17 Relationship Between Semen Parameters and Morphometric Characteristics of Zulu Rams
J. N. Ngcobo A B , A. Maqhashu B , F. V. Ramukhithi A , L. P. Kruger A , K. A. Nephawe B and T. L. Nedambale BA Germplasm Conservation and Reproductive Biotechnologies, Agricultural Research Council, Irene, South Africa;
B Department of Animal Sciences, Tshwane University of Technology, Pretoria, South Africa
Reproduction, Fertility and Development 30(1) 148-148 https://doi.org/10.1071/RDv30n1Ab17
Published: 4 December 2017
Abstract
Zulu sheep is an adapted breed of South Africa with desirable traits such as their ability to thrive in a harsh environment and tolerant to various diseases. However, they are endangered, with their population size not exceeding 1000, and hence are associated with high inbreeding rates. Therefore, to limit biodiversity loss, there is a need to characterise and conserve its genetic materials. The aim of the study was to evaluate the relationship between morphometric characteristics and semen parameters of Zulu rams and conserve these genetics. The study was conducted at the Agricultural Research Council. Rams (n = 6, age = 3 years and average weight = 42 kg) were fed a standard diet and water was provided ad libitum. Semen was collected twice a week, using an artificial vagina, over 4 consecutive weeks. Semen volume, spermatozoa concentration, motility parameters, and viability were evaluated immediately after arrival in the laboratory. The experiment was carried out during breeding season (March to May 2017). Body measurements (rump height, body length, scrotum circumference, body weight, scrotal width, and scrotum length) were measured in the morning following the fasting period (night) using flexible measuring tape. Pearson correlation coefficient in Minitab 17 (Minitab Inc., State College, PA, USA) was used to determine the relationship among variables. A moderate significant correlation (P < 0.001) between body weight and %live spermatozoa (r = 0.46) was observed. Of note, a very weak (r = 0.28) significant correlation (P < 0.05) between scrotum circumference and live spermatozoa was observed. A very weak (r = 0.06) nonsignificant correlation (P > 0.05) was found between scrotum circumference and semen volume. These results indicate that body weight and scrotum circumference provide reliable spermatozoa viability estimates. Positive correlation between scrotum circumference and semen volume shows that scrotum circumference can be used to predict semen volume.
