Evaluation of physical and ultra-structural attributes of bulls' semen with variable freezing potential

This experiment was conducted to determine the physical and ultra-structural attributes of fresh bull semen and assess their potential use for freezing and AI. A total of 40 semen samples collected from 4 mature bulls (10 samples per bull) were analyzed. The semen samples were examined for colour, volume, concentration, pH, general and progressive motilities, morphologically normal spermatozoa, acrosome and DNA damage, and lipid peroxidation. Transmission Electron Microscopy (TEM) was also performed to evaluate the ultra-structures of the spermatozoa. Results showed the semen colour varied from bull to bull from creamy-white in bull #1, to milky in bulls #2 and 4, then cloudy in bull #3. Highest sperm concentration, lipid peroxidation and pH were recorded from bull #4. Highest volume, progressive motility, morphology, less acrosome damage and viability were from bull #2. While best values for general motility and DNA damage were obtained from bull #1. TEM revealed 92.5, 90.0 and 82% of intact heads for bulls #1, 2 and 3, respectively, much higher than 62.5% for bull #4 and 32.5, 25.0, 37.5% of total defective spermatozoa for bulls #1, 2 and 3, respectively, much better than 80.0% in bull #4. Conclusively, bulls #1, 2 and 3 were consistently satisfactory in most parameters evaluated and hence their semen can be used for freezing. On the other hand, bull #4 expressed higher (p<0.05) sperm concentration but yet was unsatisfactory in most other parameters assessed, including low live:dead ratio and high percentage of abnormalities recorded, manifesting poor potential of freezability

Herd growth parameters and constraints of camel rearing in Northeastern Nigeria

Abstract The one-humped camel, Camelus dromedarius, is an important pack and ride, dairy and meat animal in semi-arid northeastern Nigeria. This study was carried out to document reproductive information for scientists and farmers on camel rearing for improved productivity. A structured open-ended questionnaire on herd growth parameters and constraints of camel-rearing in the region was administered to 147 respondents. Results showed that most camel owners were middle aged, married, Arab men with over 20 years of experience in camel-rearing. The camels were made up of predominantly mixed breeds originating from eastern and northern Africa. Sexually matured heifers are detectable at three years of age, have good body conformation and are receptive to bulls during estrus. They have a long rutting period that stretched from rainy to harmattan seasons (July to January). Length of gestation is 13 months, and pregnancy is detectable by observing a successfully mated cow raising her tail on being approached by a bull at two weeks into pregnancy or the distension of the abdominal region towards mid pregnancy. Up to 60% conception rate was reported while age of cow at first parturition was five years. Other herd growth parameters reported include calf mortality rate of up to 40%, milking duration of one year and productivity of at least 10 calves per cow per life time. Only 4% of respondents in this study consult veterinary care while few (23%) respondents helped the dam to suckle its new born. Abortion, biting flies, trans-border conflicts and armed banditries were the major constraints to camel production in the study area. It was concluded that despite the knowledgeability of camel herders in this study, there appears to be poor herd management that needs to be addressed by adequate education and access to veterinary care in order to improve productivity