dc.description.abstract |
Indigenous breeds adapt and survive in often challenging environments and diverse agroecological
areas representing an important genetic resource for livelihood of their owners
and the national economy at large. Therefore, there is a need to improve the productivity of
indigenous animals through developing sustainable breeding programs so as to enhance their
competitive advantage in the face of crossbreeding threats. The current study was performed
in Kafta Humera district of Tigray National Regional State of Ethiopia with the general
objective of developing sustainable breeding program for improving performance of Begait
goat to assure the livelihoods of the breed owners and to survival of Begait goat as a breed.
Specific objectives of the current study were to: (i) describe production systems and breeding
practices for Begait goat breed (ii) evaluate some reproductive and productive performance
parameters of the breed under village (on-farm) and research (on-station) management (iii)
identify breeding objective of the breed owners using own-flock ranking experiment and
developing bio-economic models and (iv) design and evaluate alternative breeding schemes
for genetic improvement of the breed. This dissertation contained five papers/manuscripts.
The results of Paper I were based on survey of 150 (100 small-scale and 50 large-scale)
sample household heads, in-depth focus group discussions and personal observations. The
results revealed that agricultural production system in the area was mixed crop-livestock
production system. Two types of goat farming systems were identified specifically small-scale
and large-scale farming systems. Goat flock sizes were 23.21±13.42 and 68.43±15.38 under
small-scale and large-scale farming systems, respectively. The results indicated that farmers
under the two farming systems keep goats to generate cash income, milk and meat for home
consumption with different index value. Natural pasture, browse species, crop residues and
crop aftermath were the accessible feed resources. Rivers, ponds and borehole were available
water sources for domestic use and for watering animals in the study area. Mating under the
two farming systems was uncontrolled because of communal grazing and watering points.
Small-scale and large-scale farmers use body size, twinning ability and milk yield for does
whereas body size, growth rate and libido for bucks as selection criteria both with different
index values. Water shortage, feed and grazing land shortage, insufficient veterinary service
and lack of market demand were the most significant goat production constraints in the area.
Papers II and III were based on monitoring data collected under two management systems
(on-farm and on-station) during the period between October 2014 and December 2016. The
results showed that the overall least squares means and standard error (±SE) of body weight
at birth (BW), three month (3MW), six month (6MW), nine month (9MW) and twelve month
(12MW) were found as 2.69±0.03, 10.71±0.44, 15.60±0.53, 18.30±0.43 and 22.36±0.52 kg,
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respectively. The overall mean pre-weaning daily weight gain (ADG-I) was 89.10±1.54 g/day,
whereas post-weaning daily weight gain (ADG-II) was 54.24±1.75 g/day. The overall mean
values of age at puberty, age at first kidding (AFK) and kidding interval (KI) were
214.58±1.20, 429.24±6.46 and 238.75±2.04 days, respectively. Litter size (LS) in the current
study ranged from 1 to 3 with the mean of 1.52±0.02 kids per doe per kidding (Paper II). The
overall mean daily milk yield (DMY), lactation milk yield (LMY) and lactation length (LL)
included: 0.61±0.01 kg, 64.3±1.23 kg and 104±1.22 days, respectively (Paper III). Nongenetic
factors estimated (management system, kid sex, parity number, birth type and birth
season) highly significantly (p<0.001) influenced almost all body weights, reproductive and
milk production parameters (Papers II and III). Under semi intensive management mean
body weight of Begait kids at birth, 3, 6, 9, and 12 month were 2.81±0.04, 11.12±0.43,
16.45±0.49, 19.58±0.37 and 24.13±0.48 kg, respectively whereas the corresponding figures
under extensive management were 2.59±0.03, 10.32±0.46, 14.76±0.57, 17.06±0.49 and
20.62±0.54 kg. Age at puberty, AFK and KI of semi intensively managed Begait does were
209.93±1.65, 415.09±9.01 and 233.77±3.12 days, respectively. The corresponding values of
these traits in extensive management were 219.00±1.63, 444.33±9.09 and 242.79±2.66 days.
The DMY, LMY and LL were 0.75±0.01 kg, 85.6±1.04 kg and 111±1.21 days under semi
intensive management, respectively whereas under extensive management these were
0.55±0.01 kg, 56±1.43 kg and 101±1.57 days. Breeding objective traits were defined using
own-flock ranking experiment and based on calculated economic values obtained developing
bio-economic models (Paper IV). Traits highly preferred by farmers were body size, LS and
DMY, whereas traits with the greatest economic values included: LS, 6MW and pre-weaning
kid survival rate (SR) in their order of magnitude. Under Paper V, three alternative breeding
schemes: two central nucleus-based (government ranch and commercial breeding schemes)
and one village-based (cooperative village breeding scheme) were evaluated for annual
genetic and economic gains and operational feasibility. The breeding schemes differed in
number of tiers, flock size and selection method. The results indicated that central nucleusbased
schemes were slightly better in genetic and economic gains when compared to villagebased
scheme. Government ranch breeding scheme seems more operationally feasible for
improvement of the breed than the other schemes as government is investing in conservation
and improvement of the breed. By the end of Growth and Transformation Plan III,
government planned to export meat from Begait goat, sheep and cattle breeds, and developed
a roadmap for its implementation, which can be considered as good opportunity. If it is not
successful,the alternative schemes can be implemented with careful consideration of their
limitations. |
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