Review of beef cattle breeding research and achievements in Ethiopia

A literature review was conducted based upon 17 research reports on the beef cattle breeding activities in Ethiopia with an objective of summarizing and compiling research fi ndings in different experiments on breeding works of beef cattle in Ethiopia and indicating future research directions. The review testifi es that 27 breeds or types of cattle with 7 distinct breed categories were identifi ed in Ethiopia. The review also summarizes the birth, weaning and yearling weights of indigenous cattle and their crosses at different levels of exotic blood. Conclusions and future research directions were also indicated in this review document. Review Article Review of beef cattle breeding research and achievements in Ethiopia Tesfaye Alemu Tucho*, Tatek Woldu and Berhanu Shelima Adami Tulu Research Center P.O. Box 35, Zeway, Ethiopia Received: 30 November, 2020 Accepted: 17 March, 2021 Published: 19 March, 2021 *Corresponding author: Tesfaye Alemu Tucho, Adami Tulu Research Center P.O. Box 35, Zeway, Ethiopia, E-mail:


Introduction
In Ethiopia there is no specifi c cattle breed which is exclusively selected and used for beef production, because there has been no development of the indigenous breeds for particular production traits. The indigenous cattle breeds are used for multi purpose traits particularly for milk, meat and draft as well as manure production. The country produces beef in different ways. Major proportion of beef comes from old oxen, culled cows, surplus young bulls and fattened bulls from urban and peri-urban fatteners. Consequently, the major proportion of beef produced in Ethiopia is not of high in quality and quantity.
The country has high potential for beef production. Ethiopia, situated in the horn of Africa, is a country with low level of beef production as compared to other countries in Eastern Africa. Evidences show that level of beef productivity in this country is 110kg per head, which is 25-30% lower than other countries in Eastern Africa and 50% lower than the world average (212/head) [2]. Likewise, Ethiopia has the lowest level of beef in terms of volume output, which is 27 and 7% lower than East Africa and the whole Africa, respectively. The less than desirable performance in this sector is mainly attributed to lack of research activities focusing on beef animals, poor nutrition, and low genetic potential of local cattle for beef production and lack of proper fattening system.

Reproductive performance
The three major traits that contributed to cattle meat production are reproductive performance, viability and growth rate. A high calving rate is essential for profi table calf production and these calves must survive and grow rapidly to obtain satisfactory slaughter weights at early age. Most studies in Ethiopia, however, indicate that reproductive performance of the local cattle is low and inadequate. Information on age at puberty is scanty and widely variable with the crossbred heifers more favorable than Zebu. Environmental factors, particularly nutrition determines pre-pubertal growth rates, reproductive development, onset of puberty and subsequent fertility.
For example a study at Abernossa i.e. strategic nutritional supplementation, only in dry season, to young Borana and Borana x Friesian heifers improved growth rates and reduced age at puberty by about 2 months [5]. A study by Sineshaw For example Studies at Abernossa ranch on Borana heifers, showed the mean age at fi rst calving of 44-54 months to be reduced to 28-30 months through a mere strategic dry season supplementation [5,6]. The variation in pregnancy rates in Borana cattle has been attributed to the yearly variation in nutrition (rainfall effect) ( Table 1) calving during the dry season and in poor body condition had pregnancy rates ranging from 22 to 46 % at Abernosa ranch [5].
During periods of adequate nutrition, fertility rates were satisfactory even for zebu cows. For example, at Bako Research Center, a mean calving rate of 93 % was reported for many years [7]. Similarly, in 1989 at Abernosa, when there was good rain, pregnancy rates in Borana cows ranged from 80 to 94 % in four breeding units [5]. Wide variability in pregnancy rates reported for zebu and crossbred cattle suggests genetic, environmental, and management factors can affect herd fertility.
Although Artifi cial Insemination (AI) practice with proper heat detection methods contribute to the success of AI operations; year, season, age, and parity of the cow will also contribute to variation in NSC.
Zebu cattle have long calving interval, which infl uences herd reproductive effi ciency and meat production. Economically optimal and practically achievable calving intervals have to be found for different genotypes of cows under different production and management systems.
Aspects of bull reproduction have been totally ignored in boost beef production and export earning by Improvement of indigenous breeds to attain a desired marketable weight at earlier age. This can be achieved through, selection of indigenous cattle for superior growth performance, cross breeding with appropriate beef breed, improving feed quality and quantity, improving animal health, establishing different cooperatives specialized for rearing, growing and fi nishing of beef cattle for local and export market.
The objectives of this review paper are:

Genetics and breeding
The recent DARGIS [3], data base report indicated that there are about 27 types\breed of cattle are identifi ed in Ethiopia.
They are categorized into 7 distinct breed categories, these are:  Friesian bulls and was infl uenced by dry season nutritional supplementation [5]. The results suggest that reproductive activity in these bulls occurs at earlier ages than was speculated and identifi cation of bulls at younger age for performance testing could be accomplished. Superior bulls in terms of body growth and reproductive capacity therefore could be identifi ed at younger age in order to enhance genetic gains in a selection program.

Growth traits of different genotypes
Birth Weight (BWT): Early growth traits are important, because it is associated with other performances [8]. Research has shown that higher birth weight followed by faster growth rate in females leads to earlier breeding age and other things being equal, increased lifetime productivity [8]. was obtained as the level of exotic inheritance increased from 0 to 75%. Likewise, an increase of about 2.9 kg (9.6%) was obtained between F 1 crosses and crosses with 75% exotic inheritance. This suggests that further incorporation of exotic genes beyond 50% resulted in consistent increase in BWT.
In all the reports considered for this review, lower BWT was observed for local Horro calves and crossbred calves born to Horro dams and Jersey sires.

Average Daily Gain (ADG)
The infl uences of environmental factors (calf rearing system, housing, feeding, health care etc) are appearing to play infl uential role in average daily gains of newborn calves.
Studies showed that [18], among other factors, calf rearing system (partial suckling or bucket feeding system) plays signifi cant role in affecting average daily gain of calves. Average value showed that local breeds and F 2 crosses had similar ADG even though there were large differences in BWT.
This could be on one hand attributed to loss of hybrid vigor and Kiwuwa, et al. [13], Beyene [8], Ababu [14], Sendros [9]. Abdinasir [15], Beyene [8], Sendros [9], Hailu [10]. Beyene [8], Amsalu [11], Hailu and Tadelle (Table 3). Large differences in body weight at weaning among local calf breeds could be originated from two possible sources. Firstly, differences in BWT might be attributed to differences in WWT, i.e. calves heavier at birth are also heavier at weaning. Secondly, rate of gain per day is another important source for the difference in WWT i.e. calves, which gain higher per day were heavier at weaning than calves whose daily gain were low.
There was no difference in WWT between F 1 Friesian and Simmental calves, but both crosses were heavier than Jersey calves by about 14 kg (14%). A comparison of WWT among F 2 crosses showed that F 2 Friesian crosses were heavier by about 6.97 kg (7.6%) and 2.73 kg (2.8%) than F 2 Jersey and F 2 Simmental crosses, respectively. Further comparison of WWT among high grades showed that 75% Friesian crosses were 16.6 kg (18.25%) and 6.2 kg (6%) heavier at weaning than 75% Jersey and 75% Simmental crosses, respectively.
Two breed crosses were heavier by 3Kg (6%) than three breed crosses at the age of 90days. This signifi cant (P<0.05) weight difference was also refl ected in average daily weight gain from birth to 90days, where two breed crosses gained 31gm (9.7%) more weight daily than three breed crosses when all genetic groups are simultaneously considered, F 1 crosses were heavier at weaning followed by 75% exotic inheritances, F 2 crosses and local in the order mentioned.

Yearling Weight (YWT)
At one year of age, F 1 Friesian crosses were heavier than their Jersey counterparts by about 12.65 kg (9.3%), but lighter than F 1 Simmental crosses by about 3.72 kg (2.4%).
The average body weights of Fogera and their F1 calves were 146.8 kg and 153.3 kg at one year and 188.9 kg and 214.1 kg at two years of age, respectively (Addisu Bitew and B.P Hegede. 2002) ( Table 4).
Overall comparison among all genetic groups showed that F 1 crosses were heavier than local; F 2 crosses and crosses with 75% exotic inheritances by about 27.67 kg (23.34%), 14.67 kg (11.15%) and 9.36 kg (6.8%), respectively. Though F 1 crosses were heavier than crosses with 75% exotic inheritance and F 2 crosses, inferiority of the later genotypes in YWT might be attributed to unmet level of management practices that could support optimum growth in large sized crosses.
Crossbred calves with 50% Simmental blood had the heaviest (P < 0.05) weight at all ages after birth. Crossing Borana cattle with Simmental breeds improved growth performances of calves with 50% Simmental blood and further upgrading to 75% of Simmental blood did not improve growth performance under tropical condition. Male calves were signifi cantly heavier at birth (P < 0.01) and at all other ages (P < 0.05) than female calves, and they grew 6.2% and 10% faster than females during pre and post weaning periods, respectively (Amsalu Sisay, 2003). Borana X Simmental cows had signifi cantly (p < 0.001) the heaviest weight at calving (381.3 ± 5.95 kg), estrus (322.3 ± 3.07 kg), service (330.6 ± 4.00 kg) and conception (344.2 ± 4.56 kg), while Horro cows had the lightest weight.

Conclusion and recommendation
• Very much limited research activities were undertaken in the country relative to the genetic resources for beef production.
• Appropriate breeding strategies and models should be designed for Improvement of indigenous breeds to attain a desired marketable weight at an earlier age (i.e. either by management, within breed selection or cross breeding with exotic breeds for the intended purpose) • Future beef cattle breeding activities should consider carcass characteristics, market demand and economic aspects.
• There is no much data on post weaning and matured body weight performance of indigenous cattle or their crosses; generating such data should be considered in the future.
• In addition to the breed improvement programs; enhancing feed quality and quantity as well as prevention and control of animal disease has to be given due attention.