Environmental and Physiological Aspects of Prepartum Behavior in the Sow

334 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.Experiments were conducted to identify some environmental and physiological factors involved in the prepartum behavior of sows. Eight of 12 penned sows offered 3 kg straw from a wire basket took substantial amounts of straw and used it to construct farrowing nests during the 24 hours preceding birth of first piglet. Most activity was directed at straw and was much the same for all sows. Manipulation of a cloth tassel by 13 prepartum sows in farrowing crates increased significantly during the 24 hours preceding birth. Prepartum behavior of 16 penned sows given straw in a basket (or no straw) and a cloth tassel (or no tassel) were compared. Sows offered straw took straw from the basket and directed most activity at it. Sows provided a cloth tassel only nosed and pulled the tassel significantly more than sows given both straw and tassel and often ripped pieces of cloth from it and directed rooting and pawing at it, suggesting that the tassel served as a substitute for nesting material. All sows engaged in similar durations of typical prepartum activity.Injection of sows with prostaglandin F\sb2a (PGF\sb2a) on day 112 postcoitum and 24 hours postpartum provoked nestbuilding behavior within minutes. Sows injected with cloprostenol, an analogue of PGF\sb2a, did not exhibit an immediate behavioral response. Endocrine changes stimulated by PGF\sb2a and cloprostenol were compared to identify any endocrine events that may have been associated with differences in behavioral response to the compounds. Plasma prolactin increased within 15 minutes after injection of PGF\sb2a but more gradually and never to as high a peak after cloprostenol. Both prostaglandin compounds provoked a decline in progesterone, a surge in relaxin, and neither influenced estrone concentration. Differences in pattern of prolactin release after injection of the two compounds suggests differences exist in their action on the hypothalamus or pituitary. These are most likely responsible for differences in behavioral effects of the compounds. Prolactin may play a role in the onset of nestbuilding behavior in the sow. Alternatively, it may be released simultaneously by some hypothalamic mechanism that is also responsible for triggering the behavior.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Behavioral differences of laying hens with fractured keel bones within furnished cages

High prevalence of keel bone fractures in laying hens is reported in all housing systems. Keel fractures have been associated with pain and restricted mobility in hens in loose housing. The objective was to determine whether keel fractures were associated with activity of hens in furnished cages. Thirty-six pairs of LSL Lite hens (72 wk) were enrolled in the study. One hen with a fractured keel and one hen without were identified by palpation in each of 36 groups of hens housed in either 30 or 60-bird cages stocked at 750cm2/hen. Behavioral activity of each hen was recorded by four observers blind to keel status using focal animal sampling for 10 min within a 2 hr period in the morning (08:00-10:00), afternoon (12:00-14:00), and evening (17:00-19:00). All hens were observed during each of the three sample periods for three days totaling 90 min, and individual hen data was summed for analysis. Hens were euthanized 48hr after final observations, dissected, and classified by keel status: F0 (no fracture, N=24); F1 (single fracture, N=17); F2 (multiple fractures, N=31). The percentages of time hens performed each behavior were analyzed using a mixed procedure in SAS with fracture severity, body weight, cage size, rearing environment, and tier in the model. Fracture severity affected the duration of perching (P=0.04) and standing (P=0.001), bout length of standing (P<0.0001), and location (floor vs perch) of resting behaviors (P=0.01). F2 hens perched longer than F0 hens, 20.0% ± 2.9 and 11.6% ± 3.2. F2 hens spent less time standing, 15.2% ± 1.5, than F0 and F1 hens, 20.7% ± 1.6 and 21.6% ± 1.8. F2 hens had shorter standing bouts (22.0 sec ± 4.2) than both F0 and F1 hens, 33.1 sec ± 4.3 and 27.4 sec ± 4.4. Non-fractured hens spent 80.0% ± 6.9 of total resting time on the floor whereas F1 and F2 hens spent 56.9% ± 12.4 and 51.5% ± 7.7, resting on the floor. Behavioral differences reported here provide insight into possible causes of keel damage, or alternatively, indicate a coping strategy used to offset pain or restricted mobility caused by keel fractures