Behavioral and physiological responses of dairy goats to isolation.

Eight Nubian and eight Alpine dairy goat does were used in a crossover experimental design to determine the effect of 30 min of isolation on behavior and plasma concentrations of thyroxine (T4), triiodothyronine (T3), cortisol, norepinephrine (NOR), and epinephrine (EPI). Isolation was hypothesized to produce an emotional state analogous to fear. Focal animal behavior was recorded for the initial five min of isolation. Blood samples were obtained via jugular cannulae at 0 (immediately prior), 10, 20, 30 (during isolation), 40, 50 and 60 min (after return to their group). Response to isolation was characterized physiologically by increased plasma concentrations of NOR (p less than 0.01), but not T3, T4, cortisol or EPI, indicating a sympathetic discharge. Isolated goats also vocalized more frequently (p less than 0.01) and spent a greater amount of time sniffing, trotting and rearing (p less than 0.05). The Nubian does reacted more strongly (elevated NOR, trotting and rearing, p less than 0.01) to isolation than the Apline does.

Behavioral and physiological responses of dairy goats to food thwarting.

Eight Nubian dairy goat does in one experiment, and eight Alpine dairy goat does in a second experiment, were randomly allotted to food-thwarted or fed groups in a crossover experimental design. Food thwarting was hypothesized to produce an emotional state analogous to frustration. After a 1-week training period during which the goats of both breeds were conditioned to being simultaneously fed in adjacent feeding stalls, frustration was induced in half the goats by feeding only alternate does. Focal animal behavior was recorded for the initial five min after feeding frustration commenced. Blood samples were collected via a jugular cannula before, during and after frustration was induced for thyroxine (T4), triiodothyronine (T3), cortisol, norepinephrine (NOR), and epinephrine (EPI) determinations. Food thwarting was characterized by increased plasma concentrations of NOR, and increased incidences of pawing, head movements, mouthing of objects, behaviors directed toward neighboring does being fed, and rearing (p less than 0.01). When data were pooled across experiments, breed had a strong influence on cortisol (p less than 0.05), with Nubian does having higher concentrations regardless of treatment. Concentrations of hormones were not significantly correlated with behaviors. These findings suggest that frustration may elicit a discharge of NOR but not EPI.

Effect of confinement method on physiology and production of gestating gilts.

Four replicates of 12 Dekalb crossbred gilts were blocked by breeding dates and randomly allotted to four treatments: tethers, crates, loose stalls and dirtlot. Ear vein cannulas were established and blood samples obtained from each gilt on d 2, 9 and 65 of treatment Blood cell counts, blood chemistry profile (12 items), triiodothyronine (T3), thyroxine (T4), basal cortisol and cortisol in response to administration of adrenocorticotrophic hormone (CR-ACTH) were determined. Tethered gilts had depressed CR-ACTH at d 2, probably related to their active struggles against the tethers during the initial period following restraint. Triiodothyronine was greatest in gilts housed loose with access to stalls, probably reflecting the fighting that often occurred among those gilts, and was lowest in gilts on dirtlot on d 2. Glutamic pyruvate transaminase was elevated in gilts on dirtlot at d 9 and 65, probably a result of their increased exercise. Behaviors indicative of "restlessness" were negatively correlated with CR-ACTH at d 9 and 65. Gilts were initially stressed when restrained in tethers, but their CR-ACTH became equivalent to that of gilts in other housing by 9 d. Housing had no effect on production.

Effects of changing housing on physiology of calves.

Holstein bull calves were assigned to be reared in either a stall until 47 d of age, then moved to a hutch; a hutch until 47 d, then moved to a stall; or an elevated pen. Jugular blood samples were obtained at 42, 49, and 56 d of age. Two trials were run during the fall of successive years with 5 to 7 calves per treatment per trial. Stalls were .56 X 1.2 m with elevated wooden slotted floors. Pens were 1.2 X 1.5 m with elevated wooden slotted floors and were located in the same open front building as the stalls. Hutches were 1.2 X 1.2 X 2.4 m long, and calves were restrained with a collar and 2.4-m chain. Calves were placed on treatment between 12 to 24 h after parturition. A treatment by day interaction for triiodothyronine, thyroxine, and adrenocorticotrophic hormone-induced cortisol release indicated that conditions responsible for treatment effects were largely reversed 9 d after moving from stalls to hutches or hutches to stalls.

Effect of feeding method on nonnutritive oral activities in Holstein calves.

Forty Holstein heifer calves were assigned to be fed whole milk from either bucket, bucket with pacifier, nipple bottle, or nipple bottle with pacifier. The pacifier was a nursing bottle with an unperforated nipple. Calves were housed in individual hutches and fed twice daily. Calves were 3 d of age at first observation and were observed biweekly until 42 d of age. Observations were conducted beginning at either 1000 or 1400 h from September through March. A novel object (bicycle inner tube), selected to serve as a focal object for the sucking drive, was placed in the calf's environment and calf behaviors observed during the next 5 min. Time of observation did not influence nonnutritive oral behaviors (sniffing, licking, sucking, chewing, oral grooming, and nose licking). Time spent in nonnutritive oral behaviors increased with age. Regardless of availability of a pacifier, bucket-fed calves spent more time in sniffing the focal object than bottle-fed calves. Calves with access to pacifiers sucked other objects more than calves without pacifiers. The more curious animals spent more time involved in nonnutritive oral behaviors.

Comparison of four methods of calf confinement. I. Physiology.

Holstein bull calves were blocked by birth order and randomly assigned to one of three treatments in trial I: stall (N = 7), pen (N = 7) and hutch (N = 7), and to one of four treatments in trial II: stall (N = 6), pen (N = 5), hutch (N = 6) and yard (N = 8). Stalls were elevated, .56 X 1.2 m, with wooden slatted floors. Stalled calves were tethered from the front with a collar and .5-m chain. Pens were elevated, 1.2 X 1.5 m, with wooden slatted floors and were located in the same open-front building as the stalls. Hutches were 1.2 X 1.2 X 2.4 m long and open on one end. Hutch calves were restrained with a dog collar and 2.4-m chain. Yard calves were housed as a group in a 3.6 X 7.9 m, outdoor enclosure, of which one-half was a covered, three-sided structure. Calves were placed on treatment between 12 to 24 h of age, bottle-fed 1.9 liters colostrum twice daily for 2 d and then bucket-fed 1.9 liters milk replacer twice daily, with continuous access to hay and grain. Jugular blood samples taken at 6 wk were analyzed for blood cell counts, blood chemistry profile (13 items), triiodothyronine (T3), thyroxine (T4), basal cortisol and adrenal response (cortisol) to exogenous adrenocorticotrophic hormone (ACTH). Average daily gain from 0 to 42 d was highly variable and was not significantly different for different treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of four methods of calf confinement. II. Behavior.

Holstein bull calves (N = 46) were blocked by birth order and randomly assigned to be individually reared in stalls, pens or hutches (trials I and II) or as a group in a 3.6 X 7.9 m yard (trial II only). Treatments differed by the degree of restraint and social isolation imposed, with stalls the most restrictive and yard the least. Stalls and pens had wooden slatted floors; hutches and yard were on ground. Calves were placed on treatment within 24 h of birth and remained on treatment 6.5 wk. Total time standing or lying per 24 h in situ at 5 wk was not affected by treatment (P greater than .05), but hutch calves changed position between standing and lying more often than others (P less than .05), in order to remain in sun or shade. At 6.5 wk, calves (N = 24) in trial II were individually open-field tested for 20 min in the presence of alien calves. Stall and pen calves performed more actions utilized in locomotion and defense and engaged in more social behavior than hutch or yard calves (P less than .05). Only stall and pen calves stumbled and fell, but observations were insufficient to allow statistical analysis of these incidents. Treatment effects were found with respect to vocalizations: stall and pen calves emitted more "baaocks," while yard calves emitted more "moos." Results of this study and of a companion physiological study of the calves suggest that the intensification of drives induced by chronic suppression of their release may be accompanied by physiological responses associated with chronic stress.