Effects of burning on diet quality and associated production systems of cattle and goats in acacia savannahs of Kenya
Abstract
A one-year study on the seasonal effects of burning on the dietary
nutrition of cattle and goats was conducted at Kiboko from March 1982 to
March 1983. Four esophageally fistulated heifers and two goats were
utilized to collect diet samples from two adjacent burned and unburned
paddocks. Pre-burn and post-burn herbaceous plant species frequency and
density were"evaluated in both paddocks. Post-burn shrub/woody plant
species were evaluated for density and canopy parameters. Diet samples
were subjected to laboratory analysis for crude protein CCP) and organic
matter digestibility COMO). Digestible energy was calculated.
Burning did not significantly affect the frequency and density of
most of the important forage species but enhanced species diversity and
density of forbs and subshrubs at the expense of some desirable forage
grasses. Burning enhanced the regeneration of some important browse
species.
The highest diet quality values for cattle occurred during the wet
seasons, while the dry seasons had the lowest values. Burning enhanced
dietary CP content during the wet seasons and into the early part of the
dry seasons. Also, burning had positive effects on dietary OMD during
the wet seasons but for shorter durations.
The seasonal trend of dietary quality contents for goats was similar
to that of cattle but the seasonal variations were not as dramatic as in
cattle. Burning had detectable positive effects on dietary CP and OMD
of goat diets during the wet season only.
A cattle nutritional profiles model for Sahiwal, Boran and small
East African shorthorn zebu breeds with January, May and October mean
calving dates was run to estimate daily CP and net energy (NE) balances
at selected production levels and rainfall conditions. For above average
rainfall conditions and unlimited forage availability, the heavier,
higher milk-yield breeds benefited mare than the lighter breeds, and the
October mean calving date was mare preferable. Under low rainfall conditions,
there were many months of NE deficits, where the heavier
Sahiwal had higher deficits than the Boran and zebu during lactation
periods. No calving date was definitively better than the others because
of prolonged NE deficits.
Publisher
Faculty of Agriculture, University of Nairobi
Description
MSc