Effect of Season on Dry Matter Intake and Reproductive Activity of Merghoz Buck Goats in West of Iran

Document Type : Research Article

Authors

1 Department of Animal Science, Faculty of Agriculture, Razi University, Kermanshah, Iran

2 Department of Animal Science, Faculty of Agriculture, University of Jiroft, Jiroft, Iran

Abstract

Ten male Merghoz goats with initial live weights of 29.2 ± 1.2 kg (Mean±SE) were used to investigate the effect of natural changes in photoperiod on dry matter intake (DMI) and reproductive activity during a 365 day study. The bucks were housed in individual pens, under natural daylength condition at west of Iran, Kermanshah (34˚ 18¢N and 47˚ 3¢E and 1420 m above sea level). A diet was offered with an estimated concentration of metabolizable energy and crude protein of 7.9 MJ and 98.8 g per kg dry matter (DM) respectively. Live weight, DMI, and additive daily gain (ADG) of individual animals were recorded weekly. The serum testosterone concentrations were determined in blood samples collected at monthly intervals. During the observation period, semen was collected monthly with the aid of an electro-ejaculator and examined microscopically immediately after collection. The physical parameters of semen and the semen index were recorded. The sexual behavior and testicular size of goats were assessed monthly throughout the study period. The highest DMI was observed during summer (64.3±0.9 g/kg BW0.75) and spring (62.2±2.9 g/kg BW0.75) however, the lowest was recorded in the winter season (54.0±0.9 g/kg BW0.75). The seasonal values of ADG (g/d) ranked spring > summer > winter > autumn. Bucks demonstrated the highest sexual behavior in late summer and, thereafter during autumn, using the lower (P<0.05) number of mounts per ejaculation and a higher frequency (P<0.05) to sniff, approach, and vocalize a doe with estrous status. This was coincided with a higher (P<0.05) level of plasma testosterone (8-10.1 ng/mL) and the best semen quality (semen index: 744-989×106/mL) and quantity (semen volume: 1.1-1.2 mL per ejaculate), higher testis length (13.3-14.7 cm) and width (6.0-6.1 cm) and scrotal circumference (32.2-35.5 cm). It is concluded that, in Merghoz bucks, the seasonal pattern of DMI and reproductive activity may be attributed to each other as well as photoperiod.

Keywords


Abbasi M.A. and Ghafouri-Kesbi F. (2011). Genetic co (variance) components for body weight and body measurements in Makooei sheep. Asian-australas J. Anim. Sci. 24, 739- 743.
Akhtar P., Khan M. S., Mohiuddin G. and Abdollah M. (2000). Effect of inbreeding on different performance traits of Hissardale sheep in Pakistan. Pakistan Vet. J. 20(4), 169-172.
Boujenane I. and Chami A. (1997). Effects of inbreeding on reproduction, weights and survival of Sardi and BeniGuil sheep. J. Anim. Breed. Genet. 114, 23-31.
Caballero A. and Toro M.A. (2000). Interrelations between effective population size and other pedigree tools for the management ofconserved populations. Genet. Res. 75, 331-343.
Crow J.F. and Kimura M. (1970). An Introduction to Population Genetics Theory. Harper and Row, New York, USA.
Dorostkar M., Faraji-Arough H., Shodja J., Rafat S.A., Rokouei M. and Esfandyari H. (2012). Inbreeding and Inbreeding Depression in Iranian Moghani Sheep Breed. J. Agric. Sci. Technol. 14, 549-556.
Ercanbrack S.K. and Knight A.D. (1991). Effects of inbreeding on reproduction and wool production of Rambouillet, Targhee, and Columbia ewes. J. Anim. Sci. 69, 4734-4744.
Falconer D.S. and Mackay T.F.C. (1996). Introduction to Quantitative Genetics, Fourth Edition, London, Longman, UK.
Farkas J., CurikI., Csato L., CsornyeiZ., BaumungR. and Nagy I. (2007). Bayesian inference of inbreeding effects on litter size and gestation length in Hungarian Landrace and Hungarian Large White pigs. Livest. Sci. 112(1), 109-114.
Ghavi Hossein-Zadeh N. (2013). Inbreeding effects on average daily gains and kleiber ratios in Iranian Moghani sheep. Iranian J. Appl. Anim. Sci. 3(3), 545-551.
Gomez M.D., Valera M., Molina A., Gutierrez J. P. and Goyache F. (2009). Assessment of inbreeding depression for body measurements in Spanish Purebred (Andalusian) horses. Livest. Sci. 122, 149-155.
Hussain A., Akhtar P., Ali S., Younas M. and Shafiq M. (2006). Effect of inbreeding on pre-weaning growth traits in Thalli sheep. Pakistan Vet. J. 26(3), 138-140.
Jafari S. (2014). Estimation of genetic parameters for body measurements and their association with yearling live weight in Makuie sheep breed. World. Appl. Sci. J. 29(2), 188-192.
Kleiber M. (1947). Body size and metabolic rate. Physiological. Rev. 27, 511-541.
Leroy G., Mary-Huard T., Verrier E., Danvy S., Charvolin E. and Danchin-Burge C. (2013). Methods to estimate effective population size using pedigree data: Examples in dog, sheep, cattle and horse. Genet. Sel. Evol. 45(1), 1-10.
Lush J.L. (1945). Animal Breeding Plans, third ed. Ames, Iowa State College.
Lucy I.W., Tregenza T. and Hosken D.J. (2007). Inbreeding, inbreeding depression and extinction. Conserv. Genet. 10, 1-10.
Lynch M. and Walsh B. (1998). Genetics and Analysis of Quantitative Traits. Sinauer Associates, Sunderland, MA, USA: Sinauer Associates. Inc. 86, 127-135.
Mandal A., Pant K.P., Notter D.R., Rout P.K., Roy R., Sinha N. K. and Sharma N. (2005). Studies on inbreeding and its effects on growth and fleece traits of Muzaffarnagari Sheep. Asian-Australas J. Anim. Sci. 10, 1363-1367.
Marete A.G., Junga J.O. and Mosi R.O. (2011). An analysis of inbreeding levels and factorsaffecting growth and reproductive traits inthe Kenya Alpine dairy goat. Livest. Res. Rur. Dev. 23(12), 1-8.
Maximini L., Manrique-Gomez A. and Fuerst-Waltl B. (2011). Inbreeding and its effect on performance traits in Austrian Meat Sheep. Am. Chem. Soc. 76(3), 213-217.
Meyer K. (1989). Restricted maximum likelihood to estimate variance components for animal models with several random effects using a derivative-free algorithm. Genet. Sel. Evol. 21, 317-340.
Meyer K. (1992). Variance components due to direct and maternal effects for growth traits of Australian beef cattle. Livest. Prod. Sci. 31, 179-204.
Miglior F. (2000). Impact of inbreeding-Managing a declining Holstein gene pool. Pp. 108- 113 in Proc. 10th Holstein world festival Federation. Conf., Sydney, NSW, Australia.
Norberg E. and Sorensen A.C. (2007). Inbreeding trend and inbreeding depression in the Danish populations of Texel, Shropshire and Oxford Down. J. Anim. Sci. 85, 299-304.
Paddaiah G. and Madhavi D. (2001). The effect of parental consanguinity and inbreeding on the anthropometric measurements of the new born babies revisited. Int. J. Health Geogr. 1(3), 187-190.
Petrovic V.C., Maksimovic N., Petrovic M.P., Petrovic M.M., Ilic Z.Z., Muslic D.R. and Mikulec D.P. (2012). Effect of inbreeding on body growth traits and sperm DNA fragmentation level in rams. Anim. Sci. Pap. Rep. 31(1), 27-33.
Queiroz S.A., Albuquerque L.G. and Lanzoni L.A. (2000). Inbreeding effects on growth traits of Gyr cattle in Brazil. Brazilian J. Anim. Sci. 4, 1014-1019.
Rollins W.C., LabenR.C. and Mead S.W. (1956). Gestation length in an inbred jersey herd. J. Dairy Sci. 39(11), 1578-1593.
Safari E., Fogarty N.M. andGilmor A.R. (2005). A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep. Livest. Prod. Sci. 92, 271- 289.
Sajjad-Khan M., Afzal A., Hydar A.U. and Iqbal-Chata A. (2007). Effect of inbreeding on growth and reproduction traits of Beetal goats. Arch. Tierz. Dummerstorf. 50(2), 197-203.
Salako A.E. (2006). Application of morphological indices in the assessment of type and function in sheep. Int. J. Morphol. 24(1), 13-18.
Santana-JR M.L., Oliveira P.S., Pedrosa V.B., Eler J.P., Groeneveld E. and Ferraz J.B.S. (2010). Effect of inbreeding on growth and reproductive traits of Nellore cattle in Brazil. Livest. Sci. 131, 212-217.
SAS Institute. (2005). SAS®/STAT Software, Release 6. SAS Institute, Inc., Cary, NC.
Swanepoel J.W., Van Wyk J.B., Cloete S.W.P. and Delport G.J. (2007). Inbreeding in the dohne merino breed in South Africa. South African J. Anim. Sci. 37, 176-179.
Van Wyk J.B., Fair M.D. and Cloete S.W.P. (2009). Case study: the effect of inbreeding on the production and reproduction traits in the elsenburg dormer sheep stud. Livest. Sci. 120(3), 218-224.
Van Wyk J.B., Erasmus G.J. and Konstantinov K.V. (1993). Inbreeding in the Elsenburg Dormer sheep stud. South African J. Anim. Sci. 23(3), 77-80.