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>0.05) and liver (P<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

Agricultural Academy

Abstract Moneva, P., S. PoPova-Ralcheva, v. SRedkova, M. kRuSteva and d. Gudev, 2011. Reliability of some endocrine and behavioral indices of stress. Bulg. J. Agric. Sci., this investigation accentuates on the reliability of some endocrine (cortisol and prolactin), behavioral (bleating frequency, prevalence of feed and defense response) and immune (heterophil/lymphocyte ratio) indices of stress. our study comprised several experimental designs with laying hens, cows, does and kids. We found sizable stress response to blood sampling procedures that was registered as early as the first minutes after catching of the bird. there were pronounced individual differences in stress-sensitivity demonstrated by plasma cortisol levels which varied from low to high values. heterophil to lymphocyte ratio, unlike cortisol began to change after a latent period of 10-15 min. following the start of stress stimuli. When combined with cortisol this ratio allowed us to differentiate stress stimuli induced by the handling procedures from those induced by a certain environmental and technological factors. Plasma cortisol level turned out to be reliable stress indicator in does, previously habituated to blood sampling procedures. However, kid separation at the time of weaning caused significant plasma cortisol enhancement. there was no stress when the kids were prevented from suckling but remained to their mothers. the frequency of bleating did not correspond to plasma cortisol dynamics indicating that it is not reliable stress indicator in this particular case. exposure of cows to heat stress elicited short-term increase of plasma cortisol followed by a quick decline to values that were within the normal range in spite of the elevated rectal temperature. Plasma prolactin increased and remained high throughout the heat load period. these results demonstrate that plasma cortisol level can not be used as a universal stress-indicator

THYROID HORMONE LEVEL AND RELATIVE LIVER WEIGHT IN MALE TURKEYS IN RELATIONSHIP WITH THEIR WELFARE**

**Original scientific paper Abstract: The objective assessment of poultry welfare is presently a global problem, which is directly related to poultry products. The investigations on the possibilities for evaluation of the physiological comfort of turkeys by the use of alternative indicators are scarce. The aim of the present study was to determine the reliability of liver weight and thyroid hormone level in male turkeys from Local Bulgarian hybrid as indicators of their welfare. Plasma thyroxine levels were determined by radioimmunoassay method (RIA). The relative liver weights and plasma thyroxine levels of the I-st group turkeys (Local hybrid, reared on the litter) were significantly higher than in the II-nd one (Local hybrid, reared on the slat floor). A correlation between plasma thyroxine levels and plasma corticosterone levels in male turkeys, raised on the litter was established. A close relationship was found between liver weight, plasma thyroxine levels and the status of 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<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<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<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

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<0.01), followed by gradual decline by 60 and 90 min. (P<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

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