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Biomedical subjects

J M McFarlane

Publications and source records attributed to J M McFarlane.

15 recordsLinked to original sources
PubMed1995

A comparative study of the tortuosity of the splenic artery.

The splenic artery of four mammals--pig, greyhound, rhesus macaque, and olive baboon--was studied to determine its tortuosity and pattern of convolutions. The results were compared to those previously gathered in humans. It was found that the isolated cadaveric arteries showed a noticeable species variation in mean index of tortuosity. In the pig and dog, the artery was nearly straight throughout its length, with a very low index of tortuosity, not significantly different in the two species (P > 0.1). The artery was significantly more tortuous in the rhesus macaque and baboon than in both pig and dog, (Ps < 0.001), with a single large convolution present in the proximal one-third. In humans, the artery is commonly tortuous throughout its length and is significantly more tortuous than in the pig and dog (P < 0.001), but not significantly more tortuous than in the baboon (P > 0.1) and only just significantly more so than in the rhesus macaque (0.02 < P < 0.05). The speculation that the tortuosity of the artery may be related to habitual posture, being less in the pronograde pig and dog than in the partly orthograde rhesus macaque and baboon, is not supported by results in the wholly orthograde human.

Animals↗
PubMed1989

Multiple concurrent stressors in chicks. 1. Effect on weight gain, feed intake, and behavior.

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.

Animals↗
PubMed1989

Multiple concurrent stressors in chicks. 2. Effects on hematologic, body composition, and pathologic traits.

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.

Ammonia↗
PubMed1989

Multiple concurrent stressors in chicks. 3. Effects on plasma corticosterone and the heterophil:lymphocyte ratio.

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.

Ammonia↗
PubMed1988

Some indicators of welfare of crated veal calves on three dietary iron regimens.

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)

Animal Nutritional Physiological Phenomena↗
PubMed1988

Turning and walking by gilts in modified gestation crates.

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)

Animal Welfare↗
PubMed1988

Footing and gait of pigs on different concrete surfaces.

Because pigs frequently lose their footing and slip, it is important to understand slipping and its relation to different floor surfaces. An experiment was conducted to evaluate the gait and footing of young pigs walking on concrete floor surfaces having known friction characteristics and to determine critical skid resistance values in terms of the fitness of a concrete surface for flooring in pig quarters. Barrows were cinematographed with a high-speed 16-mm camera as they walked on various surfaces, and gait and footing were subsequently analyzed in motion studies. The six concrete floor test pads with different surface treatments (fine and coarse sand, fine and coarse broom, wood float and steel trowel) were evaluated for friction coefficient (skid resistance value) using a British pendulum tester both before and after pig tests. Leg angle, pastern angle and time variables were not related with average skid resistance value of the different floors. However, slip variables during a stride's stance phase per se were well related to surface-treatment differences in average skid resistance. Thus, the average skid resistance value generated by the British pendulum tester yielded one piece of objective information useful in assessing the fitness of concrete surfaces for floors in pig quarters. All the surfaces except the steel trowel surface had average skid resistance value of greater than 65 British pendulum number, and they all reduced a pig's chance of slipping relative to the steel trowel (less than 60 British pendulum number). The front leg was a more sensitive indicator than the rear of a floor's effect on the pig's gait and footing.

Animals↗
PubMed1988

System for studying multiple concurrent stressors in chicks.

A chick caging system was designed to impose 2(6) p64) factorial combinations of six stressors concurrently by means consistent with the guidelines devised by the Consortium for the Development of a Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching (1988). The system was tested to study the consistency of the effects of the stressors on health, behavior, and performance. Aerial ammonia, beak-trimming, coccidiosis, intermittent electric shock, environmental heat, and loud noise were employed with methods or at intensities determined to depress chick rate of gain. The system repeatedly imposed the same degree of stress from respective stressors.

Animal Welfare↗
PubMed1988

System for exposing chicks to experimental intermittent electric shock.

A system for imposing mild electric shock on chicks was developed to study effects on health, behavior, and performance. A floor of parallel steel rods was wired so that the chick's foot or feet completed an electric circuit. Droppings spanning the gap between energized rods and ground rods caused short-circuiting occasionally and temporarily, creating a random-interval/random-duration generator. In one 48-h period, on average, the floor remained electrified for 2.7 +/- .19 min (mean +/- SD) then off 4.5 +/- .64 min. Chicks seemed to habituate to the shock over time. Therefore, in one experiment, the current from one point on a foot to another was increased daily from an estimated 2.9 mA on Day 1 to 8.7 mA on Day 7. When exposed to this electric shock regimen between 10 and 17 days of age, chicks' weight gain was reduced by 12%, feed intake by 5%, and gain:feed by 8%.

Animals↗
PubMed1978

Neonatal respiratory distress. A simple cradle for micrognathia and glossoptosis.

Infants born with micrognathia and glossoptosis may present as a grave emergency, with recurrent bouts of respiratory distress and cyanosis. The management of this condition is discussed, with particular reference to conservative measures. A new cradle has been designed to facilitate the management of these children during the neo-natal period.

Airway Obstruction↗
PubMedDate not supplied

Bacterial vaginosis and Chlamydia trachomatis among pregnant abused and nonabused Hispanic women.

OBJECTIVE: To compare the prevalence of bacterial vaginosis (BV) and Chlamydia trachomatis (CT) among abused and nonabused pregnant Hispanic women. DESIGN: Retrospective audit of charts of 233 pregnant, abused Hispanic women and 468 pregnant, nonabused Hispanic women. SETTING: Three urban prenatal clinics of a public health department in the southwestern United States. SAMPLE: The medical records of 701 pregnant Hispanic women. MAIN OUTCOME MEASURE: Diagnosis of BV and/or CT among abused and nonabused pregnant women. RESULTS: Combined prevalence of BV and CT was significantly higher for abused women (z score = 2.55; df = 138; p < .05). There was no significant difference between abused and nonabused women for CT alone (z score = .96; df = 33; p < .05); however, prevalence of BV was significantly higher for abused women (z score = 1.99; df = 104; p < .05). CONCLUSION: In this sample of pregnant Hispanic women prevalence of BV was significantly higher in those who had been abused, indicating the need for targeted screening of all abused pregnant women for BV.

Adolescent↗