Effects on chick performance of ammonia and heat stressors in various combination sequences

The purpose of the present study was to evaluate the effects of previous experience with a stressor on chicks' subsequent performance when exposed later to the same stressor or to a different stressor. Performance was measured in chicks exposed to aerial ammonia, environmental heat, or both in reciprocal sequences in two consecutive periods. Four (2 x 2 factorial) treatment combinations of ammonia [0 ppm (a) or 125 ppm (A)] and heat [30 C (h) or 36.5 C (H]) stressors were imposed in each of two consecutive 4-day periods, giving a total of 16 treatments. Weight gain (G), feed intake (F), and the gain:feed ratio (G:F) in Periods 1 (Days 9 to 13 posthatch) and 2 (Days 13 to 17 posthatch) were analyzed. Stressors decreased performance in both periods, but the effect was greater in Period 2. Synergism between A and H in Period 2 decreased chicks' G, F, and G:F in Period 2. Stress-depressed productive traits in Period 1 were succeeded in Period 2 not by residual negative effects but by compensatory responses: prior exposure to stressors in Period 1 was not detrimental to the chicks' subsequent G or G:F in Period 2. For example, chicks switched from Treatment ah in Period 1 to AH in Period 2 had lower G in Period 2 than did those going from either Ah, aH, or AH in Period 1 to AH in period 2. It was concluded that exposure to stressors early on enhanced the chicks' ability to cope with the same or with different stressors later and that compensatory responses occurred as the result of short-term exposure to stressors.

Isolation and sequence analysis of a beta-tubulin gene from Aspergillus flavus and its use as a selectable marker

An altered beta-tubulin gene that confers resistance to benomyl [whose active ingredient is 2-(methoxycarbonylamino)benzimidazole (MBC)] was isolated from a DNA library of Aspergillus flavus and used as a selectable marker for transformation. The beta-tubulin gene was cloned into a plasmid vector containing the pyr-4 gene of Neurospora crassa, and transformants were selected either for uracil prototrophy or MBC resistance. Transformants selected for uracil prototrophy were of three phenotypic classes: sensitive, intermediate, and resistant to MBC. Transforming DNA appeared to integrate at several sites in the genome, with the more resistant phenotypes having more copies of the altered beta-tubulin gene than the sensitive and intermediate phenotypes. Transformants were also selected on medium containing MBC. The average frequency of transformation (1 to 3 transformants per micrograms of transforming DNA) was lower than that obtained by selection for uracil prototrophy, presumably because of failure to select transformants that contained few copies of the altered beta-tubulin gene. The sequence of the beta-tubulin gene was determined and compared with the published sequence of the benA gene of A. nidulans; the beta-tubulin gene was found to be highly conserved between the two Aspergillus species. Notable differences were that the beta-tubulin gene of A. flavus lacks intron 6 present in benA and has an additional leucine at position 148. This is the first gene sequence reported from an aflatoxin-producing fungus and adds to the growing body of knowledge of the beta-tubulin genes and their use as selectable markers for transformation of filamentous fungi.

Oxygen supplementation during exercise in cystic fibrosis

Fourteen female and 22 male patients with cystic fibrosis (CF), 8 to 29 yr of age, performed two progressive exercise tests to exhaustion on a cycle ergometer, breathing normoxic air (21% O2) for one test, and hyperoxic air (30% O2) for the other test. The order of gas administration was randomized. Minute ventilation (VE), oxygen uptake (VO2), end-tidal CO2 tension (PETCO2), work rate, oxyhemoglobin saturation (SAO2), and heart rate (HR) were measured throughout the tests. The SaO2 of 11 patients at peak exercise was 90% or less ("Low Sat" group). The SaO2 of 23 patients remained above 90% throughout the exercise ("High Sat" group). Hyperoxic air minimized desaturation during exercise in the Low Sat group to 2 +/- 2% compared to a decrease of 10 +/- 5% with normoxic air. The decrease in saturation was not significant for the High Sat group (1 +/- 1% for both 21% and 30% O2). Peak work rate and VO2 did not differ significantly between normoxic and hyperoxic conditions. However, VE and HR at peak exercise tended to be lower, and PETCO2 was higher during peak exercise with 30% O2 than 21% O2 for both groups. During submaximal exercise, O2 desaturation was diminished and HR was significantly lower with supplemental O2, specifically in the Low Sat group. VE was significantly lower for both groups during submaximal exercise with hyperoxic air. The results suggest that O2 supplementation minimizes O2 desaturation and enables patients with CF to exercise with reduced ventilatory and cardiovascular work.

Behavioral and endocrine responses of sows to prostaglandin F2 alpha and cloprostenol

Behavioral and endocrine changes in the sow following injection with prostaglandin F2 alpha (PGF2 alpha) or its analogue, cloprostenol (CLO), were monitored to identify endocrine correlates of prepartum activity (nest-building). On Day 112 postcoitum, within 15 min after injection with 10 mg PGF2 alpha, sows offered straw in pens engaged in intense prepartum activity, but few behavioral changes occurred during the first 2 h following administration of 175 micrograms CLO. The temporal pattern of prepartum activity, however, was affected by both prostaglandins. In control sows, most prepartum activity came during Hours 16-0 before delivery of first piglet (delivery). After CLO, sows engaged in nest-building more during Hours 32-17 and less during Hours 16-0. In another experiment, sows in farrowing crates were injected with saline, 175 micrograms CLO, or 10 mg PGF2 alpha on Day 112 and blood was collected 0, 15, 30, 60, and 90 min later. Another sample was collected when spontaneous prepartum activity was first observed. For approximately 90 min after PGF2 alpha treatment, sows rooted, pawed, and bit and rubbed faces on crate bars; after saline and CLO, this behavior was rarely observed. After prostaglandin treatment, plasma progesterone tended to decline, a 10-fold rise in relaxin came within 15 min, but estrone did not change. Plasma prolactin rose 10-fold within 30 min after PGF2 alpha treatment, and rose more gradually after CLO treatment. When sows exhibited spontaneous prepartum activity (approximately 7 h before delivery), endocrine status was characterized by low progesterone, high estrone:progesterone ratio, and high prolactin.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway and alveolar pressures during perfluorocarbon breathing in infant lambs

Previous studies exploring the utility of liquid breathing using perfluorocarbon have reported proximal airway pressures (Paw) as high as 70 Torr during inspiration, generating concern about the safety of this form of mechanical ventilation. Effects on the pulmonary capillary bed are, however, more likely related to alveolar pressure (PA) than to Paw, and data on PA during liquid breathing are limited. In this study in infant lambs, we reconstructed the pressure waveforms of PA during liquid breathing by using an occlusion technique and compared these with Paw waveforms. Peak PA (18.6 +/- 10.4 Torr) was significantly less than peak Paw (31.5 +/- 10.5 Torr, P less than 0.001), indicating a large resistive pressure drop (14.4 +/- 4.5 Torr) across the bronchial tree. Mean PA (mPA) was very similar to mean Paw (mPaw) [bias = -2.0 Torr, standard error of the average difference = 0.27 Torr, predictive value of mPaw for mPA (r2) = 0.978], suggesting that mPaw, which is easily measured, may be used to estimate mPA during perfluorocarbon liquid breathing. These data show that alveoli do not experience the same large swings in pressure as the proximal airway does during liquid breathing and that simple measurements of mPaw can be used to approximate mPA during liquid breathing.

Use of survey data and small area statistics to assess the link between individual morbidity and neighbourhood deprivation

STUDY OBJECTIVE

The aim of the study was to examine the relationship between sociogeographic factors and health, using a particular social indicator of neighbourhood deprivation.

DESIGN

The study analysed the relationship between health problems (reported by randomly selected respondents to a household survey) and an area social indicator for the neighbourhoods where the respondents lived (based on census data). The area social indicator tested was the underprivileged areas indicator developed by the St Mary's Hospital Department of General Practice, London. Generalised linear interactive modelling with a logistic model was used to test the strength of the relationship between social indicators and morbidity, and to calculate the probability of reporting illness or consultations for survey respondents living in different types of area.

SETTING

The study population was derived from three London health districts and their corresponding census enumeration districts.

PARTICIPANTS

Responses were obtained from 738 households drawn from the local taxation evaluation list (66% of those sampled), and 1384 persons over 16 participated in the survey (94% of eligible adults in households surveyed). Of these, 1221 provided complete data on health problems. The survey population was considered representative of the general population in the areas studied since its characteristics were similar to those reported for the population as a whole in the 1981 census.

RESULTS

Within different age and sex groups, those living in very deprived areas, with high underprivileged area scores, were more likely to consult their doctor and to report various indicators of poor health than those living in privileged areas, with low underprivileged area scores.

CONCLUSIONS

The underprivileged areas index may provide a useful surrogate indicator to estimate morbidity and use of general practitioner services in small areas. It is likely to be most effective in areas where sociodemographic profiles of the local population are highly contrasting.

Behavioral responses of periparturient sows and juvenile pigs to prostaglandin F2 alpha

Within minutes after prostaglandin F2 alpha (PGF2 alpha) injection on d 112 postcoitum and again in the last few hours before delivery of the first piglet around 22 h later, sows in pens intensely rooted and pawed, which is typical prepartum nestbuilding behavior. Control sows engaged in most such typical prepartum activity (TPA) within 16 h before delivery. The overall frequencies and durations of TPA for the 48-h prepartum period were not influenced by injection, but injection of PGF2 alpha did alter the temporal pattern of behavior and resulted in a bimodal profile of activity. The PGF2 alpha injected 24 h postpartum immediately induced TPA in sows, but it was less intense and shorter than prepartum TPA. Postpartum only, some PGF2 alpha sows rubbed or kicked at their abdomens and seemed to experience discomfort. Because PGF2 alpha elicited TPA both pre- and postpartum, TPA probably was not directly triggered by changes in plasma progesterone concentration or in the estrogen:progesterone ratio. After injection of .5 or 1 mg PGF2 alpha, prepubertal pigs (approximately 10 kg) lay more but also changed posture more often. After PGF2 alpha, slight or no TPA was seen, but pigs pawed more often, showed signs of abdominal discomfort, defecated more often, stretched and arched their backs and scratched or kicked at their sides or abdomens. Most PGF2 alpha-induced TPA by prepartum sows probably is not caused by some general peripheral effect, but rather by some neural or endocrine change that stimulates nestbuilding specifically in animals primed by the endogenous endocrine environment of late pregnancy.

Evaluation of a HSV specific monoclonal antibody reagent for laboratory diagnosis of herpes simplex virus infection

A new FITC-conjugated HSV specific monoclonal antibody reagent (Syva Co., Palo Alto, Ca) was evaluated for the confirmation of HSV clinical isolates. The reagent was also compared to type-specific monoclonal antibodies for the pre-CPE detection of HSV from clinical specimens in centrifugation culture and by direct examination of specimens smears by direct immunofluorescent antibody staining (DFA). HSV was isolated from 75 of 232 specimens (32%). All 75 isolates were confirmed with both the type-specific antibodies and the HSV-specific reagent. In centrifugation culture HSV was detected in 36 of 105 (34%) specimens. The HSV specific reagent detected all 36 specimens that were positive with the type-specific reagents. HSV infection was diagnosed by DFA in 31 of 50 (62%) specimen smears. The HSV-specific reagent detected all 31 positive specimens. This reagent confirmed and detected all HSV positive specimens that were positive by the type-specific monoclonal antibody reagents. The reagent contains monoclonal antibodies specific for both HSV1 and HSV2 in a single mixture, which produces a highly sensitive HSV FA staining reagent.

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.

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.

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.

Effects of sow-crate design on health and performance of sows and piglets

The effects of sow-crate design on certain health and performance traits of 211 sows and their piglets were evaluated with a 2 X 2 X 4 factorial arrangement of crate width (narrow [N = 55 cm] or wide [W = 64] between lowest horizontal pipes), length (short [S = 183 cm] or long [L = 198] from rump stop to front gate) and side type (lower side of sow crate "fingered" [F], "bowed" bottom bar--marking the sow zone 19.3 cm wider at the bottom--20 cm above the floor [B], or straight bottom bar 20 cm [S20] or 25 cm above the floor [S25]). Between d 107 to 110 postcoitum and d 21 postpartum, no crate design variable affected the sow's body-weight change, but side type tended to affect the most prominent head-neck and leg integumentary lesions. Number of stillborn piglets/litter was greater with W crates than with N, except with crates having S20 sides, and was greater with L crates than with S. More piglets were crushed to death in W crates than N crates, and stillbirth frequency was greater in L crates than in S, but overall preweaning piglet mortality was affected by no crate-design feature. At both 7 and 21 d of age, piglets' knee lesions were most severe with S20 crates and least with S25, whereas face-lesion score was unaffected by crate design. Piglet body weight at age 21 d was least with S20 crates and greatest with F and S25. No crate-design variable affected within-litter variation in piglet growth rate. Sow-crate design affected important health and performance traits of piglets through postnatal d 21.

Effects of sow-crate design on sow and piglet behavior

The effects of sow-crate design on certain behaviors of sows and piglets at farrowing and again approximately 3 wk later were evaluated with a 2 x 2 x 4 factorial arrangement of crate width (narrow [N = 55 cm] or wide [W = 64] between lowest horizontal pipes), length (short [S = 183 cm] or long [L = 198] from rump stop to front gate) and side type (lower side of sow crate "fingered" [F], "bowed" bottom bar 20 cm above the floor [B], or straight bottom bar 20 cm [S20] or 25 cm above the floor [S25]). Farrowing-crate design influenced both sow and piglet behaviors both during and immediately after parturition and during nursing-suckling bouts approximately 3 wk later. Activities of 51 sows and their piglets were videorecorded during and immediately following parturition. Sow-crate design affected neither the interval between births of successive piglets in a litter nor the frequency of standing by the sow during parturition. Latency from birth to first mammary contact (LMC) was greater with S25-sided and S sow crates, and especially with S, W crates. A significant interaction occurred between sow-crate side type and dimensions; LMC was longer when S25 sides were combined with S or W crates. Data on suckling behavior were collected from 113 litters over three successive sucklings approximately 3 wk after farrowing. Sow-crate design had no effect either on the consistency with which a piglet suckled a particular teat or teat pair or on the frequency of multiple-teat use. Piglets maintained fewer functional teats with S, S20 crates. The distribution of functional teats between rows was less symmetric with S crates. Piglets nursed with their bodies over a side bar more frequently with B- and S20-sided crates. The sow permitted her piglets to suckle while she was in a vertical stance more frequently with S and N crates, and especially with S, N crates. Sow-crate design affected important behaviors of sows and piglets both during and immediately after parturition as well as during nursing-suckling bouts about 3 wk later.

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%.

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.

Energetics of sows and gilts in gestation crates in the cold

Seventy pregnant sows and gilts in gestation crates with unbedded concrete-slat floors and partitions in common (which permitted contact by neighbors) in a closed house with air temperature 10 to 12 degrees C during cold weather were studied for 3 wk. The animals' lower critical temperature and thermoregulatory heat and feed requirements were estimated from measured variables, including ME intake, body weight and its change and body surface temperature, and other calculated values and assumptions. Estimates for a 165-kg sow or gilt in such an environment were: lower critical temperature = 15 degrees C; thermoregulatory heat requirement = 126 to 161 kcal/d per 1 C degree of coldness (higher as pregnancy progresses); and thermoregulatory feed requirement = 42 to 54 g/d per 1 C degree of coldness (assuming 3 kcal ME/g of diet). The sow's lower critical temperature was affected by state of pregnancy; in late pregnancy it was 1.6 to 2.6 C degrees lower than in early pregnancy. These estimates of the pregnant sow's thermoregulatory heat and feed requirements at effective environmental temperatures below the lower critical temperature accord well with those published before. But this estimate of the pregnant sow's lower critical temperature is approximately 5 C degrees lower than several made in laboratory settings on animals held individually, with no opportunity to huddle. The fact that every sow and gilt in this experiment could make mechanical contact with at least one neighbor at all times, and sometimes two, might account for much of the difference in lower critical temperature estimates.

Structure, organization and expression of cyanobacterial ATP synthase genes

The genes encoding the nine polypeptides of the ATP synthase from Synechococcus sp. PCC 6301, a unicellular cyanobacterium, and Anabaena sp. PCC 7120, a filamentous cyanobacterium, have recently been isolated and their sequences determined. These represent the first such sequences available from procaryotic organisms that perform oxygenic photosynthesis. Similar to the organization in chloroplasts, the ATP synthase genes of both cyanobacteria are arranged in two gene clusters which are not closely linked in the chromosome. Three of the genes located in one cluster in cyanobacteria, however, are localized in the nuclear rather than the chloroplast genomes of plants. The cyanobacterial ATP synthase genes are ordered in the same manner as those in the single gene cluster of Escherichia coli. Cyanobacteria contain an additional gene denoted atpG which appears to be a duplicated and diverged from of the atpF gene. The larger cyanobacterial cluster, atp 1, is comprised of eight ATP synthase subunit genes arranged in the order atpI-atpH-atpG-atpF-atpD-atpA-atpC. An overlap between the atpF and atpD gene coding regions observed in Anabaena sp. PCC 7120 is absent in both Synechococcus sp. PCC 6301 and E. coli. The second cluster of genes, atp 2, contains the remaining two ATP synthase genes in the order atpB-atpE. Unlike the situation in many chloroplast genomes, this gene pair does not overlap in either cyanobacterial species. In Anabaena sp. PCC 7120, atp 1 and atp 2 each comprise an operon and the transcription initiation sites for each gene cluster have been identified. The cyanobacterial ATP synthase subunits are much more closely related in sequence to the equivalent polypeptides from chloroplasts than they are to those of E. coli. The similarity in chloroplast and cyanobacterial ATP synthase subunit sequences and gene oreganization argue strongly for an endosymbiotic origin for plant chloroplasts.

Genes encoding the alpha, gamma, delta, and four F0 subunits of ATP synthase constitute an operon in the cyanobacterium Anabaena sp. strain PCC 7120

A cluster of genes encoding subunits of ATP synthase of Anabaena sp. strain PCC 7120 was cloned, and the nucleotide sequences of the genes were determined. This cluster, denoted atp1, consists of four F0 genes and three F1 genes encoding the subunits a (atpI), c (atpH), b' (atpG), b (atpF), delta (atpD), alpha (aptA), and gamma (atpC) in that order. Closely linked upstream of the ATP synthase subunit genes is an open reading frame denoted gene 1, which is equivalent to the uncI gene of Escherichia coli. The atp1 gene cluster is at least 10 kilobase pairs distant in the genome from apt2, a cluster of genes encoding the beta (atpB) and epsilon (atpE) subunits of the ATP synthase. This two-clustered ATP synthase gene arrangement is intermediate between those found in chloroplasts and E. coli. A unique feature of the Anabaena atp1 cluster is overlap between the coding regions for atpF and atpD. The atp1 cluster is transcribed as a single 7-kilobase polycistronic mRNA that initiates 140 base pairs upstream of gene 1. The deduced translation products for the Anabaena sp. strain PCC 7120 subunit genes are more similar to chloroplast ATP synthase subunits than to those of E. coli.

Prepartum behavior of gilts in three farrowing environments

To determine effects of the farrowing environment on prepartum behavior, five gilts were monitored continuously for 48 h prior to parturition in each of three farrowing systems: 1) an open farrowing pen (2.1 x 1.5 m); 2) a turn-around farrowing pen, which allowed the gilt to turn around (2.4 m long; 1.8 m wide at back, .6 at front) and 3) a straight farrowing crate (sow zone = .6 x 2.1 m). Videorecords were summarized as three 16-h segments (Period A = 48 to 32 h before the first piglet was delivered, B = 32 to 16 h and C = 16 to 0 h) for analysis of activity over time. In all systems, frequencies of postural changes and oral-nasal activities directed at the floor or wall increased as farrowing was approached, the highest frequencies occurring in Period C. Respective times spent standing, sitting and engaged in oral-nasal activities directed at floor or wall also increased over time. Pawing occurred almost exclusively in Period C. Lying upright (ventral posture) occupied a greater portion of lying time as the gilt's activity increased over time, whereas feeding and drinking behaviors did not change over time. The only behavior affected by the experimental environments was the frequency of 90 degree turns. Gilts in both open and turn-around pens showed an increasing turning frequency over time, and they turned more often in the open pen than in the turn-around pen.(ABSTRACT TRUNCATED AT 250 WORDS)

Perfusion method for preparing pig brain cortex for Golgi-Cox impregnation

The perfusion procedure described in this paper produces high quality impregnation of pig visual and somatosensory cortical neurons with a Golgi-Cox solution. Starting within 30 min after death, pig heads were perfused with a fixative solution composed of a mixture (v/v) of liquid phenol, 5%; formalin, 14%; ethylene glycol, 25%; methanol, 28%; and water, 28% for two periods of 4 hr each. After perfusion, the heads were chilled for at least 18 hr. The entire brain was removed from the skull and then placed in 10% buffered formalin, where it remained for at least 10 days before taking the blocks that were to be immersed in the Golgi-Cox solution. Three weeks spent in the Golgi-Cox solution typically produced uniform neuron impregnation. The tissue blocks were then embedded in celloidin and sectioned at 120 micron. This procedure avoids the following difficulties: Golgi-Cox methods that produced excellent results with rodent or primate tissue were unsuccessful with pig tissue, placing fresh tissue in Golgi-Cox solution resulted in incomplete neuron impregnation, and immersion fixation in 10% buffered formalin without perfusion resulted in excessive staining of glia.

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)

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.

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)

Dairy animal welfare. Public mood and how we respond

Farm animal welfarism is a complicated, dangerous issue for animal agriculture today. The public mood is complex. Much of the public's positive perception of farmers and their practices is based on myths, not understanding. Many farmers do not rate the animal welfare issue as a clear and present concern. Consumers decide whether or not to eat foods of animal origin mainly on the basis of factors other than ethical concerns. Still, the job of educating our fellow citizens so as to engender their enlightened support of animal agriculture will need to be done deftly. Approximately 10% of our citizenry who are undecided on this issue ultimately will decide our industry's course. At this time, we in animal agriculture need to respond in a well-organized fashion. We should develop educational materials and programs about animal production practices for our fellow citizens, especially youngsters, and we should establish guidelines for the care and use of agricultural animals in agricultural research and teaching to ensure the continuing opportunity for scientists in agricultural businesses and in research and teaching institutions to use agricultural animals in their programs.

Pulmonary bacterial deposition and clearance during ascarid larval migration in weanling pigs

Pulmonary deposition and clearance of bacteria were measured in weanling pigs, half of which had been inoculated at age 31 days with larvated Ascaris suum ova. Seven days later, when breathing signs of larval migration were pronounced, all pigs were exposed to aerosolized Escherichia coli (strain B). Then, either immediately after aerosol exposure (for deposition assessment) or immediately after a 120 minute period in filtered air (for clearance), bacteria in the pigs' lungs were counted. Ascarid ova-inoculated pigs did not differ significantly from control pigs for number of bacteria in the lungs after aerosol exposure, but after the 120 minute clearance period they had 7.2 times more than did the control pigs. Thus, in weanling pigs, the breathing-pattern changes that were evident during ascarid-larval migration did not affect pulmonary deposition of inhaled bacteria significantly, but the presence of ascarid larvae in the lungs was associated with impaired pulmonary bacterial clearance.