Due to the lately increased oral nitrate intake of humans and animals the influence of 3% KNO3 in the diet on growth and the thyroid hormone and somatomedin-C-concentration in the serum was to be tested in an experiment with growing pigs in case of different iodine supply. The investigations were undertaken in 3 groups with 9 piglets each. The animals were 6 weeks old: 1. nitrate-exposed, 2. pair-fed to group 1 (without nitrate), 3. ad libitum without nitrate. The mean daily weight gains amounted to 242, 274 and 393 g respectively, after a five-week test period. Compared to the ad libitum control group, the T4-, T3-, rT3- and Sm-C-level of nitrate-exposed animals was significantly lower after 5 weeks. There were no statistically relevant differences between nitrate-exposed and pair-fed animals with regard to the T3- and Sm-C-level. After the 5-week test period with an iodine supply covering the requirement the rations of all 3 groups were supplemented with further 0.8 mg iodine/kg. The T4-, T3- and rT3-levels of the animals of group 1 normalized within one week. The Sm-C-levels of the nitrate-exposed and pair-fed group were still decreased. The investigations show that an increased nitrate intake via food and drinking water influences the thyroid hormone metabolism. It should be taken into consideration in the etiology of endemic struma. Furthermore, excessive nitrate intakes influence the Sm-C-concentration and thus growth due to food intake depression.

SummaryCarcass composition and quality of guinea-fowls, phesants, pigeons, muscovy ducks and rabbitsThe carcass composition and quality of guinea-fowls, phesants, pigeons, muscovy ducks and rabbits have been investigated. The highest slaughter yield was in phesants (78%) and guinea fowls (75%). In rabbits the slaughtering loss was by 38%. Phesants (76%) and guinea-fowls (70%) had also the highest meat yield of the eviscerated carcass. Pigeons contained with 35% breast meat of total meat the highest value. Phesants and guinea-fowls have a higher breast and leg meat proportion than other domesticated poultry species. The edible carcass of phesants and guinea-fowls contained more protein (22 resp. 20%) and less fat and energy. Different meat quality parameters have also been examined. Under consideration of nutritional aspects of humans the consumption of phesants and guinea-fowls can be recommended.

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Even with a high vitamin E offer, Se deficiency (less than 38 micrograms/kg DM of the ration) led to a 33% lower conception rate (P less than 0.05) in goats and to a greater than 50% lower number of kids on the 91st day of life. The Se deficiency reduced the milk production significantly by 23% during the first 56 days of lactation, the milk fat production by 11% and the milk protein production by 12%.