MONTHLY VARIATION IN THE CONCENTRATIONS OF MACROELEMENTS IN THE GOAT SEMINAL PLASMA IN HUMID TROPICAL CLIMATE

Abstract

The objective of this study was to evaluate if there was variation in the composition of some macroelements in the seminal plasma of goats. Animals were raised under appropriate nutritional management (fed according to NRC), in tropical, humid climate during the twelve months of the year. Twenty male goats were used with an average age of 22.41±5.91 months. Also, semen was collected every week either by artificial vagina or eletroejaculation. At all collections, semen was centrifuged at 4000g/20 min/4ºC and the seminal plasma was stored in Eppendorf tubes at – 18°C until used for analysis. At the end of the period of collections, weekly samples were pooled by month (four/month), making a total of 240 samples to be used for biochemical analysis. The parameters were analyzed by SAS statistical program. When submitted to analysis of variance, the month of the year presented significant variation (P <0.05) for mineral concentration in the seminal plasma. A higher concentration of calcium was observed in the month of October and the lowest in November. Phosphorus reached the highest concentration in May and the lowest in September. Concerning the magnesium, the highest concentration was reached in June and the lowest in March. It is concluded that the concentration of minerals in the seminal plasma of goats varied along the year. 
KEY WORDS: Biochemistry, male goat and minerals.