The Choice of Breeding Objectives and Selection Criteria Decided by Breeders of Various Goat Breeds and Factors Influencing Them

Knowledge of breeding objectives and selection criteria is essential for a successful breeding program, a questionnaire was prepared, and distributed among breeders of various goat breeds in Abu-Dhabi Emirate to explore their breeding objectives and selection criteria of various goat breeds that they raise. A total of 293 different goat herds with a total of 49911 heads of goats were investigated. A stepwise logistic regression was applied using LOGIST procedure of SAS. The results suggest that goat breeders in UAE are breeding goats mainly for meat production (94%), adaptability to environment (40%), and disease resistance (35%). Only few breeders considered milk production (21%) as breeding objective. Factors influenced breeders’ decision on breeding objectives were breed of goat, region, property type, and herd size. Nine out of the twelve doe selection criteria chosen by goat breeders are considered objective selection criteria and only three are subjective selection criteria. Growth rate, fertility, twining ability and body morphology selection criteria were considered the most important on the average by Emirati goat breeders with a medium proportion (60–65%). Goat breeders have put slightly more pressure on buck subjective criteria. The most important buck selection criteria were growth rate (80%) and body morphology selection criterion (76%) then fertility, buck being one of twins and breed purity with averages in 50-55%. Although; increasing meat production was the main breeding objective, an effective breeding program must incorporate different selection criteria for does and bucks considering differences in breeds, regions, property types and herd sizes.


Introduction
Goats are important farm animals raised for meat, milk, hide, and fiber.They are greatly adaptable to a wide variety of environmental conditions and manufacturing systems.As a result, there are over 576 breeds available worldwide, and their population is growing [1] [2] .Goats' population in United Arab Emirates also increasing; according to Statistics Book [3] there were more than 1.3 million head of goats in Abu-Dhabi Emirate, and represents more than 37% of the overall animal heads in the Emirate.Although, raising goat in the United Arab Emirates is considered a part of the Emirati tradition, it is economically inefficient in terms of input use [4] .This is because most goat breeders in the UAE do not raise goats for revenue, in contrast they consider it as hoppy and as a source of milk and meat mainly used for family consumption.Breeders select a breed based on its morphostructural and production characteristics.Maintaining biodiversity among breeds requires distinctive breeding objectives for each breed.However, breeders are often concentrating on morphostructural more than production traits as criteria for selection [5] [6] .Several goat breeds were observed in the Emirate during a preliminary investigation, and breeders were attempting to improve productivity by random crossing of different breeds (unpublished data).These breeds of goat were imported and found in many countries of the region.Understanding the breeding objectives and selection criteria of the farmers assist in improving the various goat breeds found in the region, Though, there is no an animal breeding program for improving goats and data is lacking on breeder's belief on breeding objectives of the different goat breeds they own.The traditional method for determining breeding objectives is by using mathematical equations related to profit take into account cost and returns constituents to derive economic weights that to quantify the genetic change [7] .However, definitions of breeding objectives through research may not be adopted in reality if they did not reveal the belief of the breeders.The failure of many breeding programs aiming at genetically improve livestock breeds was mainly due to absence of breeders' opinion in outlining breeding objectives for their animals [8] [9] .Traditional economic values often fail to notice the meandering value of subjective traits that may be profitable under certain conditions, characteristics related to animal wellbeing and impact to environment that could affect breeders' decision despite the fact being not easy to be defined [10][11] .Recently, other approaches were used to derive breeding objectives for animal improvement programs as to use specified-preference practices by consumers or breeders.In these practices, questionnaires are prepared to ask breeders to pick from multiple-choice questions [12] .For animal breeders, this attitude involves analyzing breeders' preferences in relations to their belief in the paybacks which might be achieved through genetic improvement [13][14] .
Many factors could affect the breeders' choice of breeding objectives and selection criteria, this includes region, production system, breed, housing type and herd size [5][6] [15] .Low fertility in commercial beef farms is acknowledged by some breeders in South Africa while it is not accepted in other type of farming where breeders are aiming for high fertility [16] .In United Arab Emirates, no studies were found so far identifying the breeding objectives and selection criteria applied by Emirates goat breeders.Therefore, this investigation is a substantial effort to realize the breeders' desires from different goat genetic resources in UAE.This will be valuable to breeders to improve productivity of their animals and to provide applicable genetic improvement program.The aim of this study is to explore the breeding objectives and selection criteria recognized by breeders of various goat breeds and examine the potential factors might affect their decisions.

Study area
The study was conducted in the three regions of Abu-Dhabi Emirate the Abu-Dhabi, Al-Dhafra and Al-Ain with their subregions between December 2015 and September 2016.The Emirate is found between 22°40" and 25°N and 51° and 56°E and it is a hot desert area, with low rainfall, and its skies are clear all-year-round.Average maximum annual temperature exceeds 39°C with high humidity during the period from June to September, while cooler temperatures (19°C) are experienced from November to March.

Sample selection
A stratified random sample of 230 goat breeders from all regions was interviewed based on the number of goats in each sub region [17] .The sample was selected based on interviewing 5 breeders per one percent of goat population, with a minimum of 3 breeders in each sub region.Selected breeders possess a total of 293 herds of various goat breeds with a total of 49911 heads of goats.
The government do not allow breeders to graze their animals outside their properties.Three property types are found: random and registered animal farms, and mixed farms of animal and plants [18] .The registered animal farms and mixed farms were originated by the municipalities as a group of farms and distributed among the local breeders.However, random animal farms were originated by a group or single breeders in a random places and they were not registered.
Both animal farms (registered and random) were allowed to raise only various species of animals but not to grow crops or trees while mixed farms and are allowed to grow crops, vegetables and trees and raise animals.Two types of herds were found one of which pure goat or mixed with sheep.If number of adults were up to 150 heads, herds were categorized as small, if number of adults were between 151 to 350 heads, herds were categorized as medium and large herds with adult animals were more than 350 heads.

Breeders interview
A questionnaire was prepared and tested to collect data related to goat breeding in the Emirate.A trained interviewer specifically asked the breeders about their goat herd breeds, herd size, productivity characteristics, breeding objectives, and selection criteria about their replacement does and bucks, and if they were homegrown or brought from other herds.
The questionnaire also included additional information with relative to the geographical site, farm location and the gender of the owner, Breeds that were only found in one or two farms were grouped as one group called "Others".

Statistical analysis
Survey data was statistical analyzed using the Chi-square test of the FREQ procedure of the Statistical Analysis System (SAS) [19] .In the initial statistical analysis owner gender was assumed as a factor; however, no one criteria was affected by gender (Figure 1B).After that, stepwise logistic regression was applied using LOGIST procedure of SAS [19] to study the influence of available factors on breeding objectives and selection criteria and to calculate the odds ratios to estimate the comparative importance of the different levels of influences on breeders' choices.

Results and Discussion
Breeding objectives Table 1 presents the breeding objectives chosen by Emirati breeders for different goat breeds.The results suggest that goat breeders in UAE are breeding goats mainly for meat production (94%).This is in agreement with Malawi goat breeders [20] .Elsewhere, the most important breeding objectives for goats was cash income from sale of live goats and in second place by meat and milk production for home consumption [21][22] .Goat meat is preferred by many local people of the UAE with growing demand for it in the market of the Gulf States [21] .Other researchers reported multiple breeding objectives chosen by breeders to improve productivity of their goats, including meat and milk for home consumption, cash from selling live animals, insurance against emergency, wealth, dowry, and manure [23][24] .Although, differences were not significant (P > 0.1), numerically some breeds were 100% raised for meat production such as Boer, Omani, and Pakistani goats while only 82% of the Shami (Damascus) goat breeders chose meat production as breeding objectives for their goats.The second most important breeding objective for goats was the adaptability to environment (40%, Table 1).Also, this breeding objective was not significantly (P > 0.1) different among different breeds.However, breeders raising exotic breeds, such as Boer, Others breeds and crossbred goats, gave more attention to adaptability environmental conditions (50 -56%) than those raising local breed (36%) or breeds of adjacent countries such as Omani (14%); which is a justifiable decision, since the later breeds are already adapted to the harsh environmental conditions dominating the Gulf States.Disease resistance was considered by a reasonable proportion of breeders (35%) as a breeding objective with differences among different goat breeds (Table 1).Similar to adaptability to environment, disease resistance was more considered by breeders of exotic breeds.Though, more pronounced, and significant (P < 0.05) differences were revealed between exotic and local breeds.For instance, 60% of the Boer, 56% of crossbred, 44% of Others breeds 43% of Ardi and 42% of Pakistani goat breeders considered disease resistance while only 7% of the Omani, 9% of Shami and 14% of Jamodi goat breeders considered this breeding objective (Table 1).

Breed
Milk production was only considered by 21% of the breeders as a breeding objective (Table 1).This is because most breeders of the UAE do not sell or process goat milk.They either consume it fresh or leave it for the labor and the goat kids to consume.On the contrary, breeders in many countries considered milk production as the main breeding objective for goat keeping [5][24] .In Brazil and other industrial countries, breeders consider not only milk yield but also milk quality [25] .Anyway, goat improvement strategy should consider breeders breeding objectives and their traditional breeding practices [23] .Although, milk production as breeding objective was highly significant (P < 0.01) differences among breeders of different goat breeds were found.Shami, Ardi, Pakistani and Boer breeds, in addition to the crossbred goat breeders gave attention to milk production only between 30% and 38%.Though, only breeders of Shami and Pakistani goats were most likely to milk their goats.
More of Boer goats than Ardi and Shami breeders emphasized body morphology (30%, 20% and 18%, respectively) as a breeding objective for their goats than other purebred breeders.These three breeds are always displayed in the shows of livestock in the Emirate and judged on their unique morphological characteristics.Breeders in Jordan emphasized more the unique morphological characteristics to each breed as it was the second most important breeding objective with higher proportion of breeders (46%) selecting Shami goats for them [5] .Although multiple breeding objectives were considered by breeders in Ethiopia, they emphasized the breed unique morphology [23] .Breeders, in general, believe that the breed unique morphology related to high productivity in a breed, therefore, selection for unique morphology improves productivity [5] .On the other hand, fiber is mostly of no value to breeders in UAE, though 25% of the crossbred goats' breeders considered fiber as a breeding objective for their goats with no clear reason.

Factors influencing breeding objectives
Many factors influenced breeders' breeding objectives including breed, region, property type, and herd size (Table 2).Similarly, in Ethiopia, breeders' decision on breeding objectives was different due to breed raised [23] .Breed of goat significantly influenced breeders' decision on disease resistance, milk production and breed unique morphology.The odds ratio (OR) revealed that the breeders of Shami and Omani goats were worried the least with disease resistance then the breeders of Jamodi and Salali goats and then by the other breeders.This could be due to that these breeds were more resistant to diseases than other breeds raised under the UAE conditions.Regarding breeding objective of milk production, the breeders were concerned the most were crossbred, Shami and Ardi goats' breeders and the least concerned breeders were those raising Jamodi followed by Local goats' breeders.Ardi goats' breeders were the most worried about breed unique morphology then Boer goats' breeders and then by breeders of Shami and Salali goats.meat, milk, and cash income and disease resistant and others emphasis more the breed unique morphology [24][26] .The influence of region on breeders' decisions on breeding objectives may reflect differences due to ecological, social factors, economic and marketing opportunity available in different regions [25] .Breeders in Al-Dhafra region were extremely more worried about adaptability to environment and disease resistance than breeders in both Al-Ain and Abu-Dhabi regions and those of Al-Ain were more worried than those in Abu-Dhabi.In general, Al-Dhafra region has harsher environmental conditions than the other two regions and more facilities like fresh water and clinics available for breeders in these two regions than that for breeders of Al-Dhafra region.Similarly, the breeders of Al-Ain region were more likely to select goats for breed unique morphology than those of the other regions of the Emirate, though the differences in OR (19.50) were higher than the previous two objectives.Figure 1A displays the distribution of different breeds in the three regions which was highly significantly different (P < 0.01).In general, more than 57% of the surveyed goats' population is in Al-Ain region.However, more than 50% of Ardi goats were found in Al-Dhafra region.
Property type, which might reflect the production system, significantly (P < 0.05) affected the breeders' decision to select for milk production (Table 2) and with breeds' scattering significantly (P < 0.01) different among different property types (Figure 1C).Breeding objectives definitions by breeders often reveal the relative social and economic importance of certain characters within a production system [23][27] .Breeders who are owners of registered animal farms were more possible to select for higher milk yield than those of other property types.It is good to know that more than 51% of the overall sampled goats were in the random animal farms while around 14% only found in the registered animal farms which might have contributed to breeders' decision to select for milk production under the registered animal farms (Figure 1C).
Herd size significantly affected breeders' decision to select for diseases resistance (P = 0.01) and breed unique morphology (P < 0.05) with small herds being the most in both characteristics (Table 2).This indicated that breeders of small herds are more interested in selecting their goats to be more resistant to diseases and to fit more with breed unique characteristics.Breed distribution in different herd sizes were significantly different (P < 0.01, Figure 1E), with medium sized herds has more than 42% of all goat population.

Selection criteria of does
Doe selection criteria for the replacements of different goat breeds are presented in Table 3. Nine out of the twelve selection criteria were considered objective selection criteria and only three were subjective selection criteria.Similarly, breeders in Ethiopia also select for subjective and objective selection criteria [24] .The three subjective selection criteria were the first (body morphology 60%) was among the most important, the second (breed purity 40%) was in the middle and the third (doe sources 18%) was the least important by breeders of the different goat breeds.Multiple selection criteria were considered by breeders in other countries [5][21][22] [24] .Choosing body morphology and performance characteristics as selection criteria by the breeders suggest that breeders are selecting their animals on two-stage procedure; first use body morphology and family history in early stage of life then use production and reproduction characteristics at later stage [21] .Fertility, twining ability, body morphology and growth rate selection criteria were considered the most important on average by goat breeders in Abu-Dhabi Emirate with a medium proportion of breeders choosing them (60% -65%).Fertility traits, twining ability and growth rate were among the most important selection criteria reported by several researchers [22][23] .Fertile does that produce twins with high rate of kidding are favored by the breeders because they contribute more to their income [23] .However, some breeders revealed that twining is not welcomed because does with twins produce weak kids that might not survive the harsh environment of the UAE.Many other criteria were also reported as most important such as milk yield, age at first kidding, body morphology and color [21][22] [24] .In general, breeders believe that selection for some body morphology characteristics is a tool for improvement of meat and milk productivity and longevity traits [5][23] [24] .Tabbaa and Al-Atiyat [5] found that goat breeders in Jordan were the most concerned with doe source as a selection criterion for their replacement does.Fertility and twining ability were not significantly different among goat breeds, while growth rate and body morphology were significantly (P < 0.01) different among breeds.The highest percentage of breeders considering growth rate and body morphology as selection criteria was for crossbred goats (92%), however, for Boer goats they were 80%.This might signify the importance of these criteria for crossbreeding goats.High proportion of breeders considered growth rate criteria for Ardi, Pakistani and Omani goat.Similarly, body morphology was highly considered by Shami goat breeders and breeders of the Others breeds.
Disease resistance was considered next by goat breeders for their doe selection criteria with no significant differences among breeds (52%, Table 3).Goat breeders were also concerned with average merit, kidding ease and breed purity selection criteria with proportions in (40 -47%).Kidding ease and breed purity were significantly (P < 0.01) different among different breeds.Kidding ease was the most concern for crossbred goats (92%), which might be due to the fact that crossing large breed bucks with smaller does, in order to obtain kids with high growth rate, creates a kidding problem for these does.Breed purity was most important for Boer goats (90%); this is because of the high value for this exotic breed in the market of the Emirate.Last season productivity and dam merit were important for 33 -35% of the goat breeders with significant (P < 0.01) differences among different breeds.Kebede et al. [23] stated that breeders in some parts of Ethiopia consider dam merit as the second most important doe selection criteria after milk yield.Longevity (25%) and doe source (18%) were the least concerned selection criteria by goat breeders.A sustainable and successful breed improvement program needs to include all different categories of selection criteria requested by breeders that improve production efficiency to enhance economic gain, however, measurement ease of selection criteria should also be considered [21][28] .The breeding programs should also be designed considering good management practices such as better feeding and health in addition to good selection criteria [21] .

Factors influencing selection criteria of does
Doe breed significantly (P < 0.01) affected breeders' decision on selection criteria toward body morphology, kidding ease, breed purity, last season productivity, dam's merit, and doe source (Table 4).Differences in breeders' decision on selection criteria due to breed were stated by other researchers [23] .Crossbred goats' breeders were the most concerned with body morphology as a selection criterion for their replacement does as odds ratio shows (2.49), and followed by Boer (1.39), other breeders then followed.The odds ratio revealed also that crossbred goats' breeders were the most worried about their replacement does with several other selection criteria including kidding ease, last season productivity, dams' merit, and their doe replacement source.Salali goat breeders comes next in kidding ease, Jamodi goats' breeders comes next in last season productivity, Shami goat breeders comes second in dam merit and Ardi goat breeders comes next in doe replacement source.Boer goats' breeders were the most concerned with breed purity for their replacement doe selection criteria with Shami goat breeders comes next (Table 4).
The region where the farm is located significantly influenced several doe selection criteria included growth rate, body morphology, disease resistance, kidding ease, breed purity, last season productivity, and dams' merit (Table 4).Similarly, Asefa et al. [24] reported significant differences in breeders' decision on selection criteria in different regions of the same country.Region differences may reflect environmental condition differences or differences in marketing opportunity [24][28] .
Therefore, in order to have a successful breeding program different selection criteria and selection strategy need to be adopted in different regions even for the same breeding objectives [20] .As the odds ratio revealed, breeders of Abu-Dhabi region were the most worried about body morphology and growth rate as selection criteria for their replacement does, while Al-Ain breeders were the most concerned with breed purity and dams' merit.On the other hand, Al-Dhafra breeders were the most concerned with disease resistance, kidding ease and last season productivity.
Property type, which represents the production system in UAE, significantly influenced the breeders' decision on doe selection criteria toward twining ability, growth rate, body morphology and disease resistance (Table 4).Production system was reported to influence breeders' decision on selection criteria [23] .Breeders of the registered farms were the most worried about twining ability and growth rate, while breeders of the random farms were the most concerned with body morphology and disease resistance.Breeders of the mixed farms were in the middle for all selection criteria except for body morphology they were the least concerned.
It is important to mention that breed distribution among different herd types was significantly (P < 0.01) different and that almost 85% of the herds were mixed with sheep (Figure 1D).Herd type significantly influenced the breeders' decision on only two doe selection criteria one of which is the growth rate and the other is last season productivity (Table 4).The odds ratio revealed that pure goat breeders were concentrating more on last season productivity (3.22) and less on growth rate (0.38).On the other hand, herd size significantly influenced fertility, breed purity and last season productivity (Table 4).
Breeders of the small herd size were concentrating on fertility and breed purity while large herd breeders were more concerned with last season productivity.

Selection criteria of bucks
Decisions on replacements buck selection criteria for different goat breeds are presented in Table 5.Similar to doe selection criteria, nine out of twelve selection criteria are considered objective selection criteria and only three are subjective selection criteria.However, Abu-Dhabi Emirate breeders have put slightly more pressure on buck subjective criteria than that for doe (Table 3).Similarly, breeders in Ethiopia slightly put more pressure on morphological characteristics for replacement buck selection than that for doe selection criteria [23] .However, Jordanian breeders put more pressure on bucks' objective selection criteria than that for does [5] .The most important buck selection criterion for the Emirati breeders was growth rate (80%), with no significant differences among different breeds, however, percentage of breeders considering this criterion ranged from 67% for Salali and Shami goats to 100% for Boer and crossbred goats (Table 4).Abraham et al. [22] (2017) reported that breeders emphasized growth rate, body size and libido as selection criteria for bucks.On the other hand, Kebede et al. [23] stated that growth rate and prolificacy of bucks were considered by the breeders as the least important criteria for buck selection.Body morphology selection criterion (76%) was the second in importance for the breeders after growth rate with also, no significant difference among different breeds (Table 5).Similarly, Ahmed et al. [21] reported that breeders ranked body morphology as second for buck selection criteria.However, Asefa et al. [24] found that breeders put body morphology in the first rank for both bucks and does selection, since they consider body morphology a tool for improvement of performance characteristics.The range of percentage values for breeders choosing this criterion for their different breeds was from 66% for Local goats to 95% for Pakistani goat, though, the value for Shami and crossbred breeders was 93%.
Fertility, buck being one of twins and breed purity came in the third place as selection criteria with averages in 50 -55%.
Fertility characteristics for buck selection such as testicular characteristics, libido, and prolificacy were emphasized by breeders elsewhere [22][23] .Fertility was most considered by breeders of Ardi (74%), Boer (70%), Shami (67%) and crossbred (67%) goats with significant difference (P < 0.05) among different breeds while buck being one of twins was considered most by breeders of Boer and crossbred (80%) then by breeders of Shami (67%) with trend (P < 0.1) of  Property type significantly influenced only 3 buck selection criteria (Table 6).Odds ratios reveal that breeders who own registered farms are more concerned in buck being one of twins than breeders of the other farms types while breeders of the random farms and mixed farming were more worried about testicular size and buck source selection criteria.
Registered farm owners might have received higher level of support from the government therefore they are less concerned with fitness characteristics of their bucks.Likewise, researchers have highlighted the importance of production systems on breeders' decision on selection criteria, especially those related to fitness traits [21][23] .Herd type significantly (P < 0.05) influenced only buck dam twining ability with breeders of mixed herds of both small ruminants were more concerned with dam twining ability than breeders of pure herds (Table 6).Breeders of medium (151 -350 heads) and small (<151 heads) sized herds were significantly (P < 0.05) less concerned about replacement buck fertility than those of large herds (>350 heads), with odds ratios of 0.49 and 0.42, respectively.

Conclusion
Breeders of Abu-Dhabi Emirate do not have predetermined breeding objective in order to improve their bucks and does according to defined selection criteria.Breeders need to predefine accurately their breeding objectives to improve

Statements and Declarations
Funding: This research received no external funding.

Table 2 .
Factors influencing selection of different breeding objectives for goat breeds and their odd ratios in Abu-Dhabi Emirate.

Table 3 .
Proportions of breeders selecting doe selection criteria for the different goat breeds in Abu-Dhabi Emirate.

Table 4 .
Factors influencing selection of doe selection criteria for goat breeds in Abu-Dhabi Emirate.

Table 5 .
Proportions of breeders selecting buck selection criteria for the different goat breeds in Abu-DhabiEmirate.

Table 6 .
Therefore, an essential extension strategy is needed to raise breeders' understanding and provide them with practical guidance toward genetic improvement program that satisfy their needs and improve their animals' productivity.Goats in Abu-Dhabi Emirate are raised for multiple purposes; however, increasing meat production was the main breeding objective.Though, a successful breeding program needs to formulate different selection criteria for bucks and does considering differences in breeds, regions, property types and herd sizes.Factors influencing selection of buck selection criteria for goat breeds in Abu-Dhabi Emirate.BM: Body morphology, FR: Fertility, BT: Being twin, BP: Breed purity, DR: Disease resistance, MR: Mortality, KE: Kidding ease, DM: Dams merit, DT: Dam twining ability, TS: Testicle size, BS: Buck source.Others: African, Haw, Hawarez, Jabali, Maltese, Saanen, Zafari, Saedi, Rahbi and Somali.