Developing countries, affected by population growth as well as an increase in incomes and urbanization, have to deal with a massive increase in demand for food of animal origin and a change in food habits that is often not satisfied by local production [1]. The same applies to Ethiopia. Livestock plays a central role in Ethiopia by sustaining millions of resource-poor farmers in different ago-ecological environments, ranging from pastoral and ago-pastoral to mixed farming systems that entirely depend on draft animals for the cultivation of crops [2,3]. Despite the ample potential, the dairy sector was not well developed (annual milk growth rate in production: 2.1%) to conform to the annual population growth (3.4%) and demand in the country [4]. In the country, the per capita milk consumption is 16 kg/year [5], which is much lower than the sub-Saharan African, African, and world per capita consumption averages, which were 30.8 kg, 27 kg/year, and 100 kg/year, respectively [6].

Genetic improvement of dairy cattle is essentially achieved by the selective mating of the best sires to the best cows and retaining the best of the resulting heifers. Selective breeding is the most powerful tool in breed improvement [7]. The best animals may be described as those that have the highest overall economic value. The development of the selection objective is a prerequisite to the determination of the aggregate economic value of individual animals. The selection goal attempts to characterize the overall aim of the breeding program [8]. Furthermore, a verbal description of the selection goal provides an easier way to initiate the selection process than a mathematical one. A selection objective is a list of all the traits that are desirable to improve and their relative importance. In general, the selection goal must be defined and related to satisfaction, the economics of production, and consequently profitability, because most dairy farmers would be more satisfied with an increase in profit [8]. In addition to the section goal, the list of traits that influence the selection goal (objective traits) must be identified. In the Ethiopian dairy farms, there is no documented information regarding the selection goals or list of objective traits of the producers. Therefore, the aim of this research was to define the selection goals and list of objective traits for large, medium, and small dairy farms in Ethiopia.

Description of the Study Area

The study was conducted on large, medium, and small-scale dairy production farms located in Dire Dawa, Harar, Bishoftu, and Mekele towns in Ethiopia. Moreover, institutional dairy farms at Haramaya University and the Holete Agriculture Research Center were used for the study.

Dire Dawa

Dire Dawa is geographically located in eastern parts of Ethiopia between 9°27'E and 49'N latitude and between 41°38' N and 19'E longitude and is located 515 km away from Addis Ababa. Topographically, it is a dissected mountainous region, with its altitude varying from 950 meters above sea level in the northeast lowlands to 2,260 meters above sea level in the southeast highlands. Dire Dawa has bimodal rainfall, with the mean annual rainfall varying from 550 mm in the northern lowlands to about 850 mm in the southern mountains. The mean annual maximum and minimum temperatures of the town are 31.40 °C and 18.410 °C, respectively. The total human population of the town is estimated at 288,000, with a growth rate of 2.5% [9].

Harar

The Harari region is one of the nine administrative regions of Ethiopia. Harari National Regional State is located at a distance of 525 km east of Addis [10]. The Harari region lies between latitude 9°24'N and 9°42'03"E and 42°16'E longitude. The Harari region has a wet tropical climate and receives an annual rainfall between 596 mm and 900 mm in a bimodal pattern. It is located at an altitude of 1850 meters above sea level and has a mean annual maximum and minimum temperature of 25 and 10°C, respectively. The total human population of the town is estimated at 125,000, with a growth rate of 2.6% [9]. 

Bishoftu

Bishoftu is a town and separate district located in the East Shewa zone at a distance of 45 km south-east of Addis Ababa, Ethiopia. The town is located in the east Showa zone of the Oromia region, and it lies at 9° North latitude and 40° East longitude at an altitude of 1850 meters above sea level in the central highlands of Ethiopia. It has an annual rainfall of 866 mm, of which 84% is in the long rainy season (June to September) and the remaining in the short rainy season extending from March to May. The mean annual maximum and minimum temperatures of the area are 26°C and 14°C, respectively, with a mean relative humidity of 61.3% [11].

Holota

Holota is a town and separate district in the Oromia special zone surrounding Finfinnee. The town is located 40 km west of Addis Ababa at 9°30' N and 38°30' E, with an altitude range of 2300–3800 meters above sea level. The annual mean temperature ranges from 14°C to 24°C, and the annual rainfall ranges from 900 to 1100 mm. According to the population and housing census of 2007, the population of the town is 23,296.

Mekele

Mekele, the regional capital city of the Tigray region, is located in the northern Ethiopian highlands, 777 km north of the national capital city, Addis Ababa. Geographically, it is located between 13⁰24’ and 13⁰36’ latitude and 39⁰25’ and 39⁰38’ longitude. It has an average altitude of 2200 meters above sea level, with a mean minimum, mean maximum, and mean average monthly temperatures of 8.7, 26.8, and 17.6° C, respectively. Mekelle has an estimated total population of 215,546 [9].

Figure 1: Map of Study Area.

Sampling Technique and Data Collection

The research was conducted at large, medium, and small-scale dairy cattle farms in some major towns in Ethiopia. Dairy farms were selected purposefully based on information from the agricultural development offices of the respective towns. Based on the outcome of the discussion, dairy farm producers were selected purposefully. Data were collected from recorded sheets at the respective dairy farms. Moreover, a questionnaire survey was conducted to acquire detailed information on selection goals and objective traits of the crossbreed and Holstein Friesian dairy cattle at the three scales of production systems. A total of 236 households were interviewed using a semi-structured questionnaire. The households were used to generate data on cattle herd size and structure, important traits perceived by owners, selection goals, and objective traits for dairy cattle production.

Data Analysis

Statistical analysis software [12] was used to describe the herd size and structure and the relative emphasis and economically relevant traits of Holstein Friesian and crossbreed dairy cows across all the production systems. A one-way analysis of variance was applied for quantitative dependent variables, using production systems as independent variables.

Index = (R_n × C₁ + R_n-1 × C₂ ... + R₁ × C_n) / ∑ (R_n × C₁ + R_n-1× C₂ + ... + R₁ × C_n)

Where,

R_n = the last rank 

C_n = the % of respondents in the last rank

C₁ = the % of respondents ranked first

Herd Size, Structure and Dominant Breeds of Dairy Cattle

Breeds of dairy cattle, herd structure, and herd size used in large, medium, and small-scale dairy production systems are summarized in Tables 1 and 2. In the study farms, the majority of the dominant breeds across the Holstein Friesian dairy producers were pure Holstein Friesian, followed by both pure Holstein Friesian and Holstein Friesian crossbreeds with an overall mean percentage value of 60.56 and 37.77, respectively, whereas for the crossbreed dairy producers, the dominant breeds were Holstein Friesian crossbreed dairy cows only, followed by both pure Holstein Friesian and Holstein Friesian crossbreeds with an overall mean percentage value of 78.89% and 21.11%, respectively. The result revealed that large-scale crossbreed producers had larger Holstein Friesian crossbreed cows than the result of Emebet [13], who reported that 33.3% of Holstein Friesian crosses were under urban dairy production systems in Dire-Dewa, Ethiopia. With the exception of a few farms, like Harmaya Hniversity and Holleta agricultural research centers, which had other breeds of dairy cows (Boran, Jersey, local breeds, and their crossbreeds), the majority of the study farms had only Holstein Friesian and Holstein Friesian crossbreed cows.

In the current study, milking cows showed a significant difference (P<0.05) for Holstein Friesian dairy cows under the three production systems. In the large-scale Holstein Friesian dairy producers, there were larger milking cows (20.85±9.11), followed by calves less than one year (19.00±3.45) and pregnant heifers greater than one year (16.70±6.63), respectively. The herd structure in the other two systems was different from the former one. Medium and small scale Holstein Friesian dairy producers had larger calves less than one year (13.95±3.72 and 3.57±1.13), followed by milking cows (12.20±3.35, 3.5±1.13) for medium and small scale producers, respectively. There were 4.88±1.78 pregnant heifers greater than one year in medium scale and 1.93±0.78 dry cows in small scale Holstein Friesian dairy producers, respectively. Comparing to the other Holstein Friesian producers who crossbred dairy producers, large-scale Holstein Friesian dairy producers had their own breeding bulls (1.70±1.30). This indicated that male calves were culled at an early age on the other dairy farms to avoid competition for resources. Moreover, it was an indication for the use of external breeding bulls or AI by the three systems. The overall mean obtained for Holstein Friesian dairy cattle producers for milking cows (12.18±4.53) was higher than Gatwech [14], who reported 6.15 heads in mixed crop livestock and 2.17 heads in urban dairy production in Gambella, south-west Ethiopia. Similarly, for crossbreed dairy producers, milking cows were significant (P<0.05) among the three scales of production. Respondents under large-scale crossbreed dairy cattle producers had higher milking cows (17.25±7.5) and higher calves less than one year (17.25±7.78), followed by pregnant heifers greater than one year (11.75±3.75) and non-pregnant heifers greater than one year (10.35±4.85), respectively. On a large scale, medium-scale crossbreed dairy producers had larger dairy cows (5.20±2.63), followed by calves less than one year (5.17±2.62), and pregnant heifers greater than one year (4.11±1.65), respectively. Unlike the large and medium-scale crossbreed dairy producers, small-scale crossbreed dairy producers had higher calves less than one year (2.99±1.15), followed by milking cows (2.55±0.70) and pregnant heifers greater than one year (1.67±1.02), respectively. The mean number of crossbreed milking dairy cows, pregnant heifers greater than one year, and calves less than one year per household obtained in this study was higher than the findings of Asaminew and Eyasu [15] in northwestern Ethiopia and Belay and Geert [11] for small-holder dairy farmers in Jimma Town, Ethiopia.

The present study revealed that size was significant (P<0.05) among Holstein Friesian dairy producers. Farmers under large, medium, and small-scale Holstein Friesian dairy producers had an average of 55.80±13.42, 19.75±3.71, and 3.50±1.14 pure Holstein Friesian milking cows, respectively. Similarly, for crossbreed dairy producers, herd size was significant (P<0.05) across the three scales of production. In the study farms, dairy cattle producers had an average of 42.90±7.93, 14.53±4.33, and 4.31±0.82 heads of crossbreed dairy cows under large, medium, and small-scale farms, respectively. The average herd size obtained from the study areas for large-scale crossbreed dairy production was lower than Emebet [13], who reported that large-scale dairy production holds on average 140.7±59.7 heads of crossbred dairy cattle under urban dairy production systems in Dire-Dewa, Ethiopia. In the study farms, a sizable number of farms had other livestock species other than dairy cattle. The majority of the respondents, both Holstein Friesian and crossbreed dairy producers, had other livestock, with an overall percentage of 64.44% and 76.42%, respectively.

Table 1: Mean (±SD) Herd Size, Herd Structure and Dominant Cattle Breeds per Household for Holstein Friesian Dairy Cattle.

 n= number of respondents, *means with the same letters are not significantly different, HF= Holstein Friesian.

Table 2: Mean (±SD) Herd Size, Herd Structure and Dominant Cattle Breeds per Household for Crossbreed Dairy Cattle.

n=number of respondents, HF= Holstein Friesian * means with the same letters are not significantly different.

Selection Goals for Holstein Friesian and Crossbreed Dairy Cattle

Selection goals for both Holstein Friesian and crossbreed dairy cows are presented in Tables 3 and 4. The selection goal is like a mission statement that attempts to characterize the overall aim of the breeding program [8]. Farmers' dairy farms in the present study mainly depend on improved forage and hay, concentrate, and crop residues to improve their dairy products. The current study also revealed that the major limiting resources for Ethiopian dairy farms were the capacity of production facilities (cow space) and feed resources [46]. The reasonable selection goals for farmers in these production systems were profit per unit area of grazing land and profit per unit feed intake. For large-scale Holstein Friesian dairy producers, the selection goals of their farms were based on profit per land, followed by profit per land and pasture, with an index value of 0.45, 0.28, and 0.27, respectively. Unlike on a large scale, for medium-scale dairy producers, their selection goals were greatly attached to profit per pasture, followed by profit per land, and both profit per land and pasture, with an index value of 0.39, 0.32, and 0.29, respectively. On the other hand, the main selection goals for small-scale Holstein Friesian dairy producers were based on profit per pasture and profit per land, followed by both profit per pasture and land with an index value of 0.40, 0.40, and 0.20, respectively (Table 3).

For crossbreed dairy producers, the main selection goals for large-scale dairy producers were profit per pasture, followed by profit per land and pasture, and profit per land with an index value of 0.38, 0.32, and 0.30, respectively. Unlike large-scale crossbreed dairy producers, the selection goals for medium- and small-scale dairy farms were based on profit per pasture (0.41 and 0.47) followed by profit per land (0.32 and 0.30), and both profit per pasture and land (0.27 and 0.22), respectively (Table 4). Comparing to the Holstein Friesian dairy producers, the overall selection goal of crossbreed dairy producers was mainly concerned with profit per pasture, followed by profit per land and both profit per land and pasture with an overall index value of 0.42, 0.31, and 0.27, respectively (Table 4), whereas the selection goal of Holstein Friesian dairy producers was mainly focused on profit per land, followed by profit per pasture and both profit per land and pasture with an overall index value of 0.39, 0.35, and 0.26, respectively (Table 3).

Table 3: Selection Goal of Respondents for Holstein Friesian Dairy Cattle.

n= number of respondents, R1= rank 1, R2= rank 2, R3=rank 3, TI = total index

Table 4: Selection Goal of Respondents for Crossbreed Dairy Cattle.

n= number of respondents, R1= rank 1, R2= rank 2, R3= rank 3, TI = total index

The Relative Emphasis of Traits for Holstein Friesian and Crossbreed Dairy Cattle

The relative emphasis traits for Holstein Friesian and crossbreed dairy cattle are presented in Table 5. In the study farms, there was no significance difference (P>0.05) for production and reproduction traits between large and medium-scale Holstein Friesian dairy producers, but there was a significance difference (P<0.05) between small-scale and the other two production systems for production and reproduction traits. Holstein Friesian dairy producers were given more emphasis for production traits, followed by reproduction and type traits, with an overall mean percentage of 75.20, 13.55, and 7.64, respectively. Likewise, for the crossbreed dairy cattle producers, production, reproduction, type, and secondary traits were given more emphasis, with an overall mean percentage value of 74.56, 13.55, 9.23, and 3.35, respectively. There was no significant difference (P > 0.05) for production and reproduction traits between medium- and small-scale crossbreed dairy production, but there were significant differences (P<0.05) between large-scale and the other two production systems for production and reproduction traits under crossbreed dairy producers. The relative emphasis given for production traits in the Ethiopian dairy farms was higher than Denmark and lower than Israel, which was reported at 34% and 80%, respectively [16]. The overall relative emphasis given for production traits was higher than the world relative emphasis given, which was 57%, whereas for type traits and secondary traits, the relative emphasis obtained in the current study was lower than the world index relative emphasis, which was reported at 16% and 27% for type traits and secondary traits, respectively [17].

Table5: The Relative Percentage of Traits More Emphasis in Different Production System (Mean ±SE).

n=number of respondents, *Means with the same letters are not significantly different.

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