Effects of multiple concurrent stressors on female Hubbard x Hubbard chicks were studied in a 2(6)-factorial experiment that employed as stressor treatments aerial ammonia (A, 0 or 125 ppm), beak trimming [B, sham handled or beak trimmed/cauterized on trial Day 1 (posthatch Day 10)], coccidiosis (X, gavage with 0 or 6 x 10(5) sporulated Eimeria acervulina oocysts), intermittent electric shock (E, 0 or between 2.9 and 8.7 mA), environmental heat stress (H, air temperature 30.4 or 34.8 C), and continuous noise (N, 80 or 95 dB). Plasma corticosterone concentration on trial Day 7 was unaffected by any stressor or stressor combination, but the heterophil:lymphocyte ratio (H/L) was increased by A, E, and H. Also, the B x X interaction was significant for H/L. The H/L increased linearly from .53 to .86 as number of concurrent stressors increased from zero to six. These findings indicate that the chick's leukocyte changes in response to stress are less variable and more enduring than its corticosterone response, and H/L are sometimes a more reliable indicator of stress.

Effects of multiple concurrent stressors on Hubbard x Hubbard chicks (Days 10 to 17 posthatch) were studied in a 2(6)-factorial experiment that employed as treatments aerial ammonia (A, 0 or 125 ppm), beak trimming (B, sham handled or beak trimmed/cauterized), coccidiosis (X, gavage with 0 or 6x10(5) sporulated Eimeria acervulina oocysts), intermittent electric shock (E, 0 or between 2.9 and 8.7 mA), heat stress (H, 30.4 or 34.8 C) and continuous noise (N, 80 or 95 dB). All stressors, except noise, decreased weight gain (G), increased coefficient of interindividual variation in gain (CV-G), and decreased feed intake (F) and feed conversion efficiency (G/F). Of a possible 57 interactions, only four were significant for G, two for CV-G, and of a possible 26 interactions, only two were significant for F, none for G/F. As number of simultaneous stressors ("order") increased, G, F, and G/F decreased and CV-G increased, all linearly. Time chicks spent standing was increased by X; time spent eating increased by X; and time spent drinking decreased by H. No effect of order and few stressor interactions were detected for the behaviors. Although behavior results were inconclusive with respect to synergism, antagonism, or additivity of stressors' effects, performance results indicated that chicks responded to each stressor occurred singly or concurrently with up to five others. The results suggest that in practical production situations, where ordinarily poultry experience more than one stressor at the same time, effects of multiple concurrent unrelated stressors on performance may be estimable to a first approximation by summing effects of respective stressors when acting alone.

Holstein calves were managed from less than 1 wk of age as in the special-fed veal industry but subjected to three dietary regimens (n = 10/group): low dietary iron (LI = approximately 5 mg iron/kg dry milk replacer) throughout 16 wk; 2) high then low dietary iron (H-LI = 140 mg/kg through d 18, then approximately 5 mg/kg through wk 16; a typical industrial scheme) or 3) high dietary iron (HI = approximately 105 mg/kg throughout the study). Several physiologic, behavioral and health indicators of welfare were monitored at various times. From wk 7 on, blood hemoglobin concentration was higher in HI calves than in LI, whereas that in H-LI calves was intermediate. Blood red cell count was higher in HI calves than in LI from wk 11 to 16, and was higher in HI than in H-LI from wk 14 to 16. Ratio of blood segmented neutrophils to lymphocytes (an indicator of stress) did not differ due to dietary regimen. Between wk 2 and 16, lying time increased from 69.5 to 76.6% of total time. Oral behaviors (e.g., licking and gnawing) occupied less than 15% of total time. Dietary regimen did not affect time spent either lying or engaging in oral behaviors. Calves in all dietary-regimen and slaughter-age groups experienced high frequencies of pneumonia, digestive-tract maladies and trichobezoars, but neither disease nor medical-treatment frequency was related to dietary regimen. Live, hot-dressed carcass and liver weights of the five calves/group slaughtered at 16 wk were not affected by dietary regimens, but carcass grade was highest for LI calves and lowest for HI.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of multiple concurrent stressors on Hubbard x Hubbard chicks (Days 10 to 17 posthatch) were studied in a 2(6)-factorial experiment employing as treatments aerial ammonia (A, 0 or 125 ppm), beak trimming (B, sham handled or beak trimmed/cauterized), coccidiosis (X, gavage with 0 or 6 x 10(5) sporulated Eimeria acervulina oocysts), intermittent electric shock (E, 0 or between 2.9 and 8.7 mA), heat stress (H, 30.4 or 34.8 C), and continuous noise (N, 80 or 95 dB). Packed-cell volume (PCV) was decreased by X and increased by A and H. A quadratic relationship between PCV and number of simultaneous stressors (order) was detected. Heterophil percentage was increased and lymphocyte percentage decreased by A, E, H, and order. Monocyte percentage was increased by N, eosinophil percentage increased by X, and basophil percentage decreased by A, X, and H. Basophil percentage decreased linearly with increasing order. Whole carcass water percentage was increased by X, chloroform-methanol extract percentage (dry matter) (CME) decreased by X, and CP percentage (dry matter) increased by A. Neither water, CME, nor CP percentage changed in relation to order. Lesion severity did not change in any tissue as stressor order increased. With few exceptions, each stressor affected hematologic, body composition, and pathologic traits in a similar manner whether imposed singly or concurrently with up to five other stressors. The results suggest that in practical production situations, where ordinarily poultry experience more than one stressor at the same time, effects of multiple concurrent unrelated stressors on performance traits can be estimated to a first approximation by summing effects of respective stressors when acting alone.

Mated gilts in gestation crates designed specially so gilts could turn or walk at will did turn around and walk. In Exp. 1, in crates 2.1 m long, flared at one end and pointed at the other, and 56 or 61 cm wide at center, gilts' turning frequency averaged 11.2 turns/d. Neither feeder nor waterer location, independent of the other, influenced turning frequency. Most turns apparently were not motivated by any obvious external stimulus. Narrowing crates from 61 to 56 cm reduced turning rate from 12.9/d to 8.9/d. Gilts spent more time facing the feeder when it was at the flared end (F; 66.1%) than when it was at the pointed end (P; 49.4%). Turning was followed by standing or lying, without simultaneous eating or drinking, 65.3% of the time. A greater proportion of turns were succeeded by eating or drinking when feeder and waterer were located in opposite ends of the crate (39.2%) instead of in the same end (29.7%). As a result of turns followed by only standing or lying, gilts were oriented head by head 52.9% of the times. Mean time of day for turning was 1016 in wide crates and 0855 in narrow crates. Also, mean turning time with waterer at P vs at F was 1012 vs 0928. In Exp. 2, a 2 X 2 factorial arrangement of treatments compared crates that were either 2.1 m or 3.4 m long and had either flared or rectangular ends. Neither length nor shape affected gilts' total daily duration of standing. Gilts stood up 8.3 times/d in rectangular crates, 13.9 times/d in flared.(ABSTRACT TRUNCATED AT 250 WORDS)