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Сельскохозяйственная биология, 2010, № 6, с. 35-40.

УДК 636.2.033:636.082.2:636.082.1

USE OF INTRABREED RESERVES IN SELECTION OF BEEF CATTLE

L.K. Ernst¹, L.Z. Mazurovskii², N.P. Gerasimov²

For the purpose of perfection of the methods and selection techniques for an increasing of genetic potential of the Hereford cattle population on Southern Urals in scientific-practical experiments the authors studied the relative influence of environmental factors and father’s genotype on main selecting determinants. The complex estimation of pedigree and productive qualities of young beef cattle is an important way for creating of highly productive herds with desirable type. In this case it is expedient to use all available intra-breed reserves by means of biotechnology modern methods.

Key words: beef cattle, selection, suitability, breeding value, heredity, activity of blood enzymes, resistance degree.

 

Building a national pool of highly productive beef cattle is being currently performed in Russia, which task includes the import of pedigree animals from countries with developed livestock breeding. Using in breeding work of foreign genetic material gives the chance to improve quality of domestic beef cattle (1). Despite the progress in breeding work on many breeds and types of beef cattle, there are some open problems concerning the use of best imported gene pool in improving the Hereford breed designed with the use of advanced biotechnology methods (2). In particular, these are poorly studied issues of productivity and pedigree qualities of Hereford cattle, as well as adaptability to environmental factors and genetic potential of imported animals.

The purpose of this study was to develop best practices and techniques of breeding beef cattle aimed at increasing the genetic potential of the Hereford breed population in Southern Ural.

Technique. A series of experiments was performed upon a young livestock of Hereford cattle. Relative influences of environmental factors and fathers’ genotypes on main pedigree indices were determined using two-factor analysis of variance (3). Two sequential experiments were set: young bulls and heifers - descendants of bulls-sires with different body types (3 groups, n = 20) were estimated by their own productivity under the conditions of summer and winter keeping in the pedigree farm “Amur” (Chelyabinsk province) in 2005-2007. Body types were determined as described (4, 5). Adaptability, productivity and pedigree  quality of Hereford cattle from different eco-genetic groups were studied in 2008-2010 in the farm “AF Kalininskaya” (Chelyabinsk province) upon three groups of bulls (n = 20): the Ural type of Hereford (I group), the cross Ural type of Hereford x Canadian Hereford (II group) and the Canadian type of Hereford (III group) obtained by transplantation of embryos - descendants of best ancestors. Factors of natural resistance (indicators of nonspecific humoral immunity) and enzyme activity of blood serum (aspartate aminotransferase - AST and alanine aminotransferase - ALT) were determined by common methods (6-8).

The data were statistically treated using the programs Microsoft Excel 2003 and Statistica 6.0.

Results. The effect of animals’ eco-genetic origin on live weight of calves was observed even in early ages (Table 1). Thus, live weight of newborn calves obtained by embryo transplantation exceeded their analogues by 2,4-2,7 kg (9,02-10,27 %; P> 0,999). As calves were getting older, the priority of Canadian cattle was raising too: by the 3rd month, it reached 5,5-11,0 kg live weight (4,58-9,59 %; P <0,95, P> 0,99), and 6,7-13,1 kg (2,76-5,39%; P <0,95, P> 0 , 95) - by the 8th month. By the age of one year, a maximum live weight was established in Canadian Hereford cattle who exceeded two other groups at 36,2-48,4 kg (9,75-13,49%; P> 0,999). By the end of the control growing period (15 months), the differences in average live weight increased up to 40,0-58,8 kg in favor of the imported  animals (8,81-13,51%; P> 0,999). The minimum live weight in all age periods was observed in the Ural type of Hereford. In this case, outbreeding crosses of different eco-genetic groups contributed to obtaining the young livestock with a new hereditary complex - an intermediate expression of the live weight parameter.

It is obvious, that these distinctions in live weight of young livestock from different eco-genetic groups were the result of unequal growth rates. From birth to weaning, the calves of Canadian origin obtained by embryo transplantation (III group) exceeded two other groups by live weight (Table 1) thereby showing a maximum growth rate - 881,3 ± 12,72 g/day which was at 16,5-44,1 g/day higher than in analogues (1,91-5,27%; P <0,95, P> 0,95). A similar trend in body weight gain was observed in post-weaning period. At the age of 8-12 months, average daily increase in body weight was maximum in group III (241,4-290,2 g; 21,86-27,49%; P> 0,999). In the next age period (12-15 months), adverse weather conditions negatively affected productivity in all groups. Average daily weight gain reduced by 840,1-953,3 g, which affected the indices of growth intensity for the period of testing own productivity of young livestock (8-15 months). However, climatic factors didn’t affect ranking bulls by their average daily weight gain: the bulls of Canadian origin were superior by this parameter among all the calves aged 8-15 months (the advantage of 156,1-214,6 g; 15,27-22,27%; P> 0,999 ).

In general for the whole period of control growth (0-15 months), the lowest growth rate was observed in the Ural Hereford cattle – 896,3 g, which was less than in groups II and III at, respectively, 42,0 and 123,7 g (or 4.48 and 12,13%). At the same time, group II (the cross Ural Hereford x Canadian Hereford) exhibited an intermediate growth rate. Consequently, heterogeneous crosses provided the improving effect on average daily increase in live weight.

The influence (%) from the genotype of bulls-sires with different body types on productivity indices in their progeny – young bulls (a) and heifers (b): 1 — live weight at the age of 8 months, 2 – live weight at the age of 15 months, 3 – average daily gain in live weight during the period 8-15 months, 4 – live estimates of beef quality, 5 –  manifestation of body type, 6 – a complex index considering manifestation of body type (the pedigree farm “Amurskoe”, Chelyabinsk province, 2005-2007). Denotations: abscissa – Productivity Indices, ordinate – Share of Influence, %

The young livestock was assessed by own productivity under different farming techniques depending on season of the year (winter and summer), which allowed to reveal a relative influence of father’s genotype (Figure) and environmental factors on manifestation of pedigree traits. The obtained data indicate that the impact of paratypic factors at weaning (8 months) causes strongest modifying effect on growth and development of both bulls and heifers. At the same time, the share of influence of bulls-fathers amounted to 2,73-3,84%. By the end of control growth period (15 months), genotype effects increased and reached 17,96-28,56%.  Average daily weight gain and expression of body type  were also highly determined by hereditary factors – respectively, 21,14-26,41 and 18,86-23,37%, which proves expedience of selection by growth rate and body type. Typing progeny by exterior was included  into the total complex index of estimate, which resulted in increase of fathers’ genotype contribution into pedigree qualities of progeny (up to 18,01-25,41% of all determinative factors) and more reliable assessment of breeding value of sires (on 6,24-8,55%).

Estimation of own productivity of young bulls from different eco-genetic groups revealed the priority of Canadian cattle by all indices (Table 2). The greatest advantage of Canadian sires’ genotype was observed in indices of body weight, average daily weight gain and manifestation of body type – respectively, 8,6-12,7; 14,8-20,3 and 15,4-29,3%. Thus, estimates of body type expression in this group was 0,66-1,26 points higher than in their analogues (P> 0,999). In general, bulls from all groups had a balanced and proportionate exterior typical for beef cattle (broad, rounded body with a well-developed muscles).

The development of the complex index considering exterior types of livestock provided a more accurate assessment of pedigree value of young bulls. Thus, the complex index of estimation the young bulls not considering their body type equaled to 8,0-11,4 in different eco-genetic groups, with this estimate - 9,9-15,9%. It is notable that crosses between animals from different eco-genetic groups improved the expression of pedigree traits in progeny.

The revealed distinctions in enzyme activity of blood serum were determined by unequal intensity of metabolic processes in bulls from different eco-genetic groups (Table 3). It was established that Canadian Hereford cattle surpassed their analogues from other groups by transamination enzyme activity, which is the biochemical evidence of higher body weight gain in bulls obtained by embryo transplantation. Thus, group III showed higher enzyme activity in summer period: AST - by 0,006-0,009 umol/(h x l) (0,50-0,80%), ALT - by 0,01-0,02 mmol/(h x l) ( 1,12-2,27%). In winter, the activity of AST was similar in groups II and III, which exceeded group I by 0,01 umol/(h x l) (0,85%); for ALT, group III surpassed the analogues by 0,03 mmol/(h x l) (3,49%) (the advantage was statistically insignificant).

Indices of natural resistance to environmental factors were found to be equal in all experimental animals (see Table 3).

The highest bactericidal activity of blood serum was detected in calves aged 12 months in winter (68,54-70,30%), which index was maximum in group I exceeding the peers by 1,74-1,76%. In summer, bactericidal activity was lowest and its maximum value was detected in animals the cross Ural Hereford ? Canadian Hereford (group II) (0,46-0,56%).

The feature of b-lysine is raising its activity under different environmental influences (9). Therefore, the level of  b-lysine activity in blood serum is highly dependant on paratypic factors. Like the previous parameter, the activity of b-lysine was highest in 12-months-old animals from all groups in winter (15,46-15,88%), and somewhat lower (13.12 -14.68%) – in summer. In all age periods, the Ural type of Hereford (I group) demonstrated the inferior activity of b-lysine compared with other groups of calves: 0,91-1,56% lower in summer and 0,26 - 0,42%. - in winter. This pattern suggests genetically determined adaptation of the Ural Hereford population to economic and climatic conditions of farming. At the same time, the Canadian type of Hereford showed highest levels of of  b-lysine activity in both winter and summer in response to adverse environmental factors.

The content of lysozyme in the blood of bulls from different eco-genetic groups varied within physiological norm without any significant intergroup differences. A somewhat higher lysozyme content was detected in winter (2,96-3,08 ug/ml).

In general, all groups of animals tended to age-dependant increase in activity of non-specific immunity factors; though, no reliable intergroup differences in natural resistance were established. Young animals from all three groups showed high adaptability to environmental and economic conditions, and nonspecific resistance of the Canadian Hereford cattle (group III) didn’t yield to that of the Ural Hereford (I group).

Thus, the assessment of young bulls from different eco-genetic groups by their own productivity revealed significant advantage of the Canadian Hereford, whose adaptability was comparable to that of the Ural type of Hereford. Outbreeding cross-selection of animals provided the improving effects on manifestation of pedigree traits and allowed to obtain the progeny with new combination of determinants. The complex index of estimation considering animal body type provides reliable assessment of the genotype of young animals. The metabolic profile of blood serum can be used as an objective criterion for evaluation the beef productivity and adaptivity in calves the Hereford breed.

The authors thank the staff of the complex analytical laboratory of the All-Russia Research and Development Institute of Meat Cattle Breeding for their assistance in determination of natural resistance and enzyme activity.

REFERENCES

1. Dubovskova M.P., Kayumov F.D. and Dzhulamanov K.M., The Use of Bulls-Sires of Modern Selection for Improvement of Productivity of the Kazakh Whiteheaded Breed, Vest. myasnogo skotovodstva, Orenburg, 2008, vol. 61, issue I, pp. 80-88.
2. Bel’kov G.I., Dzhulamanov K.M. and Gerasimov N.P., The Use of Biological Potential of Hereford Cattle for Production of High-Quality Beef, Vestn. RASKhN, 2010, no. 1, 79-81.
3. Plokhinskii N.A., Biometriya (Biometry), Moscow, 1970.
4. Belousov A.M. and Dubovskova M.P., Fundamentals of the New Method for Estimation of Bulls-Sires upon Productivity of Their Progeny, Vestn. myasnogo skotovodstva, Orenburg, 2009, vol. 62, issue I, pp. 39-44.
5. Normy otsenki plemennykh kachestv krupnogo rogatogo skota myasnogo napravleniya produktivnosti (Norms for Evaluation of Pedigree Qualities in Beef Cattle), Moscow, 2007.
6. Bukhanov O.B. and Sozykin V.L., Photonephelometric Method for Determination of Bactericidal Activity of the Blood, in Factory estestvennogo immuniteta (Factors of Natural Immunity: Compilation of Sci. Works), Orenburg, 1979, pp. 43-45.
7. Bashmakov G.A., Factors of Natural Resistance and Methods of Their Study, Voenno-med. zhurn., 1982, no. 6, pp. 38-40.
8. Kolb V.G. and Kamyshnikov V.S., Spravochnik po klinicheskoi khimii (The Guide to Clinical Chemistry), Minsk, , 1982.
9. Sarukhanov V.Ya., Isamov N.N., Tsarin P.G., Mirzoev Je.B. and Kobyalko V.O., Method for Determination of Beta-Lythic Activity of Blood in Agricultural Animals, S.-kh. biol., 2007, no. 7, pp.  123-125.

1Russian Academy of Agricultural Sciences, Moscow 117218, Russia; 2All-Russia Research and Development Institute of Livestock Breeding, RAAS, Orenburg 460000, e-mail: vniims.or@mail.ru

Received July 13, 2010

All-Russian Institute for Selection and Seed-Breeding of Vegetables All-Russian Selection and Technological Institute of Horticulture and Breeding Nursery Institute of Agricultural Biotechnology Joint Stock Company "GosNIISyntezBelok"