A Comparison of Apparent Digestibility of Nutrient in Caspian Horse Feeds as Determined by Total Collection of Faeces, Acid Insoluble Ash and Lignin Methods

The aim of this research is to compare indigestible internal markers acid insoluble ash (AIA) and acid detergent lignin (ADL) and total collection of faeces (TCF) for apparent digestibility estimation in Caspian horse. Analyses were carried out on wheat straw, alfalfa, barley and maize, for dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF) and acid detergent fiber (ADF). Using change over design including 4 ration diet, 4 period and each period was 12 days with 4 Caspian horse with 3-5 years age and reared in individual cages. The results digestibility of DM, OM, NDF, ADF did not show any significant differences among the ADL, AIA and total collection of faeces methods, but digestibility of CP and EE were significantly higher than the ADL and AIA methods. A weak correlation was found between total collection techniques and AIA, for crude fat (EE) and ADF, whereas there was a high correlation (R2=0.89) between AIA and total collection of faeces for the digestibility of crude protein. The results obtained in this study show that there were no significant difference between internal markers (acid-insoluble ash and acid detergent lignin) and total collection techniques of faeces for estimation apparent digestibility of nutrients in Caspian horses.