A study was conducted to determine the effects of dietary safflower oil and/or tallow with or without vitamin E supplementation (0, 100 or 200 mg/kg) in a feed for laying hens, on laying performance and traits of internal quality of eggs. The feed was based on wheat and corn. A total of 54 laying hens (Warren Isabrown) were assigned at an age of 25 weeks to nine treatment groups (6 birds per treatment in 3 cages of 2 hens each). Eggs were collected during the whole feeding period (8 weeks) beginning after one week of adaption to the experimental diets. They were kept in a temperature controlled room at 4°C up to 6 months.<br>Laying rate, egg weight, daily feed intake and feed efficiency were neither affected by dietary fat source nor by the vitamin E supplementation. The vitamin E concentrations were increased (p<0,001) due to vitamin E addition. Thiobarbituric acid reactive substances (TBARS) were increased (p<0,001) by increased vitamin E concentration in egg yolk, whereas the oxidative stability was slightly increased after storage. The proportion of polyunsaturated fatty acids (PUFA) of egg yolk was increased (p<0,001) and the monounsaturated fatty acids (MUFA) were decreased (p<0,001) by dietary safflower oil respectively. Saturated fatty acids (SFA) were not influenced by fat source. Dietary vitamin E resulted in a decrease of PUFA (p<0,01) and SFA (p<0,01) in fresh yolk lipids, whereas MUFA did not change. Storage of eggs up to 6 months generally caused a higher content of SFA,MUFA and PUFA compared to fresh egg yolk.
Which stakeholders in the dairy sector have an influence on the productive life of dairy cows? Research results from FiBL and Agroscope suggest that broad-based cooperation is needed to create structures for a longer productive life.
Agriculture is aiming to reduce greenhouse gas and ammonia emissions. Agroscope showed that for dairy cattle housing, feed composition plays a role in these emissions as well as wind and temperature.
Lazzari G., Münger A., Eggerschwiler L., Borda-Molina D., Seifert J., Camarinha-Silva A., Schrade S., Zähner M., Zeyer K., Kreuzer M., Dohme-Meier F.
Tannin-containing feedstuffs like Acacia mearnsii and sainfoin (Onobrychis viciifolia) have a measurable impact in reducing methane emissions from dairy cows. However, since these feedstuffs in some cases lead to productivity losses, careful consideration must be given to their use.