Alemayehu Tegegne

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Ninety-five cows (79 Boran and 16 Boran-Brahman crossbreeds) and 107 heifers (55 Boran and 52 Boran x Friesian F1 crossbreeds) were used to determine estrus response, estrus response interval and pregnancy rate following synchronization with prostaglandin (PGF(2)alpha), a progesterone-releasing intravaginal device (PRID) and Synchro-mate B (SMB). The(More)
Plasma progesterone concentrations were determined weekly during gestation averaging 283 +/- 2 d in Ethiopian zebu (Bos indicus) cows. Mean progesterone levels increased from 0.2 +/- 0.1 ng/ml at oestrus (service) to 3.1 +/- 1.6 ng/ml on d 7 and 8.1 +/- 2.1 ng/ml on d 21. Progesterone levels remained elevated throughout pregnancy. Hormone concentration(More)
Small East African Zebu cows (n = 120) which calved during the dry season were used to determine the effects of postpartum nutritional supplementation and suckling intensity on body weight, body condition score, reproductive performance and on calf mortality and preweaning growth performance. Cows were allocated based on calving body weight to either(More)
This study tested the hypothesis that purebred Boran (Bos indicus) cows and crossbreds of Boran and Holstein respond differently to long-term changes of feeding level in nutrient partitioning to milk and body fat stores. A total of 27 cows of these two genotypes were subjected either to a low or a high feeding level from their first oestrus as heifers until(More)
The effect of suckling on post-partum ovarian function was monitored by weekly plasma progesterone determinations using enzyme immunoassay in 16 Small East African Zebu (Bos indicus) cows maintained with a fertile bull. Five cows continuously suckled their calves (COS), but starting 30 d after calving 6 cows remained with their calves which were prevented(More)
Five tropically adapted buck breeds extensively managed in Ethiopia were studied to determine possible effects of breed and age on body size and testicular traits. In all, 177 bucks were selected following stratified random sampling, and evaluated in three age groups: <14 months (young), 14-19.5 months (intermediate) and 19.6-24 months (old). The breeds(More)
Gonadal and extragonadal sperm reserves were determined in testicular and epididymal tissues obtained from Boran (n=10) and Boran x Friesian (n=12) bulls fed either a high or low plane nutrition diet for a 1-year period. The bulls were 32 months of age at castration. Mean (+/-SEM) daily body weight gains over a 1-year period were 776+/-34 and 264+/-34 g/day(More)
In this study, feed intake and sperm morphology were evaluated in Ogaden bucks supplemented with either agro-industrial by-products or khat leftover. Thirty-five bucks at about 1 year of age, and 15 +/- 1.5 kg initial body weight, were involved in a 12-week feeding programme that had four diet groups. The control (C) diet comprised grass hay alone, fed ad(More)
Data collected over a 10-yr period on 1,778 service intervals in 1,111 Arsi (Bos indicus), cows at the Ethiopian Ministry of Agriculture ranch were analyzed. Conception rate to first service was 48%, cows calving from June to February being more likely to conceive at first oestrus. Overall interval between services in animals returning for insemination(More)
The effects of work and diet supplementation on progesterone secretion and on incidence of short luteal phases and ovulations without estrus was investigated in 40 postpartum F(1) crossbred dairy cows. These cows were allocated to 1 of 4 treatment groups: Group SPNW, supplement-nonworking; Group SPW, supplement-working; Group NSNW, nonsupplement-nonworking;(More)