A.M. Florea

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REPRODUCTION INDICES IN THE BOTOSANI KARAKUL FEMALES AND THEIR EVOLUTION IN THE REPRODUCTION PERIOD

A.M. Florea, Gh. Hrincă, I. Nechifor, C. Pascal, Claudia Ionela Nechifor

Abstract
    The study quantifies the reproduction function in sheep belonging to the Botosani Karakul breed by means of some indices analyzing their values in their dynamics during the five years (2008-2012) within the same animal population. From the initial population, a part of animals got out of herd during the experiment (by mortalities, sterility or other causes). The three main reproduction indices (fertility, birth rate, fecundity) recorded similar values in the first two years, in order that in the last three years their levels to be higher, their evolution having an ascendant curve. The sterility is more common in the middle of reproductive period (especially in the second year), the onset of reproduction activity being characterized by low sterility and almost inexistent at its end. The abortions are more common in the first reproduction year, becoming rarer and rarer in the rest of the range. Simple parturitions are the most frequent throughout the reproduction period; double births are few in the first two years, then their incidence increases, especially in the last two years. As such, the simple lamb index shows a regression curve, while the twin lamb index presents an upward curve. Sex ratio is the unit in the first three years and higher than one in the last two years. The highest natal mortality is recorded at the beginning of reproduction activity; in the next years the natal mortality is generally low. So, the best reproduction indices were recorded in the last three years of reproduction activity.

Key words: reproduction indices, reproduction period, mating, Karakul sheep