Keywords : Awassi sheep

Genetic variants of the bone morphogenetic protein gene and its association with estrogen and progesterone levels with litter size in Awassi ewes

Marwa A. Ali; Alaa H. Kadhim; Tahreer M. Al-Thuwaini

Iraqi Journal of Veterinary Sciences, 2022, Volume 36, Issue 4, Pages 1017-1022
DOI: 10.33899/ijvs.2022.132903.2143

This research aimed to assess the genetic polymorphism of the BMP15 gene concerning sex hormone levels and birth type in Awassi ewes. The genome DNA of 138 Awassi ewes was isolated (52 ewes produced a singleton and 86 produced twins). The BMP15 gene exon-2 was amplifiable by polymerase chain reaction (PCR), so two genotypes were identified based on 141 bp amplicons: TT and TA. A sequencing reaction revealed a novel mutation, c.50980646T>A, in the TA genotype. This single nucleotide polymorphism (SNP) showed a high association (P≤0.01) with sex hormone levels and litter size, sheep containing this SNP had higher levels of sex hormones and larger litter sizes than sheep without it. Ewes with the TA genotype had a 1.89 litter size than their TT counterparts. Logistic regression confirmed that the c.50980646T>A SNP increased litter size. In conclusion, the c.50980646T>A SNP appears to be significantly related to reproductive traits (especially sex hormone levels and litter size) in Awassi sheep. With these results, mutations of the BMP15 gene are suitable for developing marker-assisted selection programs to increase Awassi sheep litter size. 

Study of the relationship between the production of milk and some of its components with the growth of lambs in two breeds of Iraqi sheep

S.F. Al-Dabbagh

Iraqi Journal of Veterinary Sciences, 2019, Volume 33, Issue 2, Pages 87-95
DOI: 10.33899/ijvs.2019.163172

A total of 1116 records Awassi ewes and 432 of Hamdania ewes were collected and which belong animals resource department, Faculty of Agriculture and Forestry at the University of Mosul for the years 2008, 2009 and 2010 to study the effect of genetic and non-genetic factors in milk production and some of its components from birth until weaning. The results showed significant effects (p≤0.05) for the breed and highly significant effects (p≤ 0.001) for the year, mother's age, sex, and type of birth in the daily milk production. There was a highly significant effect of year in milk fat, protein, and lactose. same there was a significant effect for age at weaning on birth weight, and highly significant effects for the breed, year, age of dam, sex, type of birth, and age at weaning on birth, weaning and weight gain from birth to weaning. The highest value for repeatability was 0.398, 0.309 in Awassi ewes for weight gain and in Hamdani ewes for daily milk yield respectively. Phenotypic and genetic correlation between protein and lactose in Awassi ewes 0.507 and 0.410, and in Hamdani ewes 0.641 and 0.157 respectively were highly significant.

Effect of body weight of ewes and milk yield in productive performance of lambs, milk yield and components of Awassi sheep

Khalid Sultan; Mohammed Reyad Mohammed

Iraqi Journal of Veterinary Sciences, 2019, Volume 33, Issue 1, Pages 9-16
DOI: 10.33899/ijvs.2019.125555.1074

In the current study, 32 Awassi ewes 2 -3 years aged were used with their lambs for 12 weeks, to evaluate the effect of Body Weight (BW) and Milk Yield (MY) on Body weight BW, Body Weight Gain (BWG), MY and milk components. After lambing, ewes were weighted directly, then at the 1st week of lambing, ewes were milked for 2 consecutive days, in order to determine the milk yield, Ewes divided randomly to 4 groups depending on their body weights and milk yield, the groups were: 1st group: ewes with high BW and high MY, 2nd group: ewes with high BW and law MY, 3rd group: ewes with low BW and high MY, 4th group: ewes with low BW and low MY. The result showed a significant increase (P≤0.05) in BW in heavy ewes (HE) groups at the 2nd, 4th, 6th and 8th weeks, the best significant interactions (P≤0.05) were recorded in the 1st, 2nd and 3rd group at 8th weeks. Also, there is a significant increase (P≤0.05) in BWG in the HE at 8th week. The effect of MY was evident in milk production, MY of HW and high milk (HM) increased significantly at the 2nd, 4th, 6th and 8th weeks. Also a significant increase (P≤0.05) in milk fat% in HM ewes at 2nd, 6th and 8th weeks after lambing. On other hand the results revealed a significant increase (p≤0.05) in lactose % in Light Ewes Milk (LE) at 8th week and Low Milk Ewes (LOM) at 4th week, also solid non-fat components % increased significantly in LE at 2nd week and HW ewes. In conclusion, the body weight of the lambs that born from the ewes with (heavy weight and high milk production) were significantly higher than other lambs, also, milk production of these ewes was significantly (P≤0.05) higher than other groups.