S-Y.  Landau and D. Kababya

In Israel, ranging dairy goats belong to the Mamber or Damascus breeds: the Mamber are small, non-prolific and low-yielding goats, compared with the larger framed, prolific, high-yielding Damascus (400 lly). Ligneous vegetation accounts for 60 and 80% of foraging time, respectively. Mamber goats re-constitute their body depots of energy soon after kidding, whereas Damascus, even though heavily supplemented (1.5 kgld. of concentrates), undergo negative balance of energy during 3 months. Tannin concentration in evergreen foliage is high and depresses the availability of proteins and energy for animals. Therefore, supplements are aimed at providing degradable protein to the goats. The neutralisation of tannins by poly-ethylene glycol (PEG 4000) increases the digestibility of protein and organic matter from foliage. In cron farm, trials, supplementation with PEG was associated with improved milk production in Damascus, but not Mamber goats, and increased prolificacy in Marnber, but not Damascus goats.

English title:

Supplemental feeding of dairy goats grazing mediterranean rangelands