| dc.description.abstract | A study was done based on records generated in the periocl 1980- 1992 in 398 smallholder herds in 23 districts located in the high and medium potential areas at low, medium and high aItitudes to evaluate two long term breeding policy options in the smallholder, grade dairy cattle populations by use of a demographic stationary
state productivity model-PRY. The first option was the current policy, where there was equal sharing of imported and locally progeny tested AI semen for breeding both the large- and smallscale herds. The second option was whereby there would be use of semen of bulls bred and progeny tested within the smallholder herd environment. The inputs to the productivity model were estimated by least squares analysis procedures. The grade dairy breed groups were Friesian, Ayrshire, Guernsey, Jersey, Nondescript, two F1. crossbreds of Friesian or Ayrshire (FL and Jersey or Guernsey (FS with zebu' and their respective backcrosses RJ, and Rs; and the Kilifi breed. The respective overall means' and standard deviations for lactational milk yield, calving interval, ag~ at~ first calving and selective cull ing rate of heifer and cow were 2430.71 and 477.71 kg, 13.88 and 1.64 months, 39.48 and 8.10 months, 9.20 and 5.0 %; and 23.40 % and 6.03 %. The respective overall mea ns and standard deviations for survival rates were 83.80 and 30.90; 83.20 and 21.31; 84.30 and 32.66; 88.02 and 28.38; 80.01 and 30.21.; and 84.36 and 31.02% for pre-weaning period of female and male calf; post-weaning period of young stock female and male; and for cows and bulls. On basis of productivity model, the R], was found not to
be sustainable under the smallholder environment. The ovecall productivity in Ksh/kg dry matter intake per animal-year were 1.322, 1.501, ,1.896, 2.369, 1.967, 1.950, 2.257, 2.218 and 2.176 for friesian, Ayrshire, Guernsey, Jersey, Nondescript. FL, FS, RS
and Kilifi respectively. These results confirmed the suitable breed groups choices to be Jersey, FS, RS Kilifi, FL and Nondescript. | en |
