Methods for estimation and nutritional influencing of thermoregulation and heat stress in dairy cows and sheep as well as impacts of changing climatic conditions on the feed value of maize silage

Lohölter, Malte

Methods for estimation and nutritional influencing of thermoregulation and heat stress in dairy cows and sheep as well as impacts of changing climatic conditions on the feed value of maize silage

2013

Lohölter, Malte

This thesis aimed to evaluate the effects of rising atmospheric CO2-concentrations and drought during cultivation on the feed value of maize silage and interactions with climatic conditions during feeding as well as to test the effects of dietary concentrate proportion and niacin supplementation on thermoregulation and milk yield of dairy cows using new boli for intraruminal pH and temperature measurement. Atmospheric CO2-concentration and drought had limited effects on the feed value of maize silage. Heat exposure during feeding increased the digestibility of plant cell walls. Increased concentrate proportions stimulated milk performance and reduced the body temperatures during heat but enhanced the risk of ruminal acidosis. Niacin heightened milk production but did not affect thermoregulation. The evaluated boli served to analyse the fermentation in the forestomach but need further improvement.

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