ON THE SUCKLING BEHAVIOR AND THE DEVELOPM ENT OF BIOCHEMICAL PARAMETERS IN PIGLETS KEPT IN A GROUP HOUSING SYSTEM FOR SOWS - PRELIMINARY-RESULTS

The suckling behaviour, the development of daily weight gains and bioc hemical blood parameters (immunoglobuline G, total protein, glucose, u rea) were investigated during the suckling period (35 days) of piglets (Sus scrofa) in a group housing system for nursing sows (group P: 4 p rimiparous sows, 34 piglets; group M: 4 multiparous sows, 43 piglets). Following an imprinting period of 10 days, piglets were given the opp ortunity to leave the farrowing pen and to interact with the other sow s (variant e: suckling bouts at own mother only, variant f: suckling b outs also at one or more unfamiliar sows). Although a number of piglet s suckled at unfamiliar sows (Pf = 73.5%; Mf = 32.5%; p = 0.01), only those piglets that stayed with their own mother after mixing had some ''physiological advantages'' (Pe: daily weight gain from day 10 to 35, p = 0,05; Me: IgG, p 0,05). Piglets of primiparous sows had a lower t eat pair fidelity within the imprinting period (day 1 to 10). During t his time, piglets of both groups suckling at unfamiliar sows showed a lower teat pair fidelity (P: ns; M: p = 0,05), tended to prefer the po sterior part of the udder, and their blood glucose and urea contents w ere higher (P: ns; M: p = 0,05). This was interpreted as an indication of competitive strain which obviously encouraged the piglets to leave their mothers. It is necessary to carry out further systematical stud ies on sociophysiological mechanisms.