The objective of study was to evaluate the effect of forage concentration (F:C) and forage particle length (FPL) on sorting, feeding behaviour, intake, growth and body measurements of growing calves. Twenty-eight weaned calves of body weight 156.79 ± 33.44 (mean ± SD) were used in 2 × 2 factorial arrangements with the factors FPL of hay grass (full and short) and hay grass concentrations (low, 50% and high, 65%). The treatments were as follows: full length (FL) with low F:C (50:50), FL with high F:C(65:35), short length (SL) with low F:C (50:50) and SL with high F:C (65:35). Increasing F:C and decreasing FPL enhanced sorting for short and fine particle and sorting against long particle (p < 0.05). Dry matter intake (DMI) was decreased by decreasing the FPL (p < 0.05). Increasing F:C (65:35) increased the DMI (p < 0.05). A positive interaction between FPL and F:C was found for (daily weight gain) DWG, weight gain (WG) and feed conversation ratio (FCR) (p < 0.05). In case of feeding behaviour, interaction for eating time and eating time per kilogram DM was present. Increasing the F:C increased the eating time in both FL and SL (p < 0.05). Chopping of hay had decreased the chewing time (p < 0.05). Increasing F:C increased chewing time per kilogram DMI. High F:C decreased the lying time (p < 0.05) in FL and SL treatments (p < 0.05). Increasing F:C reduced the overall abnormal behaviour (p < 0.05). These results suggested that animals performed better at higher F:C at SL diet. Intensity of sorting for short and fine particle and against long particle increased at higher F:C and SL diets. Eating time and eating time per kilogram DMI increased by increasing F:C level in both FL and SL treatments. Chewing time increased by increasing the FPL, while increasing the F:C enhanced the chewing time per kilogram DMI and reduced animal's abnormal behaviour.

The present study analysed the changes in the quantity and composition of biogas produced from the excreta of swine, rabbit and poultry during monsoon and summer seasons. The highest volume of biogas production was observed in rabbit excreta (0.0813 ± 0.0007m3), followed by poultry excreta (0.0778 ± 0.0005 m3) and swine excreta (0.0738 ± 0.0004 m3). Methane concentration was higher in biogas produced from rabbit excreta (70.96 ± 0.19) followed by that from poultry excreta (66.87 ± 0.21) and swine excreta (62.41 ± 0.20), whereas carbon dioxide concentration was highest in swine excreta (28.07 ± 0 .32) followed by rabbit excreta (24.54 ± 0.15) and poultry excreta (22.14 ± 0.14). The biogas production was significantly higher (P less than 0.01) in the summer season compared to monsoon in all three substrates. It was observed that daily mean temperature had a significant positive relationship and relative humidity had a negative relationship with the quantity of biogas produced (P less than 0.01). The gas production also had a significant positive correlation with the temperature and pH of the digesta.