| dc.description.abstract | Performance of Saanen/Toggenburg crosses and their Alpine sired crossbreds in
Nyeri district in Central Kenya was studied. Data was analysed for 112 does which
kidded between 1994 and 1996 and 59 kids (31 singles and 14 twins) born between
January and June, 1996. The animals were reared under zero-grazing system. Milk
yield and liveweight of kids were recorded at weekly intervals, while births and
deaths were recorded as they occurred. Data on reproductive performance such as
number of services per conception and kidding interval were extracted from the
doe card. The factors included in completely fixed statistical analyses models
were agricultural area, month of kidding, sex of kid, type of birth, breed of doe
and parity in all the four traits and breed by agricultural area interaction as
an additional effect in lactational milk yield.
The productive traits analysed were lactational milk yield (kg), birth weight
(kg), pre-weaning average daily gain (ADG) (gms) and weaning weight (kg). Their
respective means and coefficients of variation were 108.24±65.51 : 60.52%;
2.87±0.76 : 26.51%; 91.79±27.62 : 30.09%; and 13.34±3.36 : 25.18%.
Agricultural area, month of kidding, breed of doe, breed by agricultural area
interaction and lactation length significantly (P<0.05) affected milk yield,
while type of birth significantly (P<0.05) affected birth weight. None of the
above factors significantly affected ADG and weaning weight. However, the
agricultural areas located in the main coffee zone performed better in all the
four traits compared to the area located in the marginal coffee zone.
The Fl Alpine sired crossbreds had significantly (P<O.05) higher lactational milk
yield (141.60±27.14 kgs) compared to the Saanen/Toggenburg crosses (65.39±11.92
kgs). However, the Saanen/Toggenburg crosses performed better
compared to the Alpine sired crossbreds in birth weight (3.28±0.29
Vs 2. 83±0. 51 kgs), pre-weaning ADG (85. 31±10. 58 Vs 82.7 3±30. 64 gms)
and weaning weight (12.55±3.73 Vs 12.44±1.29 kgs). However, these
differences were not statistically significant (P>O.05).
Female kids performed better, though not significantly (P>O.05), in
pre-weaning growth compared to their male counterparts. Single born
kids and kids born of older does performed better than twins and
kids born of younger does. However, the differences were not
statistically significant (P>0.05).
Twinning rate, pre-weaning kid mortality and number of services per
conception for all the does were estimated at 31.11%, 10.17% and
1.36±0.68 respectively. Kidding interval for the Saanen/Toggenburg
crosses was estimated at 380.8±114.7 days. It was not possible to
estimate this trait for the Fl Alpine sired crossbreds because they
were in their first kidding.
It was concluded that crossing of the Saanen/Toggenburg crosses
with the Alpine bucks improved the lactational performance. Further
research is necessary to determine performance of dairy goat
crosses in the study area using a larger data set over a longer
period. | en |
