Effect of season of fertilization on live weight of Ile-de-France lambs

Tanya Ivanova, Evgeniya Achkakanova

Abstract: The aim of the study was to determine the effect of fertilization season on the live weight of Ile de France lambs.The study was carried out in two consecutive years with 649 lambs (233 numbers born during fertilization of the ewes in the months from August to October (autumn fertilization) and 416 numbers born during fertilization in the month of April (spring fertilization)). The animals are under the selection control of the Ile de France Breeding Association, raised on a farm in northeastern Bulgaria. Live weights were measured at birth, at 30 days and at 70 days, with a deviation of ± 2 days. Biological fecundity was determined as the ratio of the number of live births, stillbirths and aborted <br>lambs to the number of lambed ewes. The information was processed using the methods of variational statistics. The effect of the season of fertilization on the studied parameters was determined by the ANOVA model of the one-factor analysis of variance, the reliability of the influence of the factor was <br>determined by the values of Fisher’s F-test, and the reliability of the differences between the studied groups - by the Student’s t-test, with the statistical package Data Analysis, Excel 2021, Microsoft. A highly reliable effect of the factor fertilization season on the live weight of the lambs on the 30th and 70th day was found (F=3.86***). Lambs realized a higher average live weight at autumn fertilization, 18,733 kg at day 30 and 35,418 kg at day 70 respectively, compared to spring fertilization 17,332 kg and 33,893 kg at the same ages in 2018. The biological fertility of ewes was in the range of 146%-154%.

Keywords: fertility; fertilization season; Ile-de-France; live weight; sheep

Date published: 2023-04-28