THE EFFECTS OF MALIC ACID AND ITS SALTS ON RUMEN FERMENTATION, LACTATION AND FATTENING PERFORMANCE OF CATTLE

Zadnjih su godina enzimi, kulture kvasaca, aromatične biljke i organske kiseline alternativni dodaci hrani preživača. Ti dodaci nisu jamstvo za visoku proizvodnju ili proizvodnost, ali mogu biti važni za poboljšanje fermentacije u buragu, zdravlje životinja, proizvodne pokazatelje, reprodukciju i kakvoću životinjskih proizvoda. Organske kiseline mogu biti korisne zahvaljujući antimikrobnom djelovanju na fermentaciju u buragu. Najčešće organske kiseline su karboksilne kiseline. Dikarboksilne kiseline kao što je jabučna kiselina prirodno se nalaze u krmivima u različitim razinama. Katkada se nalaze u natrijevim, kalijevim ili kalcijevim solima ili dvostrukim solima. Jabučna kiselina ili njezine soli smanjuju koncentraciju mliječne kiseline u buragu stimulirajući korištenje laktata pomoću Selenomonas ruminantum. Isto tako je moguće da je dodavanje jabučne kiseline ili njezinih soli u hranu preživača djelotvorno u smanjenju pada pH neposredno nakon hranjenja. Osim toga, poznato je da uključenje jabučne kiseline u hranu smanjuje broj protozoa i emisije metana. Prema nekim radovima jabučna kiselina poboljšava performanse životinja i ekologiju buraga, dok prema drugim radovima nema djelovanja prema tim kriterijima. Oprečni rezultati mogu se pripisati razlikama u životinjama, vrsti krmiva, dozrelosti krmiva, omjeru krmivo:koncentrat, količini jabučne kiseline i kemijskom sastavu ja¬bučne kiseline dodane u hranu. Stoga je potrebno dalje in vivo istraživanje kako bi se došlo do konačnih zaključaka.Enzymes, buffers, yeast culture, aromatic plants and organic acids are alternative feed additives added to ruminant diets in recent years. These additives are not a warranty for high production or productivity. But they can be important to improve rumen fermentation, animals’ health, performance, reproduction and the quality of animal products. Organic acids could be beneficial due to the antimicrobial effect on rumen fermentation. The most common organic acids are the carboxylic acids. Dicarboxylic acids such as malic acid naturally are found in forages at different levels. They are sometimes found in their sodium, potassium, or calcium salts, or double salts. Malic acid or its salts reduce lactic acid concentration in rumen by stimulating lactate utilization by the Selenomonas ruminantium. It is also possible that supplementing ruminant diets with malic acid or its salts are effective in reducing the drop in ruminal pH just after feeding. Moreover, it is known that the dietary in-clusion of malic acid decreases protozoa numbers and methane emissions. Some studies report that malic acid improves animals’ performance and rumen ecology, yet other studies claim no effects on these criteria. The contrastive results might be due to the differences in animals, forage type, forage maturity, forage:concentrate ratio, quantity of malic acid and the chemical form added in the diets. Therefore, more in vivo research is required so as to have a final conclusion

Diversity of phytoplankton in Kucukcekmece Lagoon channel, Turkey

The composition and functional groups of phytoplankton in the channel from Kucukcekmece Lagoon to the Marmara Sea were investigated. Some water-quality parameters and nutrient variations were also recorded. Water samples were taken from the water surface between May-August 2008 at 5 sampling sites including the lake and the sea

Phytoplankton composition of Sazlidere Dam lake, Istanbul, Turkey

The phytoplankton composition of Sazlidere Dam lake was studied at 5 sampling sites between December 2003 - November 2005. A total of 67 taxa were recorded, representing Bacillariophyta (31), Chlorophyta (18), Cyanophyta (9), Chrysophyta (1), Cryptophyta (1), Dinophyta (3) and Euglenophyta (4). Bacillariophyta members constituted the dominant phytoplankton group in terms of species number. Nygaard's compound index value and composition of phytoplankton indicate that the trophic state of Sazlidere Dam lake was changing from oligotrophic to mesotrophic