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.

Effect on Benzoic Acid Production of Yoghurt Culture and the Temperatures of Storage and Milk Heat Treatment in Yoghurts from Cow, Goat and Sheep Milk

“…The hippuric acid content varied between 5.78 and 25.11 mg kg −1 in goat milk and between 20.29 and 55.58 mg kg −1 in sheep milk. Nevertheless, they did not observe any increasing or decreasing trend, as observed by Güler et al [ 22 ].…”

“…Carpio et al [ 21 ] state that the content of hippuric acid in milk is influenced by various factors, such as seasonality or farming method (organic vs. conventional). Significantly higher amounts of hippuric acid in goat milk were reported by Güler et al [ 22 ], who determined hippuric acid contents in goat milk from two breeds of goats (Shami and Kilis) local to Turkey. Samples were taken each month from May to October during the lactation period.…”

The Improved Method for Determination of Orotic Acid in Milk by Ultra-Fast Liquid Chromatography with Optimized Photodiode Array Detection

“…Therefore, the presented method based on relatively inexpensive and widely available C18-columns, and the very simple and rapid pre-column sample preparation method, provides the analytical procedure suitable for routine determination of OAc in milk samples. Our improved reversed-phase UFLC method with optimized photodiode detection to be an alternative to other analytical chromatographic methods that use very expensive ionexchange columns [8,21,24,25]. Moreover, co-elution of other organic acids and overlapping peaks in ion-exchange columns have been frequently observed [24].…”

“…Fortunately, there was no overlapping of the OAc peak with background fluctuations and components present in those stored samples of milk of sheep and cows. Our improved reversed-phase UFLC method with optimized photodiode detection to be an alternative to other analytical chromatographic methods that use very expensive ion-exchange columns [8,21,24,25]. Moreover, co-elution of other organic acids and overlapping peaks in ion-exchange columns have been frequently observed [24].…”

Importance of Bioactive Substances in Sheep’s Milk in Human Health

“…Cows’ milk contains the most orotic acid, followed by sheep’s milk and then goat’s milk. In addition, the content of this component in milk depends on the season of the year, the stage of lactation and the breed of the animal [ 80 , 81 ]. In ruminants, the highest concentration of orotic acid in milk is observed in the middle of lactation [ 78 ].…”