7th World Congress on Genetics Applied to Livestock Production, August 19-23, 2002, Montpellier, France

THE ROLE OF THE EXPERIMENTAL STATION OF SERTÃOZINHO (SP)-BRAZIL IN THE PRESERVATION AND SELECTION OF BREEDS AND

A.G. Razook1,2, L.A. Figueiredo1, L.M. Bonilha Neto3, J.N.S.G. Cyrillo1,2, M.E.Z. Mercadante1, J.B.F. Trovo4, A.C. Ruggieri1 and I.U. Packer5,2

1 EEZS-IZ Sertãozinho, SP-Brazil, CP63, CEP:14160-900 2 CNPq Scholarship, Brazil 3 EEZA-IZ Andradina, SP, Brazil 4 EMBRAPA-Cuiabá, MT, Brazil 5 ESALQ-USP-Piracicaba, SP, Brazil

INTRODUCTION According to Santiago (1972) most of the Zebu breeds were brought to Brazil during the XIX century, mainly from India and Africa. In the last two decades of XIX century a German importation company, specialized in commerce of wide animals, was the main responsible to import Zebu animals from India to Brazil (Santiago, 1984). At the end of that century, Zebu was considered a "zoo" animal. In the beginning of the last century, Brazilian breeders started to go to India looking for the "hump cattle", mainly because its adaptation to tropical environment. Many importation of the Zebu breeds Gir, Guzerá, Nelore and Sindi were done during the last century until the seventy decade. Simultaneously to that process of Zebu importation from India, in 1930 the Government of The State of São Paulo (SP)-Brazil bought, from coffee farmers, the Experimental Station of Sertãozinho for the purpose of maintaining and studying resources especially Bos indicus and their crosses. Therefore, since 1933 the Station, which belongs to the Instituto de Zootecnia-IZ (SP), maintains purebred herds of Gir, Guzerá and Nelore for beef production. In Brazil the Nelore breed, which represents more than 80% of the total Zebu cattle, is utilized mainly for beef production while Gir is for dairy and Guzerá for dual purpose.

The Caracu, also preserved at The Sertãozinho Station, is an European origin breed which was brought to Brazil by the Portuguese settlers in the XVI century. The first group of animals arrived in the State of São Paulo and during the colonization process was spread out to the South, Central and North parts of Brazil. By 1900, the Caracu was the most important bovine breed in Brazil (Lima et al., 1992). This importance was because its multiple purpose (beef, dairy and draft animals). In the beginning of the XX century the Government of the State of São Paulo started a genetic improvement program which was discontinued in the year sixties. The reason for this interruption was high inbreeding of the herd and a severe reduction of Caracu herds due, mainly, to crossbreeding with Zebu that was being brought to Brazil. In 1976 a preservation project of the Caracu breed was initiated in an effort to save it from extinction and, in 1979 it was transferred to Sertãozinho Station to be selected for growth rate with the same management provided for the Zebu breeds. This paper reports some results of the performance in the last 20 years, on growth traits, on each of these herds, submitted to selection based on yearling weights.

Session 24. Sustainable breeding plans in developed countries Communication N° 24-05 7th World Congress on Genetics Applied to Livestock Production, August 19-23, 2002, Montpellier, France

MATERIAL AND METHODS General description of herds and lines. The Zebu herds (Gir, Guzerá and Nelore) started to be formed in Sertãozinho (SP) in 1933. All the herds were constituted mostly by the purchasing of bulls and cows from private breeders. They were maintained at the Station as a purebred population and also in some crossbreeding experiments. At this time, the main selection was based on phenotypic racial traits, under the influence of the importation, because breeders were looking for "racial purity". In 1976 a selection project was initiated having as selection criteria yearling weights and in 1980 the Zebu selection lines were established. All the details concerning the formation of these lines were described by Razook et al. (1998). The Nelore (NeS) and Guzerá (GuS) herd sizes was fixed in 120 cows and 6 bulls (2 and 3 years old). A Nelore control line (NeC) was also established composed of 60 cows and 4 bulls with the same age. The Gir herd started with 80 cows and 6 bulls and was maintained in this size and the Caracu (Ca) started with 60 cows increasing to 150 and 8 bulls nowadays. The breeding season was 90 days starting in November (Spring). A single sire natural mating groups were used, composed of 15 cows for 2 years old bulls or 25 for 3 years old. Close relationship between bulls and cows were avoided by examining the pedigrees and more recently by a computer program by Polastre et al. (1992). The cows and calves were maintained in similar pastures (mostly Panicum maximum) throughout the suckling period. No creep feeding was used and the weaning was around 210 days age. The males started the performance test just after weaning up to 13 months (168 days of feeding) and the females remained on pastures until 18 months.

Selection Criteria and Performance Records. For all the breed herds and selection lines, male selection was based on high selection differentials for final weight on test corrected to 378 days (Y378) and females were selected based on weight at 550 days (Y550). Annually about 7-10% of the males and 55% of the females were selected from the contemporary groups. In the NeC line, bulls and heifers were selected with selection differentials around zero. The annually culling rate was 20% for females, according to pregnancy status and age (more than 10 years), and 50% for males, with 3 years of age. The traits measured and analyzed were birth weight (BW), weaning weight (W210), yearling weight for males (Y378) and for females (Y550), daily weight gain on feedlot for males (G112) and mature weight of cows (5 years or more) obtained at the end of the breeding season (Wmat).

Statistical Analyses. The performance records were analyzed by least squares, within breed, fitting models that included effects of year and month of birth and age of cow. For the Nelore breed, the models included also line effect. The inbreeding coefficient was obtained by the software of Polastre et al. (1992).The pedigree file for Zebu breeds included information since 1933 and for the Caracu animals born in the fifties.

RESULTS AND DISCUSSION The Table 1 shows the averages of the inbreeding coefficients and the adjusted means for the selection criteria (Y378 and Y550) and for correlated growth traits by breed herd and sex. All the values are related to the first four years of progenies (1981/84) and for the last four (1997/00). The comparison of these periods of time gives an idea about part of the genetic change that occurred in each line.

Session 24. Sustainable breeding plans in developed countries Communication N° 24-05 7th World Congress on Genetics Applied to Livestock Production, August 19-23, 2002, Montpellier, France

Table 1. Inbreeding coefficient and adjusted means for growth traits by sex and herd for 1981-84 and 1997-00 progenies

CaA GirA GuSA NeSA NeCA TraitB 81/84 97/00 81/84 97/00 81/84 97/00 81/84 97/00 81/84 97/00 Inbreed.(%) 0.9 1.5 3.0 4.6 7.0 4.5 3.6 4.0 3.1 4.9 ------Males------N 724 571 825 941 496 BW (kg) 30 35 25 26 28 28 30 33 29 28 W210 (kg) 188 208 161 180 174 199 182 207 171 180 Y378 (kg) 319 352 240 292 288 326 296 341 279 287 G112 (g/d) 806 922 533 733 716 826 735 888 693 706 ------Females------N 833 542 824 924 448 BW (kg) 29 32 23 25 26 26 28 30 27 25 W210 (kg) 174 198 141 163 156 182 159 189 156 161 Y550C (kg) 250 296 199 256 238 288 249 311 243 260 Wmat (kg) 496 542 416 419 463 460 467 519 486 451

A- Ca : Caracu, Gir : Gir, GuS : Guzerá Selection, NeS : Nelore Selection, NeC : Nelore Control .B- N : number of individuals, BW : birth weight, W210 : weaning weight at 210 days, Y378 : final weight at 378 days, G112 : daily gain on feedlot, Y550 : weight at 550 days, Wmat : mature weight of cows at the end of breeding season. C- Averages of 1997/99 period.

The inbreeding was maintained for all herds in reasonable levels and the values of the first progenies of Gir and Nelore reflects the introduction of genetic variability, through AI, prior to the initiation of the selection process. For the Ca, the lowest values are explained by the introduction of bulls and dams from outside herds which also occurred during selection. The same reason explains the reduction of inbreeding in the Guzerá line, caused by the introduction of heifers from an other herd.

Concerning the growth traits, especially for those where direct selection was applied, the adjusted means for GuS, NeS and NeC are higher than those reported by Razook et al. (1998) with 15 years of progeny. In that paper the authors reported genetic changes ranging from 0.6 to 1.0 % of the NeC average, by year (1.4 to 3.0 kg annually depending on the trait). For most of the NeC traits there also was an increase on the means which was due mainly to environmental effect (3% and 7% respectively for Y378 and Y550). Normally the Gir is a smaller breed than Nelore and Guzerá. The opposite happens with Caracu which is normally bigger. It is possible to verify, from Table 1, that the Gir had a very significant response to the selection process. For direct and correlated traits the means for the first four years were lower than NeC, and changed to higher values (21% and 28% between periods, for Y378 and Y550 respectively). On the other hand the Caracu performances had a less rate of change, which can be explained by the lower selection pressure on female side (increasing herd) and by the introduction of outside bulls, some of them from dual purpose herds. The rate of change in Gus was also lower than NeS, which can also be explained by the lower selection intensity (Razook

Session 24. Sustainable breeding plans in developed countries Communication N° 24-05 7th World Congress on Genetics Applied to Livestock Production, August 19-23, 2002, Montpellier, France

et al., 1998). There was no correlated response in BW of GuS contrarily to the other selected herds. As expected, the mature weight of cows did not change too much mainly because the higher replacement rates. It is important to emphasize that Wmat means are from cows of different contemporary groups but the same breeding season. For the NeC there was a reduction in mature weight because in the first progenies some foundation cows (bigger) were still in the herd. The means of the Zebu herds shown in this paper, for the last 4 years, are higher than those reported by Josahkian (2001) for the National Breeding Association of Zebu (ABCZ), which is an evidence of the positive responses of the selection applied in these herds.

CONCLUSION The Nelore, Guzerá and Gir Zebu breeds and the Caracu, which is a tropical adapted European origin cattle, are very important genetic resources in Brazil and in many countries of Latin America where beef production is based mostly on grazing systems. In seventy years of existence the Experimental Station of Sertãozinho (SP)-Brazil preserved these important breed herds, which were submitted to an effective selection program for growth traits with significant genetic changes.

REFERENCES Josahkian, L.A. (2001) ABCZ 1 (4) : 44-45. Lima, M.L., Bonilha Neto, L.M., Figueiredo, L.A. and Razook, A.R. (1992) Zootecnia 30 : 1- 12. Polastre, R., Tamburo, F.J.Z. and Laperuta Filho, J. (1992) “Manual para utilização do Sirege”. UNESP, Botucatu (SP). Razook, A.G., Figueiredo, L.A., Bonilha Neto, L.M., Trovo, J.B.F.T., Packer, I.U., Pacola, L.J., Cyrillo, J.N.S.G., Ruggieri, A.C. and Mercadante, M.E.Z. (1998) Proc 6th WCGALP 23 : 133-136. Santiago, A.A. (1972) “O Gado Nelore”. Instituto de Zootecnia, São Paulo, Brazil. Santiago, A.A. (1984) “O Guzerá”. Editora Tropical LTDA, Recife, Brazil.

Session 24. Sustainable breeding plans in developed countries Communication N° 24-05