Animal production from native pasture (veld) in the Free State Region - A perspective of the grazing ruminant

Abstract

The seasonal variation in diet selection and herbage intake of cattle and sheep and the effects on animal performance at various research centres are put into perspective, taking into consideration the annual rainfall and its distribution. The most important constraint on animal production from pastures, appears to be an insufficient intake of digestible nutrients in relation to animal requirements, which may at times be aggravated by deficiencies of specific nutrients in the herbage. Supplementary feeding may increase the nutrient intake of grazing ruminants and correct deficiencies in pastures. However, despite considerable costs incurred, animal response to supplementation can at best be described as unpredictable and far less than might be expected from feeding standards. Renewed efforts towards gaining a more comprehensive understanding of, and explanation for, the interactions between the integrated animal/plant biological system of grazing conditions, are discussed.

Seisoenale wisseling in dieetseleksie en weidinginname deur beeste en skape asook die invloed daarvan op diereprestasie by verskeie navorsingsentrums word, binne die raamwerk van verskille in jaarlikse reënval sowel as verspreiding, in perspektief geplaas. Die grootste beperking wat op diereprestasie vanaf veldweidings geld, is klaarblyklik 'n onvoldoende inname van verteerbare voedingstowwe in verhouding tot voedingsbehoeftes, wat soms vererger word deur 'n tekort aan spesifieke voedingstowwe in die weidings. Aanvullende voeding mag die voedingstofinname van weidende herkouers verhoog en tekorte in weidings vir diereproduksie regstel. Ten spyte van aansienlike kostes daaraan verbonde, is die responsie egter wisselvallig en aansienlik minder as wat vanaf voedingstandaarde afgelei kan word. Hernieude pogings ter bereiking van 'n omvattender kennis en begrip van die interaksies tussen die geïntegreerde dier / plant biologiese sisteem wat onder  weidingstoestande heers, word bespreek.

Keywords: Animal performance, DM production, diet selection, feed intake, native pasture (veld), supplementation.