Foraging strategies of goats as influenced by season, vegetation and management

Abstract

The first of two experiments was initiated in August 1975 to investigate methods to improve the management of goats on rangelands. Experiment I compared the botanical and nutritive composition of diets collected from esophageally-cannulated Angora and Spanish goats over a 4-year period in two distinctly different pastures. Pasture 14 was ungrazed by domestic livestock for approximately 30 years and its vegetation allowed maximum expression of dietary preferences. Pasture 4 was a heavy, continuous grazed pasture in poor range condition that offered a limited variety of plants. Total standing crop declined as annual rainfall declined. Warm season perennial forbs in pasture 14 provided more consistent forb production than the annual forbs in pasture 4. Edible browse was more abundant in pasture 14 than pasture 4. Angora goats generally consumed more grass than Spanish goats. Grass selection of Spanish and Angora goats differed more in the heavily grazed pasture than in the exclosure. Generally, the amount of forbs eaten by goats closely paralleled availability. Spanish goats selected significantly more browse than Angora goats. Dry weather caused an increase in selection of browse and resulted in a greater difference between Angora and Spanish goats in selection of browse. Slightly higher yearly averages of dietary protein were associated period. Crude protein and digestibility did not respond the same for all collection periods. Low fecal weight was associated with hot dry weather and mature forage. High fecal weight occurred in the fall when acorn availability was greatest. Organic matter intake and dry matter intake averaged 2.4 and 3.9% of body weight, respectively. Under this particular stocking rate and weather conditions, one could conclude that increased grazing pressure, caused by a 4-day graze period in a SDG system, had little effect on goat nutrition. there is a need to place goats in an alternate pasture, void of the main grazing herd, two important criteria should be observed: (1) regrowth should be readily available in the alternate pasture, and (2) the alternate pasture should probably be the next pasture to be grazed. This would help prevent over-utilization of more preferred plants species.