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This study was carried out to investigate the effects of dietary energy levels on growth performance, blood parameter, and intestinal morphology of Pekin ducks in low temperature. A total of 500, 21-d-old Pekin ducks (initial BW = 1,089 ± 5.21 g) were evenly assigned to five dietary treatments (2,950, 3,000, 3,050, 3,100, or 3,150 kcal AME/kg, calculated on an as-is basis) with four replicates (pens) for each treatment (25 ducks per pen). During the experiment, hens were provided with feed and water ad libitum. Overall, increasing dietary energy levels corresponded to an increase of final body weight and body weight gain (linear, p < 0.01). Feed intake decreased (linear, p < 0.01) and feed conversion ratio increased (linear, p < 0.01) with increasing levels of energy. There were no significant differences (p < 0.05) in the level of leukocytes between groups. However, heterophils decreased (quadratic, p < 0.05) and lymphocytes increased (linear, p < 0.01) as inclusion of dietary energy levels increased. The H/L ratio increased (linear, p < 0.01) with increasing dietary energy levels while serum corticosterone levels decreased at overall experimental periods. Triglycerides increased (linear and quadratic, p < 0.05) with increasing dietary energy levels. There were no significant changes in villus height or crypt depth of the jejunum at overall experimental. In conclusion, increasing concentrations of dietary energy levels up to 2,950–3,150 kcal/kg in diet. Additionally, 3,150 kcal/kg dietary energy had been revealed more beneficial and could be practiced as protective management for the Pekin ducks reared under low ambient temperature (8°C to 10°C).

The present investigation was carried out to compare the impact of cinnamon and clove powders and their oil additives as anti-stressors on quails under heat stress which is one of the riskiest environmental conditions that influence poultry all over the world in general and Iraq in particular. For this purpose, 420 quails (5 weeks old) were chosen and randomly grouped into seven treatments with different treatments (T0: control (standard diet), T1: 2 g clove powder/kg diet, T2: 1 ml clove oil/kg diet, T3: 2 g cinnamon powder, T4: 1 ml cinnamon oil/kg diet, T5: 1 g clove powder+1 g cinnamon powder/kg diet, T6: 0.5 ml clove oil+0.5 ml cinnamon oil/kg diet) added to standard diet. The quails were fed with these diets for 17 weeks. The results indicated that adding clove, cinnamon, and their oils to quail diet under heat stress led to significantly (p

An experiment was conducted to evaluate the effect of different housing system (cages vs. floor system) on behavioral patterns and welfare of broiler chicks. One hundred and twenty broiler were allocated in to two housing system (cages and floor pen) in full environmental controlled pens for four weeks. Assessment of welfare was through measuring general behavioral, tonic immobility test and heterophil: lymphocyte ratio (HLR). Compared to cage reared birds, floor reared broilers exhibit higher level of feeding, drinking, crouching, walking behavior while caged birds were more often standing and also showed either more wing stretch, leg stretch or both wing& leg stretch than floor reared group. Moreover, shortest duration of tonic immobility test was observed in floor reared birds than those housed in cages. HLR were significantly higher in cages than floor group. At the end of this experiment our obtained data suggested that housing in cages has adverse effect on welfare as it impair general behavioral patterns, birds showed more fearfulness also higher HLR which over all indicated stressful conditions for birds. In conclusion, cages should not be recommended for broiler rearing from welfare point of view.

Life-history stages such as reproduction and molt are energetically costly. Reproductive costs include those associated not only with offspring production, but also protecting and provisioning young. Costs typically associated with molting include decreased thermoregulatory and locomotive performance, and increased metabolic and nutritional costs. Energetic demands may disrupt homeostasis, particularly in terms of its maintenance (e.g., oxidative stress and immunity). Few investigators have explored the relationship between effort (increased metabolic rate) and oxidative status and stress by comparing life-history stages with different energetic demands. However, comparative studies are crucial for understanding the processes of energy allocation and their consequences for different physiological functions. Our objective was to determine how two highly demanding life-history stages, breeding and molting, affected oxidative balance in Chinstrap Penguins (Pygoscelis antarcticus), a species where these two activities do not overlap. We found that the heterophil/lymphocyte (H/L) ratio was significantly higher during breeding than molting; oxidative damage was also higher during breeding. In contrast, we found no significant differences between these stages in total antioxidant capacity. We also found sex differences, with males having greater oxidative damage than females. Our results suggest that breeding is more stressful and more demanding for Chinstrap Penguins than molting, and provide further support for the relationship between effort, in terms of increased metabolic rate, and oxidative balance., his study was funded by the Spanish Ministry of Economy and Competitiveness (CTM2011‐24427 and CTM2015‐64720). RCC held a Spanish Ministry of Economy and Competitiveness FPI grant (BES2012‐059299).

Measuring the ratio of heterophils and lymphocytes (H/L) in response to different stressors is a standard tool for assessing long-term stress in laying hens but detailed information on the reliability of measurements, measurement techniques and methods, and absolute cell counts is often lacking. Laying hens offered different sites of the nest boxes at different ages were compared in a two-treatment crossover experiment to provide detailed information on the procedure for measuring and the difficulties in the interpretation of H/L ratios in commercial conditions. H/L ratios were pen-specific and depended on the age and aviary system. There was no effect for the position of the nest. Heterophiles and lymphocytes were not correlated within individuals. Absolute cell counts differed in the number of heterophiles and lymphocytes and H/L ratios, whereas absolute leucocyte counts between individuals were similar. The reliability of the method using relative cell counts was good, yielding a correlation coefficient between double counts of r > 0.9. It was concluded that population-based reference values may not be sensitive enough to detect individual stress reactions and that the H/L ratio as an indicator of stress under commercial conditions may not be useful because of confounding factors and that other, non-invasive, measurements should be adopted.

Leucocyte profiles, especially the heterophil/lymphocyte ratio (H/L), are widely used to assess immune function and stress in birds. In this study, we investigated whether leucocyte profiles in a small colonial seabird, the little auk (Alle alle), are related to age (chicks, adults), sex or biometric traits, including body mass. We blood-sampled chicks at 4–8 and 14–18 days of life and chick-feeding adults with 14–20- and 24–30-day-old chicks. Relative numbers of heterophils and H/L generally differed among chicks and adults, with the highest values in adults with 14–20-day-old chicks and the lowest ones in 4–8-day-old chicks. Females had a higher proportion of lymphocytes than males. The relative numbers of eosinophils were similar in all the groups. The percentage of monocytes tended to differ among the age categories. Analyses of chicks revealed that the percentage of heterophils and the H/L ratios were significantly higher in older than in younger chicks. The opposite pattern was recorded for lymphocytes. In 14–18-day-old chicks, H/L (stress level) was negatively related to body mass, head-bill length and bill width. This time period is energetically stressful as nestlings start to exercise their wings outside the nest chamber. This suggests that the origin of stress in nestlings was mainly nutritional. We found a significant positive correlation between body mass at fledging and the relative number of eosinophils at 14–18 days of life, indicating a higher level of stress in lighter nestlings. The significant relationship between fledging age and the percentage of monocytes at 14–18 days of life suggested a poorer state of health in chicks that fledged at an older age.

Analysis of blood has been commonly used in the clinical assessment of the health status of birds and typically encompasses a suite of haematological assays. Determination of the heterophil to lymphocyte (H/L) ratio has been commonly reported as an alternative measure of leukocyte values, particularly in studies of naturally occurring physiological influences on birds. Relatively few studies have assessed the H/L ratio values of birds undergoing haematological assessment as part of an investigation of health status. In the current study, the H/L ratio was retrospectively determined for birds that had undergone a haematological assessment as part of a clinical investigation of health. Of the 176 adult birds assessed, encompassing 70 species and 17 orders within the Aves, the H/L ratio was between 0.19 and 64.67 and was greater than 2.0 in 68.8 % of birds. The current study illustrates that the H/L ratio of birds can be markedly affected by disorders of health which should be considered when interpreting any H/L ratio value.

Caribbean flamingo social structure, how pair bonds affect the structure of the flock, and how social stress affects health measured by heterophil to lymphocyte ratios (H/L) were investigated at the Philadelphia Zoo. It was hypothesized that a hierarchy may become apparent by analyzing agonistic interactions and that paired individuals would share similar places within the hierarchy. Furthermore, it was hypothesized that a negative relationship between H/L ratio and dominance would exist. Forty observations were conducted and in 70% of interactions instigating bird(s) won the encounter, suggesting either some advantage for instigating birds or a prior expectation of an encounter's outcome based upon an understanding of the flock's hierarchy. The flock possessed a semi-linear hierarchy (in terms of wins/losses) and birds with higher pair-bond strengths maintained dominant positions, suggesting that pair-bonding may help individuals become more successful in agonistic encounters. Birds who won more often had higher lymphocytes percentages and analyses suggested a trend indicating dominant birds may be less stressed. A semi-linear hierarchy was also found in terms of initiation/being targeted, and a bird's rank on the dominance (wins/losses) and initiate/target hierarchies were positively correlated, suggesting that subdominant birds were targeted by dominant birds more frequently than vice versa.

The objective of the current study was to evaluate the effect of feeding time restriction in alternate day on performance and Heterophil to Lymphocyte (H/L) ratios as indices stress of broiler chickens. A total 180 seven day-old unsexed broiler chicks were randomly allocated to three treatments: chicks fed ad libitum (P-0); chicks had free access to feed from 07:00 to 09:00, 12:00 to 13:00 and 17:00 to 18:00 (P-1) and from 07:00 to 09:00 and 17:00 to 18:00 (P-2). The feeding time restriction was given at 7, 9, 11, 13, 15, 17, 19 and 21 days of age and chicks was access feed ad libitum on alternate days (8, 10, 12, 14, 16, 18 and 20 days of age). The chicks were fed ad libitum during 22 to 42 days of age. Body weight gain, feed intake and feed conversion ratio in feed restricted broilers were lower (p

An electron microscopy study, in combination with modeling and image simulation, of four different reconstituted ferritin samples: recombinant human H and L homopolymers, and H and L heteropolymers of native L-subunit-rich horse spleen and H-subunit-rich human heart ferritins, points out the existence of a correlation between iron core shape and protein shell.

Heterophil to lymphocyte ratio, plasma corticosterone and tonic immobility test, plumage and leg score (Food Pad Dermatitis, FPD) are frequently used as indicators of welfare in chickens. Three traditional Italian chicken breeds (60 birds/group) were studied: Valdarnese Bianca (VB), Bionda Piemontese (BP) and Robusta Maculata (RM). At 80 days of age, reactivity was tested through Tonic Immobility (TI) and plumage and leg score tests. Immediately after phenotypical and behavioural tests, the blood samples were collected from the ulnar vein of chickens. TI duration was not significant among the breeds (VB 72.2 ± 8.3 s; BP 95.2 ± 9.0 s; RM 76.5 ± 8.6 s; mean ± SEM). RM and BP needed a mean number of induction significantly higher than VB (RM = 1.84 ± 0.1; BP = 1.96 ± 0.1; VB = 1.38 ± 0.1; p

The objectives of this study were to examine the effects of beak trimming age on performance criteria, H-L ratio, antibody production, the percentage of spleen and liver and external appearance. The chicks (Barred Rock) were randomly divided into 4 beak-trimming groups (non-trimmed (control), a trim at 1 d (1D), at 10 d (10D) and at 10 wk (10W)), each of 132 chicks. There were 6 replicate cages at beak trimming groups at rearing period. At 18 wk of age a total of 144 pullets were transferred to the layer house, and the pullets were housed at 323 and 646 cm(2)/hen with 8 and 4 birds per cage in three-deck layer cages. There were a total of 24 replications with 12 replications equally divided between the high and low density cages, and the beak trimmed treatments were randomly and equally divided within each density. As a result of this experiment differences among groups in body weight in rearing phase were disappear in the laying phase. Low feather condition was found in untrimmed hens. H-L ratio in both pullet and laying phase was higher in hens of untrimmed groups. Cage area affected all examined parameters except that body weight, mortality rate, cracked, broken and unshell egg rates, shell breaking, shape index, shell thickness, meat-blood spot rates, spleen and liver percentages, throat injures and antibody production to SRBC.

Wild birds exposed to stressors may modulate their investment in immunity. We studied the leucocytes of breeding burrowing parrots (Cyanoliseus patagonus) in Patagonia during five breeding seasons, during which global climate events such as a strong La Nina and a weak El Nino occurred. We observed strong inter-annual variation in the ratio of heterophils to lymphocytes (H/L), with higher H/L during the adverse conditions of La Nina compared with the favourable conditions of El Nino for the studied region. Nevertheless, highest H/L were found in the breeding season following a La Nina event; this is probably explained by a combination of long-term detrimental effects of climatic conditions and other, e.g. biotic, stressors. Males had higher H/L than females, and H/L ratios were negatively related to individual body condition.

Animals are kept in captivity for various reasons, but species with a slower pace of life may adapt to captive environments less easily, leading to welfare concerns and the need to assess stress reliably in order to develop effective interventions. Our aim was to assess welfare of semi-captive timber elephants from Myanmar by investigating the relationship between two physiological markers of stress commonly used as proxies for welfare, faecal glucocorticoid metabolite concentrations (FGM) and heterophil/lymphocyte ratios (H/L), and link these measures to changes in body condition (determined by body weight). We further assessed how robustly these two markers of stress performed in animals of different age or sex, or in different ecological contexts. We measured FGM concentrations and H/L ratios between 2016 and 2018 from 316 samples of 75 females and 49 males ranging in age from 4 to 68. We found a positive and consistent link between FGMs and H/L ratios in Asian elephants, irrespective of their sex, age, or ecological context. Our results will help to inform managers of (semi-) captive elephants about using heterophil/lymphocyte ratio data from blood smears on site as a potentially cheaper and faster alternative to determining stress than measuring faecal glucocorticoid metabolite concentrations in the laboratory.

The number of lymphocytes in chicken blood samples decreased and the number of heterophils increased in response to stressors and to increasing levels of corticosterone in the chicken feed. The ratio of heterophils to lymphocytes was less variable than the number of heterophil or lymphocyte cells, and the range of values for this ratio was greater than the range of values for heterophils and lymphocytes among control and experimental groups. The heterophil/lymphocyte ratio appears to be a more reliable indicator of levels of corticosterone in the feed and to social stress than were the plasma corticosteroid levels.