Effect of noise on the physiological functions in fowl. 1. Effect of primary strong noise on the 11-OHKS level in broilers and leghorns]

The effects of first noises on broilers and white leghorns were tested by plasma levels on 11-hydroxycorticosteroid (11-OHKS). The noises were 100 dB, 60 to 8,00 Hz, and applied 30 minutss to one group of broilers, aged 14, 28, and 56 days, and to another group of broilers and white leghorns in adult age. The reactions were compared. Acoustic stimulation was followed by temporary activation of the hypothalamic pituitary-suprarenal system. The rise of the plasma glucocorticosteroid level in leghorns was three times as high as that in adult broilers, which was interpreted as a reflection of stronger organic stress. Reactions differed in intensity, depending on age as well. Plasma-11-OHKS levels went up by 32 per cent maximum in broilers aged 56 days or by 73 per cent in animals aged 14 days or 120 per cent in those aged 28 days. The above results seemed to support the conclusion that noises of the above quantity and quality represented stress on fowl.     

Effect of noise on the physiological functions in fowl. 3. Effects of primary and repetitive acoustic stimulation on glucose and free-fatty-acid plasma levels in broilers of different age groups]

The effects of first and repetitive noise applications to broilers, aged 14, 28, and 56 days, were tested by the responses of the energetic substrates plasma glucose concentration and free fatty acids. The plasma concentrations of glucose and free fatty acids in broilers at slaughter age with no exposure to noise were higher than those in younger animals. Regular daily noise application of 100 dB, 60 to 8,000 Hz, for 30 minutes, which began on the first day of age, led to rises in the plasma glucose levels of animals aged 56 and 28 days even prior to renewed acoustic stimulation, which obviously was a conditioned reflex. Such rises were accompanied by decline in plasma concentrations of free fatty acids, which phenomenon was attributed to higher initial values of plasma glucose. First as well as repetitive noise application led to changes in the plasma content of energetic substrates. Both the direction and magnitude of the reaction appeared to depend on the given initial value. The plasma level responses of glucose and free fatty acids were opposite to one another in all animals, 56 days of age, which were exposed to repeated noise.     

General adaptation syndrome (Selye) in the calf. 5. Effect of increased glucocorticosteroid values on the phagocytosis activity of luekocytes, the function of RHS and the morphology of lymphatic organs]

Studies were conducted with the view to elucidating the correlations between increased glucocorticosteroid levels in the blood and the defense potential of calf organism against infectious diseases. The test animals were exposed to several substances (ACTH, cortisol, colibacteria, coliendotoxin), and even one to two days of increased 11-OHKS values were followed by marked decline in phagocytosis activity of leucocytes. In addition, RHS function was considerably reduced, after ten to thirteen days of application had elapsed, since at that point the disappearance of intravenously applied bacteria from circulating blood of test animals took place at rates which were much lower than those recorded from untreated calves. Differentiated length of stress or action (four to thirteen days) was followed by conspicuous changes in the lymphatic tissue of calf organism, with severe involution of thymus and follicular atrophy of intestine-associated lymphatic tissue having been the major findings. The results seem to suggest that rise in adrenocortical hormone level under stress may reduce potential organic defense to infection.     

Vitamin A toxicity: comparative changes in bone of the broiler and leghorn chicks

Severe skeletal lesions were produced in both broilers and leghorns orally administered toxic levels of vitamin A (330 or 660 IU vit. A/g body weight X day) for 21 consecutive days. Hypervitaminosis A in broilers produced an osteodystrophy characterized by abnormal thickening of the proliferative-maturation zone, metaphyseal sclerosis, hyperosteoidosis, decreased number of osteoclasts, and parathyroid gland hyperplasia. In leghorns, the osteodystrophic lesions were characterized by a thin proliferative-maturation zone, a relatively thickened hypertrophy zone, flattened spindle-shaped osteoblasts, and osteoporosis. In both broilers and leghorns given excessive vitamin A, the osteogenic layer of periosteum in all bones was thin.     

Haematological and blood chemistry "comparison values" for clinical pathology in poultry

Twelve blood chemistry values, six haematological values and bodyweight were estimated for six-week-old specific-pathogen-free brown leghorns. Observations were based on 208 birds sampled from 11 groups. Subsequently the same values were estimated for specific pathogen free brown leghorns and broiler hybrids of differing ages. These estimates have been designated "comparison values" and were intended for reference use in clinical pathology. Results were compared with 14 "comparison value" estimated obtained previously for six-week-old commercial broiler hybrids. Haematological values varied with age and type of bird. Differences were observed between bird types in serum protein, serum cholesterol, uric acid, calcium and potassium levels and in weight. The significance of these differences is discussed.     

The effects of chronic intermittent noise exposure on broiler chicken performance

Effects of different noise levels (70 or 80 dB) that broilers were exposed to during the entire fattening period and also the effect of the timing of the first exposure to intermittent noise in the course of fattening (day 1 vs. day 7) were monitored. After 7 days of exposure to intermittent noise, experimental chickens already showed a significant decrease in live body weight in comparison with the control group. The difference between the group exposed to intermittent noise at 70 dB and the group exposed to 80 dB levels was not statistically significant, although the mean live body weight of broilers in the latter was lower during the entire fattening period. The chickens exposed to intermittent noise from day 1 of age showed lower mean live weight throughout the fattening period compared to chickens exposed to the same level of intermittent noise only from day 7 of age, although at the end of fattening the difference was statistically significant only in chickens exposed to the higher level of intermittent noise (80 dB).     

Pathogenesis of ascites in broilers raised at low altitude: aetiological considerations based on echocardiographic findings

This study reports novel insight into the aetiology of pulmonary hypertension and ascites in broiler chickens. The scope of measurements was focused on anatomical and functional parameters, and blood flow patterns in leghorns (resistant to ascites), fast-growing broilers (susceptible to ascites), broilers developing ascites, and ascitic broilers evaluated in vivo using echocardiography, and further examined in the context of postmortem findings. Both, in vivo observed features and postmortem findings, showed clear differences between broilers and leghorns, and between normal and ascitic broilers. Abnormalities in the heart chamber geometry and blood flow patterns were detected upon echocardiographic examination in all ascitic broilers. Right and left atrio-ventricular (AV) valve regurgitation were common findings in ascitic broilers and some apparently normal broilers, with left AV valve insufficiency being a predominant feature with respect to degree and frequency of occurrence. Blood flow disturbances were not detected in leghorns. Left ventricular fractional shortening (functional parameter) was considerably reduced (P < 0.01) in ascitic birds (mean: 21.7 +/- 2.0 SE) in comparison with normal broilers (mean: 39.1 +/- 3.6 SE), or leghorns (mean: 43.3 +/- 2.4 SE). The presented findings indicate that pathological and functional changes in the left ventricle and atrium play a significant role in the pathogenesis of ascites in broilers. Severe dilation of the left atrium and pulmonary veins seen on postmortem examination, as well as regurgitant blood flow in the left atrium, demonstrated by Doppler study in ascitic birds, provide evidence that chronically elevated pressure in the left atrium is involved in the aetiology of pulmonary hypertension and ascites in fast-growing broilers.     

Effect of long-lasting noise on the plasma concentration of catecholamines, glucocorticosteroids and PBI in pigs]

Exposure of pigs with a body mass of 25-30 kg to long-lasting motor noise (108 dB, 60-8000 Hz, 72 hours) results in a considerable increase of catecholamine concentration in the plasma. Coincidently there is a sharp continuous decrease of the 11-OHKS in the plasma during the whole period of exposure to noise. Immediately after stopping the acoustic irritation the concentration of plasma corticosteroids increases again. The electroencephalogram (EEG) giving evidence of inhibition signs during exposure to noise an adaptation effect of the information processing system is concluded. The increase of the PBJ during the period of acoustic stress points to an increased function of the thyroid gland but simultaneously it is considered to be an expression of the elevated adrenergic situation. By reason of the strong deviation of the three observed regulatory systems must be concluded that longer-lasting exposure to noise with the applied quality and intensity represents a stress situation for pigs having noise character as established for men. A possible influence on the productivity of the pork type pig by permanent acoustic stress is indicated.     

The role of first line of defence mechanisms in the pathogenesis of cellulitis in broiler chickens: skin structural, physiological and cellular response factors

The present study examined several basic attributes of first-line defence mechanisms in the skin as potential factors that may explain the susceptibility of broiler chickens to cellulitis. The variables including structural characteristics of the skin, physicochemical properties and cellular responses to the challenge with pathogens were compared between two categories of chickens, a strain of fast-growing commercial broiler chickens (susceptible to cellulitis) and leghorn chickens (resistant to cellulitis). There were substantial differences between leghorns and broilers with regard to physiological characteristics of the skin. Broiler skin was more amenable to injury and the wound-healing process was slow. Compared with leghorns, the lesions resulting from sub-dermal challenge in broilers were more severe and disseminated over a larger area. Mobilization of phagocytic cells (heterophils and macrophages) in leghorns was brisk even in the areas distant from the site of infection, whereas only few heterophils were recruited in the skin of broilers. The functional competence of heterophils in broilers was inferior when compared with leghorns. Based on the present finding, the predisposition of broilers to cellulitis appears to be primarily associated with the inferior first line of defence of their skin. Broilers in commercial situations may be at higher risk to succumb to even minor infection and eventually develop cellulitis because: (1) structural weaknesses of the skin may predispose broilers to skin injury and thus the risk of skin infection by pathogens is increased; (2) broiler skin surface is more likely to provide a conducive environment for colonization of Escherichia coli; (3) in the event of infection, poor recruitment of phagocytic cells to the site of infection may readily lead to widespread colonization of the tissue by pathogens causing cellulitis and (4) poor functional quality of the phagocytic cells that are mobilized compromise the ability of the host to contain the spread of infection.     

Influence of antigen concentration, inoculation interval, number of exposures, type of housing, and placement concentration on the tear antibody response to Brucella abortus in chickens.

A series of trials was run in leghorn chicks to examine select conditions affecting the tear antibody response to killed Brucella abortus antigen given by eyedrop administration. Specific conditions examined were concentration of antigen, number of antigen exposures, and interval between antigen exposures. Trials were also run to determine the earliest age at which the assay was functional in both broilers and leghorns. Two types of housing (isolators and battery cages) were examined, as were two levels of placement concentration, or bird density (0.32 and 0.64 ft. [0.03 and 0.06 m2]/chicken). All trials included intraperitoneally inoculated chicks as a comparison; tears as well as serum were assayed for antibodies. Of the various antigen regimens evaluated, two exposures of 20% B. abortus given 3 days apart was found to give a satisfactory antibody response in the tears 1 week later. Furthermore, response to B. abortus was found to be somewhat proportional to age, with the minimum age for a satisfactory response being 3 weeks in leghorns or 4 weeks in broilers. Statistically, there were no differences in antibody responses due to the types of housing or levels of placement used.     

Detection of serum antibodies in Eimeria tenella-infected chickens by enzyme linked immunosorbent assay (ELISA) with merozoite and oocyst antigens.

Soluble antigens prepared from sporulated oocytes and second generation merozoites of E. tenella were used for enzyme linked immunosorbent assay (ELISA) to investigate antibody in sera of two breeds of chickens, i.e. commercial broilers and SPF single comb white leghorn layers, which were experimentally infected with E. tenella. In broilers inoculated with oocysts at 15 days of age, ELISA values increased rapidly after day 19 post inoculation (PI) and reached the maximum lebel on days 29 and 32 PI against both merozoite and oocyst antigen. The values against merozoite antigen were significantly higher than those against oocyst antigen. In SPF layers infected at 15 days of age, the values increased gradually after 7 days PI. There were no significant differences between values against two antigens. Generally, the values in broilers tended to be higher than those in SPF layers, especially against merozoite antigen. In broilers inoculated with oocysts at 1 and 15 days of age, ELISA values increased rapidly and reached the maximum level on days 11 and 20 post second inoculation (PSI) against merozoite and oocyst antigens respectively and then the values against merozoite antigen decreased. The values against merozoite antigen were markedly higher than those against oocyst antigen. In SPF layers inoculated twice, the values reached the highest on day 11 PSI as in the case of broiler; however, after that day, the values against both antigens decreased. The sera reacted similarly against both antigens. The values against merozoite antigen were significantly higher in broilers than in SPF layers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Efficacy of coarse-spray administration of a reovirus vaccine in young chickens.

Coarse-spray (CS) administration of a commercial S1133 reovirus vaccine in chickens for prevention of clinical viral tenosynovitis (VT) infection was evaluated. In Expt. 1, one-day-old specific-pathogen-free (SPF) white leghorns were vaccinated with a combination of reovirus, Newcastle disease (ND), and infectious bronchitis (IB) vaccines by CS and infectious bursal disease vaccine by the subcutaneous (SQ) route. In Expt. 2, one-day-old commercial broilers were vaccinated by CS with reovirus vaccine and Marek's disease (MD) vaccine by SQ. In Expt. 3, one-day-old commercial broilers received reovirus vaccine in combination with ND-IB vaccines at 1 day of age by CS and MD vaccine by SQ. Some birds received an initial or second vaccination at 7 days of age by CS or the drinking-water (DW) route. Birds vaccinated by CS at 1 day of age with reovirus vaccine did not produce circulating virus-neutralizing antibody against reovirus, although they had resistance to VT infection. In contrast, initial or booster vaccination at 7 days of age by CS or DW resulted in an antibody response and greater resistance to challenge than did CS vaccination at 1 day of age. There was no difference in efficacy between CS and DW routes at 7 days of age. The reovirus vaccine did not interfere with other vaccines as measured by serologic (ND-IB-IBD) or challenge (MD) studies.     

Energy and protein concentration of broiler rations in Cuba. 4. Female broilers in the summer

A total of 1,900 female broilers of the variety White Plymouth Rock was tested with 4 energy concentrations (10.5, 11.5, 12.6 and 13.6 MJ metabolizable energy/kg feed) and 4 protein concentrations (15.0, 17.5, 20.0 and 22.5% CP) in their first 56 days of life in 16 test groups. The animals were kept in cages and were directly exposed to the natural Cuban summer temperatures from their 15th day of life onwards. As every test group was run with 6 repetitions, the results could be variance analytically calculated. In a comparison of male and female broilers in summer one can state that the female animals achieved a lower intake of feed, energy and crude protein as well as a lower live weight than the male animals. In winter the female broilers consumed between 15.7 and 36.4% more feed and achieved a live weight gain between 11.1 and 43% higher than in summer. It could be shown that the maximum live weight of the female broilers could be achieved in summer if rations containing 12.6 MJ metabolizable energy and 20% CP are fed in a one-phase feeding system.     

Aversiveness of motion and noise to broiler chickens

1. The aversiveness of motion and noise to broiler chickens was examined using a passive avoidance technique. Birds were initially trained to peck a key a fixed number of times to obtain food. After training, food could still be obtained by key pecking, but feeding was immediately followed by 1 min exposure to noise or motion. Birds could delay or avoid exposure by delaying or avoiding key pecking, hence foregoing food. Reduced pecking rate was therefore taken as a measure of aversion. 2. In experiment 1, simultaneous motion and noise, but not noise alone, resulted in a significant decrease in pecking rate in comparison with baseline rates obtained after training. 3. In experiment 2 there was no significant difference in the pecking rates of 4 groups of broilers during training. However, after exposure to 1 of 4 types of motion, strongly significant differences in pecking rates were found between the groups. The mean latency to peak 3 times was significantly greater for birds exposed to gentle vibration, with a single jolt after 55 s, than for birds exposed to simple harmonic motion in either the horizontal or vertical plane. Birds exposed to circular motion in the horizontal plane had a significantly greater mean pecking latency than birds exposed to simple harmonic motion in the vertical plane. 4. Baseline latencies to keypeck in experiments 1 and 2 were longer than expected. In experiment 3 a direct comparison of baseline pecking was made between broilers and laying hens. The hens had significantly shorter pecking latencies.     

Ultrastructural and molecular changes in the left and right ventricular myocardium associated with ascites syndrome in broiler chickens raised at low altitude

The present study examines ultrastructural and molecular changes in ventricular myocardium associated with ascites cases in fast-growing broilers raised at low altitude. Extensive ultrastructural lesions were seen in the left and right ventricular myocardium of broilers with fulminant heart failure and ascites. Significant changes included lesions in the myofibril contractile apparatus, altered mitochondria, marked reduction in the myofibril component, and changes in the extracellular matrix (ECM) architecture. No lesions were observed in hearts of slow growing broilers, but mild to moderate changes (predominantly in the left ventriculum) were apparent in the hearts from some clinically normal, fast-growing broilers. SDS-PAGE profiles of washed myofibrils showed several distinctly different bands in preparations from left ventricular myocardium of ascitic birds. Western blot analysis of these samples revealed several fragments of myosin heavy chain, M-protein, and titin. Based on gelatinolytic activity, matrix metalloproteinases (MMP) in the cytosolic fraction of ventricular myocardium homogenates were identified as MMP-2. The relative activity of this enzyme appears to be considerably higher in preparations from broilers, particularly in the preparations from the left ventriculum of fast-growing broilers, in comparison to leghorns or slow growing broilers. The nature and distribution of the changes in the heart indicate that chronic cardiomyopathic process in the left ventricular myocardium occurs during the development of ascites. It is postulated that progressive deterioration of the left heart pump function caused by initial lesions in the left ventricular myocardium is a significant factor in the development of pulmonary hypertension and the pathogenesis of ascites in broilers raised at low altitude.     

Effect of medicated feed on tracheal infection and population of Mycoplasma gallisepticum in chickens

Six-week-old broilers were fed 50 g tylosin/ton, 400 g chlortetracycline (CTC)/ton, or unmedicated feed and then challenged intratracheally with R strain Mycoplasma gallisepticum (MG). Feed-grade antibiotic medication did not prevent infection, but medication did lower the number of isolations from treated birds compared with controls. Only tylosin significantly lowered MG counts in the trachea. The log10 ID50 of birds receiving tylosin, CTC, or unmedicated feed were 5.8, 4.4, and 2.9, respectively. Six-week-old leghorns were placed on the three diets described previously and challenged with the R strain of MG. Birds were sacrificed at various times up to 10 weeks postchallenge (PC). Compared with the control diet, the tylosin-medicated diet significantly reduced the tracheal MG count from day 1 to 4 weeks PC, whereas the CTC-medicated diet significantly lowered the tracheal MG count only at 3 days PC. In all groups, the MG count gradually declined after 1 week PC; by 8 weeks PC it was essentially the same in all groups. It was concluded that continuous medication has the potential for reducing MG tracheal populations only during the initial phase of an outbreak.     

Reduced erythrocyte deformability as a possible contributing factor to pulmonary hypertension and ascites in broiler chickens.

Deformability of erythrocytes and hematological parameters in white leghorn and broiler chickens were measured at age 7, 14, 21, 28, and 35 days. For deformability testing, a simple vertical apparatus containing a polycarbonate membrane with 5-microns pores was used. This technique assesses erythrocyte deformability by measuring the filtration time of an erythrocyte suspension through the pores. There was a significant difference in filtration time between the leghorns and broilers at all sampling times. These results indicate that reduced erythrocyte deformability in broilers may be one of the predisposing factors that increase resistance to blood flow and alter the rheology of blood in the microcirculation in the lung. Increased resistance to flow may result in pulmonary hypertension, heart failure, and ascites in broiler chickens.     

酵母培养物与抗生素对肉仔鸡生长性能及免疫机能影响的研究

用 2 1 0只 1日龄艾维茵肉仔鸡 ,随机分成 7组 ,即 :对照组、 0 1 %、 0 3%、 0 5 %、 0 7%、 0 9%酵母培养物组和抗生素组 (5mg/kg ) ,每组设 3个重复 ,每个重复 1 0只鸡 ,试验期 2 8d,研究不同添加水平的酵母培养物和抗生素对肉仔鸡生长性能和免疫机能的影响。试验结果表明 :0 3%的酵母培养物组日增重、日采食量、饲料转化率 ,较对照组略有提高 ,但差异不显著 (P >0 0 5) ,抗生素组与对照组和酵母培养物组相比差异显著 (P <0 0 5) ;各组之间营养物质代谢率差异不显著 (P >0 0 5) ,酵母培养物组有提高的趋势 ;酵母培养物显著降低大肠杆菌的数量 ,提高双歧杆菌的数量 (P <0 0 5) ,抗生素显著降低了大肠杆菌和双歧杆菌的数量 (P <0 0 5) ;酵母培养物显著提高了肉仔鸡血清IgA、IgG水平(P <0 0 5)和IgM水平 (P >0 0 5)。     

Enteropathogenicity of Dutch and German avian reoviruses in SPF white leghorn chickens and broilers

The enteropathogenicity of avian reoviruses (ARVs), isolated from chickens affected with malabsorption syndrome (MAS) from The Netherlands and Germany was studied. In the first trial seven different ARVs isolated from MAS cases were inoculated in 1-day-old specific pathogenic free (SPF) white leghorns. The pathogenicity was compared with 2 ARVs isolated from cases of tenosynovitis, namely reference strain S1133 and a Dutch strain. Although a difference in the severity of the clinical disease was observed, all reoviruses could induce vacuolar degeneration and sloughing of the epithelium of the small intestine at day 2 post inoculation (PI) till day 7 PI. Two Dutch and one German ARV derived from MAS causing the most severe intestinal lesions at day 2 PI, were further studied in the second trial using SPF broilers. These reoviruses did not cause weight gain depression in the broilers although lesions in the small intestine were present from day 1 up to day 4 PI and were more severe than in the white leghorn chickens. In one of the inoculated groups apical denuded villi were already present at day 1 PI. At day 7 PI the small intestine of the infected broilers appeared to be normal. Reovirus antigen was detected in the cytoplasm of the enterocytes at the tip and middle section of the affected villi both in layers and in broilers. To study the role of intestinal CD4+ and CD8+ T-cells and macrophages/monocytes in the pathogenesis of ARV, the numbers of these cells of the jejunal villi of one infected and the control broiler groups were compared. CD4+ T-cells were detected in low numbers and only in the infected broiler group at day 14 PI. The numbers of CD8+ T-cells and macrophages/monocytes were significantly higher in the infected broiler group than in the control broiler group at day 7 and 14 PI and at day 7 PI respectively. Our study indicates that the reovirus alone cannot induce intestinal lesions as found in MAS chickens. Moreover, CD8+ T-cells may play a major role in the pathogenesis and or reovirus clearance in the small intestine.     

Tissue and plasma antioxidant status in response to dietary methionine concentration and source in broilers

This study hypothesized that plasma and tissue antioxidant status of broilers is positively influenced when dietary Met concentrations exceed, and negatively when they go below NRC recommendations. In addition, different Met sources are hypothesized to affect the antioxidant defence system differently. Day‐old male Cobb‐500 broilers (n  = 336) were allotted to seven groups and phase‐fed three wheat–soya bean meal‐based basal diets during days 1‐10, 11‐21 and 22‐35. The basal diets (Met? group, Met + Cys concentration 15% below NRC recommendations) were supplemented with 0.10%, 0.25% or 0.40% Met either as DL ‐Met (DLM ) or DL ‐2‐hydroxy‐4‐(methylthio) butanoic acid (DL ‐HMTBA ) (equimolar comparison). Growth performance and carcass weights were lower in the Met? group compared to the groups whose diets met or exceeded Met requirements. The antioxidant defence system was not influenced by the Met source. However, in the liver, concentrations of glutathione increased with increasing dietary Met concentrations. Tocopherol concentrations in the liver at days 10 and 21 were lower in the Met? group than in the groups supplemented with Met. However, liver concentrations of thiobarbituric acid reactive substances (TBA ‐RS ) and protein carbonyls (PC ) were largely not influenced by dietary Met concentration. Plasma tocopherol concentrations at day 35 were lower, and those of TBA ‐RS and PC at day 35 were higher in Met? group than in the groups fed the Met‐supplemented diets. In jejunum, but not in liver, relative mRNA abundances and activities of superoxide dismutase, catalase and glutathione peroxidase were higher in the Met? group than in the groups fed Met‐supplemented diets. These data indicate that suboptimum supply of Met results in decreased antioxidant concentrations in plasma and body tissues, and increases oxidative stress in the jejunum mucosa. However, supplementation of Met in excess of the requirements (based on NRC ) compared to diets adequate in Met + Cys did not influence the antioxidant defence system.