No abstract

I . Male broiler chickens were given a sodium chloride-deficient or NaCI-adequate diet from 7 to 2 1 d of age in Expt I and 28 to 56 d of age in Expt 2.2. NaCI-deficient chickens had a markedly poorer growth and food conversion efficiency than those given the NaC1-adequate diet.3. NaCl deficiency was associated with an increase in basal metabolic rate and increases in oxygen consumption, heat production and respiratory quotients were also noted. The glycogen content of chicken livers was also higher.4. Measurements of acid-base balance were found to be changed in NaC1-deficient chickens. Values for pH and bicarbonate content in blood plasma were lowered.5. NaCl deficiency increased the packed cell volume and thyroxine level in blood plasma. Sodium and chloride contents in blood were lowered.6. Results are discussed in relation to the decreased food conversion in NaCI-deficient chickens.

The experiment was carried out on 12 Black-and -White Lowland bulls with an average body weight of 400 + 50 kg divided into 4 groups and fed concentrates and meadow hay according to the INRA system. After 2 months of adaptation, the level of metabolites in the rumen was determined and the diet for the respective groups was supplemented with yeast cultures: Saccharomyces cerevisiae 1026, Saccharomyces carlsbergensis brewery strains SK-1, BS-Bratislava or wine strain T-81. All yeast supplements caused changes in yeast cell density, protozoa number, pH, ammonia concen tration and VFA proportion in the rumen of bulls. The greatest growth ability and largest effect on fermentation in the rumen was demonstrated by the brewery strains, Saccharomyces carlsbergensis and Saccharomyces cerevisiae 1026.

I. Test diets were given to chicks from I to 28 d of age. The basal diet contained soyabean meal as the sole source of protein and contained no vitamin BIZ.2. The basal diet supported poorer growth and feed conversion efficiency than did the same diet supplemented with 0.01, 0.03 or 0.3 mg cyanocobalamin/kg. 3. Each of the four diets was also offered with a supplement of 20 g propionic acid/kg. This caused a significant growth depression at all but the highcst lcvel of cyanocobalamin addition.4. Methylmalonic acid was detected in the excreta of chicks that received the supplements of o and 0.01 mg cyanocobalamin/lig diet, and in those of chicks receiving 0.03 mg only for the chicks that were also receiving propionic acid.j. The results suggest that giving the odd-carbon, propionic acid to chicks may increase their requirement for vitamin B,2.

Krill meal was used as a protein feed in rations for broiler chickens and laying hens and its nutritional effectiveness was studied in comparison with conventional feed-stuffs of animal origin. In experiments with 650 broiler chickens from 1 to 28 and from 29 to 56 days to fattening krill meal was added to the standard feedmixture in lieu of fish meal, and dried skim-milk, and at higher levels also in lieu of soyabean oilmeal. In the experiment with 22 layer hens kept in individual cages 3% of the fish meal were substituted by 3% of krill meal. The performance of chickens fed on diets with krill meal was lower in comparison with analogical groups fed on fish meal. Higher levels of krill meal, exceeding 15 and 11% in the first and second period of feeding respectively, reduced the weight gains and feed intake of chickens. The fatty acid C14, C18 and C18:1 content of internal body fat was changed in chickens fed on higher levels of krill meal. In the experiment with hens krill meal decreased the feed efficiency, the pigmentation of egg yolks, however, was more intensive and the vitamin A content of yolks was increased in comparison with the control group. The results show that krill meal can be used as a partial substitute of fish meal in the feed of broilers and hens.