Evaluation of non-genetic factors affecting calf growth, reproductive performance and milk yield of traditionally managed Sheko cattle in southwest Ethiopia

Reproductive performance of Horro and Horro-crossbred dairy cows in Ethiopia's subhumid tropical environments

Estrus detection, timing of insemination, feeding, and health care practices are all factors that can significantly affect cattle breeding efficiency and lifetime production. In Ethiopia's subhumid environment, the age at first calving, number of days open, duration from calving to first heat, and number of services per conception are economic traits that affect reproductive performance of Horro and Horro-crossbred dairy cows. Data collected at Ethiopia's Bako Agricultural Research Center between 1980-2019 was used to study the reproductive performance of Horro and Horro-crosses with Holstein Friesian and Jersey dairy cows. We identified overall mean ± standard error values of factors that affect reproductive performance, including age at first service (AFS) (29.2 ± 0.2 months), age at first calving (AFC) (39.8 ± 0.2 months), number of services per conception (NSC) (1.76 ± 0.4 months), calving interval (CI) (13.2 ± 0.3 months), days open (DO) (94.3 ± 4.3 days), conception rate (CR) (75.0 ± 1.3%), and replacement rate (RR) (28.4 ± 0.3%). The odds ratios of the 60-day and 90-day nonreturn rates (NRR) were 0.22 and 0.96, respectively. Sire and dam breed and birth period had significant (P < 0.001) effects on AFS and AFC, while season and dam parity had significant effects on CI and DO. Inconsistencies regarding feeding, heat detection, inseminator skills, insemination timing, animal health, and other husbandry practices may extend periods of AFS, AFC, CI, and DO. To optimize reproductive performance in Horro cows and Horro crossbreeds in Ethiopia's subhumid environments, improving management practices should be a priority.

Growth Performance and Survival Rate of Fogera and Their Crossbred Calves at Government Ranches in Ethiopia

The economic benefit of dairy products can be enhanced by increasing the efficiency of growth and survival rate of calves. The objective of the study was to evaluate the effects of non-genetic factors on pre- and post-weaning growth traits and mortality rate of pure Fogera and their F1 cross Fogera × Holstein Friesian calves at the Andassa and Chagni Cattle Breeding and Improvement Ranch. Retrospective types of study design and direct measurement were used to collect the data. A total of 3,626 for pre-weaning weight records and 107 for post-weaning measurements were used for analysis. Genotype, sex, dam parity, year of birth, the season of birth, and location were the considered production factors. The overall least square means (LSM ± SE) of birth weights were 22.33 ± 0.12 and 24.56 ± 0.11 kg for Fogera and their crosses, respectively. The overall LSM ± SE of weaning weights were 93.25 ± 0.85 and 111.63 ± 0.84 kg for Fogera and their cross calves, respectively. The overall post-weaning weight for Fogera and their cross calves were 101.02 ± 1.62 and 111.08 ± 2.65, respectively. All variables considered in the model, except dam parity, significantly (P &lt; 0.05) affected post-weaning weight. The overall recorded mortality rate was 3% which was nearly the optimum that many scholars agreed to successful rearing practices.

Production, reproduction and some adaptation characteristics of Boran cattle breed under changing climate: A systematic review and meta-analysis

Introduction

Climate change affects livestock production and productivity, which could threaten livestock-based food security in pastoral and agro-pastoral production systems of the tropics and sub-tropics. Boran cattle breed is one of the hardiest Zebu cattle reared by Borana Oromo pastoralists for milk and meat production. However, there is limited comprensive information on production, reproduction and adaption traits of the Boran cattle in Ethiopia. Thus, this paper aims to compile the main production, reproduction and some adaptation traits of Boran cattle based on systematic review and meta-analysis of peer reviewed published and unpublished literature.

Methodology

A combination of systematic review and meta-analysis based on PRISMA guideline was employed. Accordingly, out of 646 recorded articles identified through database searching, 64 were found to be eligible for production, reproduction and adaptation characteristics of the Boran cattle, 28 articles were included in qualitative systematic review while 36 articles were used for quantitative meta-analysis.

Result

The Boran cattle breed has the ability to survive, produce and reproduce under high ambient temperature, utilize low quality forage resources, and resist water shortage or long watering intervals and tick infestations. The review revealed that the breed employs various adaptation responses (morphological, physiological, biochemical, metabolic, cellular and molecular responses) to cope with harsh environmental conditions including climate change, rangeland degradation, seasonal feed and water shortages and high incidences of tick infestations. The meta-analysis using a random-effects model allowed provision of pooled estimates of heritability and genetic correlations for reproduction and production traits, which could be used to solve genetic prediction equations under a population level in purebred Boran cattle. In addition, heritability and genetic-correlation estimates found in the present study suggest that there is high genetic variability for most traits in Boran cattle, and that genetic progress is possible for all studied traits in this breed.

Conclusion

The Boran cattle breed has the ability to survive, produce and reproduce under high ambient temperature, utilize low quality forage resources, and resist water shortage or long watering intervals and tick infestations. However, currently there are several challenges such as recurrent droughts, pasture deterioration and lack of systematic selection and breeding programs that play to undermine the realization of the potential of the breed. Thus, we recommend systematic selection for enhancing the reproductive and production performances without compromising the adaptation traits of the breed coupled with improved management of rangelands.

Genomic signatures of adaptive introgression and environmental adaptation in the Sheko cattle of southwest Ethiopia

Although classified as an African taurine breed, the genomes of Sheko cattle are an admixture of Asian zebu and African taurine ancestries. They populate the humid Bench Maji zone in Sheko and Bench districts in the south-western part of Ethiopia and are considered as a trypanotolerant breed with high potential for dairy production. Here, we investigate the genome of Sheko cattle for candidate signatures of adaptive introgression and positive selection using medium density genome-wide SNP data. Following locus-ancestry deviation analysis, 15 and 72 genome regions show substantial excess and deficiency in Asian zebu ancestry, respectively. Nine and 23 regions show candidate signatures of positive selection following extended haplotype homozygosity (EHH)-based analyses (iHS and Rsb), respectively. The results support natural selection before admixture for one iHS, one Rsb and three zebu ancestry-deficient regions. Genes and/or QTL associated with bovine immunity, fertility, heat tolerance, trypanotolerance and lactation are present within candidate selected regions. The identification of candidate regions under selection in Sheko cattle warrants further investigation of a larger sample size using full genome sequence data to better characterise the underlying haplotypes. The results can then support informative genomic breeding programmes to sustainably enhance livestock productivity in East African trypanosomosis infested areas.