2.1.1. Animal Management

At the BED site, four permanent staff and 12 daily workers were employed for daily follow-up of the flock and to record specified biological data. The major veterinary supplies used for the treatment of animals were albendazole (Albenza), oxytetracycline (Terramycin) 10% plus multivitamin, oxytetracycline 10% plus Ivermectin, oxytetracycline 20% plus albendazole, plus multivitamin, oxytetracycline 10% plus albendazole, triclabendazole/Egaten (facenex), Pen-Strip, mineral block, deanol, and tetracycline eye ointment topical. Vaccination was periodically offered for the most common and endemic diseases (like peste des petits ruminants, contagious caprine pleuropneumonia, anthrax, blackleg, ovine Pasteurellosis, and sheep pox) along with deworming using 300 mg albendazole and dipping. Heart water or cowdriosis was the most frequently occurring problem. For that reason, animals were treated with oxytetracycline 10% IV to minimizing heartwater disease [30].

Animals that have been exposed to a contagious disease or those that are suspected of carrying disease were quarantined in the special quarantine house of the BED site. Those animals were quarantined at least for 1 month to monitor animals for signs of illness and to ensure that they are healthy before being joined into the flock or to prevent the spread of infectious diseases. Young female sheep were kept to replace older females that were culled or removed from the crossbreeding program. Furthermore, additional replacement ewes were purchased from the local market to enhance the productivity and resilience of the flocks. These replacement animals were tested and certified for its negative fertility problems, serologically tested and certified for ovine brucellosis. To minimize external parasite, load regular monthly dipping was undertaken.

Sheep flocks in the BED site were provided ad libitum roughage composed of medium-quality grasses and legumes. The types of grasses in the study site are Napier grass (Pennisetum purpureum), desho (Pennisetum pedicellatum), Rhodes (Rhodes maximum), and other local grasses, whereas legume types are lablab, stylo, and Sesbania provided to the animals with a ratio of 3:1 (grass:legume). The provision of feeding was partly through a cut-and-carry system and partly free grazing on the medium-quality pasture farm. Intensive feeding was also undertaken for pure Dorper sheep to minimize problems associated with adaptation.

All pure-bred pregnant ewes and lambs were kept indoors and fed throughout the year, while dry ewes were allowed to graze on pasture during the day. In addition to pasture, concentrate feeds composed of various ingredients such as wheat bran (62.2%), noug cake (16.5%), cottonseed cake (16.5%), limestone (3.5%), and salt (1.3%) were provided as a supplement for the sheep. The amount of concentrate supplemented varied based on the stage of production (growing lambs, pregnant ewes, lactating ewes, and maintenance), as well as factors such as age, weight, body condition, availability of high-quality forage, health considerations, and seasonal changes

Lambs were offered about 100 g concentrate supplementation per day. Sheep kept indoors were supplemented with concentrate twice a day (half of the daily recommended amount before noon and the other half in the afternoon). For sheep, which graze on pasture, concentrate feeds were given in the morning. Sick animals were given additional supplementation in the evening. Higher amount of concentrate is usually given to animals during dry seasons compared to wet seasons. For instance, pregnant ewes on average were supplemented with 300 g and 500 g in wet and dry seasons, respectively [30].

2.1.2. Study Design and Source of Data

The BED site data were collected from Dorper × indigenous sheep flock at the Mente Dubo BED site for 8 years and were utilized for this study. The mortality and causes of death or exit/culling of the lambs from the flock were recorded by veterinary expert. Survival from birth to 3 months of age was considered for the evaluation. The fixed factors included in the study were lamb blood level (1 = 50%, 2 = 75%, 3 = pure Dorper), lamb birth type (1 = single, 2 = twin), sex (1 = male, 2 = female), lambing season (1 = heavy rain, 2 = light rain, and 3 = dry), and year of birth (2012–2019). The body weight of animals was measured using small ruminant weighing scale with an accuracy of 100 g. Small ruminant weighing scales are tools that consider the size, weight, behavior, and welfare of sheep and goats during the weighing process.

2.2.1. Sampling Technique and Data Collection

Then we utilized a semistructured questionnaire. We collected data from 39 participants from Damot Sore, 3 participants from Damot Gale, and 37 participants from Damot Pulasa districts of the Wolaita Zone. The data focused on on-farm field observations and assessments, including adaptability of crossbred lambs, their productivity, market performance, farmers’ management practices, farmers’ preferences, their interest in future crossbreeding, and any production constraints they faced. In addition, focus group discussions were conducted in each of the districts; the groups contained 11 participants at Damot Sore, 5 participants at Damot Pulasa, and 6 participants at Damot Gale district. Participants for the focus group discussions were selected based on their experience in crossbreeding in their respective localities. During the focus group discussions, Kebele development agents, district operational research project coordinators working on livestock, and Kebele leaders were included. These focus group discussions were conducted to validate previously collected information on individual farmers and to obtain additional information on the future fate of crossbreeding.

2.2.2. Data Management and Statistical Analysis

3.1.1. Birth Weight (BWT) and Weaning Weight (WWT)

At the BED site under semi-intensive management, the overall least squares means (LSM) for BWT and WWT were 2.84 ± 0.06 and 15.40 ± 0.90 kg, respectively (Table 2). Lamb blood level significantly (p < 0.001) affected BWT and WWT. The results indicated that pure Dorper and 75% crossbred lambs showed nonsignificant differences in weight at birth and weaning. However, 50% F1 crossbred lambs had lower weights at birth and weaning (Table 2). Birth type had a significant effect (p < 0.001) on lamb birth weight but not on WWT. Single-born lambs were heavier (3.16 kg) than twin-born lambs (2.53 kg). Similar findings have been reported previously by Teasfeye et al. [37]. The lower body weight of twin lambs may be due to limited uterine space and inadequate nutrient availability during pregnancy, as well as competition between the twins for the limited milk supply from the dam [38].

Lamb sex did not affect BWT or WWT, which is consistent with previous reports [7]. Season had marked (p  < 0.05) effect on lamb BWT, with lambs born during heavy rain season having heavier BWT (3.09 kg) compared to those born in dry season. Lambs born during light rain season had the lightest BWT (2.63 kg). The difference in BWT among seasons could be a direct reflection of feed availability [30], as the quality of feed deteriorates during dry season [39].

Birth year was a significant source of variation for both BWT and WWT, with the heaviest BWT and WWT recorded in 2015 and the lowest in 2017. The trend in BWT and WWT across years was variable, which could be attributed to climatic factors and year-to-year variations in rainfall that affected forage availability and quality. In a nearby area, Doyogena sheep community-based breeding site, heavier birth, weaning, and 6-month weights were reported in 2015 [38], which the authors attributed to lower rainfall recorded in 2017 from 9 years of data. This reduction in rainfall may have decreased forage availability during late gestation, leading to the lower weights observed. Similar results have been reported in other studies [22, 29, 40, 41]. Similar result was also reported by [29, 42, 43]. The interaction effect between season and year was also significantp  < 0.01.

The mean overall BWT of 2.83 kg obtained in the present study was heavier than the previously reported 2.55 kg [44] but lower than 3.04 and 3.11 kg report from Debre Birhan Center and Sirinka Agricultural Research Center, respectively [22, 45]. Similarly, the overall WWT of 15.40 ± 0.90 kg was comparable to 14.07 and 13.7 kg reported for Dorper × local sheep from Sirnka and Debre Birhan agricultural research centers, respectively [22, 45]. The variation in BWT and WWT in previous findings from different research centers could be explained by differences in nutrition, climate, and management practices. The current overall WWT was also comparable to the WWTs of well-known local sheep breeds managed under ongoing community-based breeding programs, such as Bonga 16.1 ± 0.07 kg), Doyogena (14.84 kg), and Menz sheep (8.99 kg) [37, 46, 47].

3.1.2. Average Daily Weight Gain From Birth to 90-Day Age

The average daily weight gain from birth to weaning (ADG0-3) of the lambs was 137.78 ± 99 g/day. Both lamb blood level and birth year had a significant impact (p < 0.001) on average daily weight gain from birth to 90 days age (weaning age). However, lamb birth type, sex, and lambing season had no significant effect (p > 0.05) on ADG0-3. Lambs that were 100% pure Dorper or 75% crossbred had significantly higher (p < 0.001) ADG0-3 compared to 50% crossbred lambs. This suggests that pure Dorper and 75% crossbred lambs had faster weight gains, though it is important to also consider factors such as disease resistance, nutritional efficiency, and adaptability.

The year in which the lambs were born had significant impact (p < 0.001) on their average daily weight gain (ADG0-3). Lambs born in 2015 had fastest growth rate (198.00 ± 19.9 g/day), while the slowest weight gain was observed in lambs born in 2017 and 2018. However, daily weight gain from birth to 90 days was statistically nonsignificant among the years 2012, 2013, 2014, 2015, and 2016. This difference in weight gain could be due to fluctuations in the quality and quantity of feed available over the years, attributed to variability in climatic factors and their impact on pasture production. The present study’s results for ADG0-3 were higher than the reports from previous studies by Lakew et al. [45] and Abede et al. [22].

3.1.3. Preweaning Lamb Survival

The result of preweaning survivability rate and the influences of different risk factors are presented in Table 3. The overall preweaning survival of lambs was 77.7%. Relatively higher preweaning survival up to weaning (86.0%) was reported by Tesema et al. [15] for Dorper × Tumele sheep in the northeastern part of Ethiopia [48]. This difference can be explained by differences in climate and weather conditions, disease and parasites, quality of available feed, and animal management practices.

Survivability (80.6%) of single-born cross-lambs was higher than that of twins (70.4%). The possible reason for the higher risk of death for twin lambs could be lower BWT and competition with their littermates for colostrum and milk [49]. Many authors documented similar findings [50]. This suggests that improvements in management interventions are needed for multiple-born lambs. The sex of the lambs had nonsignificant (p > 0.05) influence on lamb survival, indicating that male and female lambs may have similar levels of resistance to diseases and parasites. In this case, there may not be any inherent differences in survival rates between male and female lambs.

However, preweaning survival was affected by season of birth p < 0.01. Accordingly, 70%, 86.3%, and 78.3% of lambs survived during dry, heavy rain, and light rain seasons. The differences in preweaning lamb survival across birth seasons can be attributed to several factors, including nutrition and feed availability, disease and parasite challenges, environmental stress, and management practices. During dry season, reduced forage and feed quality may influence ewe nutrition and milk production, leading to lower lamb survival, while the heavy and light rain seasons have better-feed availability, allowing ewes to maintain better body condition and provide more milk, resulting in higher lamb survival. Seasonal variations in disease and parasite challenges, as well as extreme weather conditions, can also negatively affect lamb health. Therefore, BED site may need to amend management strategies based on seasonal conditions, which could influence lamb survival rates. To better understand the specific causes, further investigation into ewe nutrition, disease prevalence, environmental factors, and management practices across seasons would be necessary. Higher lamb mortality rates of 53.2% and 31.8% were recorded in 2014 and 2016, respectively. Survival rates observed for crossed-bred lambs were comparable to those observed by other researchers for various Ethiopian sheep breeds under semi-intensive management system [19].

3.1.4. Cases of Lamb Mortality

Previous studies by Brien et al. [51] and Dwyer [52] indicated that the majority of lamb losses occurred in preweaning age. In the current study, the most common causes of lamb mortality were pneumonia (24%), infectious diseases (21%), internal parasites (11%), tick infestation (9.02%), heartwater (7.8%), contagious pustular dermatitis (Orf) (6.85%), and others (18.85%, including exposure, and premature birth) (Figure 2). Infectious diseases occur throughout the year, while the internal parasite commonly occurs after the rainy season and mid-dry season of the year. The high infestation of ticks was mainly occurring during the rainy season starting early June to late September [53]. Identification of disease and fecal examination were done in collaboration with Sodo Regional Veterinary Laboratory.

3.2.1. HH Characteristics

Characteristics of the respondent HH considered for on-farm assessment are presented in Table 4. The average age of the respondents was 40 ± 6.45 years, while the family size was 7.19 ± 1.77 persons per HH. The study found that 82.3% of the HHs were headed by males. The majority of the respondents had completed primary school (26.1%) or had basic literacy skills (25.3%). On average, each HH owned 1.09 ± 0.77 ha of land.

3.2.2. Sheep Flock Structure

Respondent farmers were asked about the sheep structure currently kept in their homes, as shown in Table 5. The average sheep flock size (both indigenous and crossbred sheep) per HH in this study was 2.0 ± 2.00, 2.03 ± 1.25, and 2.69 ± 1.92 in Damot Gale, Damot Pulasa, and Damot Sore districts, respectively. The mean flock size per HH is smaller than the report of [17] for Awassi and Dorper crossbred sheep in South and North Wollo zone of Ethiopia. This variability of sheep flock size is expected since the area is well-known for extreme land shortage and dense population, which affect feed source and grazing area [6].

Producers commonly kept two to three breeding ewes to be sired by Dorper crossbred sires or local sires in a group. The proportions of crossbred sheep in the visited farmers were 37.5% in Damot Gale, 21.44% in Damot Pulasa, and 14% in the Damot Sore area. Producers did not want to keep male lambs after weaning age, so they sold them to nearby markets. Accordingly, the proportions of crossbred sheep in the visited farmers were very small compared to the local sheep type. However, all the respondent farmers had experience and had participated in the Dorper crossbreeding program. The sheep flock structure reported by the respondent HH farmers is relatively smaller than the previous reports of 3.7 Lakew et al. [29] and Lakew et al. [45] on average.

3.2.3. Purpose of Keeping Sheep

There are several reasons why sheep are kept in the country. Some of the main purposes of keeping sheep in Ethiopia include meat production, wool production, milk production, income generation, saving, manure production, skin production, and cultural and religious practices [1]. In this regard, the purpose of keeping sheep (both indigenous and crossbred) in the study areas is presented in Table 6. The first goal in keeping sheep was as a source of income (index = 0.28), while others kept sheep for saving (index = 0.25) and meat (index = 0.23). Farmers kept sheep: those keeping them for income generation prioritize generating immediate profits from selling sheep. On the other hand, those keeping sheep for saving focus on building up assets and accumulating wealth over time by using sheep as a long-term investment. All the respondents replied that keeping sheep (indigenous and crossbred) in the area is not for a specific purpose. The possible reason for most people keeping sheep for income generation in the area is that there is a high demand for sheep and sheep products in the areas, particularly in Delbo Market. This creates a strong market for sheep and can provide an opportunity for farmers to sell their sheep for a good price to cover regular home needs, school fees, and purchase inorganic fertilizers. Another possible reason is that sheep require relatively low inputs, such as feed and water, and have a short generation interval. Lakew [45] and Abebe [47] reported similar purposes for keeping sheep in their findings. During the discussion, beneficiary farmers described how they sell sheep to pay various expenses, including school fees and inputs such as seeds and fertilizers, as well as other supplies for their children, family clothing, and to pay land taxes. These findings are in line with other reports [13, 48].

3.2.4. Marketing

The results indicated that both local and crossbred sheep were sold to local traders, consumers, and others, as reported by the study participants (Table 7). The study found that local sheep fetched a better price than crossbred sheep. There was a statistically significant difference (p ≤ 0.05) in price between local and crossbred sheep in 2018–2019, with local sheep being sold at a higher price. Specifically, crossbred and local lambs aged 3–6, 6−9, 9–12, and above 12 months were sold for the following prices, respectively: 20.40 USD versus 19.50 USD, 31.26 USD versus 25.91 USD, 43.02 USD versus 38.43 USD, and 72.37 USD versus 59.95 USD. It is worth noting that the average exchange rate in 2018 was 36.61 ETB per USD, while it was 29.2123 ETB per USD in 2019 [54].

The average local sheep price was estimated to be near 78.97 USD, while the average price of the crossbred was near 56.398 USD although the revenue fluctuates depending on the weight and appearance of animals. The lower cost of raising local sheep can result in a higher profit margin for farmers, due to higher market prices. Local sheep may also have better meat quality, such as better color, flavor, tenderness, and fat content, leading to increased demand and prices. Market preference and cultural factors can also influence the price difference. In Ethiopia, local sheep may be preferred due to cultural reasons, leading to higher demand and prices. In contrast to the current study, Lakew [18] reported that crossbred lambs had high demand at an early age resulting in a higher market price compared to local sheep.

3.2.5. Attributes Used for Determining the Selling Price of Sheep

In Ethiopia, the selling price of sheep is determined by several attributes, including age, weight, gender, breed, health and body condition, market demand, and location [55]. Understanding these factors is essential for sheep farmers and traders in Ethiopia to make informed decisions about pricing and marketing their sheep [56, 57]. According to the current study, the three main attributes that were considered by respondents in determining the selling price of crossbred sheep were physical appearance, coat color, and age (Table 8). The study further ranks these attributes in order of importance, with physical appearance being the most important attribute (ranked first), followed by coat color (ranked second), and age (ranked third).

The study also provides index values for each attribute, with physical appearance having an index value of 0.33, coat color having an index value of 0.22, and age having an index value of 0.21. This information provides important insights into the factors that influence the selling price of crossbred sheep in the study areas and may be useful for sheep farmers and traders in the area who are looking to market their sheep more effectively. For example, by paying attention to the physical appearance and coat color of their sheep, farmers may be able to command a higher price in the market. Similarly, understanding the importance of age in determining the selling price of sheep can help farmers and traders make informed decisions about when to sell their sheep to maximize profits.

3.2.6. Farmers’ Perception for Dorper Crossbred Sheep Over Local Sheep

For the success of indigenous sheep genetic improvement, understanding the farmers’ views, animal/trait preferences, environments, and trait priorities is important. The study found that farmers have significantly different perceptions of crossbred and local sheep based on several factors, including color, twinning rate, heat tolerance, drought tolerance, disease tolerance, feed requirement, grazing ability, and market preference (Table 9).

Farmers appreciated crossbred lambs in terms of faster growth rate (odds ratio [OR] = 1.95 and p  < 0.05), docile behavior (OR = 2.12 and p ≤ 0.01), meat quality (OR = 1.85 and p  < 0.05), and market preference (OR = 2.77 and p ≤ 0.001). According to the farmers’ responses, the advantages of local sheep breeds over Dorper crossbreeds were disease resistance and market potential. This suggests that farmers in the study areas prioritize resilience and marketability when selecting sheep breeds for their flocks. Previous studies by Gizaw and Getachew [20] and Lakew et al. [18] reported higher growth performance of Awassi crossbred lambs over Menz sheep and Dorper crossbred lambs over local Tumelie sheep in the North Shewa and Wollo Amhara regions of the country. A more recent report by Tesema et al. [17] also found that Dorper crossbreds were preferred (9.30–72.2 times greater) for their growth rate and physical appearance compared to indigenous Tumele sheep, which aligns with the findings of the current study. The results of the focus group discussions and key informant interviews confirmed that crossbred lambs require better overall management systems and regular monitoring compared to local sheep. The results of focus group discussion and key informant interviews confirmed that crossbred lambs require better overall management systems and require regular monitoring compared to local sheep. During the focus group discussions, participants explained that crossbred lambs could perform as well as local sheep if they were properly managed with appropriate feeding, healthcare, and housing sanitation. However, due to human population pressure and feed shortages, the participants were unable to provide the necessary care for the crossbred animals. This may have contributed to the crossbreds not reaching their full genetic potential and, in some cases, even experiencing weight loss and reduced productivity. To address this, the participants recommended allocating land for forage production, developing high-yield and high-quality feed, and storing enough hay for the dry season. Although local sheep had better acceptance among the farmers, the overall results were comparable, and the participants suggested that Dorper crosses could be used as an alternative breed in the Wolaita region, which aligns with previous findings of Kebede [58] and Tesema [17]. These insights into farmer preferences and priorities are important for developing sheep breeds that are well suited to the local environment and meet the needs of farmers and consumers. Incorporating these preferences into breeding programs can lead to increased productivity, profitability, and sustainability in the sheep genetic improvement program.