Influence of environmental factors on birth weight variability of indigenous Serbian breeds of sheep

The present investigation was carried out to study the influence of environmental factors on the birth weight variability of two breeds of sheep. Animals used in this research were taken from the Pirot and Svrljig indigenous sheep breeds. The data were collected from 1999 to 2009 and were analyzed to determine the effect of the year and season, age of the lamb, weight of the lamb, birth type and sex on the birth weight of lambs. Both sheep breeds were managed in the same farm and under the same farm conditions. Statistical analysis was performed by using GLM procedure of SAS statistical package program. Results showed that young (2 to 3 years) and old (6 to 7 years) mothers gave birth to lighter lambs, while sheep in the middle age (4 to 5 years) gave birth to lambs with the heaviest body weight. However, the differences were respectively significant (P 0.05). The values of birth weight observed for quite a number of years ranged from 3.27 to 3.52 kg in Pirot and 3.34 to 3.51 kg in Svrljig breed (P < 0.01). Lambs born in the spring-summer season has the heaviest body weight at birth. Conversely, the significant difference (P < 0.05) can only be interpreted as the factor of food source.

[1]  Robert S. Leiken,et al.  A User’s Guide , 2011 .

[2]  A. Mohamadi,et al.  Estimation of genetic parameters for body weight at different ages in Mehraban sheep , 2010 .

[3]  M. Talebi,et al.  GENETIC AND NON-GENETIC FACTORS AFFECTING MORTALITY IN LORI-BAKHTIARI LAMBS , 2009 .

[4]  H. Baneh,et al.  Effects of environmental factors on growth traits in Ghezel sheep , 2009 .

[5]  S. Bishop,et al.  Genetic parameters for early lamb survival and growth in Scottish Blackface sheep. , 2008, Journal of animal science.

[6]  M. Yaqoob,et al.  ENVIRONMENTAL FACTORS AFFECTING BIRTH WEIGHT IN LOHI SHEEP , 2008 .

[7]  P. Perisic,et al.  Investigation of genetic and paragenetic parameters of milk production in sheep. , 2008 .

[8]  D. Gardner,et al.  Factors affecting birth weight in sheep: maternal environment. , 2007, Reproduction.

[9]  J. Arendonk,et al.  Reproductive performance and mortality rate in Menz and Horro sheep following controlled breeding in Ethiopia , 2006 .

[10]  R. Borg,et al.  Adjustment of lamb birth and weaning weights for continuous effects of ewe age , 2005 .

[11]  B. Mioč,et al.  Seasonal variations in lamb's birth weight and mortality , 2005 .

[12]  M. Fisher.  A review of the welfare implications of out-of-season extensive lamb production systems in New Zealand , 2004 .

[13]  M. Bryant,et al.  Seasonality of reproduction in sheep , 2003 .

[14]  C. Hansen,et al.  Consistency of genetic parameters of productivity for ewes lambing in February, June and October under an 8-month breeding management , 2002 .

[15]  J. Dhillon,et al.  Genetic and non-genetic parameter estimates for growth traits of Bharat Merino lambs , 2001 .

[16]  S. Cloete,et al.  Environmental and genetic aspects of survival and early liveweight in Western Australian Merino sheep , 2001 .

[17]  J. N. Clarke,et al.  Genetic and environmental factors affecting lamb survival at birth and through to weaning , 2000 .

[18]  J. Brameld,et al.  Maternal nutrient restriction during early to mid gestation alters the relationship between insulin-like growth factor I and bodyweight at term in fetal sheep. , 2000, Reproduction, fertility, and development.

[19]  R. Sormunen-Cristian,et al.  Out-of-season lambing of Finnish Landrace ewes , 1999 .

[20]  J. Wallace,et al.  Nutrient partitioning and fetal growth in rapidly growing adolescent ewes. , 1996, Journal of reproduction and fertility.

[21]  W. J. Boylan,et al.  Breed and environmental effects on components of ewe productivity in terms of multiple births, artificial rearing and 8-month breeding cycles , 1995 .

[22]  R. F. Kelly,et al.  Effects of ewe breed and management system on efficiency of lamb production: III. Meat characteristics. , 1991, Journal of animal science.

[23]  R. F. Kelly,et al.  Effects of ewe breed and management system on efficiency of lamb production: II. Lamb growth, survival and carcass characteristics. , 1991, Journal of animal science.

[24]  F. Pirchner,et al.  Performance of merinolandschaf and bergschaf under an accelerated lambing system , 1989 .

[25]  D. Mellor,et al.  Daily changes in the curved crown-rump length of individual sheep fetuses during the last 60 days of pregnancy and effects of different levels of maternal nutrition. , 1979, Quarterly journal of experimental physiology and cognate medical sciences.

[26]  J. Robinson,et al.  Studies on reproduction in prolific ewes , 1977, The Journal of Agricultural Science.

[27]  J. Robinson,et al.  The influence of maternal nutrition on ovine foetal growth , 1977, Proceedings of the Nutrition Society.

[28]  A. Russel,et al.  The effect of level of nutrition at two stages of pregnancy on the performance of primiparous ewes. , 1973, Proceedings of the Nutrition Society.

[29]  A. Russel.  Relationships between energy intake and productivity in hill sheep , 1971, Proceedings of the Nutrition Society.