On – farm evaluation of performance of Sukuma and Malya goats and their crosses in Maswa District, Tanzania
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Date
2019
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Publisher
Sokoine University of Agriculture
Abstract
Goat production is an integral component of small holder agriculture in Tanzania but
farmers have been keeping indigenous goats which have poor genetic potential for growth
and have small mature body size. Goat keepers can improve mature body size by crossing
with improved breeds. However, in Tanzania there is paucity of information on
performance of crossbreds in comparison to their parents. The effects of breed, sex, birth
type, season of birth, year of birth and dam weight class on growth performance of kids
born, twinning rate of dams, genetic parameters and finally farmers’ preference on
crossbreds and indigenous Sukuma goats were investigated. Sixty participating farmers
were trained on basic meat goat management. Does of either breed i.e. Sukuma or Malya
goats to be used in breeding program were dewormed and unwanted bucks in the herds
were castrated. Breeding bucks were kept separately by chosen farmers. Dams were
initially weighed then were mated to bucks in a such a way that Malya bucks were
allowed to mate with Malya does and Sukuma does while Sukuma bucks were allowed to
mate with Sukuma does only. Goats were allowed to free graze on natural vegetation
within each household’s farmland without supplementing them. Kids born of pure Malya,
Sukuma and crossbred (Malya x Sukuma) goats were monitored for over two years. Data
on growth traits from birth to one year and some reproduction traits were recorded. The
results showed that all growth traits of Malya kids were highest, which were 2.37±0.03 kg
for birth weight, 11.08±0.19 kg for weaning weight, 13.04±0.22 kg for 32 weeks’ weight,
25.91±0.41 kg for yearling weight, 75.67±2.63 g/day for pre-weaning growth rate,
57.79±2.56 g/day for post-weaning growth rate and 63.29±1.70 g/day for birth to yearling
growth rate followed by crossbred kids which had 2.18±0.05 kg, 7.22±0.26 kg, 9.60±0.30
kg, 21.99±0.55 kg, 47.90±2.94 g/day, 55.60±2.86 g/day and 53.23±1.90 g/day of
corresponding growth traits. Sukuma kids were the least with 1.66±0.06 kg for birth
weight, 5.13±0.34 kg for weaning weight, 7.53±0.38 kg for 32 weeks’ weight, 14.22±0.71
kg for yearling weight, 30.19±3.81 g/day for pre-weaning growth rate, 35.45±3.70 g/day
for post-weaning growth rate and 33.83±2.45 g/day for birth to yearling growth rate. Sex
of the kids affected all weights at different ages at P<0.001 for birth weights, 32 weeks
weight and yearling weight and at P<0.01 for weaning weight. Birth type statistically
influenced birth weights, weaning weights, 32 weeks weight and pre-weaning growth rate.
Single born kids (birth weights of 2.15±0.03 kg, weaning weights of 8.25±0.17 kg, 32
weeks weight of 10.54±0.20 kg and pre-weaning growth rate of 55.37±1.91 g/day)
performed better than twin born kids with 1.99±0.04 kg, 7.37±0.22 kg, 9.58±0.25 kg and
47.14±2.28 g/day for corresponding growth traits, respectively. Weaning weights
(8.81±0.23 kg), 32 weeks weights (10.62±0.26 kg), yearling weights (21.46±0.48 kg) and
pre-weaning growth rate (59.79±2.32 kg) for kids born in year 2010 were higher
compared to 6.81±0.19 kg, 9.50±0.21 kg, 19.96±0.39 kg and 42.71±1.98 g/day for kids
born in year 2011 for respective growth traits. Pre-weaning growth rate was affected by
sex of kids (P<0.05), birth type (P<0.01) and year of birth (P<0.01) but not season of birth
(P>0.05). Overall twinning rate of does that kidded was 34.47% and was significantly
influenced by breed in which Malya does had higher (46.48%) twinning rate than that of
Sukuma does (20.49%). Genetic parameters were computed based on Malya sires.
Heritability estimates for 32 weeks weight, yearling weight, pre-weaning growth rate,
post-weaning growth rate and birth to yearling growth rate were low ranging from
0.11±0.02 to 0.18±0.02. However, moderately high heritability estimates were found for
birth weight (0.43±0.04) and slightly lower for weaning weight (0.23±0.03). Genetic
correlations between weights at different ages were positive and ranged from 0.17
between weaning weight and yearling weight to 0.49 between weaning weight and 32
weeks weight. Phenotypic correlations were low to moderate. Genetic correlations
between growth rates at different stages were positive and negative ranging from -0.39
between pre-weaning gain and post-weaning gain to 0.90 between post-weaning weight
gain and birth to yearling weight gain. Corresponding phenotypic correlations ranged
from -0.38 between pre-weaning and post-weaning growth rate to 0.89 between post-
weaning and birth to yearling growth rate. Heterosis from crossbred (Malya x Sukuma)
goats were positive for birth weight (8.19%), yearling weight (9.59%), post-weaning
weight gain (19.26%) and birth to yearling weight gain (9.62%). However, heterosis for
weaning weight, 32 weeks weight and pre-weaning gain were negative. Farmers preferred
crossbred goats as they performed better with many more good attributes (large body size,
94%; premium price, 92%; high growth rates, 80%) than bad attributes (prone to diseases,
16%; perform poorly in drought conditions, 8%) and they had superior body
measurements (body length, 60.58±0.46 cm; heart girth, 77.59±0.58 cm; height at withers,
66.35±0.42 cm and body weight, 35.07±0.52 kg) compared to body measurements of
Sukuma goats (body length, 49.58±0.42 cm; heart girth, 65.07±0.54 cm; height at withers,
56.74±0.39 cm and body weight, 21.56±0.48 kg). From the study, it was concluded that
mature body size of Sukuma can be improved by crossing them with Malya goats under
farm condition with extensive system of management. Pre-weaning weight gains are
influenced by maternal environment. Moderate heritability for birth and weaning weight
suggest that selection based on these traits will improve genetic progress. Most of growth
traits are moderately correlated, so indirect selection can result into moderate correlated
response. And lastly is that farmers appreciated the crossbreeding program.
Description
Dissertation in Tropical Animal Production 2019
Keywords
Farm evaluation, Sukuma-malya goats, Maswa District, Tanzania, Goat production, Goat improved breeds