF therefore has predictive value about the corresponding PR.

The research was carried out on the basis of the breeding farm «Ababkovskoe» Nizhny Novgorod region. In the period of 2006-2015 518 heads of animals dropped out the herd. They formed the electronic database for studying the influence of paratypical factors on indicators of productive longevity of red Gorbatov cows. The analysis involving the method of grouping animals had been carried out. In the course of the study it was established that the increase in milk yield during the first lactation lead to an extension of productive life (r = 0.17). The best indicators (5.70 lactations) were observed in first-calf heifers having the yield of 5001-6000 kg of milk. Lifetime production and milk yield during the first lactation had a weak positive relation (r = 0.30). Cows with productivity of 5001-6000 kg of milk during the best lactation had the longest productive use (5.58 lactations). In general, there was an average positive relation between these indicators (r = 0.48). Power of influence of the highest lactation milk yield on the lifetime milk yield was 22.47% (F > Fst). In conditions of the red Gorbatov breed gene pool preservation the recommended milk yield for the first-calf heifers should be 4000-5000 kg of milk. The growth of milk production in subsequent lactations resulted in extension of the economic use of cows and increase in other productive indicators. Half of the animals in the herd (50.7%) had a coefficient of milk yield 751-1000 kg of milk per every 100 kg of live weight In this group there was the highest level of live weight (455 kg, р Fst). The most optimal live weight for red Gorbatov cows during the first calving is not less than 460 kg. Low weight leads to a rapid drop out of animals from the herd

Sex differences in growth, blood indicators, carcass values and meat quality in nutrias were evaluated. In the fattening experiment, 136 nutrias of both sexes (1 : 1 ratio) were fattened until 8 months of age. At the end of the experiment, 18 males and 18 females with average weights were selected for the determination of biochemical indicators, carcass value and meat quality. The growth of males was significantly higher than in females; the differences were 12% at three months of age and increased to 24% at eight months of age. The effect of sex on the biochemical indicators of blood was observed in total protein (P ≤ 0.029), albumin (P ≤ 0.012), urea (P ≤ 0.019) and cholesterol (P ≤ 0.026), with higher values in males. In the case of haematology examination, the significantly higher values in males were in the number of erythrocytes (5.10 × 1012/l) and in the haematocrit value (55.8%). Dressing out percentage was higher in males (P ≤ 0.039), and other parameters of carcass value were not affected by sex. For the meat physical properties, only lightness (P ≤ 0.019) was higher in males. In the case of the chemical composition of meat, ether extract (P ≤ 0.033) and energetic value (P ≤ 0.024) were lower in females. The results of this study show high differences in the growth of male and female nutrias, whereas carcass composition, physical meat quality and meat chemical composition are less affected by nutria sex.

The article gives scientific substantiation of using silicon-containing new feed additive “Energosil” for replacement gilts. The studies were conducted in pig-breeding complex of the Center for Practical Training of Agricultural Specialists in Mordovia Republic. There were three experimental groups of replacement gilts (10 animals each). The effect of various dosages of Energosil (5.0, 7.5, and 10 mg per kg of body weight) on digestibility, nutrient utilization, and animal growth energy was studied. The most optimal dosage of a new feed additive in their rations was revealed, which constituted 5 mg / kg of the animal live weight. It was established that the animals from the first experimental group, who received silicon-containing feed additives of this amount digested the nutrients of the diet better than their counterparts from the other groups. Compared to the control group, the digestibility of dry matter increased by 3.62% (p0.05).Replacement gilts of the first experimental group, who were given Energosil in the amount of 5 mg / kg body weight in addition to the basic ration, retained nitrogen in their bodies by 17.1%, calcium by 55.9% and phosphorus by 69.7% more than their counterparts from the control group. It contributed to an increase in body weight of gilts from the first group compared to control counterparts by 10.8%. Increased dosages of Energosil (7.5 and 10 mg / kg body weight) also had a better effect on the growth energy of gilts compared with the control group. The feed additive in the amount of 7.5 mg kg of animal live weight contributed to an increase in animal weight compared with control counterparts by 6.21 kg or 4.8% (p 0.05) compared with the control counterparts.

Pre-weaning is an important stage in sheep production systems focussed on meat production. In this stage, maternal ability has a key role in lamb development and productivity. The objective of this study was to evaluate the effect of breed and litter size at birth on the ewe and lamb pre-weaning performance under tropical conditions. The lambs and their dams were managed in a feedlot system during 56 days in individual pens. Milk production was estimated weekly by the weight-suck-weight method. Daily milk production (DMY), total milk production (TMY), body weight change during the lactation (BWC), litter weaning weight (LWW) and ewe weaning efficiency (EE) were estimated as ewe pre-weaning performance; and, birth weight, weaning weight at 56 days and average daily gain were estimated as lamb pre-weaning performance. Katahdin ewes produced more TMY than Pelibuey ewes (p

In this study, nine non linear growth curve models were used to determine the goodness of fit by the body weight measurements of the total number of 178 partridges(Alectoris chukar), 93 females, and 85 males, respectively. The R2(coefficients of determination) values for the total partridges, females and males in Brody, Gompertz, Logistic, von Bertalanffy, asymptote regression,exponential, Monomolecular, Richards and Weibull-type were 0.985, 0.980 and 0.984, 0.997, 0.998 and 0.998, 0.996, 0.999 and 0.999, 0.995, 0.995 and 0.996, 0.985, 0.980 and 0.984, 0.891, 0.871 and 0.892, 0.985, 0.980 and 0.984, 0.997, 0.999 and 0.999, 0.997, 0.999 and 0.999, respectively. The R2 values for Gompertz, Logistic, von Bertalanffy, Richards and Weibull-type were >0.99, while the exponential (