Pasture supplies less Metabolisable Protein (MP) than required by lambs until they reach about 30 kg live weight. When MP (casein) was infused into young lambs there was less gut damage due to better development of immunity.
Bioactive forages (e.g. plantain and chicory) can help reduce worm burden. Condensed tannins (CT) can physically damage worms but plants with a sufficiently high CT content do not thrive well under NZ conditions. Sequiterpene lactones and lectins can also have a direct anti-parasitic effect.
Feed intake is greater for plants with lower structural carbohydrate and higher mineral content (e.g. clover vs. grass). Increased intake moves the break point of MP intake vs requirement from 30 kg to about 23 kg liveweight.
Larvae survival/distribution is lowe with chicory, plantain, clover and lucerne compared to grass.
Faecal volume and dry matter percent must be considered when using FEC as a measure, as increased intake increases faecal volume and gives a falsely low FEC and improved digestibility reduces faecal volume to give a falsely high FEC.
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