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Evaluation of productivity of sexually precocious Nelore heifers

Published online by Cambridge University Press:  16 February 2015

A. P. N. Terakado*
Affiliation:
Department of Animal Science, Sao Paulo State University (UNESP), Jaboticabal, 14884-900 SP, Brazil
M. C. Pereira
Affiliation:
Department of Animal Science and Rural Development, Santa Catarina Federal University (UFSC), Florianopolis, 88040-900 SC, Brazil
M. J. Yokoo
Affiliation:
Embrapa Southern Region Animal Husbandry, Center of Livestock Research of South Brazilian Fields, Bage, 96401-970 RS, Brazil
L. G. Albuquerque
Affiliation:
Department of Animal Science, Sao Paulo State University (UNESP), Jaboticabal, 14884-900 SP, Brazil
*
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Abstract

The objectives of the present study were to investigate the influence of yearling weight on the occurrence of early pregnancy and to determine differences between precocious and non-precocious heifers in terms of pre- and postnatal calf mortality, calf weight and height, mature cow weight, and stayability of the cow in the herd. Data from 26 977 females of a Nelore herd that participated in the breeding season between 1986 and 2004 were analyzed. The influence of yearling weight on sexual precocity and differences between precocious and non-precocious heifers in pre- and postnatal calf mortality and stayability were analyzed using the GENMOD procedure of the SAS program. Differences in the growth traits between precocious and non-precocious animals were estimated by contrast analysis. Three groups were analyzed for postnatal mortality: first calving of the heifers, calves born from the third calving and all offspring of the cow. In order to have a standardized calving to conception period for all females (precocious and non-precocious), calves born from the second calving were not included in the analysis. This was necessary because the first calving to conception period (days open) of precocious heifers was longer than for non-precocious due to farm reproductive management. No differences in postnatal mortality rates, from the third calving, were observed between the two groups of heifers studied. Analysis of all offspring of the dams showed a 9% higher probability of death of calves born to precocious heifers compared with calves born to non-precocious heifers. With respect to stayability, precocious heifers presented 33% greater odds to remain in the herd until 5 and 6 years of age and 28% greater odds to remain in the herd until 7 years when compared with non-precocious heifers. Precocious heifers weaned calves (205 days) significantly heavier than non-precocious ones, 1.410 and 0.797 kg considering the weaning weights of all offspring and of the third calving, respectively. With respect to sexual precocity, the results suggest that the probability of heifers to become pregnant at 16 months of age increases with increasing weight. However, heifers weighing more than 240 kg present practically the same pregnancy probability. Nevertheless, exposure of heifers during the early breeding season is recommended for beef cattle herds raised in tropical regions in view of the numerous benefits demonstrated here.

Type
Research Article
Copyright
© The Animal Consortium 2015 

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References

Beef Improvement Federation (BIF) 2002. Guidelines for uniform beef improvement programs, 8th edition University of Georgia, Athens, Georgia, USA.Google Scholar
Beretta, V, Lobato, JFP and Netto, CGM 2002. Produtividade e eficiência biológica de sistemas de produção de gado de corte de ciclo completo no Rio Grande de Sul. Revista Brasileira de Zootecnia 31, 9911001.CrossRefGoogle Scholar
Boldman, KG, Kriese, LA, Van Vleck, LD, Van Tassell, CP and Kachman, SD 1995. A manual for use of MTDFREML. A set of programs to obtain estimates of variances and covariances [DRAFT]. United States Department of Agriculture, Agricultural Research Service, Lincoln, Nebraska, USA.Google Scholar
Dias, LT, Faro, LE, Fries, LA and Albuquerque, LG 2000. Estimativas de parâmetros genéticos para perímetro escrotal e idade ao primeiro parto em animais da raça Nelore. Proceedings of the 37th Reunião Anual da Sociedade Brasileira de Zootecnia, July 24 Viçosa, Minas Gerais, Brazil, 223–225.Google Scholar
Eler, JP, JAIIV, Silva, Ferraz, JBS, Dias, F, Oliveira, HN, Evans, JL and Golden, BL 2002. Genetic evaluation of the probability of pregnancy at 14 months for Nellore heifers. Journal of Animal Science 80, 951954.CrossRefGoogle ScholarPubMed
Greer, RC, Whitman, RW, Staigmiller, RB and Anderson, DC 1983. Estimating the impact of management decisions on the occurrence of puberty in beef heifers. Journal of Animal Science 56, 3039.Google Scholar
Jenkins, TG and Ferrell, CL 1994. Productivity through weaning of nine breeds of cattle under varying feed availabilities: I. Initial evaluation. Journal of Animal Science 72, 27872797.Google Scholar
Martín Nieto, L, Silva, LOC, Rosa, NA and Gondo, A 2003. Análise da curva de crescimento da circunferência escrotal de touros da raça Canchim e do grupo genético MA. Archives of Veterinary Science 8, 7579.Google Scholar
Montaño-Bermudez, M and Nielsen, MK 1990. Biological efficiency to weaning and to slaughter of crossbred beef cattle with different genetic potential for milk. Journal of Animal Science 68, 22972309.Google Scholar
Pearson, RE and Miller, RH 1981. Economic definition of total performance, breeding goals and breeding values for dairy cattle. Journal of Dairy Science 64, 857869.CrossRefGoogle Scholar
Pereira, E, Eler, JP and Ferraz, JBS 2000. Correlação genética entre perímetro escrotal e algumas características reprodutivas na raça Nelore. Revista Brasileira de Zootecnia 29, 16761683.Google Scholar
Pereira, E, Eler, JP, Costa, FAA and Ferraz, JBS 2001. Análise genética da idade ao primeiro parto e do perímetro escrotal em bovinos da raça Nelore. Arquivo Brasileiro de Medicina Veterinária e Zootecnia 53, 116121.CrossRefGoogle Scholar
SAS Institute 2000. SAS/STAT Software: changes and enhancement through release 8.2. SAS Institute Inc., Cary, NC, USA.Google Scholar
Short, RE and Bellows, RA 1971. Relationship among weight gains, age at puberty and reproductive performance in heifers. Journal of Animal Science 32, 127131.Google Scholar
Silva, JAIIV, Dias, LT and Albuquerque, LG 2005. Estudo genético da precocidade sexual de novilhas em um rebanho Nelore. Revista Brasileira de Zootecnia 34, 15681572.Google Scholar
Toelle, VD and Robison, OW 1985. Estimates of genetic correlations between testicular measurements and female reproductive traits in cattle. Journal of Animal Science 60, 89100.Google Scholar
Wiltbank, JN, Gregory, KE, Swiger, LA, Ingalls, JE, Rothlisberger, JA and Koch, RM 1966. Effects of heterosis on age and weight at puberty in beef heifers. Journal of Animal Science 25, 744751.Google Scholar
Wolfe, MW, Stumpf, TT, Wolfe, PL, Day, ML, Koch, RM and Kinder, JE 1990. Effect of selection for growth traits on age and weight at puberty in bovine females. Journal of Animal Science 68, 15951602.Google Scholar