Effect of Temperature and Humidity on Storage Life and Nutrient Composition of Lick Blocks

Four types of urea molasses mineral blocks (B₁, B₂, B₃, and B₄) were manufactured using cold process. B₁ and B₂ contained 17% deoiledrice bran (DRB) whereas, B₃ and B₄ contained 17% wheat bran (WB). Further, B₁ and B₃ contained 10% mustard cake (MC); whereas B₂ and B₄ contained 10% deoiled sunflower cake (SFC). Other feed ingredients were same in all the four treatments. The blocks were stored at 15, 25, 35 and 45°C at 33,44, 64, 75 and 97% relative humidities (RH) for 120 days using static method. The temperature and humidities at higher levels i.e. more than 35°C and 65% significantly (P<0.05) affected the total sugar content, alcoholic acidity, total nitrogen content and dry matter content of lick blocks. There was no loss of total nitrogen during storage. However, the loss of DM ranged from 0.28–7.20%. The increase in alcoholic acidity was in the range 186–208.6%. There was no visible fungal or mould growth in any of experimental UMMB up to 64% RH at all the temperatures (15–45°C). However, at 97.08% RH the fungus appeared after 10,14 and 21 days of storage, respectively at 45,35 and 25°C, whereas at 75.33% RH, it appeared after 80, 95 and 120 days of storage at the same temperatures. The appearance of fungus was earlier (2-3days) on SFC based blocks than MC based blocks.