Sheep Production Systems and Breeding Practices for Selected Zones of Tigray , Northern Ethiopia

A study was undertaken to identify the production system, breeding practices and major production constraints of common Tigray highland sheep in 16 rural kebelles from eight districts of Tigray Regional State. A total of 480 households (30 households for each rural kebelle) were selected purposively to collect data through personal observations and a detailed structured questionnaire. Mixed crop-livestock production system was the dominant farming system in all the study districts. The farmers kept a variety of livestock species including sheep, goats, cattle, chickens horse, donkeys and bee colony. Sheep, principally as source of income, meat for home consumption, production of manure and for socio cultural purposes, are commonly herded with other species in the open grazing fields by young boys in a family. Mating was generally uncontrolled. Body size, growth rate and adaptability were the major traits in selecting rams, whereas ewes were selected based on body size, twining ability and lambing interval. Majority of sheep across all districts are housed in structures known as Gebella which is built from stone and mud wall and tree/corrugated iron sheet roofing separated from the main family house. The major constraints hampering sheep production in the study areas were feed shortage (0.25), lack of capital (0.24), insufficient veterinary services (0.2), limited grazing land (0.2), water scarcity (0.06) and predators (0.05) with index value indicated in parenthesis. In order to improve the productivity of sheep, it is important to involve farmers and other stockholders in addressing these constraints and designing breed improvement interventions, considering the overall farming and breeding practice of smallholders.


Introduction
The demand for livestock products is increasing as a result of increased human population and relative growth in income.Hence, sustainability of livestock production is important to ensure continuous and sufficient availability of livestock products for the current and future generations.Ethiopia has diverse livestock species and breeds that are associated with the diverse agro-ecology of the country.Sheep is among the most important livestock species and dominantly found in the crop-livestock production system.Recent statistics show the presence of 30.7 million heads of sheep in the country [1].At the farm level, sheep contribute up to 63 percent of the net cash income derived from livestock production in the mixed farming system [2].The Northern part of the country is among the areas where smallholder farmers widely practice subsistence sheep production.Overall the productivity of the sheep as measured by off take and size of animals available for market is low.Improving the sheep productivity through improved management and breeding is required as this is crucial for both food security and sustainable development of small holder farmers.Assessing the production system, indigenous knowledge of selection, management, identification of breeding goals, describing morphological characters and productivity level of the breed in their habitat are prerequisites to set up improvement programs at the smallholder and pastoral levels [3].The objectives of this study were, therefore, to characterize the existing sheep production systems and breeding practice, and to identify major constraints that limit productivity of common Tigray highland sheep.

Description of the Study Areas
The study was conducted in eight districts belonging to four zones of Tigray Regional State.The districts include Atsbie-Wemberta, Wukro-keleteAwelaelo, Ganta-Afeshume, Degua-Tembien, Enderta, Mekelle area, Offla and Alamata (Figure 1), which were purposively selected based on the availability of common Tigray highland sheep and accessibility.The study area lies' within 12˚20' and 14˚16'N latitude and 39˚15' and 39˚45' longitude.The mean annual temperature varies from 14˚C to 22˚C while the mean annual rainfall ranges from about 400 mm to around 970 mm [4].The districts are situated in an altitude range of 1500 to 3200 m.a.s.l.The farming system in all of the selected districts is characterized by crop livestock mixed farming system.The major crops grown in the lower altitude areas are sorghum, Teff (Ergrostis abysinica) and Maize while wheat, beans, barley, pea, lentil, grass pea, chick pea, rarely linseed and other highland crops are common in the mid and highland areas.

Sampling Techniques and Data Collection
Two rural villages (kebelles) were selected purposively while households to be interviewed from each of the kebeles were randomly selected among the common DOI: 10.4236/ojas.2019.91012Data pertaining to common Tigray highland sheep were collected through a household survey.A total of 480 household heads (30 per rural kebelle) were randomly selected and interviewed using structured questionnaires developed from previous researcher [5].Before conducting the formal survey, the questionnaire was pre tested and modified to match with the study area's livestock production system and for its appropriateness.The survey was carried out by enumerators under close supervision and participation of the researcher.From the field survey, information on general household characteristics, purposes of keeping sheep, common Tigray highland sheep flock structure, breeding system and selection criteria, disposal and acquisition of sheep were gathered and documented as per the questionnaires developed and pre-tested.The discussion made with the key informants were focused on collecting data pertaining to the production system and potential breeding tract of the common Tigray highland sheep breed.

Data Analysis
Statistical Package for Social Sciences (SPSS, Corp.21, Release, 2012 [6]) was used to analyze the survey data (household information, sheep husbandry and diseases management practice, feeding practice, purpose of sheep keeping, production constraints, selection criteria, acquiring and disposal of sheep), while data for land holding per-household, flock structure and reproductive performances were subjected to analysis of variance (ANOVA) using the general linear

Household Information
Mixed crop-livestock production system is the dominant farming system in the study areas.Livestock production is subsistence-oriented and it is a traditional type which is characterized by minimal inputs like in the other parts of Ethiopia.
It was demonstrated that low input production system is found in all livestock production systems prevailing in the country except in peri-urban and urban system [9].sheep farming.The overall mean family size was 6.49 ± 2.65, which is comparable with the estimation of 6.4 persons per household reported in other area [10].
Among the total household heads, 75.0% were males, which is comparable to the result reported by earlier researchers [11] [12].Household headed by female in the present study is high, which could be attributed to the death of mainly males in the prolonged internal conflict during the Derg regime and border dispute between Eritrea and Ethiopia.
The majority of the respondents (94.4%) were follower of Ethiopian Orthodox Christianity, while the remaining (5.6%) were Muslims.The overall literacy rate among the household heads was 67.4%.Small holder farmers close to the regional capital Mekelle have higher (82.9%) while those in Alamata (55.0%) and Offla (53.4%) recorded lower literacy rate.This variation could be due to the distance to the urban centers, since education facilities in such areas are likely better for offering chance to the residents to educate themselves and their children.The presence of better educational background in this study would be a good opportunity for enhancing animal genetic improvement programs in the study areas, since literate communities are more likely better to adopt and practice new technologies and also to keep performances records of animals.The present findings indicate that sheep farming is performed by every social class of the community regardless of their background characteristics and show the significant importance of sheep to the producers.

Land Holding and Farm Activities
The overall average landholding per household in the study areas was 1.0 ± 0.8 hectare (Table 2).There is significant (P < 0.05) difference between the districts.
Alamata, Enderta and Mekelle area districts have larger land holding while households in Atsbie-Wemberta, Wukro-keleteAwelaelo, GantaAfeshume, Degua-Tembien and Offla have smaller landholding with no significant difference in land size among these districts.This result shows that the average land holding size per household in the mid altitude was higher than high altitude due to the dense population in the later.Almost all respondents across the study areas indicated that the trend of land holding size per household is decreasing over time.Human population growth rate, expansion of the existing town and newly established town, establishment of governmental institutes, land degradation and soil erosion are some of the mentioned factors contributing to the declining landholding per house hold across all districts.The average landholding reported in this study was greater than 0.5 ± 0.53 hectare reported for Atsbie-Wemberta district [11].

Livestock Holding and Flock Structures
There was a significant difference (P < 0.05) in average number of sheep, goat, cattle, chicken, bee colony, donkey and horse across the districts ( 1.9 ± 1.0 b 1.4 ± 0.9 c 0.9 ±0.9 d 1.1 ± 1.3 cd 1.6 ± 1.4 P < 0.001 Donkey 1.1 ± 0.7 bc 1.0 ± 0.5 c 0.9 ± 0.5 c 1.5 ± 0.6 a 1.1 ± 0. Atsbie-Wemberta, Degua-Tembien, Ganta-Afeshume and Wukro-keleteAwelaelo districts hold lower number of sheep.This variation in livestock holding is partly related to the average land holding which has a bearing on availability and size of grazing and/or browsing lands, crop residues and crop aftermath as the main feed sources of small holder livestock producer's.Similar result for sheep holding was reported for highland sheep in Lallo Mama Midir in the central highlands [13] and Gumuz sheep in Amhara region [14] of Ethiopia.The number of sheep per household reported in the present study is larger than the sheep flocks in the mixed crop livestock production system of the western highlands of the Amhara Regional State [15].

Sheep Husbandry Practice
Husbandry practices have an implication for designing genetic improvement programs and introducing improved sheep management such as strategic health interventions at village level [16].The flock herding practices of the smallholder farmers reflects the breeding managements and has an impact on the flock size.

Housing System and Herding Practice
According to the result, 64.4%, 29.6% and 6.0% of households are housing their sheep in closed, semi-closed and open housing type respectively ( house termed locally as (Gebella) which is constructed from stone and locally available timber.All classes of the sheep were herded together during the day time though new born lambs were kept separately the first few days near the village and around the residence house of the owners.Higher percentage of respondents (80% to 85%), in Alamata, Atsbie-Wemberta, Degua-Tembien, Offla and Wukro-keleteAwelaelo keep their sheep in mixed herd along with cattle, goat and equines (Table 3).There is a mixing with other adjacent sheep flocks within a village immediately after crops are harvested (September to November) during communal grazing of crop aftermath.About 45.21%, 33.75% and 21.04% of the respondents keep their sheep during the night either together with other species or separate by species or separate by age group, respectively.

Feed Resources and Feeding Practice
The major feed sources for sheep in the eight districts are summarized in Table 4.
Natural pasture, crop residue, crop aftermath, hay, atella (by product from traditional brew) and concentrate are the major feed sources in all the study areas.
Among these feed resources, Natural pasture contributes the largest proportion followed by crop residue in all districts.The contribution of green grasses to feed farm animals is limited by the short duration of the rainfall.However, crop aftermath is replaced by grazing on common grazing land in those areas during the dry season.There was no improved forage introduced in all study sites.
Sheep generally graze the whole day and taken to water sites (rivers and streams) once a day or three to four times a week.While Natural pasture lands and residues from cereal "Teff" (Eragrostis abysinica), wheat, and barley are the major feed sources in Atsbie-Wemberta, De- gua-Tembien, Ganta-Afeshume and Offla.The available feed has poor nutritive value and is less palatable during most of the year.Moreover, sheep and goat are left to graze and browse alongside with large animals that even worsen the feed shortage as animals need to compete with each other.

Common Sheep Diseases and Health Management
Based on the results of the interview, group discussion and observations made, sheep pox, Coenurosis, Pasturellosis, External Parasites Foot and Mouth diseases, Anthrax, Foot rot and Respiratory diseases were the major diseases which affect sheep production in the study areas.Although vaccination was provided, it is limited to few common diseases.Limited animal health service delivery has been reported by sheep owners in all study areas (Table 5).

Sheep Production Constraints
The results indicate that feed and grazing land shortages, income, disease, water scarcity and loss of sheep by predators were the major constraints affecting sheep production (Table 6).Among these constraints feed shortage, income and diseases were top three constraints across the districts.Similar feed shortage is reported in different area [17].Feed shortage especially in the long dry season is critical problem in all study sites.This factor extremely affects the growth rate and body energy reserve of animals rendering them to have a low quality meat [18].
Proper feeding with high-energy diets increases the meat quality through increasing the muscle glycogen reserve, which helps to keep the pH low after rigor mortis, and improve intramuscular fat content [19].

Sheep Production Objectives
Table 7 shows the purpose of keeping sheep and their respective rank for the study area.Better understanding of the purposes of keeping sheep is a prerequisite for defining breeding goals [20].Primary reason for keeping sheep in all study areas was income generation.Other reasons mentioned by farmers according to order of their respective indices were breeding purpose (stock replacement), home meat consumption, social security, holiday ceremony and manure.
Group discussion revealed that sheep rearing for income generation and household meat consumption were common and contribute to livelihood in the study areas, especially as alternative income sources to the poor.Given the breadth of purposes that farmers have for keeping sheep, much care is required in the choice of breeding objectives and breeding strategies as the function of the animals is closely linked to the traits desired by the producers [21].Knowledge of reasons for keeping animals is a prerequisite for deriving operational breeding goals [20].

Sheep Breeding Practice and Selection Criteria
In the study areas, mating was random.There was no report of controlled mating system across the study areas.Rams run together with ewe throughout the year and castration was an uncommon practice, which leads to indiscriminate and uncontrolled breeding.Farmers who had no breeding males, purchase ram from local markets or got ram service from their neighbors.This finding is in line with previous findings [22] [23].
Selection criteria for ram and ewe with corresponding index values are presented in Table 8.The respondents prioritized body size, growth rate and adaptability as selection criteria for ram with the indices of 0.38, 0.26 and 0.14, respectively.The most important selection criteria for ewe were twining ability (index = 0.298), body size (index = 0.258) and lamb growth ability (index = 0.2).
Others like mothering ability, color, lambing interval and age at first sexual maturity were also reported as criteria but with lower rankings.This finding is comparable to that noted earlier [24].Small holder farmers in all study districts indicated that they are mostly interested in getting more money when they sell live animals.The farmers wanted animals that grow fast, with higher mature weight, and preferably with high twinning rate with expectation to sell more animals per year.

Reproductive Performances
The results on reproductive performance are presented in Table 9. Good reproductive performance is a prerequisite for any successful livestock production program.Previous study suggested that differences exist in reproductive performance among indigenous sheep breeds and their variation allow for the selection of suitable breeds for a given environment [25].
Age at first mating (sexual maturity) As indicated in Table 9, there is statistically significant difference (p < 0.05) of age at first mating (sexually maturity) for both sexes across the study sites.Sheep reared at Offla, Enderta and Alamata achieve sexual maturity early as compared to those found in Mekelle, Degua-Tembien, Atsbie-Wemberta, Wukro-keleteAwelaelo and Ganta-Afeshume districts, which could be due to access to feed.The average age sexual maturity recorded in the present study for male (7.5 ± 0.7 months) and females (8.3 ± 0.09 months) is comparable to result reported by other authors [26].
Lambing interval (LI) Lambing interval is the period between two consecutive parturitions that determines reproductive efficiency in sheep production.The lambing interval recorded for Alamata, Atsbie-wemberta, Degua-Tembien, Enderta, Ganta-Afeshume, Mekelle area, Offla and Wukro-keleteAwelaelo is slightly higher than 6.5 ± 0.7 reported for Tigray highland sheep [11] and 6.63 ± 0.19 for indigenous sheep population found in Eastern Ethiopia [27] under mixed crop livestock production system.Mekelle area, Offla, Wukro-keleteAwelaelo and Atsbie-Wemberta have lower lambing interval compared to Degua-Tembien, Ganta-Afeshume, Enderta and Alamata since the lambing interval is reasonable low, the possibility of three lambs within two years mainly depends on the availability of feed and improved management.
Age at weaning All farmers across the study sites practiced natural weaning without intervention to stop suckling.The overall reported average weaning ages for both sexes was 3.1 ± 0.02 months, with a range of 2.9 ± 0.03 in Offla to 3.4 ± 0.03 months in Wukro-keleteAwelaelo.This range was on towards the middle lower end of 3 -4 months reported for indigenous sheep breeds of Ethiopia [28] and lower than 3.9 ± 0.9 months for Gumuz sheep [29].There is limited information for reproductive performance of indigenous sheep breeds in northern Ethiopia.The possible reasons for lower weaning age may be due to short lactating period which could be likely attributed to the low quality and quantity of feeds.
Ewe Lifespan (longevity) The average reproductive life of the ewes in the study sites showed significant difference (P < 0.05) among districts (Table 9).Among the eight study districts longer ewe life span (11.0 ± 0.13 years) was recorded for Alamata sheep.Similar length of ewe life time span was noted for Bonga sheep [30].Shorter life span of ewe (7.6 ± 0.15 years) was found for sheep in Enderta district which is comparable to value reported [11].
Selling of ewes is not a common practice and ewes are rather reared for breeding purposes.But, males are sold at early age particularly during the holy days and festivals.

Sheep Acquiring and Disposal Methods
The commonest methods used to acquire sheep were birth on the farm, buying and gift in the order of listed (Table 10).Farmers across the study sites sell their animals when they face financial problems; primarily in the nearby markets where local traders are principally actors in the marketing process.The study results also indicated that higher numbers of sheep are sold and better price is fetched during holidays, although farmers sell sheep at any time of the year depending on their need for money.Sheep owners sold their sheep primarily to DOI: 10.4236/ojas.2019.91012Sheep marketing in the study areas were traditional type.All of the respondents reported that weighing balance is unknown for selling and/or buying animals; rather visual assessment was used to estimate body weight and condition of the animals and set a price.Hence, selling price was fixed by negotiation between sellers and buyers.This result is in agreement with many research reports [31] [32].Generally, smallholder farmers dispose their sheep mainly through sale and slaughter for home use.

Conclusion
Sheep in the study area were principally bred as source of income, meat for home consumption, manure, cultural and ceremonial purposes.Body size, growth rate, adaptability and twining abilities were important functional traits for sheep selection in all study sites.The practice of uncontrolled mating may result into inbreeding; however, the mixing of flocks during communal grazing, or in the neighborhood during day time helps to reduce risk of inbreeding.The sheep are kept under traditional production system which is constrained by, shortage of feed and grazing land, diseases, water scarcity, frequent drought, predators, and poor veterinary service.The level of productivity is low and less attention is given to husbandry and breed improvement.In order to raise productivity it is important to involve farmers and other stockholders in designing breed improvement interventions, considering the existing breeding practices, management systems and trait preferences of the community and the multipurpose roles of sheep.

Figure 1 .
Figure 1.Location of the study areas.

Table 1 .
Background characteristics of the respondents in the study areas.
G = Grade; N = Number of interviewed households; SD = Standard Deviation.

Table 2
).Higher numbers of sheep were found in Mekelle area, Alamata, Enderta and Offla while

Table 2 .
Small holder land holding and flock structure of the study areas (Mean ± SD).

Table 3 )
. Majority of sheep across all districts are housed in houses separated from family DOI: 10.4236/ojas.2019.91012

Table 3 .
Distribution of households according to their sheep housing systems and herd managements across eight districts.
N = Number of Respondents.

Table 4 .
Feed resources of the study areas.

Table 5 .
Local names and scientific equivalents of the common sheep diseases in the study areas.
Therefore, proper feeding of animals for growth and meat quality should be practiced carefully.DOI: 10.4236/ojas.2019.91012

Table 6 .
Ranked sheep production constraints in the study areas.

Table 7 .
Sheep production objectives in the study areas.

Table 10 .
Ways of acquiring and disposing sheep in the study areas as ranked by owners.food items, cover health, farm input (fertilizer and cropland rent), labor (herdsman and laborers) and school expenses for children and to pay back credit. purchase