Impact of subclinical mastitis on uterine health, reproductive performances and hormonal profile of Zebu × Friesian crossbred dairy cows in and around Jimma town dairy farms, Ethiopia.

A longitudinal observational study was carried out from January 2020 to July 2021 to assess the impact of subclinical mastitis (SCM) on reproductive performance and its association with uterine health of crossbred dairy cows. The California Mastitis Test (CMT) and cytobrush technique were used to screen subclinical mastitis and subclinical endometritis, respectively. Milk samples positive for subclinical mastitis were subjected to bacteriological analysis. Data from 84 clinically healthy cows collected and analyzed. The present study revealed a prevalence of subclinical mastitis of 51.2% (43 of 84). The mean days from calving to first service interval were significantly longer in subclinical mastitis positive cows than negative (control) cows (120.51 ± 24.5 and 85.15 ± 28.3, respectively) (P < 0.05). The mean number of services per conception was significantly higher in positive cows (2.51 ± 0.83) than in negative cows (1.59 ± 0.81) (P < 0.05). Lower conception and pregnancy rates at first services were observed in subclinical mastitis cows. Risk factors analysis revealed that prevalence of subclinical mastitis significantly differed with the parity and body condition score (P < 0.05). The current study revealed that subclinical mastitis was significantly and directly associated with subclinical endometritis (P < 0.05). Subclinical mastitis significantly decreased (P = 0.000) progesterone concentrations and increased (P = 0.001) the cortisol concentrations. Staphylococcus aureus were the most predominant bacterial isolates from subclinical mastitic milk, followed by coagulase negative staphylococci (CNS) and streptococci. This study concludes a high prevalence of subclinical mastitis caused by Staphylococcus aureus could inflict harmful effects on reproductive performance of dairy cows, emphasizing the relevance of mastitis control programs in dairy farms.

Repeat Breeding and Its' Associated Risk Factors in Crossbred Dairy Cattle in Northern Central Highlands of Ethiopia.

The purpose of the current study was to ascertain the prevalence and incidence of repeat breeding and related risk variables in crossbred dairy cattle in the northern Central Highlands of Ethiopia. The prevalence and incidence of repeat breeding in crossbred dairy cattle were 38.4% and 36.6%, respectively, out of the total cows and heifers taken into account for this study and handled with various production strategies. Age, parity, body condition, breeding practices, milk yield, management condition, and insemination time were all substantially (P < 0.05) associated with the prevalence and incidence of repeat breeders. Repeat breeder is more common in elderly, underweight, multiparous, high-milk producing, and AI serviced cows, as well as cows kept in poor management condition. It was deduced that the production system had a significant impact (P < 0.05) on the prevalence of repeat breeders in the research area. In addition, herd size was significantly associated (P < 0.05) with the prevalence of repeat breeder in this study. Insemination time and heat detection practices were also substantially (P < 0.05) interrelated with the prevalence and incidence of repeat breeders, indicating that incorrect heat detection and/or insemination timing had an impact on these variables. Therefore, it is suggested to increase the mindfulness of farm owners, managers, and attendants about appropriate feed and feeding management, accurate heat detection, and insemination time. To reduce the incidence of repeat breeders and the associated reproductive issues, as well as the resulting financial losses on dairy farms, health, housing, and reproductive management should also be improved.

Effect of follicular ablation and gonadotropin priming on the recovery and quality of oocytes in Boran cows.

The objective of the study was to evaluate the effect of follicle ablation, exogenous FSH application, and different coasting time prior to ovum pick-up (OPU) on the number of follicles suitable for aspiration, oocyte quality, and cleavage rate in Ethiopian Boran cows. The experiment was carried out in three parts, (I) cows were synchronized using 500 µg PGF2α given 11 days apart. Cows were then subjected to a biweekly ovum pickup session before ovulation (n = 5) or starting day 7 after ovulation (n = 4) for 3 weeks. (II) Cows were synchronized, and all visible follicles were ablated on the first days of overt estrus, and cows were grouped into those that received a divided dose of 350 IU FSH (n = 5) or 175 IU FSH (n = 5) over 3 days. In both groups, OPU was carried out weekly starting 48 h after the last FSH for 6 weeks. (III) Protocol was similar to part II, but in group with 350 IU FSH (n = 5), coasting period was increased to 72 h. The covariates of follicles and oocyte were not affected (P > 0.05) by corpus luteum presence at OPU. The mean number of medium (7.36 ± 0.57) and large (8.28 ± 0.96) follicles were significantly higher (P < 0.05) in the group that received divided 350 IU FSH. Similarly, the mean number of grade-1 (4.19 ± 0.24) and grade-2 (4.32 ± .27) oocytes, maturation rate (70.41%), and cleavage rate (47.5%) were significantly higher (P < 0.05) in the group that received 350 IU FSH. COC quality was significantly (P < 0.05) influenced by coasting period. However, both maturation and cleavage rates were not affected by the coasting period. This study demonstrated that follicular ablation and treatment with FSH improves follicular population and oocyte recovery rate in Boran cows.

Major Causes of Calf and Lamb Mortality and Morbidity and Associated Risk Factors in the Mixed Crop-Livestock Production System in Jamma District, South Wollo, Ethiopia.

Lamb and calf preweaning mortality and morbidity account for serious losses in sheep and cattle production and are, thus, a major factor in reducing profitability and adversely affecting the sheep and cattle farming. Thus, a prospective cohort study was conducted in Jamma district, Amhara Regional State, to determine the major cause of calf and lamb morbidity and mortality and associated risk factors. A semi-structured questionnaire and clinical assessment of the animals were conducted from 150 households to assess the potential risk factors. Besides, a total of 102 (81 fecal samples and 21 skin scrapings) were collected from 150 clinically ill and suspected animals to identify the cause of morbidity and mortality. The test of difference and correlation between variables were computed using chi-square and generalized linear model analysis. The total morbidity and mortality in calves were 33.3% and 2%, respectively, whereas for lamb, they were 27.3% and 32.5%, respectively. In calf, septicemia (100%) was a major cause of mortality, and diarrhea (54.6%) was the leading cause of calf morbidity followed by skin disease (30.1%), respiratory problems (12%), and septicemia (3.3%). Malnutrition was the most common problem in lambs causing up to 31.3% mortality followed by diarrhea 24% and respiratory problems 21.3%. The presence of a disease in adult cattle was significantly correlated to the presence of disease in calves (p < 0.001; r = 0.35). There was also a significantly higher positive correlation between sickness in adult sheep and lambs (p < 0.001, r = 0.45). Gastrointestinal parasitosis was identified in 82.7% of the samples collected from diarrheic and suspected calves (87.1% positive) and lambs (80% positive). Monezia species in lamb (33.3%) and Coccidia species in the calf (35.9%) had the largest morbidity rate. Ctenocephalides canis (16.7%) and Linognatus species (41.7%) were common ectoparasites identified in calves, while Melophagus ovinus was the only ectoparasite of lambs recovered (62.5%). In conclusion, the high morbidity found in calves and morbidity and mortality in lambs are known to seriously reduce the profitability of the smallholder cattle and sheep production in the area by affecting the availability of replacement animals and causing a detrimental effect on herd expansion and productivity. In further studies, establishing the specific causative agents, control of diseases in the adult, and improvement in feed resources should be the major areas that need to be considered to mitigate calf and lamb morbidity and mortality currently affecting the area.

Pre-service ultrasonic and manual evaluation of the reproductive organs of dairy cows presumed to be in estrus.

Manual and ultrasonic evaluation of the the reproductive organs of 62 dairy cows and heifers belonging to smallholder farms was conducted. The objective was to assess the efficiency of visual estrus detection method in the dairy animals that were presented for artificial insemination. Data were collected on reproductive status, body condition, estrus signs, and findings of rectal examination. Thirty-three animals were inseminated after ultrasonic evaluation while 29 animals were inseminated after manual evaluation through rectal palpation. Pregnancy diagnosis was performed using ultrasound 30 days post insemination. The most frequently observed estrus signs by the dairy owners were mucus discharge (83.9%) and mounting (67.7%) while the most frequently confirmed physical signs of estrus by rectal examination were cervical opening (88.7%), and uterine turgidity (82.3%). The overall mean (±SD) diameter of the largest follicle was 12.9 ± 3.4 mm with an average number of 3.5 follicles per ovary. The overall pregnancy rate was 29%. Evaluation of post-insemination records showed a significant difference (P < 0.05) in the diameter of largest follicle between the pregnant (14.7 mm) and non-pregnant (12.1 mm) animals. The mean (±SD) time interval between the first observed estrus sign to service were 10.5 ± 7.0 hrs and 14.5 ± 10.0 hrs for pregnant and non-pregnant, respectively. The low pregnancy rate, delayed time of insemination, and the difference in the size of dominant follicle indicate the incompatibility between visual estrus detection and optimal time of insemination. This confirms the significance of improving estrus detection and the need for combining estrus signs with pre-service evaluation of the reproductive organs either manually or using ultrasound.