Genetic and non-genetic factors influencing ingestive behavior of sheep under stall-feeding conditions

Ingestive activities of 100 stall-fed sheep (48 Muzaffarnagari and 52 1/4 S uffolle x 1/4 Dorset x 1/2 Muzaffamagari) belonging to different age and cl ass categories viz. lamb (<3 months), young (5-6 months), hogget (9-12 mont hs), pregnant, lactating and adult sheep, were recorded each minute under p ersonal surveillance for 24 consecutive hours on three occasions. The exper imental sheep were confined in a paddock (15.2 x 9.1 m) where ad.lib green fodder (lucerne/maize) and water were available to the animals all the time . Bout duration of eating, ruminating and drinking activity were recorded a long with the inter-bout duration (the time interval between two consecutiv e bouts of a particular activity). The sheep spent 7h day(-1) eating, 2 h d ay(-1) lying ruminating, 1 h day(-1) standing ruminating and 5 min day(-1) drinking. Time spent eating and drinking were more (p < 0.01) during daylig ht (0601-1800 hours), especially after sunrise and before sunset, than nigh t time (1801-0600 hours), whereas the trend reversed for rumination activit y in which peak activity was noticed after midnight. Genotype and sex had n o effect on the time spent on the ingestive activities but category of shee p varied significantly (p < 0.01). The mean duration of eating lasted 12 mi n while mean inter-bout interval among eating lasted 26 min. These interval s were almost similar among all the sheep >6 months of age. Rumination bout in lying and standing posture lasted for 14 and 9 min, respectively and th eir recurrences occurred every 2-3 h. Rumination bout and inter-bout differ ed significantly (p < 0.05) between the categories of sheep and diurnally. Young, hogget and lactating sheep took significantly (p < 0.01) more drinki ng time than the other sheep. Each drinking bout lasted about 1 min and it recurred every 2 h throughout a 24 h period. The study suggests the practic e of offering feed to stall-fed sheep at least three times a day (around 06 00, 1300 and 1900 hours) to facilitate higher feed intake. In the night, th e sheep are to be provided with adequate space to ruminate in lying posture . (C) 1999 Elsevier Science B.V. Ail rights reserved.