Effects of Waiting Period before Milking on Orotic, Uric and Hippuric Acid Contents of Milks from Shami and Kilis Goats

Abstract

The organic acids present in milk in varying quantities can reflect the health condition of the animals and the nutritional quality of milk. In rural areas, goats are maintained in pasture during whole day and milking is being started as soon as goats arrive to farm. However, it is not known whether milking during feeding as soon as goats return from pasture or after 1 hour-waiting have any effect on nitrogen-containing organic acids are the body metabolism products. Therefore, in this study we objected to determine the effects of 1 hour-waiting period before milking on orotic, uric and hippuric acids of milks from “Shami (Damascus)” and “Kilis” goat breeds during lactation period. The trial was carried out with 40 goats. The 20 goats from each breed were randomly separated to two groups at equal number. Control and experimental groups of the both breeds were milked during feeding as soon as goats return from pasture and after 1 hour-waiting following feeding, respectively. The milk samples taken with interval 30 days from May to October were used for organic acid analysis at a reverse phase high performance liquid chromatography. During lactation hippuric acid was the most abundant organic acid, followed by orotic and uric acids. Experimental group of Kilis goats had the highest level of hippuric acid. Orotic acid was higher in Shami goats than that in Kilis breed. Uric acid was the highest in control group of Shami breed. The 1 hour-waiting period before milking resulted in a significant decrease in uric acid. In general, orotic and uric acid decreased towards the end of lactation whereas hippuric acid markedly increased in the last 3 months of lactation. It was concluded that the 1 hour-waiting before milking after returning from pasture may be especially suggested to Shami goat raisers due to the low uric acid content of the milk.  

Keywords

• lactation; goat breed; organic acids containing non-protein nitrogen