دراسة علاقة تعدد أشكال جيني البرولاكتين والكابا كازيين كلآ على حدة في بعض الصفات الفسيولوجية وأنتاج الحليب في الابقار المحلية في محافظة كربلاء

A Study of Relationship Of Prolactin And kappa Casein Genes Polymorphism Separately On Some Physiological And Milk Production Traits On Local Cows In Karbala Province

Summary:
The aim of this study was conducted to investigate the role of prolactin and kappa casein genes polymorphism associated with milk traits and some hormones concentration and also investigate the effect of prolactin and kappa casein genes polymorphism on milk quality and quantity minerals concentration such as protein, lactose, freezing point, density, fat, solid non fat and Czen, and with some trace elements such as Serum Iron (Fe), Serum Phosphorus (P) and Serum Calcium (Ca), and with some hormones concentration such as Prolactin (PRL), Growth hormone (GH), Thyroid stimulating hormone (TSH), Progesterone hormone (PRO), Estrogen hormone (Es), oxytocin hormone (OXY), and also investigate the effect of prolactin and kappa casein genes polymorphism on some blood parameters namely Red blood cell count (RBC), Packed cell volume (PCV), Hemoglobin cancalated (Hb), mean corpuscular volume (MCV), mean corpuscular Hemoglobin concentration (MCHC), and White blood cell (WBC) dairy cows in Karbala province.
This study is the first of its kind in Iraq. One hundred twenty healthy dairy cows were used to collect serum and blood sample in lactation period in stage (40-120) days during December 2020 to May 2021 in the northeast of rural areas in Karbala province in Iraq.
The blood samples were classified after detecting prolactin gene and kappa casein gene polymorphism used by amplification refractory mutation system (ARMS- PCR) techniques and RFLP-PCR techniques to three genotypes groups for prolactin gene polymorphism as a wild group (AA), recessive group (AG), and heterozygosity group (GG), also kappa casein gene polymorphism to three genotypes group to wild AA, recessive AB group and heterozygosity BB group.
Our result there shows a significant decrease in the protein, lactose, fat and solid non fat percentage and density in AG, GG, AB and BB compared with Wild genotype group.
On the other hand the current result also revealed a significant increase (p≤ 0.05) in serum concentration in Iron with AA group compared with AG,GG, AB, BB while in serum phosphorus there was an increase in AA groups of kappa casein gene polymorphism compared with AB, BB groups and in serum concentration of calcium was no significant in prolactin and kappa casein gene polymorphism.
Our results showed a significant decrease (p≤ 0.05) in serum concentration in PRL, TSH, Pro hormones in AG and GG groups compared with Wild groups of prolactin gene polymorphism while there is no significant difference in GH , Esr and OXY in AG and GG groups compared with AA group while a significant decrease in TSH in AB and BB compared with AA group of kappa casein gene polymorphism, there was also no significance in GH, Pro, Es, OXY concentration of AB, BB group compared with AA groups.
The current result also revealed no significant difference in Hb, PCV, RBC, MCV, MCHC in all groups of two genotype polymorphism – the study also showed a positive correlation between TSH concentration with prolactin gene polymorphism in AA genotype group and GH with Estrogen hormone in AA group.
In conclusion our result revealed that prolactin gene polymorphism had an effect on the serum Prolactin ,TSH and Progesterone hormones concentration and quantity and quality of milk production while kappa casein gene polymorphism had no effect on casein protein percentage in cross bred dairy cows in Karbala province.