Some production traits of Hungarian Grey Cattle

Átírás

1 SUMMARY OF PhD THESIS University of Pannonnia Georgikon Faculty of Agriculturure PhD School for Animal Sciences Head of the Doctoral School and Supervisor Prof. Dr. Ferenc SZABÓ, DSC Some production traits of Hungarian Grey Cattle Written by Barnabás NAGY Keszthely, Hungary 2007

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3 1. PREMISES AND AIMS OF THE RESEARCH Hungarian Grey cattle has been kept and bred in Hungary for centuries, but in spite of it we have only a rather few data concerning the characteristics of this breed. Thus I set myself the aim to research and evaluate the factors influencing some of the characteristics (and their changes), which measure the value of Hungarian Grey cattle. During my research I set myself the following aims: 1. Measuring of birth weight and body measurements, and the counting of body proportion indexes of calbes; 2. Examination of the effect of certain genetic and environmental factors on the weaning performance, and working out additive and multiplicative factors in order to correct these effects; 3. Defining the heritability and other genetic parameters, breeding value of the animals, genetic value of populations, weaning weight, preweaning daily gain and 205-day weight using animal models; 4. Estimation of breeding value, as well as the comparison of the two models (sire and animal models) used for breeding value estimation; 5. Examination of the seasonality of calving, and its effects on the calving invetval; 6. Measurement of live weight and taking body measurements of Hungarian Grey cows and bulls, counting the body proportion indexes and phenotypical correlations; 7. Taking of the rate of growth of the breed; counting and illustrating K speed constants; 8. Measurement and evaluation of the external and internal pelvis measurements of heifers and cows. During my examinations I took my measurements, data collections and evaluations in the cattle herds of Hortobágy and other farms. 3

4 2. MATERIAL AND METHOD 2.1. EXAMINATION OF BIRTH WEIGHT AND BODY MEASUREMENTS In this part of the the research 48 newborn calves (26 male, 22 female) took part, which were born in the Hungarian Grey cow herd that was kept in the Hortobágy Gene Reserve Nonprofit Company s three winter accommodations (Darassa, Kecskés and Kungyörgy). The keeping and feeding of the herds during the examined period were the same in all the three winter accommodations. During summertime the cowherds were kept in the meadow, while winter accommodation consisted of a closed and draught-free byre and a yard connected to it. The feeding of the cows in the springtime and summertime meant the sward of the meadows, in the late autumn months and wintertime it was provided ad libitum by millet and pea haylage and hay. The animals did not get neither vitamin, nor forage alongside. We completed the taking of birth weight and of body measurements right after the birth when the newborn calves became dry by a spring-balance scale that was able to weight until 100 kg, and by measuring tape and measuring stick. Various body-size indexes out of the known body measurements data were counted EXAMINATION OF WEANING RESULTS In this part of the research there were nine Hungarian Grey cattle farms. The database contained the weaning performance of calves born between 1984 and 2004 (n= 5744, young bulls= 1481, heifer calves= 4263), being progenies of 182 breeding bulls and 2638 cows. Breeding value, the genetic and environmental variance of the characteristics, and heritability value were calculated by the sire model. The model contained fix effects and random genetic effects. The general form of the model that was applied for the weaning weight and for the preweaning daily gain: Y ijklmnop = + S i + F j + Y k + C m + I n + b(x ijklno - x ) + e ijkmnop 4

5 where Y ijklmn = the weaning weight and daily gain of weaned calf that is from the sire i, the farm j, the year k, the calving m, the sex n, and the age o ; = the average of the total observations; S i = the accidental factor of the sire; F j = the fix effect of the farm; Y k = the fix effect of the birth s year; C m = the fix effect of the calving s number; I m = the fix effect of the sex; b= regressive coefficient; e ijkmnop = residual variance. The model of the 205-day weight differs from the previous model, because the age of calves as a covariant was not built into this one, and consequently it envolved as the following: Y ijklmno = + S i + F j + Y k + E l +C m + I n + e ijklmno E l = the fix factor of the season of birth EXAMINATION OF VARIANCE COMPONENTS AND POPULATION GENETIC PARAMETERS OF GROWTH CHARACTERISTICS OF CALVES In this part of the research there were 7584 animals altogether. The examined calves were born between 1984 and 2004 (male= 1481, femole= 4263), being progenies of 182 breeding bulls and 2638 cows. There were in the pedigree 35 paternal grandsires, 104 maternal grandsires, 50 paternal grandmothers and 702 maternal grandmothers. Examined characters were weaning weight, (VS), preweaning daily gain (SGY), and 205-day weight. When calculating 205-day corrected weight, I could not use birth weights from the data base, because they were not measured. Therefore we used an average unified value of 25 kg for heifer calves and 30 kg for young bulls, because these birth weights are accepted by the Association for Hungarian Grey Cattle Breeders. For the estimation of variance components and covariance components, genetic parameters and breeding values, animal model was used. 5

6 We used the following animal model for the estimation of parameters and breeding values of the examined characteristics: y= Xb+Zu+Wm+Spe+e y = vector of observation (characteristic); b = vector of fix effect(s); u = vector of random effects (animal); m = vector of maternal genetic effect; pe = vector of maternal permanent environmental effect; e = residual variance; X = occurrence matrix of fix effects; Z = occurrence matrix of random effects; W = occurrence matrix of maternal genetic effect; S = occurrence matrix of maternal permanent environmental effect. The following parameters were estimated by the model: Additive direct genetic variance (σ 2 d), maternal genetic variance (σ 2 m), direct maternal genetic covariance (σ dm ), maternal permanent environmental effect (σ 2 pe), residual variance (σ 2 e), phenotypic variance (σ 2 p), direct heritability (h 2 d) = inheritance of genes responsible for the evolution of additive direct genetic effect (σ 2 d / σ 2 p), maternal heritability (h 2 m) = inheritance of genes responsible for the evolution of maternal genetic effect (σ 2 m / σ 2 p) direct maternal genetic correlation (r dm ), the proportion of the permanent environmental variance to the phenotypic variance (c 2 ), the proportion of the residual variance to the phenotypic variance (e 2 ) SEASONALITY OF CALVING AND EXAMINATION OF CALVING INTERVALS In this part I compared three reproduction practices. There were 7343 calvings in the evaluation, in the period between 1994 and Seasonal insemination with natual bull service. In the farm using this way of insemination multi-bull mating was in a group. According to the breeding programme, leap occurred in one season. The release of the bull occurred in March, while the separation occurred in July. In the given farm this method of leap has been used since the 1980ies. I analysed the Data of 6778 calvings in the period was examined. 2. Insemination all-year-around with natural bull services. In the farm using this way of insemination leaps occurred freely. Breeding bulls were among the cows during the whole year. In this farm they have been getting the cows pregnant again by natural leaps during the whole year since In this farm were analysed the monthly distribution of 254 calvings and the periods between them. 6

7 3. Continuous (all-year-around) artificial insemination. In the farm using this way of insemination getting the cows pregnant was solved by all-year-around artificial insemination. In this farm they have been using this reproduction practice since I evaluated the data of 311 calvings in this farm EXAMINATION OF LIVE WEIGHT AND BODY MEASUREMENTS OF GROWN BULLS AND COWS In the research data there were 23 breeding bulls (their average age was 5.7 years) kept in the winter accommodation in Kecskés, as well as 42 cows (their average age was 7.9 years) kept in the winter accommodation in Kungyörgy, both belonging to the Hortobágy Gene Reserve Nonprofit Company. We completed the taking of birth weight by a digital scale, and of body measurements in a chute corridor. The weights of the bulls were taken in bridge-scales, their body measurements were taken in captured animals by throat-clippers. I counted various body-size indexes out of the known body measurements data. The indexes show the relations of the body measurements that are connected to each other anatomically and partly physiologically as well EXAMINATION OF RATE OF GROWTH OF HEIFERS, COWS AND BULLS I took the measurements of 106 male and 102 female animals born between 1990 and For defining the intensity and the periods of growth, based on the overarching examinations of Fábián (1973) and Szcs (1987), I chose the nature-based logarithmic form from among the growth functions. For the definition of the K speed coefficient I evaluated the relationship of the data of weightings and body measurements. The formula used was the following: K= lnw 2 lnw 1 / t 2 t 1 K: speed of growth coefficient; W 1 : previous live weight and body measurements (kg, cm); W 2 : actual live weight and body measurements (kg, cm); t 1 : date of measuring the previous live weight and body measurements (day); t 2 : date of measuring the actual live weight and body measurements (day). 7

8 2.7. EXAMINATION OF EXTERNAL AND INTERNAL PELVIS MEAS- UREMENTS OF COWS AND HEIFERS The examination was made in the third herd of Hortobágy Gene Reserve Nonprofit Company and the Beef Cattle Farm of the Study and Experimental Factory Nonprofit Company of the Pannon University of Keszthely. I took the measurements and evaluated 15 heifers and 30 cows altogether. The internal diameters of the pelvis were measured by a veterinary. The measurements were taken always by the same person, in order to lessen the chance for error. We took the external pelvis measurements by measuring tape and the internal pelvis measurements by a tool for measuring birth canal (Vissac-pelvimeter), according to Holló and Horváth (1979). We counted the area of pelvis entrance based on the taken pelvis measurements with the following formula: T= a x b x T: the area of pelvis entrance (cm 2 ); a: the half of the vertical diameter (cm); b: the half of the horizontal diameter (cm); : Pythagoras-constant; its value is 3, SOFTWARES USED The database was prepared with Microsoft Excel (2000) software. The effects of environmental factors and the evaluation of the paternal model were analysed with Harvey s Least Square Maximum Likelihood Computer Programme (1990). Estimations necessary to calculate variance, covariance, genetic parameters and breeding value were made by DFREML software (Meyer, 1998), and MTDFREML software (Boldman et al., 1993). For one- and multifactorial variance analysis and counting rank correlation I used the SPSS 9.0 (1996) software. 8

9 3. RESULTS AND DISCUSSION 3.1. BIRTH WEIGHT AND BODY MEASUREMENTS OF CALVES In the given conditions of the national rigid breeding, the birth weight and the body measurements of the Hungarian Grey calves are not taken by the breeders; which means that we have a relatively few data. The Association for Hungarian Grey Cattle Breeders also works with estimated numbers (female 25 kg, male 30 kg) when evaluating birth weight. In my work I managed to take the birth weight of 48 newborn calves (26 young bulls and 22 heifers) which in average gave the following numbers: young bulls in average kg, heifers in average kg. I took several body measurements as well, out of which I calculated body measurement indexes in order to characterize the body proportions of the calves. Taking into account the height at withers and height at rump we can state that the overheight index was in average 110%. When calculating the phenotyp correlational index between the body measurements and live weight, the results showed an average or close (r= ) correlation. The birth weight of newborn calves can be calculated in the soundest way by the correlational coefficient (r= ) that comes from using the circumference of chest and the circumference of leg WEANING RESULTS The factors evaluated in my analysis, namely the farm, year of birth, age of mother and sex of calf resulted in significant differences in the weaning characteristics of Hungarian Grey calves. The season of birth did not influence significantly the weaning weight and the preweaning daily gain. During the examination of the environmental factors it became clear that the 205-day weaning weights of the calves which were born in different seasons do not differ significantly, and it is shown by the residual of the estimated averages (SE). Weaning weight, preweaning daily gain, and 205-day corrected weight gradually grew until the seventh calving. The effect of sex manifested itself in the better weaning performance of the young bulls. 9

10 Among the various examined environmental factors the weaning results of those heifers who were born from the 1 st, 12 th and 13 th calving are to be corrected in order to make the comparisons a bit more precise. We can observe that there is a significant weight difference between the weaning performance of the progenies of the breeding bulls of biggest and the smallest breeding value: weaning weight difference is 52 kg, preweaning daily gain difference is 213 g/day, and 205- day corrected weight difference is 46 kg. Therefore, when choosing and using a breeding bull, we should pay more attention to breeding value, considering such a large number of grey cattle. The heritability of the examined characteristics is between The usage of those bulls in big numbers that are transmitting a rather modest weaning weight should be judged differently in case of the breed. The main aim here is the genetic upkeeping and the raising of genetic variability of this breed, and this is a question of the type to be examined nowadays in many cases VARIANCE COMPONENTS AND POPULATION GENETICAL PA- RAMETERS OF GROWTH CHARACTERISTICS In Hungarian Grey cattle the growth characteristics of examined calves get inherited in a direct and average way (h 2 d= ). The maternal heritability of weaning weight, preweaning daily gain, and 205-day corrected weight of the calves (h 2 m= ) is weak, which means that maternal genetic effect and maternal environmental effect (c 2 = 10%) plays a smaller role in the formation of the phenotype of the calf than additive genetic effect. During the examination because of the average heritability values (h 2 d= ) for the additive direct genetic effect, the examination of progenies performance is expedient by all means for the sake of more effective selection. In the case of the examined characteristics the correlation between the direct and the maternal genetic effects is negative (r dm = between and -0.89), therefore both effects are to be taken into account together during selection. This means that during the selection of the sire we should take into account the estimated breeding value of its additive direct genetic effect and maternal genetic effect, since the correlation between the two effects is negative. Comparing the estimated breeding values by the paternal and the animal model we can conclude that although there may be difference in absolute values, which might result in a reversal of signs, the ranking of the sires does not change significantly, supported also by rank correlation values. The close rank correlation between the two models is r rang = %. 10

11 3.4. SEASONALITY OF CALVING, AND ITS EFFECTS ON CALVING IN- TERVAL Considering my examination results, we can observe seasonality in the reproduction of the Hungarian Grey cattle, the measure of which changes according to the way of insemination. In the case of seasonal leap 99% of calvings occurred in the first half of the year. Most calvings occurred in January (20.4%), February (18.3%) and March (25.7 %). Also in case of all-year-around use of bulls we can observe seasonality in the monthly distribution of calvings, since 93% of the calvings occurred in the first six months of the year. Most calvings occurred in February (17.3 %), March (27.2 %) and April (19.7 %). In the case of farms using continuous artificial insemination, the distribution of calving is more even during the whole year, even though 63% of the cows calved in the spring or early summer months. The way of insemination and the period of calving influences the time of the next pregnancy, as well as the time between two calvings. The average time between calvings of the cows was 412 days in case of farms using seasonal leap, 409 days in case of farms leaping during the whole year, and 470 days in case of farms using continuous artificial insemination. In the case of all three insemination practices we can observe that the best calving interval (around 400 days) were reached by the cows calving in the first months of the year LIVE WEIGHT AND BODY MEASUREMENTS OF GROWN BULLS AND COWS The average live weight of Hungarian Grey bulls raised and kept in the same conditions was 852 kg, that of cows was 562 kg, while their average age was 5.7 and 7.9 years, respectively. As for the height at withers, bulls (149 cm) were in average 8 cm higher than cows (141 cm). Height index counted from the examined body measurements was in average % in the case of bulls and cows. Phenotypic correlation between body measurements and weight was (r= for bulls and r= for cows). 11

12 On the basis of our results we can say that the most certain way of defining the live weight of the bulls without measuring it for real, is using the chest girth and the cannon girth on the basis of the correlational coefficient (r= ). With the help of the following equation: Y=(chest girth X 5.119)+(cannon girth X )+(inclined length of the trunk X 5.845) the live weight of the Hungarian Grey bulls can be estimated with 8% precision GROWTHRATE OF HUNGARIAN GREY HEIFERS AND BULLS In the examination I evaluated the live weight and body measurements data (taken by myself) of female and male animals. The logarithmic adjustment of the function based on the measured live weight data was R 2 = The average live weight of Hungarian grown Grey cows is 562 kg. We can express the age of breeding maturity of Hungarian Grey heifers with the help of the live weight of animals: it arrives when an animal reaches 2/3 or 3/4 of its grown weight. In the case of Hungarian Grey heifers it is 375 kg and 421 kg, based on the previous ranking. In the case of bulls the best time to take them into breeding is when their live weight is 568 kg and 639 kg. They reach this weight around the age of three. In the case of grey cattle heifers and cows, the K speed constant of the growth of the third width of rump goes down steeply, and already at the age of 300 days it reaches a very low level, but after that there is an intensive period of rising. In most farms grey heifers are taken into breeding at the age of three (1068 days), thus they calf at the age of four (1424 days) on the average for the first time. Most probably this late growth is the result of pregnancy and the mechanical processes of calving. I observed that grey heifers reach the chest girth of their grown age around the age of 1500 days. The adjustment of the function was R 2 = Grey bulls reach the chest girth of their grown age around the age of 1700 days, and after that we can only speak about a change of condition. The adjustment of the function was R 2 =

13 3.7. EXTERNAL AND INTERNAL PELVIS MEASUREMENTS OF HUN- GARIAN GREY COWS AND HEIFERS Based on the examination one can observe that the phenotypical variance of the external hip measurements of cows changed between %. From this we can conclude that the animals show great homogeneity concerning rump development. The inclined internal diameter of the pelvis of heifers was 16.2 cm, the horizontal diameter was cm, the vertical diameter was cm, the area of the pelvis entrance was cm 2 in average. The inclined diameter of the cows was cm, the horizontal diameter was cm, the vertical diameter was cm, the area of the pelvis entrance was cm 2 in average. Based on the data of internal measurements of pelvis of heifers and cows we can conclude in the following way. The internal diameters of pelvis and birth canal of Hungarian Grey heifers and cows are very advantageous from the point of view of calving, compared to the other breeds in the literature. We observed a significant difference (P<0.001) between the external and internal pelvis measurements of heifers and cows. According to these, living weight and calving influence advantageously the development of pelvis measurements from the point of view of the course of calving. The weak positive correlation (r= ) between age and the internal measurements of pelvis allows us to conclude that with the growth of age and the number of calvings the internal measurements of pelvis change only in a small extent. 13

14 4. NEW RESEARCH RESULTS 1. During my examinations using representative scaling I observed that the birth weight of Hungarian Grey young bulls is in average kg, while that of heifers is in average kg. I observed a close positive correlation (r= 0.75 and 0.87) between birth weight, cannon girth and circumference of chest. 2. As a result of my examination I observed that environmental factors (year, birthseason, farm, age of mother and sex) influence the weaning performance of Hungarian Grey calves. I observed the biggest difference in the effect of the farm, which can be connected to the keeping and forage circumstances. 3. Evaluating the weaning weight of Hungarian Grey calves with the help of the animal model, direct heritability was h 2 d= and maternal heritability was h 2 m= Estimating with the help of the animal model the residual variance is smaller ( 2 e= 351 kg 2 ) then with the help of the paternal model ( 2 e= 622 kg 2 ). 4. During the examination of three Hungarian Grey cattle farms using different reproduction practices I observed that calvings show seasonality even in farms using continuous all-year-around leap. The periods between two calvings were significantly influenced by the reproduction practices and the period (month) of calving. 5. Based on body measurements I formulated the following regressive equation for defining the live weight of breeding bulls: Y=(chest girth X 5.119)+(cannon girth X )+(inclined length of the trunk X 5.845) I counted a close positive correlational value (r= 0.92 and r 2 = 0.85) between the estimated and measured weights. 6. The logarithmic function adjusted the best to the data of live weight and body measurement. The adjustment of the function changed between R 2 = in case of live weight. 7. Observing the K speed constant of the growth of the third width of rump I came to the conclusion that the mechanical effects of calving have a significant effect on the development of grown body measurements. 8. The area of pelvis entrance of the Hungarian Grey heifers around the age of two was cm 2, while that of cows at the age of ten was cm 2, which result differed significantly from data published about beef cattle breeds both in international and in Hungarian Grey literature: it was cm 2 larger than those. The internal pelvis diameters (inclined, horizontal and vertical) and birth canals of the Hungarian Grey heifers and cows is rather advantageous from the point of view of calving. 14

15 5. LIST OF SCIENTIFIC PUBLICATIONS 5.1. SCIENTIFIC PUBLICATIONS ON THE TOPIC OF THE DISSER- TATION Copy Edited Publications in Foreign Periodicals Nagy B. Lengyel Z. Bodó I. Gera I. Török M. Szabó F. (2004): Effect of some environmental factors on weaning performance of Hungarian grey cattle population. Journal Central European Agriculture p. Copy Edited Publications in Hungarian Periodicals Nagy B. Bodó I. Gera I. Lengyel Z. Török M. Szabó F. (2004): Magyar szürke szarvasmarha állományok választási eredményei. Állattenyésztés és Takarmányozás p. Nagy B. Lengyel Z. Bodó I. Gera I. Bene Sz. Szabó F. (2006): Magyar szürke borjak növekedési tulajdonságainak variancia komponensei és populációgenetikai paraméterei. Állattenyésztés és Takarmányozás Nagy B. Bene Sz. Szabó F. (2006): Az ellések szezonalitása és annak hatása a két ellés között eltelt idre magyar szürke tehénállományokban. Magyar Állatorvosok Lapja Nagy B. Bene Sz. - Bodó I. Gera I. Szabó F. (2007): Magyar szürke bikák és tehenek élsúlya és testméretei. Állattenyésztés és Takarmányozás Nagy B. Király I. - Bene Sz. Dákay I. Szabó F. (2007): Magyar szürke tehenek és üszk küls és bels medence méreteinek vizsgálata. Állattenyésztés és Takarmányozás Papers in Conference Publications in Foreign Languages Nagy B. Lengyel Z. Bodó I. Gera I. Török M. Szabó F. (2005): Weaning performance of Hungarian Grey Calves. European Association for Animal Production, Uppsala Sweden, 5-8. June

16 Nagy B. Lengyel Z. Bodó I. Gera I. Bene Sz. Szabó F. (2005): Estimation of weaning performance of hungariangrey cattle by sire model. 5th international conference of phd students, University of Miskolc, Hungary, August Nagy, B. - Bene, Sz. - Bodó, I. - Gera, I. - Szabó, F. (2006): Live weight and body measurements of Hungarian Grey bulls and cows. 57 th Annual Meeting of the European Association for Animal Production, Session C33.46., 329.p. 17 th Sept., Antalya, Turkey Papers in Conference Publications in Hungarian Nagy B. Lengyel Z. Bodó I. Szabó F. (2003): Néhány tényez hatása a magyar szürke borjak választási tömegére. XLV. Georgikon Napok, Új stratégiák az agrárgazdaságban. Keszthely 2003 szept Nagy B. Lengyel Z. Bodó I. Gera I. Bene Sz. Szabó F. (2005): Növekedési tulajdonságokat befolyásoló környezeti tényezk vizsgálata magyar szürke választott borjak esetén. RODOSZ 6, romániai magyar doktoranduszok és fiatal kutatók szövetségének kiadványa. Kolozsvár 2005 márc Nagy B. Szabó F. Bodó I. Gera I. Lengyel Z. (2004): Választási eredményeket befolyásoló környezeti tényezk vizsgálata magyar szürke szarvasmarha állományokban. XLVI. Georgikon Napok, Új kihívások, Új lehetségek a mezgazdaságban. Keszthely szept Nagy B. Lengyel Z. Bodó I. Gera I. Szabó F. (2005): Magyar szürke szarvasmarha állományok választási eredményei. XI. Ifjusági Tudományos Fórum, Keszthely 2005 márc. 24. Nagy B. Lengyel Z. Bodó I. Gera I. Szabó F. (2005): Magyar szürke borjak választási teljesítményét befolyásoló tényezk vizsgálata. Tavaszi Szél, Debrecen május 5-8. Nagy B. Lengyel Z. Bodó I. Gera I. Szabó F. (2005): Variancia komponensek és populációgenetikai paraméterek becslése magyar szürke választott borjak esetében egyedmodellel. XLVII. Georgikon Napok és 15. ÖGA találkozó, Keszthely szept Nagy B. Bene Sz. Szabó F. (2006): Magyar szürke borjak születési súlya és testméretei. XII. Ifjusági Tudományos Fórum, Keszthely 2006 ápr. 20. Nagy B. - Bene Sz. - Bodó I. - Gera I. - Lukács G. - Szabó F. (2006): Magyar szürke bikák és tehenek élsúlya és testméretei. XLVIII. Georgikon Napok, Keszthely, szept Nagy B. - Bene Sz. - Bodó I. - Gera I. - Szabó F. (2006): Magyar szürke borjak születési súlya és testméretei. XLVIII. Georgikon Napok, Keszthely, szeptember

17 5.2 SCIENTIFIC PUBLICATIONS NOT ON THE TOPIC OF THE DISSERTATION Copy Edited Publications in Hungariam Periodicals Bene Sz. Nagy B. Nagy L. Szabó F. (2005): Különböz húshasznú szarvasmarha fajták teheneinek testméretei. Állattenyésztés és Takarmányozás p. Dákay I. Bene Sz. Nagy B. Fördös A. Márton D. Keller K. Vincze Zs. Szabó F. (2006): A borjazási idszak alakulása néhány húsmarhaállományban. Állattenyésztés és Takarmányozás Bene Sz. Nagy B. Nagy L. Szabó F. (2006): Azonos körülmények között tartott, különböz fajtájú hústípusú tehenek reprodukciós teljesítménye. Magyar Állatorvosok Lapja IF: 0,158 Dákay I. Bene Sz. Nagy B. Keller K. Fördös A Szabó F. (2006): A hasznosult szaporulat néhány húsmarha állományban. Állattenyésztés és Takarmányozás Szabó F. Füller I. Fördös A. Keller K. Nagy B. Nagy L. Bene Sz. (2006): Húshasznú magyar tarka borjak választási eredménye. 1. Közlemény:Környezeti hatások. Állattenyésztés és Takarmányozás Dákay I. Nagy B. Bene Sz.. Fördös A. Zsuppán Zs. Szabó F. (2006): Az ellések között eltelt id vizsgálata néhány hústehén állományban. Állattenyésztés és Takarmányozás Bene Sz. Füller I. Lengyel Z. Nagy B. Förds A. - Szabó F. (2006): Húshasznú magyartarka borjak választási eredménye*, 2. Közlemény: Genetikai paraméterek, tenyészértékek. Állattenyésztés és Takarmányozás Bene Sz. Balázs F. Lengyel Z. Nagy B. Szabó F. (2007): Angus borjak választási eredménye, 2. Közlemény: Genetikai paraméterek,tenyészértékek. Állattenyésztés és Takarmányozás Szabó F. Márton D. Nagy B. Nagy L. Bene Sz. (2007): Hereford borjak választási eredménye* 1. Közlemény: Környezeti hatások. Állattenyésztés és Takarmányozás Bene Sz. Balázs F. Lengyel Z. Nagy B. Szabó F. (2007): Angus borjak választási eredménye, 2. Közlemény: Genetikai paraméterek,tenyészértékek. Állattenyésztés és Takarmányozás

18 Szabó F. Márton D. Nagy B. Nagy L. Bene Sz. (2007): Hereford borjak választási eredménye* 1. Közlemény: Környezeti hatások. Állattenyésztés és Takarmányozás Bene Sz. Dákay I. Lengyel Z. Márton D. Nagy B. - Szabó F. (2007): Hereford borjak választási eredménye* 2. Közlemény: Genetikai paraméterek, tenyészértékek. Állattenyésztés és Takarmányozás Papers in Conference Publications in Foreign Languages Bene, Sz. - Füller, I. - Lengyel, Z. - Nagy, B. - Szabó, F. (2006): Genetic parameters and breeding values of weaning results of Hungarian Fleckvieh beef calves. 57 th Annual Meeting of EAAP, Session C4.29., 37.p. 17 th September, Antalya, Turkey Papers in Conference Publications in Hungarian Bene Sz. Balázs F. Nagy B. Lengyel Z. Szabó F.: Néhány tényez hatása angus borjak választási súlyára. XLVII. Georgikon Napok és 15. ÖGA találkozó, Keszthely szept Dákay I. Bene Sz. Nagy B. Lengyel Z. Szabó F. (2005): Az ellések szezonalitásának vizsgálata hazai húsmarhatenyészetekben. XI. Ifjusági Tudományos Fórum, Keszthely 2005 márc. 24. Bene Sz. - Nagy B. - Nagy L. - Szabó F. (2006): Különböz fajtájú hústípusú tehenek reprodukciós teljesítménye. XII. Ifjusági Tudományos Fórum, Keszthely 2006 ápr. 20. Bene Sz. - Balázs F. - Lengyel Z. - Nagy B. - Szabó F. (2006): Angus borjak választási tulajdonságainak variancia komponensei és populációgenetikai paraméterei. XLVIII. Georgikon Napok, Keszthely, szeptember OTHER PUBLICATIONS Nagy B. (2006): Egykor lábon mentek! Magyar Állattenyésztk Lapja Nagy B. (2006): Az els hortobágyi bikavásárok. Magyar Állatteny. Lapja Lukács G. Nagy B. Szabó F. Kocsondi J. (2006): Szarvasmarha-tenyésztés a Festetics-birtokon a XVIII. század végén. XLVIII. Georgikon Napok, Keszthely, szeptember