In a trial with 10 x 180 laying hens (LSL white), the effect of the exclusion of animal proteins from layer diets (diets B and C) was tested in comparison to a standard diet (diet A) from week 21 to week 72. Essential amino acids (EAA) were optimised on total base in diets A and B, whereas in diet C available EAA were used for the formulation. Diet A was given to four units and diets B and C to three units each. All diets were fed ad libitum as crumbs.<br>By the exclusion of animal proteins, a minor but significant reduction (- 0.9 %) was seen in egg production, whereas food consumption and egg weight were hardly influenced. Dietary differences in egg categories were small and – with the exception of dirty eggs- not significant. Mortality rates could be related to the way of EAA-formulation. The highest rate of mortality was seen in diet C in comparison to diets A and B (4.3 vs. 3.3 and 2.2 % in 52 weeks, respectively). 0.4 % of the mortality rate of diet C was due to cannibalism (diets A and B: 0.0 %). No dietary influence could be found on plumage condition and animal weight. It was concluded that the exclusion of animal proteins from diets for white layers is possible without any negative effects on performance and mortality rate, if other protein sources (e.g. plant proteins synthetic amino acids) are-also quantitatively – available and allowed by the market.
Pontiggia A., Münger A., Ammer S., Philipona C., Bruckmaier R. M., Keil N.M., Dohme-Meier F.
Even in temperate climate zones, an increase in the ambient temperature and solar radiation can cause heat stress in grazing dairy cows. Agroscope studied the physiological changes in cows caused by increasing heat load.
Lazzari G., Münger A., Heimo D., Seifert S., Camarinha-Silva A., Borda-Molina D., Zähner M., Schrade S., Kreuzer M., Dohme-Meier F.
In dairy cows, herbage-based diets often lead to increased nitrogen excretion. Tanniferous sainfoin and extract of acacia can reduce nitrogen excretion from urine and thus ammonia volatilization from slurry.
Excessive nitrogen inputs from the air lead to over-fertilisation of sensitive ecosystems. Continuous feeding optimisation can make an important contribution to reducing ammonia losses and thus nitrogen inputs.