Effect of walnut by-product and pioglitazone on reducing oxidative stress and improving milk production and reproductive performance of fresh dairy cows
This project is completed at 2018 in FKA comerical diary cow farm, Isfahan, Iran by using the Iran National Science Foundation (Kod No: 92021270)
Dairy cows during the transition period from pregnancy to lactation) 3weeks before to 3 weeks after parturition) are faced with numerous challenges. Negative energy balance and subsequent oxidative stress is one of the main problems causing many economic detriments. Higher milk production, may increase ROS in the body and limit capacity of antioxidant mechanisms for neutralizing these metabolites, Increasing ROS concentration in cells, damage the reproductive performance and immune responses. It is well known that negative energy balance reduce plasma insulin concentration and increase insulin resistance in transition period. Energy demand and unavailability of glucose for cells activate hormone-sensitive lipases (HSL) by glucagon in adipocytes. For this reason, lipolysis is increased and the concentration of non-esterified fatty acids (NEFA) will increase in blood plasma. Loss of appetite, changing cell metabolism of liver and decreasing insulin concentration are factors which increase the concentration of reactive metabolites of oxygen, inflammatory responses and cytokines releasing. The use of synthetic drugs or nutritional manipulation is the most important ways to opposition with transition period stresses. Pioglitazone, TZN derivative has known for its anti-diabetic properties and as an activator for peroxisome proliferator-activated receptors-γ (PPARγ), has been successfully used in many experiments for high producing dairy cows. Walnut is important due to high poly-unsaturated fatty acid (ω-6, ω-3 as natural ligand of PPARγ) content, polyphenols and its vitamin E content. Oil extraction by-product of this valuable crop probably can be convenient substitution for expensive and synthetic imported drugs. Therefore, the main purpose of this experiment in first stage will be determination of oxidative stress in transition dairy cows with attention to their production level and body condition scores and in second stage it will examine the effects of fatty acid profile of walnut by-product as a natural ligand of PPARγ with a synthetic compound of TZN derivative as a synthetic ligand of PPARγ for their effect on reducing physiological stress response in high producing dairy cows.