Estimate of the heritability of plasma troponin T in broiler chickens.
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Animals↗
Biomedical subjects
G W Robertson
Publications and source records attributed to G W Robertson.
Liquid chromatography with particle-beam electron-impact mass spectrometry of diacylglycerol nicotinates.
Several synthetic diacylglycerols and natural mixtures derived from soybean, egg yolk, and bovine liver phosphatidylcholines were examined in the form of nicotinate derivatives by liquid chromatography with particle-beam electron-impact mass spectrometry. High-performance liquid chromatography was carried out in the reversed-phase mode with a base-deactivated octyl-/octadecylsilyl stationary phase. The nature (size and degree of unsaturation) of the acyl residues was readily determined from the mass spectra. Uniquely, the positions of the double bonds could be deduced, although this became increasingly difficult as the degree of unsaturation of diacylglycerols containing mixed acyl residues increased. Reverse 1,2-diacylglycerol isomers could be distinguished by their mass spectra.
Animals↗
Welfare and productivity of restricted broiler breeder females fed ad libitum or restricted after the peak of egg production.
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Animal Nutritional Physiological Phenomena↗
UK survey of broiler ascites and sudden death syndromes in 1993.
1. The mean incidence of deaths from ascites in the UK in 1993 was 1.4% (0.7% in 1991 and 0.9% in 1992) and 0.8% from sudden death syndrome (SDS). In total, the economic loss to the UK Broiler Industry in 1993 as a result of these 2 conditions was 24 Pounds M. 2. Clear geographical differences emerged in the occurrence of ascites, with, not only the lowest incidences being observed in Northern Ireland, but also the peak of the mortality from ascites occurring much later in the rearing cycle than in other regions on the mainland. 3. In all regions the incidence of SDS was lower than that of ascites but the reason for this disparity remains to be established. 4. Some of the variables associated with the road transportation of day-old chicks from the hatchery to the farm appeared to influence the incidence of ascites. These included distance or time travelled, stocking density, internal lorry temperature and the length of time the lorry was heated before transport as well as the time the shed was heated before chick arrival. Temperature was also an important factor during growth (brooding and finishing). 5. Negative pressure-powered ventilation was preferred in most organisations but more ascites was seen with positive pressure ventilation. However, the lowest incidence of ascites occurred with natural ventilation. There was more ascites relative to shed orientation when the wind direction was from the west compared to the east. 6. This survey identifies the extent of the problem of broiler ascites in the UK and also highlights the importance of good management control of day-old chicks, not only following placement, but even before their arrival on the farm.
Animal Feed↗
A preliminary estimate of the heritability of plasma troponin T in broiler chickens.
1. Male and female broiler chickens of a pure line were selected over one generation for low or high plasma, cardiac-derived troponin T concentrations at 12 h of age. 2. Heritability of plasma troponin T was moderately high (h2 = 0.38 +/- 0.06), and there was no difference in mean body weights of parents (G0) of the 2 lines at 4 and 19 weeks of age. 3. This preliminary study suggests that broiler breeder companies will be able to select for resistance against heart damage and ascites.
Animals↗
Ultra-structural characteristics of bovine granulosa cells associated with maintenance of oestradiol production in vitro.
We investigated whether the maintenance of oestradiol production by bovine granulosa cells (GC) in vitro was related to GC ultra-structure, and studied the effects of inclusion of serum as a cell attachment factor on oestradiol secretion, cell morphology and ultra-structure. Bovine granulosa cells from medium-sized follicles (4-8 mm diameter), in a serum-free (SF) culture system, maintained oestradiol production for 6 days, whereas oestradiol secretion by cells cultured in serum-coated (SC) wells declined rapidly with time, in culture. SF cells formed clumps consisting of two types of cells. Cells within clumps presented a phenotype similar to GC in vivo, being spherical, tightly joined by extensive gap junctions and interdigitated pseudopodia/microvilli, had abundant rough and smooth endoplasmic reticulum (ER) and mitochondria with trabecular cristae. In contrast, cells cultured in either SC wells or in the flattened base of cell clumps from SF cultures were enlarged, containing less rough ER, had fewer mitochondria (which tended to be round) and contained endosome-like structures, morphological characteristics suggestive of early luteinisation.
Animals↗
Evidence of ultracytochemical mitochondria-derived hydrogen peroxide activity in myocardial cells from broiler chickens with an ascites syndrome.
The location of the cytotoxic reactive oxygen metabolite hydrogen peroxide was investigated ultracytochemically in broiler chickens which had been reared at sea level and had spontaneous hypoxia-induced ascites syndrome. In the ascitic birds the activity was located within the mitochondrial matrices of the cardiomyocytes, whereas in flock-mate control birds it was membrane-bound. Little or no activity was present in negative control material, which was prepared by detoxification with catalase, by extraction with acetone, by the omission of NADH and by the replacement of NADH by NADPH. The study demonstrated that there was probably hydrogen peroxide activity in the mitochondria of the ascitic birds.
Animals↗
Plasma viscosity values and the relationship with age and sex in normal commercial broiler and layer strains of chickens.
1. The plasma viscosity values of normal commercial broiler and layer strains of chicken were measured in relation to age and sex. 2. In both broilers and layers plasma viscosity values decreased at 2 weeks of age; probably reflecting the period of change from maternal plasma protein to the bird's self-synthesised proteins. 3. There was a progressive rise in plasma viscosity in both strains and sexes with age. The increase was greatest in female layers at 17 weeks of age before lay. 4. There was no overall significant difference in viscosity values between fresh and frozen-stored plasma samples.
Aging↗
Serum troponin T concentrations in two strains of commercial broiler chickens aged one to 56 days.
Troponin T is a specific and sensitive serological indicator of acute myocardial infarction in human patients. The concentration of serum troponin T was measured by an ELISA technique in two strains of healthy commercial broiler chickens (Cobb 500 and Ross I) aged between one and 56 days. The concentrations of cardiac-derived troponin T in day-old Cobb and Ross chicks were 5.74 and 8.35 ng ml-1, respectively, and much higher than in 14-day-old chicks. Between 21 and 56 days, the values were consistently lower than the mean troponin T concentration of 0.20 ng ml-1 reported previously in a group of healthy 30-day-old broilers. All the other heart measurements, including the arterial pressure index, were within normal limits. The high troponin T concentrations after hatching are probably due to an embryonic isoform that rapidly becomes replaced by an adult isoform by three weeks of age. The data suggest that in healthy birds, there is an inverse relationship between troponin T concentrations and age.
Aging↗
Identification of tissue hypoxia in the livers of ascitic and hypoxia-induced broilers using trypan blue.
1. The perfusion of livers with the vital dye trypan blue was performed to test for evidence of tissue hypoxia in 3 groups of young broiler chickens, namely, ascitic, hypoxia-induced and controls. 2. Hepatocytes that stained with trypan blue were considered to be dead or dying before fixation and represented damaged cells. 3. The proportion of trypan blue-stained hepatocytes in the livers of ascitic birds was slightly less than half that observed in the hypoxia-induced birds but significantly more than the proportion of stained cells observed in control birds. 4. Liver damage in the ascitic birds was also assessed biochemically by an altered enzyme profile. 5. The study demonstrated that increased trypan blue uptake in the livers of ascitic birds reared at sea-level may be the consequence of hypoxia stress caused by reduced oxygen utilisation.
Animals↗
Potential role of serum troponin T in cardiomyocyte injury in the broiler ascites syndrome.
1. Cardiac troponin T is a recently developed serological marker used as a sensitive diagnostic tool for early myocardial damage in 'at risk' human patients. 2. Serum troponin T values were measured in young 30-d-old broilers with ascites and in healthy age-matched flockmates. 3. The data showed a significant increase (P < 0.001) in troponin T values in ascitic broilers compared with control birds. A similar increase in the arterial pressure index in ascitic birds indicated a good positive correlation at this age. 4. The results suggest that this new assay cross-reacts with chicken cardiac troponin T antigen and that it may be an important indicator of myocardial cell damage for use in future genetic selection programmes in the combat against ascites.
Animals↗
The identification of potential aeroallergen/irritant(s) from oilseed rape (Brassica napus spp. oleifera): volatile organic compounds emitted during flowering progression.
Volatile organic compounds emitted by growing intact oilseed rape plants have been detected using an entrainment apparatus enabling volatile headspace analysis by thermal desorption coupled to capillary gas chromatography-mass spectrometry. In total, 22 volatile compounds were identified as being emitted during the flowering period. The main constituents were alpha-farnesene (a sesquiterpene); beta-myrcene (a monoterpene); linalool (a monoterpene alcohol) and the 'green leaf' volatile (E)-3-hexen-1-ol acetate. These compounds constituted between 50 and 87% (mean 68%) of the total volatiles emitted in all of the entrainments carried out with flowering oilseed rape plants. The remaining constituents consisted of a range of compounds including other terpenoids, the characteristic 'green leaf' volatile (E)-3-hexen-1-ol, short chain alcohols and ketones, organic sulphides and nitrogen-containing compounds. These were generally present as minor constituents but some plant entrainments revealed that higher relative amounts could be emitted. This was particularly apparent for dimethyl disulphide, 3-methyl-2-pentanone, 3-hydroxy-2-butanone, sabinene, isomyrcenol and (E)-3-hexen-1-ol. The possible role of the 22 compounds in respiratory mucosa and conjunctiva irritation associated with airborne releases from oilseed rape is discussed.
Air Pollutants↗
Ultrastructural demonstration of mitochondrial calcium overload in myocardial cells from broiler chickens with ascites and induced hypoxia.
Two groups of young broiler chickens, namely, naturally occurring field cases of ascites and those with an induced hypoxia, were used in an ultrastructural study to examine the localisation and distribution of intracellular Ca2+ in cardiomyocytes. Age-matched healthy flockmates were used to control each group. Deposits of Ca2+ were located extensively in the mitochondria, sarcoplasmic reticulum and Golgi apparatus and sometimes in the myocyte and endothelial cell nuclei of both groups of birds. The results suggest that the cells from the hearts of the ascitic broilers may have been exposed to hypoxia since a large proportion of control material showed no Ca2+ activity in either mitochondria or nuclei. The presence of a Ca2+ overload in the mitochondria of cardiomyocytes from ascitic birds reared at low altitude or sea level suggests that these broilers were suffering from the deleterious effects of chronic hypoxia due to poor or reduced oxygen use.
Animals↗
Importance of optimal mixtures of EDTA anticoagulant:blood for the preparation of well-stained avian blood smears.
1. This paper describes and illustrates the dangers of sub-optimal mixtures of EDTA anticoagulant:blood during the preparation of avian blood smears. 2. Excessive concentrations of EDTA lead to variable staining and make cellular differentiation more difficult. 3. It is recommended, for the use of a 2.5 ml graded blood tube containing 3.75 mg EDTA, that no less than 1.0 ml of blood be mixed.
Animals↗
Differential leucocyte responses to various degrees of food restriction in broilers, turkeys and ducks.
1. White blood cell responses of broilers, turkeys and ducks were examined at regular intervals after being subjected to various degrees of food restriction. 2. Restricted-fed broilers showed increases in heterophil and basophil numbers, together with a corresponding decrease in lymphocytes. The heterophil/lymphocyte ratio was raised. There were no differences between broiler strains. 3. After only one week of feeding restricted diets, heterophils were significantly raised in selected and unselected 2-week-old ducks. At 21 weeks of age, those ducks receiving 50% of food required to achieve their ad libitum-fed body weight had raised heterophils. 4. Ducks receiving food to achieve 25% of ad libitum-fed birds produced a marked basophilia, but no heterophilia. 5. After two weeks of food restriction, turkeys responded with significant heterophil/lymphocyte ratios following two degrees of restricted feeding. 6. It was concluded that in some poultry, a heterophilia may be the response to mild to moderate stress but a basophilia may result after severely stressing birds.
Animals↗
Whole blood and plasma viscosity values in normal and ascitic broiler chickens.
1. Whole blood and plasma viscosity values in normal and ascitic broiler chickens were measured. 2. The mean blood viscosity value in ascitic broilers was greater than that of the controls. There was a small but significant difference in the opposite direction between plasma viscosity values of the respective groups of birds. 3. Although the haematocrit and arterial pressure index values in the ascitic birds were raised, there was a fall in the concentration of total plasma protein. 4. The data suggest that the raised viscosity in the ascitic birds was caused by a polycythemia and not by any influence of plasma protein. 5. The cumulative effect of these factors, such as raised blood viscosity values and larger deformed red cells flowing through constricted lung arterioles, may contribute to the pulmonary hypertension and ascites seen in some young commercial broilers.
Animals↗
Fine structure of secondary granule inclusions in fowl heterophils after ruthenium tetroxide fixation.
Bone marrow from domestic fowls was initially fixed for electron microscopy in glutaraldehyde and post-fixed with either ruthenium tetroxide or osmium tetroxide. Inclusions with distinct outlines were revealed in the secondary granules of heterophil leucocytes after ruthenium tetroxide but not with osmium tetroxide fixation. In longitudinal orientation, these inclusions were rod-shaped and composed of microfilaments measuring 3.7 nm in diameter. In transverse section, the outline of some of these inclusions was hexagonal and therefore the inclusions may be crystalline in nature.
Animals↗
Haematology and histopathology of seven-week-old broilers after early food restriction.
The haematology and histopathology of seven-week-old broilers were examined after periods of early food restriction, for six, 10 or 14 days from six days old. After several weeks on an ad libitum diet the birds failed to compensate for the weight lost during early food restriction. Immediately after the periods of food restriction, the birds demonstrated significantly increased heterophil/lymphocyte ratios, reduced eosinophils and slightly raised basophil counts. At seven weeks old, a significant reduction was seen in red and white blood cells and thrombocyte numbers together with significant increases in mean cell haemoglobin and mean cell volume. The haematological profile demonstrated a macrocytic normochromic anaemia caused possibly by a folic acid deficiency as a result of the food restriction. Histopathological lesions were seen in the heart, lungs and liver from birds on all diets but there were more lesions the longer the food had been restricted. Lung disease was more marked where there was inadequate ventilation. Cartilaginous and osseous lung nodules were significantly fewer after food restriction. It was postulated that the increase in pathological lesions in the food-restricted birds may be associated with a stress response.
Animals↗