GROWTH OF SAHIWAL AND THEIR CROSSBRED WEANER CALVES FED ON PASTURE WITH SUPPLEMENTATION UNDER PASTORAL SYSTEM

Abstract

A cross-sectional survey was conducted by direct interview of 51 livestock farmers using a structured questionnaire in Transmara sub-County, Narok County. The households were selected randomly from a sampling frame from the sub-County wards. The objectives were to identify socio-economic and nutritional factors affecting growth of Sahiwal and Sahiwal/Zebu crossbred weaner calves under the pastoral conditions. Data collected was analysed using SPSS software, version 20.0, 2009. A feeding trial was also conducted in Naivasha at the Dairy Research Institute using 12 weaner calves (six Sahiwal calves; age 9.8 months and average live-weight, 74.7kg and six Fresian x Sahiwal crosses; age, 13.7months and average live-weight, 99.5 kg) fed natural pasture-based ration with either cottonseed cake or lucerne hay as protein supplements in a randomized complete block design. The objective was to compare the effect of breed and protein source on the performance of the calves. Feed samples were exposed to in-vitro gas production procedure to estimate their metabolizable energy (ME) and organic matter digestibility (OMD) content. A comparison of the ME and the OMD values between the two protein sources was done using the general linear model of SAS software whereas the comparison of the animal performance variables between breeds and proteins sources were done using repeated measure in a 2x2 factorial arrangement by Linear Mixed Models of SAS software and the treatments were separated at 5% level of significance by the Tukey method. Results of the survey indicated more than 90% of the livestock enterprise in this area were managed by men and that cattle (65%) formed the largest part of the livestock kept in each farm, followed by sheep and goats in that order. A majority (98%) of the farmers practiced extensive grazing system and the natural pastures were of low quality (crude protein, 4-6% and neutral detergent fibre, 70-75%). Livestock were also fed crop residues and concentrate supplementation was non-existent in most (93%) farms. The major feeding challenges encountered while raising weaner calves were the inadequate skills and knowledge on feed production and feeding. For the animal performance trial, the quality of the Lucerne hay was higher as compared to that of the cotton seed cake (P < 0.05) based on the results of the gas production at 24 hours (46.77 vs 40.84 ml), gas production rate (1.42 vs 1.26 ml / hr), ME (9.37 vs 8.60 MJ / Kg DM), and OMD (63.37 vs 58.10 %). On the other hand, the dry matter intake (3.75 vs 2.84), water intake (21.08 vs 18.02 lt / day), feed cost (74.86 vs 57.75 KES / day) average live-weight gain (0.68 vs 0.46 kg / day), feed conversion efficiency (5.64 vs 6.32 kg DM / kg live-weight gain) and net profit (60.76 vs 44.97 KES / kg live-weight gain) were higher for the crosses than the Sahiwal calves (P < 0.5). The weaner crosses of local and exotic breeds can perform better and attain the required service live-weight at an early age than the local breeds. On the other hand, Lucerne hay can substitute cotton seed cake as protein supplement without affecting growth performance and production of the weaner calves.