Hadil obid (1)*, Abdel Nasser al omer (1), Rema Al-Wadaa(1) and Ali Deeb (2)
(1). Hama Research Canter, General Commission for Scientific Agricultural Research, Syria.
(2).Department of Animal Production, Faculty of Agriculture, Al-Baath University, Homs, Syria.
(*Corresponding author: Hadil Obid , E-Mail: Hadilobaid2017@gmail.com).
Received:26/05/2023 Accepted: 7/09/2023
Abstract:
The research was carried out in the sheep research station at the Hama Research Center of the General Authority for Scientific Agricultural Research, during the period (2016- 2022), the aim of this research was to study the daily milk production rate, lactation period, twins, and some factors affecting. 548 records were used which belong to (257) A milking ewes and (51) rams, and (682) records were used to study the percentage of twins and some influencing factors (year of birth, parity mother’s age and weight, type, and sex of the newborn). The data were subjected to the general linear model, and analysis of variance was used to determine the effect of different factors using the SAS program (1996). Estimating the values of the best linear unbiased prediction (BLUP) and the characteristic of daily milk production for Parents of Awassi sheep were done by using the statistical analysis program (MTDF). The general averages of daily milk production, lactation period, and the percentage of twins were 1.35 ± 0.02 kg / day / head, 173 ± 1.3 days, % 47 respectively during the study period. Heritability and repeatability estimations of daily milk yield were found to be (0.24 ± 0.10) and (0.40 ± 0.10), respectively. BLUP yield values for daily milk have ranged between (0.92) kg for Sheep No. (3032) and the lowest value was (-0.31) kg for Sheep No. (3450) and between (0.337) kg for ram No. (1335) and the lowest values (-0.71) kg for ram No. (4025) as a deviation from the average daily milk production in the herd. It was found that many non-genetic factors affected the studied traits, they had a significant effect on the performance of the parents of sheep and rams. From the previous results it can be concluded that, there is a necessity to pay more interesting to genetic and non-genetic factors through exclusion processes based on animal records and breeding values of parents, and the necessity of introducing the percentage of twins and daily milk production into the genetic improvement program to obtain a benefit from genetically superior animals by increasing the rate of genetic improvement.
Key words: Daily milk production, Twins, Breeding values, Awassi sheep.
Full paper in Arabic: pdf