engleski

Influence of parity on pregnancy rate and progesterone level in boer goats

It is already known that parity could influence pregnancy rate in domestic animals. It is also widespread known that number of kidds could influence level of progesterone during pregnancy in goats and ewes. In this study two groups of boer goats were compared (10 primiparous goats and 10 pluriparous goats) kept in the same herd and covered by the same buck with proved fertility . The aim of the study was to determine whether parity could influence pregnancy rate and progesterone level. Number of kidds was also observed to exclude influence of kidd number on progesterone level. Blood samples were collected weekly from mating till parturition to determine level of progesterone in both groups. Goats were monitored using ultrasound probes and number of kidds were observed after parturition. Blood was centrifuged and sera samples were stored at -20°C till analysis. Level of progesterone in sera samples was determined using standard RIA method with conjugated steroids (Coat-A-Count TKPG, Diagnostic Product Corporation) without preincubation. The 125I in the pellet was quantified using gamma counter (LKB Wallac 1261 Multigamma counter, LKB, Turku, Finland) with a counting efficiency of 75%. All samples were analysed in duplicate with middle value like result and all suspect results were repeated. Program Statistica and ANOVA to perform variance analysis and linear correlations were used. Pregnancy rate and progesterone level were compared between primiparous and pluriparous group. Primiparous group had pregnancy rate 50% (5 goats) while pluriparous group had pregnancy rate 90% (9 goats). Pregnancy rate was significantly higher in pluriparous group (p<0, 05). Level of progesterone was compered between pregnant pluriparous and primiparous goats. Progesterone level was significantly higher in pregnant pluriparous goats (p<0, 05). Number of kidds didn't differ between the groups (2, 4 versus 2, 6 kidds). Level of progesterone was also compared between nonpregnant pluriparous and primiparous-nulliparous goats, but there was no significant difference between the groups. We concluded that parity influences pregnancy rate and level of progesterone in pregnant boer goats but it has no effect on progesterone rate in nonpregnant boer goats

goat; pregnancy rate; progesterone; number of kidds

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