Red clover drying coefficient dependencies on air velocity at constant drying temperature

A. Aboltins¹*, J. Tomsu² and P. Kic²

¹Latvia University of Agriculture, Institute of Agricultural Machinery, Cakstes blvd.5, LV–3001 Jelgava, Latvia
²Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, CZ16500 Prague 6, Czech Republic
*Correspondence: aivars.aboltins@inbox.lv

Abstract:

The clover is widely used as feed of animals and preservation of fodder is an important problem. This paper informs about the experimental and theoretical investigations of red clover (Trifolium pratense) drying by forced convection. This research is focused on verification of influence of different air velocities on the drying process of red clover in thin layer in mild temperatures (22 °C) and rather high relative humidity of air (70%). The initial moisture content of clover was determined by gravimetric method using the hot air drying in the electric oven. Special device for convection drying with air flow passing through material from the bottom through supporting trays with a sieve (dimensions of mesh 3 x 4 mm) by constant temperature was used for drying when the air velocity 0.7 m s^-1, 1.0 m s^-1, 1.2 m s^-1 and 2.0 m s^-1. These results was compared with drying by free convection. Changes of clover samples were determined from the measured values of weight using the gravimetric method. The function of drying coefficient K(t) is determined (using thin layer theory) and theoretical results are compared with experimental results. Using experimental results were determined relationships between air velocity and parameters included in function of drying coefficient. This allows theoretically to predict the drying process depending on the air velocity.

Key words:

Fodder feeding peculiarities when introducing the VMS automatized cow milking system

A. Saliņš*, J. Priekulis and A. Laurs

Faculty of Engineering, Latvia University of Agriculture, J. Čakstes bulv.5, LV-3001 Jelgava, Latvia; *Correspondence: ansis.salins@gmail.com

Abstract:

The research concerns fodder distribution solutions for cows which are milked using the VMS robotised equipment produced by the company DeLaval. The research is conducted at the milking cow farm ‘Līgotnes’ of the Latvia University of Agriculture study and research farm ‘Vecauce’. In the research, cattle-shed cows receive fodder in three different places: together with the basic feed mixture while eating at the feeding table, in the robotised milking stand and at the fodder feeding stations. The research has stated that this feeding system is rational. Adding fodder to feed mixture (about 10% of its mass) is necessary as it improves the feed mixture taste qualities. Hence, it increases the consumption of this mixture and also the cow yield. If fodder is not added to the mixture, the productivity of highly productive cows deteriorates and can decrease by 10%. Moreover, we can add to basic feed mixture fodder prepared at the farm using the grains grown there. Usually, such fodder is cheaper than the bought one, and therefore decreases the prime cost of the milk. Fodder is also fed also in the robotised cow milking stands as such an approach stimulates cows to visit the milking stands more frequently. But during the research we found that highly productive cows with the yield exceeding 30 kg per day do not manage to eat all the due fodder amount during milking. Therefore, fodder feeding stations are necessary for feeding of highly productive cows. They shall be placed after the sorting gates so that the cows that are not directed to milking by the automatic sorting system could visit the fodder stations. Moreover, the number of fodder feeding stations per one cow milking group should not be less than two.

Key words:

AMS, feeding cows, fodder, fodder stations.