Effect of High Levels of Ammonia in Air on Adrenal Response to Adrenocorticotropin and Forced Running in Rabbits

The aim of the present study was to assess adrenal response to high air ammonia levels in rabbits. Twenty male rabbits of the New Zealand White breed at the age of 4 months were randomly allocated into two groups: control - reared under low air ammonia levels (1.4-14.6 ppm) and experimental – reared under higher ammonia levels (28-57 ppm). The rabbits of both groups were subjected to forced running for 15 min on day 37 of the trial and two weeks later they received i.m. injection of 0.1 mg synthetic adrenocorticotropin (ACTH1-24) per rabbit. The animals were sacrificed two days after termination of the trial and some internal organs and glands were excised and weighed. Plasma cortisol levels in both groups were not significantly altered at 20 and 60 min following the end of forced running relative to basal levels. Plasma corticosterone level in the control rabbits declined at 20 min (P<0.01) and 60 min (P<0.05) following exposure to forced running and remained unchanged in the experimental group. Plasma cortisol and corticosterone concentrations in both groups declined significantly at 60 and 120 min following ACTH injection. The rabbits under high ammonia levels had heavier adrenal glands than control rabbits (P<0.01). The results are interpreted to suggest that ammonia-induced higher adrenal weight was due to hypertrophy of adrenal zona glomerulosa

Effect of Acute Heat Stress on Some Hematological Parameters, Trace Elements and Meat Quality in Rabbits

The aim of the present study was to investigate the effect of acute heat stress on some hematological parameters, trace elements and meat quality traits in rabbits. Twelve male rabbits at the age of 4 months were allocated into 2 groups: control and experimental. The experimental rabbits were exposed to intermittent solar radiation for 4 hours at 36 °C. The following parameters were determined: white blood cells (WBC) count, red blood cells (RBC) count, hematocrit, neutrophil and lymphocyte percentages, liver and meat content of chromium (Cr) and selenium (Se), pH of meat at 60 min and 24 h post mortem, meat color, myoglobin and water holding capacity (WHC). Exposure to heat increased neutrophil to lymphocyte ratio (P<0.01) and liver content of Cr (P<0.01), while WBC count, RBC count, hematocrit, liver Se, muscle Cr and Se, pH of meat at 24 h, meat color, myoglobin and WHC were not affected by the applied heat load. The experimental rabbits had significantly lower meat pH at 60 min after slaughter relative to the control rabbits (P<0.05). It was suggested that experimental rabbits had sufficient muscle glycogen at the time of slaughter needed to produce the lactic acid that reduced the ultimate pH of post-mortem muscle within the range observed in the control rabbits

Agricultural Academy

Abstract MONEVA, P., S. POPOVA-RALCHEVA, D. GUDEV, V. SREDKOVA and I. YANCHEV, 2008. Study on the metabolic implication of supplemental tryptophan in exposed to stress chickens. Bulg. J. Agric. Sci., The effect of supplemental tryptophan (5g/1Kg -1 diet) on some indices of stress, heterophil-to-lymphocyte ratios (H:L), leukocyte and erythrocyte numbers in chickens under stress induced by alternating periods of normal feeding with periods of feed and water withdrawal was investigated. Twenty chickens at the age of six weeks were randomly allocated into two groups-control and experimental. Experimental birds were deprived of feed and water and their legs tied for seventeen hours each day in four consecutive days. Body weight was registered on d 0 (baseline value), d 7 (preliminary period-free of stress) and on d 11 (experimental period). Blood samples were taken on d 0 and d 11. Relative weights of some immunobiological organs were also measured at the end of the experimental period. Supplemental tryptophan alleviated body weight decline, decreased spleen (P&gt;0.05) and liver (P&lt;0.05) relative weights, but had no significant effect on those of adrenal glands and bursa of Fabricius. Plasma urea levels were not influenced by supplemental tryptophan but plasma glucose levels declined by 14h and cholesterol levels by 17h in comparison with control group. Tryptophan supplementation prevented H: L ratio increment caused by stressor treatment. Leukocyte numbers and hematocrit values were not significantly influenced by tryptophan. Interleukin-1α response to stress declined in triptophan supplemented chickens by 14 h following the start of stressor treatment but corticosterone response was not influenced. Our results indicate that tryptophan is implicated in white blood cells dynamics and influences the pattern of the observed stress indices in chickens

Cardiovascular, endocrine and behavioural responses to suckling and permanent separation in goats

<p>Abstract</p> <p>Background</p> <p>Suckling can be a peaceful or vulnerable event for goats and kids, whereas, separation is suggested as stressful. The aim of this study was to investigate physiology and behaviour in these two different situations in dairy goats.</p> <p>Methods</p> <p>Four studies were performed with seven goats kept with their first-born kid in individual boxes. The goats were videotaped and heart rate and arterial blood pressure were recorded every minute by telemetry from parturition until 24 hours after separation. One to two days after parturition, Study 1 was performed with analyses of heart rate and blood pressure around a suckling. In Study 2, performed 3-5 days after parturition, blood sampling was done before, during and after suckling. Study 3 was performed 4-6 days post partum, with blood sampling before and after a permanent goat and kid separation. In addition, vocalisations were recorded after separation. Blood samples were obtained from a jugular vein catheter and analysed for plasma cortisol, β-endorphin, oxytocin, and vasopressin concentrations. Study 4 was performed during the first (N1) and second nights (N2) after parturition and the nights after Study 2 (N3) and 3 (N4). Heart rate, blood pressure and time spent lying down were recorded.</p> <p>Results</p> <p>The kids suckled 2 ± 0.2 times per hour and each suckling bout lasted 43 ± 15 s. In Study 1, heart rate and blood pressure did not change significantly during undisturbed suckling. In Study 2, plasma cortisol (P ≤ 0.05 during suckling and P ≤ 0.01 five minutes after suckling) and β-endorphin (P ≤ 0.05) concentrations increased during suckling, but oxytocin and vasopressin concentrations did not change. In Study 3, the goats and kids vocalised intensively during the first 20 minutes after separation, but the physiological variables were not affected. In Study 4, heart rate and arterial blood pressure declined gradually after parturition and were lowest during N4 (P ≤ 0.05) when the goats spent longer time lying down than during earlier nights (P ≤ 0.01 during N1 and N3 and P ≤ 0.05 during N2).</p> <p>Conclusions</p> <p>Suckling elevated plasma cortisol and β-endorphin concentrations in the goats. The intensive vocalisation in the goats after separation, earlier suggested to indicate stress, was not accompanied by cardiovascular or endocrine responses.</p

PRESENT STATE AND PROSPECTS FOR ANIMAL HUSBANDRY DEVELOPMENT IN THE REPUBLIC OF BULGARIA**

**Plenary invited paper Abstract: The report contains analysis on the present state, and perspectives for the development of Bulgarian animal husbandry on the eve of the integration with European union. During the period 1990-2000 the animal husbandry in Bulgaria fell into a deep crisis. After this period Bulgarian animal husbandry showed a stable trend for survival. The integration of Bulgaria with EU outlines good perspectives for the development of sheep, goat and beef cattle breeding. Another promising direction is the production of ecologically clean animal products. The development of Bulgarian animal husbandry will depend to a great extent on the reinstatement of the lost Bulgarian markets in Russia, in the countries fom the former USSR (Union of the soviet socialistic republics) and in the Arab countries by offering specific Bulgarian animal products. Key words: animal husbandry, development, Bulgaria. Bulgarian agriculture has been in a deep depression during the last 16 years. The depression affected seriously the state of our animal husbandry which is demonstrated by the current number of farm animals (table 1). This table shows a drastic reduction of number of animals through the period 1990-2000. The reduction is more emphasized in number of pigs and sheep. Similar trend is observed also in number of cattle and buffaloes. The number of goats unlike that of the other animal species shows a steady trend towards enhancement during the observed period due to the fact that they are not fastidious to the conditions of feeding and breeding which makes them the most preferred animal kind for many poor families. 34 L. Kozelov, D. Gudev _____________________________________________________________________________________ Table 1. Number of farm animals and poultry (thousand) № Animal species and categorie

POULTRY WELFARE ASSESSMENT; IS IT POSSIBLE TO AVOID HANDLING-INDUCED MENTAL STRESS INTERFERENCE?

Abstract: Monitoring and quantification of poultry welfare requires more studies on the pattern of adrenal response in hens, exposed to a large variety of stressors. The aim of this experiment was to investigate concurrent stress effects of catching, social disruption, crating and unfamiliar environment on the dynamics of plasma corticosterone level and heterophile/lymphocyte ratio in 55 weeks old, Loman breed hens. The hens were raised in a free range housing system. Twenty five hens were chosen at random for blood collection. After catching they were placed in a common crate and carried to a separate room in the same building. Blood samples were taken at 05, 15, 30, 60 and 90 min. after the crating. There was a steady increase in plasma corticosterone over the first 30 min. (P&lt;0.01), followed by gradual decline by 60 and 90 min. (P&lt;0.01) after the crating. Heterophile/ lymphocyte ratio increased significantly at 60 min. after an initial lag period of about 15-20 min. Taken together our results suggest that corticosterone alone, can not be used for animal welfare assessment. Heterophile-to-lymphocyte ratio turns to be reliable indicator of poultry welfare status but it should be combined with measurement of plasma corticosterone in order to obtain a comprehensive view of any particular poultry welfare

EFFECT OF THE PROBIOTIC “LACTINA ” ON SOME BIOLOGICAL PARAMETERS AND NONSPECIFIC RESISTANCE IN NEONATAL PIGS**

Abstract: Twenty four pregnant Danube white sows were allocated to 4 groups. All animals were fed basal diet formulated to meet their nutrient requirements. In addition to the basal diet, the sows from the II group were given the probiotic “Lactina ” (500 g/ton) from the 5 day of pregnancy until the weaning of their offspring (35 days of age) and their piglets were offered 800 g/ton Lactina during the pre-starter period and 500 g/ton throughout the starter period. The probiotic was only supplemented to the sows in the III group and to the piglets of the IV group in the same quantities as those in the second group. Both sows and piglets diets in the I (control) group were not supplemented with Lactina. Blood samples were taken from 20 randomly chosen piglets (5 in each group) at 5 and 35 days of age. The probiotic Lactina, supplemented both to the sows and piglets diets (II group) , increased complement activity in the piglets (P&lt;0.05) at 5 days of age compared to control group, while the addition of Lactina to sows only (III group) or to piglets only (IV group) did not produce significant effect. Supplemental Lactina decreased plasma cholesterol level (P&lt;0.05) at 35 days of age in II group of piglets. Plasma indol level declined in the piglets of the II group at the age of 35 days, while urea level were not changed in any of the Lactina supplemented groups, with the exception of the IV group where the piglets had higher (P&lt;0.001) urea level at 5 days of age. Taken together our results indicate that the beneficial effect of Lactina on the nonspecific response and on the studied biological parameters is most emphasized when the probiotic is supplemented both to the sows and piglets diets. Besides, Lactina stimulated complement activity at the beginning of the neonatal period (5 day) and had no effect at the end of the neonatal period (35 day). D. Gudev, S. Popova-Ralcheva, P. Moneva, M. Ignatov

Effect of weaning on some plasma metabolites in buffalo calves fed diets with or without supplemental chromium picolinate

The objective of this study were 2 fold: to determine whether the weaning (abrupt transition from liquid to solid diet) at the age of 90 days causes stress in buffalo calves, and if so, to alleviate the negative effect of stress by chromium picolinate supplementation (400 &mu;g daily). All buffalo calves were separated from their mothers immediately after birth. Chromium supplementation started 3 days before the weaning and was terminated 5 days later. Plasma cholesterol and indol levels declined significantly after weaning in both groups. Both the weaning and supplemental chromium had no effect on plasma urea level. Our results indicate that when the negative emotional arousal, caused by the interruption of the physical contact mother &ndash; calf, is avoided, as it is in our case, then the abrupt transition from liquid to solid feed at 90 d of age has no stress-inducing effect. Supplemental chromium reduced plasma cortisol levels both before and following the weaning, but had no significant effect on the determined metabolites since its effect is more pronounced during extreme stress load

Physiological indices in buffaloes exposed to sun.

ABSTRACT Ten lactating buffaloes were kept in a barn or exposed to direct solar radiation (air temperature 30.2 0 C) for 12 h. Rectal temperature (RT) and respiratory rate (RR) were measured at 8 h, 11 h, 15 h and 20 h. Both RT and RR increased significantly at temperature -humidity index (THI) -77.83, showing that the lactating buffaloes are sensitive to heat stress and are not able to maintain their core temperature within the thermoneutral zone. The same THI had no significant effect on rectal temperature elevation when the buffaloes were kept in barn. The obvious heat stress, assessed by the rate of RT and RR elevations, was not accompanied with an enhancement of plasma cortisol level. The unchanged plasma cortisol level in the buffaloes under heat is interpreted within the context of the hormonal integration and the modulating effect of hypothalamic-pituitary-adrenal axis on the other endocrine glands involved in the thermal homeostasis maintenance. These data demonstrate that lactating buffaloes need protection against the direct solar radiation