Developing embryo technologies for the eland antelope (Taurotragus oryx)

Assisted reproductive technologies developed in domestic cattle serve as a starting point in similar studies on nondomestic bovids. The common eland is a useful model species for studies on rare tragelaphine antelopes. In Chapter 3 of the present study, effects of components/attributes of protein-free embryo culture media on the in vitro development of in vitro-derived bovine embryos were evaluated. A 2 x 2 factorial study comparing effects of groups of amino acids (20aa or 11aa) in two base media (modified KSOM or BM-3) demonstrated that amino acids and base medium affected embryonic development. A subsequent 7 x 2 factorial experiment to evaluate effects of osmotic pressure and supplement type in BM-3-20aa showed that embryonic development was largely affected by supplements and identified glucose (0.2 mM) as a crucial supplement. In Chapter 4, the use of behavioral training and handling of elands in a hydraulic chute to perform transvaginal ultrasound-guided oocyte retrieval without inducing general anesthesia were evaluated. Nine of 10 females associated specific sound cues with food treats. Females varied in their response interval to audio cues and to training for voluntary entry into the chute. Handling elands for oocyte retrieval required sedation and increased blood glucose levels. In Chapter 5, type of estrous synchronization or ovarian stimulation protocol did not affect ovarian response. Animals, but not month of the year, affected ovarian response. In 37 oocyte retrieval procedures using seven females, an average of 12.8 follicles yielded 9.8 oocytes, of which up to 73% matured to metaphase II. In vitro fertilization, intracytoplasmic sperm injection and nuclear transfer resulted in embryonic development. In conclusion, the bovine embryo culture study suggests that the beneficial effects of amino acids are influenced by the base medium and glucose plays more important roles in non-ATP producing pathways. Behavioral training and handling of sedated females in a hydraulic chute is a reliable method for collecting eland oocytes, which can undergo in vitro maturation and some in vitro embryonic development

Survey of mastitis in dairy herds in the Ethiopian central highlands

Prevalence of mastitis amongst dairy herds (n=725) and cows (n=2681) of Addis Ababa milk shed was investigated. California Mastitis Test (CMT) was conducted on milk samples from individual quarters. Of 10,908 quarters examined, prevalence of clinical mastitis (SCM), nonfunctional or blocked quarters (NFBQ) and subclinical mastitis (SCM) were 1.2 percent, 3.8 percent and 38.9 percent, respectively. Subclinical mastitis had highest relative occurrence (88.1 percent). Prevalence of quarter SCM was over 40 percent in Urban (n=5402) and Peri-urban Dairy (n=2454), and 25.1 percent in Dairy Herds Intra-Urban (n=5402) and Peri-urban Dairy (n=2454) and 25.1 percent Dairy Herds Intra-Urban of the Secondary Towns (n=2334) and the same increased with the herd size. On cow basis, prevalence of SCM was 18.7 percent and was higher in crossbred (n=2287; 21.3 percent) than with zebu (n=397; 4.3 percent). Significantly more SCM occurred in parity two and above (n=1978; 20.6 percent) than those in first parity (n=699; 13.2 percent) but this did not increase with lactation number. Over 87 percent of CMT reactions were scores distributed between Score 1 to 3, and were suggestive of infection. It was concluded that SCM is highly and widely prevalent. As it is economically damaging, the need to establish diagnostic facility to be able to early detect and screen large number of samples is emphasized and further work on identification of causative agents is recommended

Limbic thalamus and state-dependent behavior: the paraventricular nucleus of the thalamic midline as a node in circadian timing and sleep/wake-regulatory networks.

The paraventricular thalamic nucleus (PVT), the main component of the dorsal thalamic midline, receives multiple inputs from the brain stem and hypothalamus, and targets the medial prefrontal cortex, nucleus accumbens and amygdala. PVT has been implicated in several functions, especially adaptation to chronic stress, addiction behaviors and reward, mood, emotion. We here focus on the wiring and neuronal properties linking PVT with circadian timing and sleep/wake regulation, and their behavioral implications. PVT is interconnected with the master circadian pacemaker, the hypothalamic suprachiasmatic nucleus, receives direct and indirect photic input, is densely innervated by orexinergic neurons which play a key role in arousal and state transitions. Endowed with prominent wake-related Fos expression which is suppressed by sleep, and with intrinsic neuronal properties showing a diurnal oscillation unique in the thalamus, PVT could represent a station of interaction of thalamic and hypothalamic sleep/wake-regulatory mechanisms. PVT could thus play a strategic task by funneling into limbic and limbic-related targets circadian timing and state-dependent behavior information, tailoring it for cognitive performance and motivated behaviors