Age-dependent changes in plasma biochemistry of yellow-legged gulls (Larus cachinnans)

Hematology and Serum Biochemistry of Coastal Seabirds Rehabilitated on the Southeastern and Southern Coast of Brazil

Complete blood counts (n=566) and serum biochemistry (n=426) were assessed in seven coastal seabirds species that underwent rehabilitation along the southeastern and southern coast of Brazil from Saquarema, Rio de Janeiro State (22°56'16.44″S, 42°18'24.16″W) to Laguna, Santa Catarina State (28°29'43″S, 48°45'39.2″W), from August 2016 to August 2020. Blood samples were collected from four species of Charadriiformes, including Kelp Gull (Larus dominicanus, n=136), South American Tern (Sterna hirundinacea, n=25), Cabot's Tern (Thalasseus acuflavidus, n=17), and Common Tern (Sterna hirundo, n=14) as well as three species of Suliformes, the Brown Booby (Sula leucogaster, n=212), Magnificent Frigatebird (Fregata magnificens, n=104), and Neotropic Cormorant (Nannopterum brasilianum, n=58). The individuals were sampled as part of the protocol required before their release into the wild when considered healthy. This work aimed to establish the normal hematologic and biochemical reference values of those seabird species and, when possible, to analyze variations among age class and sex and to compare those with the available data in the literature. In addition, we provide the first baseline data for the South American Tern, Cabot's Tern, and Neotropic Cormorant. Baseline hematologic data are crucial for assessing health status of individuals and to support management and conservation actions, including release of seabirds into the wild.

Daily and fasting variation in blood parameters and H/L ratio in house sparrows (Passer domesticus)

Fluctuations in food supply are frequent in nature during seasons, in different stages of annual cycle of animals and lately, climate change is a strong driving force that could affect food supply. An animal's capacity to resist fasting is, therefore, determined by its ability to store energy and control its allocation during periods of food restriction. Daily variations of metabolic substrates and their fluctuation during fasting are relevant to understand the acclimation to fasting. Since fasting is an ecological stressor, we investigated the daily variation of corticosterone levels in feeding and fasting in Passer domesticus Linnaeus, 1758 and its short-term effect on some biochemical parameters. We found daily variations in body mass, glucose, triglycerides, plasma total protein, uric acid and corticosterone. However, we did not find diurnal variations of hematocrit and the Heterophil:Lymphocyte ratio (H/L ratio). Moreover, we did not find sex-related differences in any parameter. Throughout fasting we found variations of glucose, triglycerides, total protein, uric acid, H/L ratio and corticosterone. During the photophase, biochemical and physiological responses to food deprivation contribute to the efficient use of resources in this small bird. In the course of fasting period corticosterone could be responsible of alterations of some blood parameters such as glucose.

Serum biochemistry profile of laying hens fed diets with fish waste oil

ABSTRACT The present study aimed to evaluate increasing levels of fish waste oil in diets for laying hens on serum biochemistry profile. 192 Hisex White laying hens at 29 weeks of age were used, with water and food ad libitum. The experimental design was completely randomized consisting of eight treatments corresponding to the inclusion levels of fish waste oil (0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5%) in the diets, with four replicates of six birds each. Data collected were subjected to polynomial regression at 5% of significance. Significant differences (P<0.05) were observed in triglycerides, glucose, total cholesterol, and uric acid. These parameters presented a decrease when hens fed diets with higher level of fish waste oil. The results of the present study indicated that the inclusion of fish waste oil caused a significant effect in the serum biochemical profile of laying hens, especially in glucose, triglycerides, total cholesterol, and uric acid concentrations. The inclusion level of 3.5% of fish waste oil caused larger disequilibrium in the serum biochemical profile of laying hens.

Changes in plasma biochemistry in breeding ring-billed gulls: Effects of anthropogenic habitat use and contaminant exposure

Gulls (Larids) have become successful at exploiting anthropogenic areas for foraging. However, little is known on the health implications of using anthropogenic habitats and on the associated exposure to environmental contaminants, particularly with respect to plasma biochemistry that is routinely used to diagnose physiological disorders and diseases. The objective of the present study was to investigate the effects of anthropogenic habitat use and exposure to ubiquitous halogenated flame retardants (HFRs) on plasma biochemistry of urban-breeding ring-billed gulls (Larus delawarensis) from one of the largest colonies in North America. Miniature GPS dataloggers were used to characterize foraging habitat use of individual gulls (n = 39) at the regional scale (urban, waste management facilities, agricultural fields, and St. Lawrence River) in the Montreal area (QC, Canada), and plasma was analyzed for a suite of biochemical measures (waste products, lipids, glucose, ions, proteins, and enzymes) and HFRs. Several confounding biological and environmental variables were also assessed including sex, body condition, time spent fasting while incubating, plasma thyroid hormone levels, time of day, capture date, and ambient temperature. As ring-billed gulls (males and females combined) spent more time foraging in urban areas, their plasma concentrations of cholesterol, albumin and activity of alkaline phosphatase increased significantly. Moreover, as the gulls spent more time foraging in agricultural fields, their plasma concentrations of phosphorous and activity of aspartate aminotransferase increased significantly. Only the activity of aspartate aminotransferase was significantly positively related to plasma HFR concentrations (PBDEs and dechlorane-related compounds). Time spent fasting while incubating, plasma thyroid hormone levels, body condition, time of day, and capture date were significantly related to certain plasma biochemical measures. The present results suggest that both the use of anthropogenic habitats for foraging and exposure to HFRs may affect the plasma biochemistry of ring-billed gulls breeding in the densely-populated Montreal area, suggesting potential adverse health effects for avian wildlife living in highly urbanized environments.

Variações fisiológicas, influência da idade e sexo no perfil bioquímico sanguíneo de aves da linhagem pesada de frango de corte na fase de recria

RESUMO Este estudo teve o objetivo de comparar o perfil bioquímico sérico de machos e fêmeas da linhagem pesada de frango de corte, nas idades de quatro, 12 e 20 semanas, em uma unidade de produção industrial, no município de Uberlândia-MG. Após a pesagem das aves, foram coletadas amostras de sangue de 15 aves de cada sexo de cada faixa etária. Os soros obtidos foram avaliados em analisador automático para os seguintes parâmetros bioquímicos: proteína total, albumina, globulinas, ácido úrico, colesterol, triglicérides, gamaglutamiltransferase, aspartato aminotransferase, alanina aminotransferase, creatina quinase, fosfatase alcalina, cálcio e fósforo. Imediatamente após a coleta de cada amostra, avaliou-se a glicemia no sangue total, utilizando-se um glicosímetro. As alterações fisiológicas e metabólicas que as aves apresentaram na fase de recria refletiram na variação dos níveis bioquímicos séricos na maioria dos constituintes avaliados, os quais exibiram diferenças significativas (P<0,05), comparando-se sexo e idade.

Impacts of Graded Levels of Metabolizable Energy on Growth Performance and Carcass Characteristics of Slow-Growing Yellow-Feathered Male Chickens

A dose-response study was conducted to investigate the metabolizable energy (ME) requirement for Lingnan chickens from 9 to 15 weeks of age. One thousand two hundred 8-week-old slow-growing yellow-feathered male chickens were allotted to five dietary ME levels (2805, 2897, 2997, 3095 and 3236 kcal/kg). The results revealed that the daily metabolizable energy intake increased (p < 0.01), whereas the feed intake and feed:gain ratio decreased linearly (p < 0.01) with the increment in dietary ME level. The final body weight and daily gain of the highest ME treatment tended (p > 0.05) to be greater than those obtained with the lower ME levels. The fat content in breast muscle showed a quadratic response (p < 0.05) to the increase in dietary energy level. The shear force values of breast muscle in the 2897, 3095 and 3236 kcal/kg treatments were lower (p < 0.05) than those of the 2997 kcal/kg treatment. In conclusion, among the tested ME levels, 3095 kcal/kg was adequate for feed intake, shear force, and plasma uric acid, and 3236 kcal/kg tended to increase the body weight, body gain, and feed conversion ratio of Lingnan males between 9 and 15 weeks of age; further studies are still required for testing higher levels.

Histomorphometric study of the anterior latissimus dorsi muscle and evaluation of enzymatic markers of broilers affected with dorsal cranial myopathy

Dorsal cranial myopathy (DCM), which affects the anterior latissimus dorsi (ALD) muscles of commercial broilers, is of unknown etiology, and it represents up to 6% of the partial condemnations in Brazilian slaughterhouses. This study was performed to achieve histomorphometric characterizations of the ALD muscles from male Cobb 500 broilers slaughtered at either 35 d or 42 d and to evaluate the effects of DCM on the enzymatic markers aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK), and lactate dehydrogenase (LDH) and on uric acid and creatinine metabolites. Blood samples (1.5 to 3 mL) and ALD muscle fragments were collected from each carcass, all of which were processed in a commercial inline processing system. For each age, twelve macroscopically normal animals and twelve animals found to exhibit DCM were randomly selected for histomorphometric evaluation and analysis of serologic profiles. Microscopic evaluations demonstrated that the muscle fibers of those with DCM exhibited a strong presence of multifocal regenerative myodegeneration as well as a substitution of muscle tissue with connective tissue (P < 0.001) through fibrosis, thus characterizing the chronicity and hardness of the affected muscle. It is suggested that DCM is a localized muscle lesion because the detected serum levels of CK (P < 0.001), AST (P < 0.001), ALT (P = 0.01), and LDH (P < 0.001) enzymes were strongly associated with the group affected by DCM. Additional studies are needed to gain an understanding of this myopathy because it is an emerging problem in the poultry industry. In addition, it is related to DCM lesions in fast-growing broilers with the greatest slaughter weights.

The influence of diet on nestling body condition of an apex predator: a multi-biomarker approach

Animal body condition refers to the health and physiological state of individuals, and multiple parameters have been proposed to quantify this key concept. Food intake is one of the main determinants of individual body condition and much debate has been generated on how diet relates to body condition. We investigated this relationship in free-living Bonelli's eagle (Aquila fasciata) nestlings sampled at two geographically distant populations in Spain. Nestlings' main prey consumption was estimated by isotopic analyses. A multi-biomarker approach, including morphometric and blood biochemical measures (i.e. hematocrit, plasma biochemistry and oxidative stress biomarkers), enabled us to integrate all the body condition measures taken. A greater consumption of a preferred prey [i.e. the European rabbit (Oryctolagus cuniculus)] improved nestling body condition, as indicated by lower levels of cholesterol in plasma, greater activity of enzymes mediating in protein catabolism, higher levels of tocopherol and glutathione, and less glutathione peroxidase activity, which also suggested lower degree of oxidative stress. On the other hand, increased diet diversity was positively correlated with higher levels of oxidized glutathione, which suggests that these nestlings had poorer body condition than those with a higher frequency of preferred prey consumption. Several factors other than diet [i.e. altitude of nesting areas, nestling sex and age, sampling time (before or after midday) and recent food ingestion] had an effect on certain body condition measures. Our study reveals a measurable effect of diet on a predator's body condition and demonstrates the importance of considering the potential influence of multiple intrinsic and extrinsic factors when assessing animal body condition.

HEMATOLOGIC AND BIOCHEMICAL PARAMETERS OF KELP GULLS (LARUS DOMINICANUS) CAPTURED IN THE CITY OF TALCAHUANO, CHILE

In order to provide tools for future health-based monitoring programs, we developed reference intervals for hematology and plasma biochemistry and partitioned data for sex and season (winter and autumn). Ninety-one physically healthy kelp gulls (Larus dominicanus) were sampled in the city of Talcahuano, Chile, during winter (July-September) of 2007, autumn (April-June) and winter of 2008, and autumn of 2009. After blood sampling, the kelp gulls were euthanized by cervical dislocation. Packed cell volume (PCV), hemoglobin, total plasma protein (TPP), and complete blood count were performed. Alanine amino transferase, gamma-glutamyl transpeptidase, lactate dehydrogenase, alkaline phosphatase (ALP), creatinine, urea, calcium, phosphorus, and uric acid were analyzed. No significant differences were found between sexes (P>0.05). When a comparison was made between the two seasons, the values of PCV, TPP, white blood cell, heterophils, eosinophils, and monocytes were significantly higher in winter than in autumn (P<0.05) while and urea and uric acid concentrations were higher in autumn. Heterophils were the predominant circulating leukocyte for all birds. There was no significant difference in body condition between autumn and winter nor between sexes. Body condition showed a significant relationship with TPP and basophil concentration and ALP activity.

Oral administration of D-aspartate, but not L-aspartate, depresses rectal temperature and alters plasma metabolites in chicks

AIMS

L-Aspartate (L-Asp) and D-aspartate (D-Asp) are physiologically important amino acids in mammals and birds. However, the functions of these amino acids have not yet been fully understood. In this study, we therefore examined the effects of L-Asp and D-Asp in terms of regulating body temperature, plasma metabolites and catecholamines in chicks.

MAIN METHODS

Chicks were first orally administered with different doses (0, 3.75, 7.5 and 15 mmol/kg body weight) of L- or D-Asp to monitor the effects of these amino acids on rectal temperature during 120 min of the experimental period.

KEY FINDINGS

Oral administration of D-Asp, but not of L-Asp, linearly decreased the rectal temperature in chicks. Importantly, orally administered D-Asp led to a significant reduction in body temperature in chicks even under high ambient temperature (HT) conditions. However, centrally administered D-Asp did not significantly influence the body temperature in chicks. As for plasma metabolites and catecholamines, orally administered D-Asp led to decreased triacylglycerol and uric acid concentrations and increased glucose and chlorine concentrations but did not alter plasma catecholamines.

SIGNIFICANCE

These results suggest that oral administration of D-Asp may play a potent role in reducing body temperature under both normal and HT conditions. The alteration of plasma metabolites further indicates that D-Asp may contribute to the regulation of metabolic activity in chicks.

Hematology and blood chemistry values in free-living imperial cormorants (Phalacrocorax atriceps)

As part of an on-going, long-term study on the reproductive ecology and health status of imperial cormorants (Phalacrocorax atriceps), blood samples were collected to establish baseline values for hematologic parameters (hematocrit, red and white blood cell counts, leukocyte profile, heterophil:lymphocyte ratio, total solids) and serum chemistries (glucose, uric acid, urea, total protein, triglycerides, cholesterol, albumin:globulin ratio, alkaline phosphatase, lactate dehydrogenase, creatine phosphokinase, aspartate aminotransferase, alanine aminotransferase, calcium, phosphorus). One hundred and eighty-four male adults from the Punta Le6n breeding colony in Patagonia Argentina were captured during the chick-rearing period of four breeding seasons, 2004 (n = 48), 2005 (n = 29), 2010 (n = 43), and 2011 (n = 64). All birds appeared to be in good body condition and no abnormalities were noted during physical examination. In general, values for the parameters reported in this study were similar to those previously described for other cormorant species. Significant interannual differences were observed in most health parameters analyzed. This study defines baseline health parameters for imperial cormorants and, coupled with previous reports on pathogen exposure, contributes to our knowledge of the overall health status of the species.

Does breeding status influence haematology and blood biochemistry of yellow-legged gulls?

We compared the haematological and biochemical values within a population of yellow-legged gulls (Larus michahellis) in the Chafarinas Islands (Northern Africa), in non-breeding (February) and breeding (May) animals. We collected blood samples from 51 adults. We found that according to the haematological data, there was a significant variation in haemoglobin content, and a higher proportion of heterophils, thrombocytes, and Haemoproteus infection in breeding individuals with a lower level in basophils. Blood biochemistry showed a higher level in plasmatic proteins, calcium, phosphorus, thiobarbituric acidreactive substances and alkaline phosphatase as well as alanine aminotransferase activity in breeding animals while cholesterol and phospholipid levels showed a lower level. There was also a sexual difference in triglycerides, albumin, thiobarbituric acid-reactive substances and alkaline phosphatase activity. Hence, the haematological and blood chemistry values of yellow-legged gulls showed some differences between breeding and non-breeding individuals as well as between sexes.

Age-correlation of blood values in the rock pigeon (Columba livia)

Hematological adaptations to age (1-17 years) and about variability per se for free-living rock pigeons Columba livia are presented. Increasing age is correlated with decreasing values of hematocrit and hemoglobin. A marked reduction of lactate dehydrogenase (EC 1.1.1.27) activity in the first 2-3 years may be caused by a training-based increase of the relative portion of the aerobically working red breast muscles (responsible for endurance) at the expense of the proportion of anaerobically working white breast muscles. The age-correlated increase in glucose could indicate a decreasing tolerance for carbohydrates. Optimal flight performance is achieved by the doves at an age of about 2-3 years; the high performance is retained until an age range of 7-9 years.

Plasma alkaline phosphatase as a sensitive indicator of age and skeletal development in wild coscoroba swans

Context. Recent studies have suggested that plasma alkaline phosphatase (ALP) can be used to assess skeletal development as well as health status in wild animals. Aims. However, the information about age-related dynamics of ALP in birds, especially in precocial species, is very scarce. Therefore, before ALP measurements can be effectively interpreted, it is necessary to determine its normal variation for each species, age group and sex. Methods. Here, we report total-ALP levels of free-living coscoroba swans (Coscoroba coscoroba) from the most important breeding and moulting population in Brazil. Data were gathered during the moulting period and categorised according to sex and the following three different age classes: chick (n = 11), young (n = 14) and mature (n = 29). Key results. ALP levels were related to the longitudinal measure of the bones, gradually diminishing with age and showing significant differences among birds of different age classes. In all age groups, no effect of sex on T-ALP concentration was detected. Conclusions. We conclude that measuring ALP facilitates the discrimination among different-aged individuals with similar plumage characteristics and body size.

Effects of acute exposure to heavy fuel oil from the Prestige spill on a seabird

Large quantities of petroleum products are released into the marine environment as result of tanker wrecks. Such catastrophic events have a dramatic impact on marine ecosystems, affecting a broad range of species. Seabirds are placed at the uppermost trophic level of the marine food chain. Therefore, important toxic effects are expected in these organisms. The recent Prestige oil spill gave the opportunity to test this. A previous study reported that yellow-legged gulls (Larus michahellis) breeding in the oiled area (17 months after the spill) showed differences both in plasma biochemistry and in the total circulating levels of polycyclic aromatic hydrocarbons (TPAHs) in blood regard to gulls sampled in clean areas. In the present study, wild yellow-legged gulls were fed with heavy fuel oil from the Prestige oil spill (P-gulls) and compared with control gulls (C-gulls) fed only with the vehicle (vegetable oil). Consistent with the cited previous findings, gulls fed with fuel oil showed reduced glucose and inorganic phosphorus levels in plasma, as well as a trend to significantly reduced creatinine values. In addition, glucose concentration was negatively related to TPAH levels. Males but not females fed with fuel oil showed higher plasma activity of asparatate aminotransferase (AST) than controls. With regard to plasma activity of gamma-glutamyl transferase (GGT), the results were opposite to the previous study. The GGT activity increased in C-females, apparently to meet with increased liver metabolism due to egg laying demands, but not in P-females. Differences to the previous study possibly reflect different adaptive responses of these enzymes to an acute short-term exposure to heavy fuel oil. Since the yellow-legged gull belongs to a complex of species widely distributed throughout the Northern hemisphere, the results as a whole might provide a tool for future evaluations of short- and long-term effects of oil spills on seabirds. Decreased glucose and inorganic phosphorus levels in plasma are expected in both short- and long-lasting exposures to fuel oil, whereas responses of AST and GGT enzymes would depend on both the sex of individuals and the temporal pattern of exposure.

Sublethal toxicity of the Prestige oil spill on yellow-legged gulls

The Prestige oil spill in November 2002 is considered the biggest large-scale catastrophe of its type in Europe, thousands of seabirds dying in the subsequent months. Here, the total concentration of 16 polycyclic aromatic hydrocarbons (TPAH) was measured in the blood cell fraction of adult and chick yellow-legged gulls (Larus michahellis) from unoiled and oiled coastal areas in North Western Spain. In addition, hematocrit, plasma metabolites, electrolytes and enzymes, as well as body mass were determined in the same individuals. Our results strongly suggest the presence of health damages of sublethal nature in adult gulls breeding in oiled colonies 17 months after the Prestige oil spill. This is supported by the following evidences: (1) gulls sampled in unoiled and oiled colonies differed in blood TPAH levels, (2) gulls sampled in unoiled and oiled colonies differed in several blood parameters indicative of physiological disorders, and (3) TPAH in blood was significantly related to several of these parameters. Differences in the level of asparatate aminotransferase (AST), gamma-glutamyl transferase (GGT), total protein, glucose and inorganic phosphorus suggest damages on some vital organs (i.e. liver and kidney) in adult birds from oiled areas. Meanwhile, chicks presented weaker effects than adults, showing only between-area differences in hematocrit. Since TPAH levels in blood did not differ between both age-groups, the stronger effects on adults should be due to their longer exposure to these pollutants and/or to severe exposure in the months following the spill. The presence of PAHs in chicks indicates that these pollutants were incorporated into the food chain because nestlings would have been only exposed to contaminated organisms in the diet (e.g. fishes and crustaceans). Our findings support the view that PAHs may deeply alter the physiology of seabirds, and emphasize the necessity of quantifying the circulating levels of these compounds in order to evaluate the sublethal effects associated to large oil spills.

Interannual variations in feeding frequencies and food quality of greater flamingo chicks (Phoenicopterus roseus): Evidence from plasma chemistry and effects on body condition

Greater flamingos in southern Spain foraged in areas distant from a breeding site, spending 4-6 days in foraging areas between successive visits to the colony to feed their chicks. During four years, we took blood samples from chicks to ascertain whether there were interannual variations in several blood parameters, indicative of food quality and feeding frequencies. When the chicks were captured, 20-31% of them had their crops empty, indicating that not all chicks were fed daily. Additional evidence of variations in feeding frequencies was obtained from a principal component analysis (PCA) on plasma chemistry values, which also indicated that there were annual variations in the quality of food received by chicks. The association of cholesterol and glucose with some PC axes indicated that some chicks were experiencing fasting periods. Of all plasma metabolites considered, cholesterol was the best one to predict body condition. Greater flamingo chicks experiencing longer fasting intervals, as suggested by higher plasma levels of cholesterol, were in lower body condition.

The effects of feed restriction on plasma biochemistry in growing meat type chickens (Gallus gallus)

The effect of feed restriction on plasma hormones (triiodothyronine - T(3), thyroxine - T(4), and corticosterone), protein, lipid, carbohydrate, and mineral metabolism and activity of plasma enzymes (creatine kinase, alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase) were studied in meat type female chickens (Gallus gallus). Ad libitum fed birds were compared with those subjected to severe and moderate quantitative feed restriction from 16 to 100 days of age. Feed restriction elevated plasma T(4) and corticosterone levels and reduced T(3). A feed restriction-induced decrease was observed for plasma protein and albumin concentrations, but not for uric acid and creatinine. Total plasma lipids, triacylglycerols, cholesterol, high density lipids, and calcium were lower for the feed restricted chickens, in particular during the latter phase of the experiment. Concentrations of glucose and phosphorus were not altered by feeding treatment. Activity of alkaline phosphatase was significantly increased in restricted chicks from day 58. Significant changes of plasma biochemical parameters induced by severe and moderate quantitative feed restriction illustrate that limiting feed intake poses an intensive stress on meat type chickens during the rapid growth period. However, activities of creatine kinase, aspartate aminotransferase, and alanine aminotransferase were significantly higher in ad libitum fed chickens during this period. This elevation in enzymatic activity may be in response to tissue damage, indicating potential health and welfare problems also in ad libitum fed meat type chickens, resulting from selection for intensive growth.