Short communication: Calving site selection of multiparous, group-housed dairy cows is influenced by site of a previous calving.

A calving cow and her newborn calf appear to have an attracting effect on periparturient cows, which may potentially influence the functionality of future motivation-based calving pen designs. In this pilot study we examined whether calving site selection of group-housed Holstein dairy cows was affected by the site of a previous calving. Ten multiparous cows moved to 1 of 2 group pens 11 (range = 4-27) d before calving were included. Each pen consisted of an open area (9 × 9 m) connected to 6 secluded areas (4.5 × 3 m each), where cows could move freely between all areas. Time of calving, location of the breaking of the amniotic sac, as well as the place of birth were recorded. In all but 1 case cows calved within a distance of 1 cow length from where the previous calving took place, suggesting that the cows did not select calving site at random. These preliminary observations indicate that choice of calving site may be affected by the site of a previous calving, potentially explained by the presence of amniotic fluids.

Splitting the scotoperiod: effects on feeding behaviour, intestinal fill and digestive transit time in broiler chickens.

1. The aim of this study was to evaluate how splitting the dark period (scotoperiod) affects feeding behaviour and associated intestinal measures in broilers. 2. Ross 308 broilers were reared to 37 d in groups given either a daily 8-h continuous scotoperiod (DARK 8) or an intermittent light schedule with two equally spaced 4-h scotoperiods (DARK 4 + 4), which yielded the same total duration of darkness per 24 h. 3. Feeding behaviour was recorded weekly from 24-h video recordings of 24 groups each of 64 birds. Empty intestinal weights as well as their contents were measured weekly at 4 time points (n = 192). Digestive transit time was estimated on d 29 using a chromic oxide marker; production variables and the extent of foot pad dermatitis were also recorded. 4. In the 3 h prior to a scotoperiod, feeding activity increased in chickens from DARK 8 but not DARK 4 + 4. This increase was reflected in a higher relative content of the crop in DARK 8 at this time. 5. Immediately following the scotoperiod, feeding activity peaked and, although the chickens in DARK 4 + 4 expressed more feeding behaviour in the first 20 min after the scotoperiod, the chickens in DARK 8 had overall higher feeding activity across the day. However, DARK 4 + 4 had a higher feed intake and weight gain. The occurrence and severity of foot pad dermatitis was similar between treatments. 6. In conclusion, broilers modify their feeding behaviour according to the prevailing light schedule. Eight consecutive hours of darkness reduced growth, but did not affect overall feed conversion efficiency, and did not appear to exacerbate hunger or foot pad dermatitis to any great extent.

Dairy goats adjust their meal patterns to the fibre content of the diet.

Few studies have investigated how meal patterns of ruminants are affected by diet fibre content. Dairy goats (N = 32) in late lactation and early gestation were housed in eight groups of four goats, with all combinations of breed (Alpine and Saanen) and lactation number (1 and 2) represented in each group. Each goat had access to its own individual feed trough placed on a weigh scale with data logged automatically. All goats were fed the same total mixed ration (TMR; 30% concentrate and 44.6% NDF in DM) ad libitum for a control period of 22 days. Using the same feed ingredients, half of the groups were then offered a High fibre diet (20% concentrate; 47.3% NDF), and the other half a Low fibre diet (40% concentrate; 41.5% NDF) for a treatment period of 16 days. Daily meal patterns (meal frequency, duration and size, feeding rate, daily feed intake and daily feeding time) were computed for each animal using a meal criterion of 8 min. The last 10 days for each period (control and treatment) were used to calculate individual period means and individual differences between the two periods. During the control period, the goats ate on average 12.1 ± 0.49 meals/day, consuming 4.2 ± 0.10 kg fresh TMR daily. When the ration changed, all measures of feeding behaviour except meal size changed asymmetrically for the goats on the two diets. Goats fed the High fibre diet reduced their meal frequency by 10%, and the first meal after feed distribution lasted 11% longer, leading to a 9% reduction in feeding rate and no significant changes in daily feed intake and daily feeding time. Goats on the Low fibre diet did not significantly change their meal frequency or meal size, but the combined changes nevertheless led to a 9% increase in daily feed intake. On the Low fibre diet, goats were able to increase their feeding rate by a third, leading to a reduction in meal durations, thus reducing daily feeding time by 13%. Goats adapt their feeding behaviour to the fibre proportion of the offered diet, with more changes when fibre content is lowered, which needs to be taken into account when comparing phenotypes and adaptability of small ruminants to different diets.

Feeding activity in groups of newly hatched broiler chicks: effects of strain and hatching time.

The feeding activity of 2 strains of broiler chickens was investigated during their first week of life in relation to their hatching time. Fast (Ross 308) and slow-growing (LB) strains were allocated to 1 of 3 (early, middle, or late hatch) single-strain groups of 80 to 100 as-hatched birds in 4 replicates divided into 2 time-separated blocks. Behavioral observations differed between blocks and were carried out at intervals on d 1 to 6, and the percentage of birds feeding (from trough or paper), drinking, or being otherwise active (block 2 only) were registered. A higher mortality caused by flip-over was seen among the late-hatching birds from the slow-growing strain. The percentage of birds engaged in feeding activity was similar for the 2 strains, but LB birds began to eat from the paper later and were observed eating from the trough less than Ross 308 birds, which in turn were less active than LB, especially in the early and middle hatch groups. Early hatch groups were observed feeding from the paper more than the middle and late hatch groups. Drinking behavior mirrored feeding from the trough, indicating that drinking was prandial. Within strain, no effect of hatch time was found on live weight at hatch, but the feeding behavior of early hatched birds led to a small, transient weight advantage on d 3 after hatch. The transition from feeding on paper to feeding only from the trough may have less effect on birds that feed from the trough sooner, such as the fast-growing strain.

Regulation and function of the CD3gamma DxxxLL motif: a binding site for adaptor protein-1 and adaptor protein-2 in vitro.

Several receptors are downregulated by internalization after ligand binding. Regulation of T cell receptor (TCR) expression is an important step in T cell activation, desensitization, and tolerance induction. One way T cells regulate TCR expression is by phosphorylation/dephosphorylation of the TCR subunit clusters of differentiation (CD)3gamma. Thus, phosphorylation of CD3gamma serine 126 (S126) causes a downregulation of the TCR. In this study, we have analyzed the CD3gamma internalization motif in three different systems in parallel: in the context of the complete multimeric TCR; in monomeric CD4/CD3gamma chimeras; and in vitro by binding CD3gamma peptides to clathrin-coated vesicle adaptor proteins (APs). We find that the CD3gamma D127xxxLL131/132 sequence represents one united motif for binding of both AP-1 and AP-2, and that this motif functions as an active sorting motif in monomeric CD4/ CD3gamma molecules independently of S126. An acidic amino acid is required at position 127 and a leucine (L) is required at position 131, whereas the requirements for position 132 are more relaxed. The spacing between aspartic acid 127 (D127) and L131 is crucial for the function of the motif in vivo and for AP binding in vitro. Furthermore, we provide evidence indicating that phosphorylation of CD3gamma S126 in the context of the complete TCR induces a conformational change that exposes the DxxxLL sequence for AP binding. Exposure of the DxxxLL motif causes an increase in the TCR internalization rate and we demonstrate that this leads to an impairment of TCR signaling. On the basis of the present results, we propose the existence of at least three different types of L-based receptor sorting motifs.

Ultradian activity rhythms in large groups of newly hatched chicks (Gallus gallus domesticus).

A clutch of young chicks housed with a mother hen exhibit ultradian (within day) rhythms of activity corresponding to the brooding cycle of the hen. In the present study clear evidence was found of ultradian activity rhythms in newly hatched domestic chicks housed in groups larger than natural clutch size without a mother hen or any other obvious external time-keeper. No consistent synchrony was found between groups housed in different pens within the same room. The ultradian rhythms disappeared with time and little evidence of group rhythmicity remained by the third night. This disappearance over time suggests that the presence of a mother hen may be pivotal for the long-term maintenance of these rhythms. The ultradian rhythm of the chicks may also play an important role in the initiation of brooding cycles during the behavioural transition of the mother hen from incubation to brooding. Computer simulations of individual activity rhythms were found to reproduce the observations made on a group basis. This was achievable even when individual chick rhythms were modelled as independent of each other, thus no assumptions of social facilitation are necessary to obtain ultradian activity rhythms on a group level.

Effects of a calm companion on fear reactions in naive test horses.

REASON FOR PERFORMING STUDY: In fear-eliciting situations, horses tend to show flight reactions that can be dangerous for both horse and man. Finding appropriate methods for reducing fearfulness in horses has important practical implications. OBJECTIVES: To investigate whether the presence of a calm companion horse influences fear reactions in naive subject horses. HYPOTHESES: The presence of a habituated (calm) companion horse in a fear-eliciting situation can reduce fear reactions in naive subject horses, compared to subject horses with a nonhabituated companion (control). METHODS: Minimally handled (n = 36), 2-year-old stallions were used, 18 as subjects and 18 as companions. Companion horses (n = 9) were habituated to an otherwise frightening, standardised test stimulus (calm companions), whereas the rest (n = 9) of the companion horses remained nonhabituated (control companions). During the test, unique pairs of companion and subject horses were exposed to the test stimulus while heart rate and behavioural responses were registered. Subsequently, subject horses were exposed to the stimulus on their own (post test). RESULTS: Subject horses, paired with a calm companion horse, showed less fear-related behaviour and lower heart rate responses compared to subject horses with control companions. Results from the post test suggest that the difference between treatment groups remained in the subsequent absence of companion horses. CONCLUSIONS AND POTENTIAL RELEVANCE: It appears possible to reduce fear reactions in young, naive horses by allowing them to interact with a calm companion horse in fear-eliciting situations.

Review: Drinking water for liquid-fed pigs.

Liquid feeding has the potential to provide pigs with sufficient water to remain hydrated and prevent prolonged thirst. However, lack of permanent access to fresh water prevents animals from drinking when they are thirsty. Moreover, individual differences between pigs in a pen may result in uneven distribution of the water provided by the liquid feed, leading to some pigs being unable to meet their water requirements. In this review, we look at the need for and provision of water for liquid-fed pigs in terms of their production performance, behaviour, health and welfare. We highlight factors which may lead to water ingestion above or below requirements. Increases in the need for water may be caused by numerous factors such as morbidity, ambient temperature or competition within the social group, emphasising the necessity of permanent access to water as also prescribed in EU legislation. The drinkers can be the target of redirected behaviour in response to feed restriction or in the absence of rooting materials, thereby generating water losses. The method of water provision and drinker design is critical to ensure easy access to water regardless of the pig's physiological state, and to limit the amount of water used, which does not benefit the pig.

Foot pad dermatitis and hock burn in broiler chickens and degree of inheritance.

A total of 2,118 birds from 2 strains were allocated to 12 groups of 93 to 100 each in 2 time-separated replicates. The development of foot pad dermatitis (FPD) and hock burn (HB) were recorded weekly from d 8 to slaughter on a set sample of live animals (7 per group). In addition, feet and hocks of all birds were investigated at slaughter at either 4, 6 (fast-growing strain), 8, or 10 (slow-growing strain) wk of age. Lesions were scored for both the left and right foot and classified according to a scale from 1 (no lesion) to 9 (very severe lesions) for FPD and from 1 (no lesion) to 3 (very severe lesions) for HB. No FPD lesions and very few low-grade HB lesions were found in chickens from the slow-growing strain. In the fast-growing strain, the first signs of FPD and HB were seen in wk 2. The incidence of both types of lesions increased thereafter. Foot pad dermatitis was more frequent in females (49 vs. 36%, P < 0.05). Body weight did not affect FPD, but more HB were found at higher BW (P < 0.01). Egg weight influenced neither FPD nor HB. Variance and covariance components were analyzed using a multivariate animal model, in which scores for FPD and HB were transformed into logarithmic scale. The analyses were carried out using restricted maximum likelihood algorithm. Heritabilities were estimated to be 0.31 +/- 0.12 (SE) for FPD, 0.08 +/- 0.08 for HB, and 0.38 +/- 0.13 for BW. Genetic correlations among these traits were low and nonsignificant. Phenotypic correlation between BW and FPD was low and nonsignificant and between BW and HB was 0.17 +/- 0.05 (P < 0.01). The relative high heritability of FPD and the low genetic correlation to BW suggested that genetic selection against susceptibility to FPD should be possible without negative effects on BW gain.

Analysis of the tobacco chloroplast DNA replication origin (oriB) downstream of the 23 S rRNA gene.

We have mapped the origin of DNA replication (oriB) downstream of the 23 S rRNA gene in each copy of the inverted repeat (IR) of tobacco chloroplast DNA between positions 130,502 and 131,924 (IR(A)) by a combination of approaches. In vivo chloroplast DNA replication intermediates were examined by two-dimensional agarose gel electrophoresis. Extended arc patterns suggestive of replication intermediates containing extended single-stranded regions were observed with the 4.29 kb SspI fragment and an overlapping EcoRI fragment from one end of the inverted repeat, while only simple Y patterns were observed with a 3.92 kb BamHI-KpnI fragment internal to the SspI fragment. Other restriction fragments of tobacco chloroplast DNA besides those at the oriA region also generated only simple Y patterns in two-dimensional agarose gels. Several chloroplast DNA clones from this region were tested for their ability to support in vitro DNA replication using a partially purified chloroplast protein fraction. Templates with a deletion of 154 bp from the SspI to the BamHI sites near the end of the inverted repeat resulted in a considerable loss of in vitro DNA replication activity. These results support the presence of a replication origin at the end of the inverted repeat. The 5' end of nascent DNA from the replication displacement loop was identified at position 130,697 for IR(A) (111,832 for IR(B)) by primer extension. A single major product insensitive to alkali and RNase treatment was observed and mapped to the base of a stem-loop structure which contains one of two neighboring BamHI sites near the end of each inverted repeat. This provides the first precise determination of the start site of DNA synthesis from oriB. Adjacent DNA fragments containing the stem-loop structure and the 5' region exhibit sequence-specific gel mobility shift activity when incubated with the replication protein fraction, suggesting the presence of multiple binding sites.

In vitro replication of mitochondrial plasmid mp1 from the higher plant Chenopodium album (L.): a remnant of bacterial rolling circle and conjugative plasmids?

According to the endosymbiotic theory, mitochondrial genomes evolved from the chromosome of an alpha-proteobacterium-like ancestor and developed during evolution an extraordinary variation in size, structure and replication. We studied in vitro DNA replication of the mitochondrial circular plasmid mp1 (1309 bp) from the higher plant Chenopodium album (L.) as a model system that replicates in a manner reminiscent of bacterial rolling circle plasmids. Several mp1 subclones were tested for their ability to support DNA replication using a newly developed in vitro system. Neutral/neutral two-dimensional gel electrophoresis of the in vitro products revealed typical simple Y patterns of intermediates consistent with a rolling circle type of replication. Replication activity was very high for a BamHI-restricted total plasmid DNA clone, a 464 bp BamHI/KpnI fragment and a 363 bp BamHI/SmaI fragment. Further subcloning of a 148 bp BamHI/EcoRI fragment resulted in the strongest in vitro DNA replication activity, while a 1161 bp-template outside of this region resulted in a substantial loss of activity. Electron microscopic studies of in vitro DNA replication products from the highly active clones also revealed sigma-shaped molecules. These results support our in vivo data for the presence of a predominant replication origin between positions 628 and 776 on the plasmid map. This sequence shares homology with double-stranded rolling circle origin (dso) or transfer origin (oriT) nicking motifs from bacterial plasmids. mp1 is the first described rolling circle plasmid in eukaryotes.

Photosynthesis in Salt-Adapted Heterotrophic Tobacco Cells and Regenerated Plants.

Tobacco (Nicotiana tabacum L.) cells growing heterotrophically in the light on supplied sucrose (S0) have previously been adapted to grow in 428 mM NaCl (S25). Among the changes occurring in salinity-adapted cell cultures are (a) elevated levels of chlorophyll compared to unadapted cells; (b) decreased levels of starch; (c) alterations in chloroplast ultrastructure, including loss of starch grains, increased thylakoid membrane structure, and the presence of plastoglobules; and (d) increased rates of O2 evolution, CO2 fixation, and photophosphorylation relative to S0 cells. These latter changes apparently derive from the fact that thylakoid membranes in S25 cells contain higher levels of photosystem I- and II-associated proteins as well as thylakoid ATPase components. S25 chloroplasts contain immunologically detectable levels of ribulose-1,5-bisphosphate carboxylase/oxygenase, whereas S0 completely lack the enzyme. These changes taken together suggest that even in the presence of sucrose, S25 cells have acquired a significant degree of salt-tolerant photosynthetic competence. This salt-tolerant photoysynthetic capability manifests itself in plants backcrossed with normal plants for three generations. These plants contain chloroplasts that demonstrate in vitro more salt-tolerant CO2 fixation, O2 evolution, and photophosphorylation than do backcross progeny of plants regenerated from S0 cultures.

Welfare of organic laying hens kept at different indoor stocking densities in a multi-tier aviary system. I: egg laying, and use of veranda and outdoor area.

Multi-tier aviary systems are becoming more common in organic egg production. The area on the tiers can be included in the net area available to the hens (also referred to as usable area) when calculating maximum indoor stocking densities in organic systems within the EU. In this article, results on egg production, laying behaviour and use of veranda and outdoor area are reported for organic laying hens housed in a multi-tier system with permanent access to a veranda and kept at stocking densities (D) of 6, 9 and 12 hens/m2 available floor area, with concomitant increases in the number of hens per trough, drinker, perch and nest space. In a fourth treatment, access to the top tier was blocked reducing vertical, trough and perch access at the lowest stocking density (treatment D6x). In all other aspects than stocking density, the experiment followed the EU regulations on the keeping of organic laying hens. Laying percentage was significantly lower (P<0.05) in D12 compared with the other stocking densities (90.6% v. 94.3% (± 0.7)), most likely due to the concomitant reduction in nest space and drinker availability per hen. No systematic effects of density were found on other laying variables (egg weight, eggs laid outside nests, aviary side preferences). Number of hens using the veranda increased with stocking density. Hens primarily used the range near the house (within 50 m) and hens kept at the lowest stocking density and the smallest group size appeared to use the outdoor area more extensively, based on an assessment of vegetation cover (P<0.05). For the measures reported here, the welfare consequences of increased stocking density were assessed to be minor; additional results are reported in the associated article (Steenfeldt and Nielsen, 2015).

Welfare of organic laying hens kept at different indoor stocking densities in a multi-tier aviary system. II: live weight, health measures and perching.

Multi-tier aviary systems, where conveyor belts below the tiers remove the manure at regular intervals, are becoming more common in organic egg production. The area on the tiers can be included in the net area available to the hens (also referred to as usable area) when calculating maximum indoor stocking densities in organic systems within the EU. In this article, results on live weight, health measures and perching are reported for organic laying hens housed in a multi-tier system with permanent access to a veranda and kept at stocking densities (D) of 6, 9 and 12 hens/m2 available floor area, with concomitant increases in the number of hens per trough, drinker, perch and nest space. In a fourth treatment, access to the top tier was blocked reducing vertical, trough, and perch access at the lowest stocking density (D6x). In all other aspects than stocking density, the experiment followed the EU regulations on the keeping of organic laying hens. Hen live weight, mortality and foot health were not affected by the stocking densities used in the present study. Other variables (plumage condition, presence of breast redness and blisters, pecked tail feathers, and perch use) were indirectly affected by the increase in stocking density through the simultaneous reduction in access to other resources, mainly perches and troughs. The welfare of the hens was mostly affected by these associated constraints, despite all of them being within the allowed minimum requirements for organic production in the EU. Although the welfare consequences reported here were assessed to be moderate to minor, it is important to take into account concurrent constraints on access to other resources when higher stocking densities are used in organic production.

Molecular characterization of avian reoviruses using nested PCR and nucleotide sequence analysis.

A nested polymerase chain reaction (PCR) with subsequent nucleotide sequence analysis identified and differentiated avian reoviruses (ARVs). PCR products amplified from the S1 gene segment of ARV of USA isolates were 738 and 342 bp, respectively. PCR products were conformed by Southern and dot blot hybridizations. The amplified cDNA fragments were cloned into the pUC18 vector and subjected to DNA sequencing. The nucleotide and deduced amino acid sequences of four USA (S1133, 1733, 2408, and CO8) and two Australian isolates (RAM-1 and SOM-4) were compared. Results of paired difference analysis and a predicted dendrogram revealed that USA isolates were closely related, but different from, Australian isolates. The deduced amino acid sequences of the N-terminal region of ARV sigma C showed a heptapeptide repeat of hydrophobic residues in all ARV isolates.

The spontaneous variation in the pattern of ventricular extrasystoles in patients recently recovered from an acute myocardial infarction.

Twelve patients between the ages of 40 and 68 years with myocardial infarction 1-6 months earlier were subjected to 24 h of ambulatory ECG monitoring for 2 consecutive d. In six patients with an average of less than 5 ventricular extrasystoles (VE) per hour during the first day, the pattern of the arrhythmias was both quantitatively and qualitatively unchanged from day to day. In six patients with an average of greater than 60 VE/h the first day, the number of VE were reduced significantly from the first to second day--in four patients by greater than 50%. The variation was greater after a day-to-day comparison than within the individual days following the division of the 24 h into 6-h periods. In general, the ventricular arrhythmias varied less following a qualitative rather than a quantitative evaluation. The evaluation of the effect of an antiarrhythmic drug in postmyocardial infarction patients requires that a considerable spontaneous variation should be taken into account when the patient is to be used as his own control. If a duration of monitoring of 24 h is employed both prior to and after the commencement of treatment, then the ventricular arrhythmias must practically disappear before the antiarrhythmic effect may be said to be documented.

Investigation of the relationship between farrowing environment, sex steroid concentrations and maternal aggression in gilts.

Maternal oestrogen and progesterone have been shown to be important in the initiation of maternal behaviour. Thirty-three Large White x Landrace gilts, housed in groups during pregnancy, were observed and aggressive interactions recorded. Individuals had jugular catheters implanted 14.5 (s.e. 0.34) days before their expected parturition date (EPD). Five days before EPD gilts were randomly allocated and moved to either a conventional farrowing crate (C; without straw, 16 gilts) or a pen (P; 2.1 x 3.1 m2; with straw bedding, 17 gilts). Blood samples were taken at frequencies determined by the proximity to farrowing onset. Piglets were removed at birth and returned 2 h after placental expulsion. The reaction of each gilt to her piglets was monitored. Gilts savaging piglets were sedated with azaperone (n = 8). There was no overall effect of farrowing environment on oestradiol and progesterone concentrations. The pre-farrowing ratio of progesterone to oestradiol was higher for (P) gilts (0.45 vs. 0.25, (P) vs. (C); S.E.D. 0.085, P < 0.05) as was their overall maximum oestradiol level (3.39 vs. 2.29 ng/ml, (P) vs. (C); S.E.D. 0.39, P < 0.01). In contrast to progesterone, oestradiol patterns varied considerably between individuals. Dominance rank value during pregnancy, but not levels of aggression, correlated positively to pre-farrowing oestradiol concentrations. Treatment with azaperone was not related to farrowing environment, piglet weight or litter size. Azaperone treated gilts showed a higher pre-farrowing oestradiol to progesterone ratio (0.55 vs. 0.29, +/- azaperone; S.E.D. 0.10, P < 0.05), significantly higher levels of oestradiol post-partum (0.7 vs. 0.19 ng/ml, +/- azaperone; S.E.D. 0.20, P < 0.001) and significantly lower levels of aggression during pregnancy (1.68 vs. 2.23 aggressive interactions/h, +/- azaperone; S.E.D. 0.15, P < 0.001). The results indicate that there are no major effects of farrowing environment on sex steroid concentrations. Maternal aggression under these conditions appears to be negatively related to aggression during pregnancy, but this is not reflected in plasma concentrations of sex steroids around parturition.

Staying good while playing god--the ethics of breeding farm animals.

Modern genetics has given us some very efficient tools with which to alter the characteristics of animals. To date, farm animal breeders have mainly used these tools to increase productivity. Thus, each new generation of farm animals matures faster, yields more milk, or produces more meat or eggs, than the previous one. Despite these apparent benefits, modern farm animal breeding has had severe negative consequences, including effects on the quality of the animals' lives and biodiversity. The aim of this paper is to discuss the goals and consequences of farm animal breeding within an ethical context. First, a description of what has happened to broilers and dairy cattle as breeders have pursued the goal of ever more efficient production is given. Second, the ethical values that ought to underlie future breeding schemes are discussed. It is suggested that there are in fact two very different ethical approaches: the 'quality of life-based' approach and the 'preservationist' approach. A view combining elements from both approaches is advanced. Finally, an example is given of how it is possible, in practice, to pursue an ethically defensible breeding goal without compromising production efficiency.

[Treatment of acute myocardial infarction--an elucidative report]. / Behandling af akut myokardieinfarkt--en klaringsrapport.

The present-day optimal treatment of patients with acute myocardial infarction (AMI) is reviewed. The prehospital phase should be as brief as possible. Emergency observation and treatment in hospital should be initiated without delay. Schematic stages for mobilization have been discarded and free mobilization is recommended. Routine acute intervention with thrombolysis is recommended for patients in whom symptoms have been present for 6-12 hours and treatment with Aspirin is recommended. Beta-blocking agents are recommended for patients with increased risk after discharge. Treatment of ventricular and supraventricular arrhythmias, block and cardiac failure are reviewed in detail. Patients without complications should be monitored for three to five days and may be discharged after seven to ten days. Exercise ECG should be carried out at discharge to assess the working capacity, ischaemia and subjective reaction. The importance of good patient information is emphasized. Cessation of smoking, control of lipids and blood pressure are important as secondary interventions. As far as possible, outpatient control should be offered after discharge. The criteria for referral to specialized cardiological departments are established both for emergency and elective referral. Patients under the age of 70 years with high risk for repeated AMI or death after discharge (with residual ischaemia) should possibly be referred for coronary arteriography.

Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains.

Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 26°C), one (HC; 16°C to 26°C) or no (CC; 16°C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity had no significant effects on their subsequent behaviour or on any of the production parameters measured, and overall, the slow-growing strain was more active than the fast-growing strain. Ambient temperature had significant effects on production measures for i657 broilers, with CC chickens eating and weighing more, and with a less efficient feed conversion than HH chickens, with HC birds intermediate. A similar effect was found for Ross 208 only for feed intake from 27 to 41 days of age. Ross 208 chickens distributed themselves in the pen with a preference for cooler areas in the hottest ambient temperature treatments. In contrast, the behaviour of the slow-growing strain appeared to be relatively unaffected by the ambient temperature. In conclusion, fast-growing broilers use behavioural changes when trying to adapt to warm environments, whereas slow-growing broilers use metabolic changes to adapt to cooler ambient temperatures.