Fat content and fatty acid pro¢le of two pike yearling groups grown on two di¡erent diets were compared. The groups originated from culture on arti¢cial feed. One group (cultured pike fed ¢rst pellet then prey-¢sh (PF)) was fed with natural food, live prey-¢sh, while the other one (cultured pike fed exclusively pellet (PP)) by trout feed through a 3-month experimental period. Growth of pike was lower with PP than with PF. The trout feed resulted in an increase of the fat content of ¢llet and the formation of abdominal fat depots. Feeding of natural food decreased the fat content. The proportion of the saturated fatty acids in ¢llet was higher in the (PF) group. The n-6 fatty acids (arachidonic C20:4n-6 and docosatetraenic C22:4n-6 acids) were lowest in PP-fed pike. Regarding total n-3 fatty acids ratio there was no signi¢cant di¡erence between the groups, but the level of a-linolenic (C:18:3n-3) acid showed signi¢cant di¡erence among groups. Aquaculture Research, 2006, 37, 96^101 Changing of fat content and fatty acid pro¢le of reared pike B Kucska et al.

The main goal of our research was to study the effects of different feed components and the treatment of the litter on the NH3 emission of equine urine. Four adult horses were used in the experiment. The basic diet consisted of 1500 g mashed oat, fed twice a day (morning and evening), and ad libitum hay. During the night the horses were kept separately in concrete floor boxes, the litter was wheat straw. The whole study was divided into 3 main periods. In the first period of the experiment the litter and the floor were treated with a probiotic supplement for two days in the evenings. In the second period of the experiment for 8 days the basic diet was supplemented with 40 ml of probiotic added to the oat. Before the third period of our study the horses were fed with their regular diet for two weeks. After that the oat was changed to a high-protein-value horse feed for 12 days. At the end of the second and third periods, the litter was treated again. Urine contaminated straw samples were collected after each period before and after the litter treatments from different places of the litter in the morning before the daily littering. From the samples, the dry matter content and the NH3 emission were measured. Statistical analysis was carried out with linear modelling. According to our results, both the probiotic treatment of the feed and the high-protein-value horse feed decreased the urine NH3 emission significantly (p<0.05). However, the NH3 emission was only slightly influenced by the litter treatment. Only in the case of probiotic feed supplement could a decrease in emission be detected, but the result was not significant. There was no difference in the dry matter content of the samples. Based on our results, we can conclude that both the high-protein-value horse feed and the probiotic supplement applied in our experiment can be useful to decrease urine NH3 emission by horses. The two-days litter treatment however seems to be too short to gain any positive effects.

The influence of dietary fat supplementations differing in the ratio of n-6 to n-3 polyunsaturated fatty acids (PUFA) on the effects of glucagon and insulin on plasma glucose, triglyceride (TG), and TG-rich lipoprotein concentrations was investigated in laying hens. Birds were fed either a low-fat control diet (LF) or diets supplemented with 4% pumpkin seed oil (PO; rich in n-6 PUFA) or 4% cod liver oil (CO; rich in n-3 PUFA). After 4 wk feeding of the experimental diets, hens were implanted with wing vein catheters and injected with porcine glucagon (20 microg/kg BW) and porcine insulin (0.5 IU/kg BW), 2 to 5 h after oviposition. Plasma glucose, TG, and TG-rich lipoprotein concentrations were determined from 10 min pre-injection to 60 min post-injection. PO diet resulted in a prolonged plasma glucose response to glucagon administration and altered hypoglycemic response to insulin. However, CO diet did not influence plasma glucose response to either glucagon or insulin administration compared to LF diet. The effects of glucagon and insulin on plasma TG and TG-rich lipoproteins were similar for all diets regardless of the amount or type of fat. The results suggest that feeding dietary fats with high n-6 to n-3 PUFA ratio alters the glucagon and insulin sensitivity of plasma glucose in laying hens. Fats rich in n-3 PUFA seem to have no influence on the plasma glucose response to glucagon and insulin.

Irrigation determines the success of water-intensive beet cultivation in Hungary. Taking into account the guidelines of the circular economy; the aim of our study was to investigate the effect of high sodium effluent from fish farms on the yield and sugar content of fodder and sugar beet in two-year-lysimeter experiment and to calculate the possibility of phytoremediation and the potential to use saline effluent water to mitigate drought effects of root biomass reduction According to our results, irrigation with effluent water did not cause yield depression in the root biomass compared to irrigation with fresh water. The effect of irrigation water quality was seen in the sodium (Na) concentration values of the roots in both years, because it was the lowest in the treatments irrigated with Körös River fresh water. The highest estimated extracted sodium amount was 83.1 kg Na/ha in case of fodder beet variety ‘Rózsaszínű Beta’ in treatment irrigated with effluent water from catfish farm (EW) in 2021, which means 7.2% of the Na applied through the effluent water. All cultivars produced higher root fresh weight when irrigated with river Körös, effluent, or diluted waters compared to control crops irrigated by scarce rain water.

The effects of feeding low-protein (LP) diets and the age and genotype of fattening pigs were evaluated in an N-balance trial. Sixty weaned piglets of two genotypes were allotted to three different diets. Besides the control diets for the crossbred Topigs 20 × DanBred Duroc (TD) and Hungarian Large White (HLW) pigs, two LP diets were fed containing 1.5 (T1.5) and 3% (T3) less dietary protein than the control. The LP diets were supplemented with crystalline lysine, threonine, tryptophan, and methionine to equalize their digestible amino acid contents. Starter diets were fed between 20–30, grower I between 30–40, grower II between 40–80 and finisher between 80–110 kg live weights. Pigs were kept in floor pens, with 10 animals per pen. In all phases, six pigs with similar live weight were placed into individual balance cages and in the frame of a seven-day long balance trial, the daily N-intake, fecal and urinary N-excretion were measured. From the data N-digestibility, the total ammoniacal nitrogen (TAN) and N-retention were calculated. All the investigated main factors, the genotype and age of pigs and the protein content of the diets had significant effects on the N-balance of fattening pigs. The determinacy of the factors depended on the investigated parameter. Fecal N-excretion and N-digestibility were steadier compared with the urinary N-exertion and TAN percentage. N-digestibility increased and the urinary N-excretion decreased when LP diets were fed. The urinary N-decreasing effect of LP diets was not linear. Compared with the control (19.6 gN/day), T1.5 treatment resulted in 14.5, treatment T3 in 12.4 g daily urinary N-excretion. The TAN and the N-retention of HLW pigs were more favorable than those of TD pigs. Based on our results, it can be concluded that the accuracy of the nitrogen and TAN excretion values of pigs, used in the calculation of the national NH3 inventories, could be improved if the genotype, the more detailed age categories and the different protein levels of feeds are considered.