Tibor Gaál

Effects of rumen-protected choline supplementation on milk production and choline supply of periparturient dairy cows.

The objective of the present study was to determine the effects of rumen-protected choline (RPC) supplementation on body condition, milk production and milk choline content during the periparturient period. Thirty-two Holstein cows were allocated into two groups (RPC group - with RPC supplementation, and control group - without RPC supplementation) 28 days before the expected calving. Cows were fed the experimental diet from 21 days before expected calving until 60 days of lactation. The daily diet of the RPC group contained 100 g of RPC from 21 days before calving until calving and 200 g RPC after calving for 60 days of lactation, which provided 25 g and 50 g per day choline, respectively. Body condition was scored on days -21, 7, 35 and 60 relative to calving. Milk production was measured at every milking; milk fat, protein and choline content were determined on days 7, 35 and 60 of lactation. Body condition was not affected by RPC supplementation. Milk yield was 4.4 kg higher for the group of cows receiving supplementary choline during the 60 days experimental period and 4% fat-corrected milk production was also increased by 2.5 kg/day. Milk fat content was not altered by treatment, but fat yield was increased by 0.10 kg/day as a consequence of higher milk yield in the RPC-treated group. Milk protein content tended to increase by RPC supplementation and a 0.18 kg/day significant improvement of protein yield was detected. Milk choline content increased in both groups after calving as the lactating period advanced. However, milk choline content and choline yield were significantly higher in the RPC group than in the control group. The improved milk choline and choline yield provide evidence that some of the applied RPC escaped ruminal degradation, was absorbed from the small intestine and improved the choline supply of the cows and contributed to the changes of production variables.

Milk production, peripartal liver triglyceride concentration and plasma metabolites of dairy cows fed diets supplemented with calcium soaps or hydrogenated triglycerides of palm oil

The aim of the study was to test the effect of rumen-inert fat supplements of different chemical forms or containing different unsaturated/saturated (U/S) fatty acid contents on milk production, milk composition and liver and blood metabolic variables of high-yielding dairy cows in the peripartal period. Thirty Holstein-Friesian dairy cows were divided into three equal groups and fed a corn silage-based diet, without fat supplementation (control) or supplemented with 11.75 MJ NEl per day of calcium soaps of palm oil fatty acids (CAS; U/S=61/39) or with 11.75 MJ NEl per day of hydrogenated palm oil triglyceride (HTG; U/S=6/94). Each diet was fed from 25+/-2 d prior to the expected calving to 100+/-5 d post partum. Compared with the control, both CAS and HTG supplementation resulted in an increase of the average milk yield. Milk fat content and fat-corrected milk yield were higher in the HTG group but lower in the CAS group than in the control group. In all groups liver triglyceride concentrations (TGL) increased from 15 d prepartum to 5 d post partum, and then decreased thereafter. At 5 d TGL was lower in the HTG group than control or CAS cows. No significant differences were detected in TGL among dietary treatments at 15 d prepartum and 25 d post partum. Higher plasma glucose and insulin and lower non-esterified fatty acids and beta-hydroxybutyrate concentrations and aspartate aminotransferase activity were measured in the HTG group than in the control or CAS groups at 5 d or 25 d post partum. Our results show that HTG may provide a better energy supply for high-yielding dairy cows in negative energy balance than CAS around calving.

Influence of rumen-protected choline on liver composition and blood variables indicating energy balance in periparturient dairy cows

Rumen-protected choline (RPC) was evaluated for effects on the lipid and glycogen content of the liver and metabolic variables in the blood plasma of dairy cows. Thirty-two Holstein cows were allocated into two groups (RPC group with RPC supplementation and control group without RPC supplementation) 28 days before the expected calving. Cows were fed the experimental diet from 21 days before calving until day 60 of lactation. The diet of the RPC group was supplemented with 100 g/day of RPC from 21 days prepartum until calving and 200 g/day of RPC for 60 days postpartum, providing 25 and 50 g of choline, respectively. Liver samples were taken by percutaneous needle biopsy, then analysed for total lipid (TLl), triglyceride (TGl) and glycogen (GLYl) contents on days -21, +7, +35 and +60 relative to calving. Blood was collected on the same sampling days and 21 days after calving. Glucose, non-esterified fatty acid (NEFA), β-hydroxybutyrate (BHBA), triglyceride (TGp), total cholesterol (TCh), urea, ammonia and aspartate aminotransferase (AST) were determined from blood samples. The TLl and TGl contents were 25.0 ± 4.3 g and 25.3 ± 3.8 g per kg wet weight (mean ± SEM), respectively, lower in the RPC group than in the control animals. No significant differences were observed in the GLYl concentrations between the two groups. However, a lower TGl: GLYl ratio was shown in the liver of cows fed the RPC diet as compared to the controls. RPC supplementation decreased BHBA while increasing TGp concentrations were shown in the blood of cows fed the RPC diet, possibly as a consequence of improved lipoprotein synthesis in, and triglyceride excretion from, the liver, together with a reduced rate of ketogenesis.

Hematologic and Plasma Biochemistry Values in White Storks (Ciconia ciconia)

Abstract Hematologic and plasma biochemistry parameters of the white stork (Ciconia ciconia) were studied. Blood samples were taken from a total of 80 adult white storks kept in captivity in Hungarian zoos and bird repatriation stations, between 2002 and 2006. Hematologic (packed cell volume, 46.3% ± 5.3%; hemoglobin concentration, 127.8 ± 20.4 g/L; red blood cell counts, 2.28 ± 0.35 1012/l/l; white blood cell counts, 21.6 ± 4.2 109/l/l; heterophils, 61.0% ± 9.8% [13.1 ± 3.2 × 109/L]; lymphocytes, 34.3% ± 9.1% [7.4 ± 2.5 × 109/L]; monocytes, 3.44% ± 2.3% [0.78 ± 0.57 × 109/L]; eosinophils 0.75% ± 0.91% [0.16 ± 0.21 × 109/L]; basophils 0.38% ± 0.56% [0.04 ± 0.07 × 109/L]) and plasma biochemistry values (aspartate aminotransferase, 267.5 ± 145.8 U/L; L-γ-glutamyltransferase, 47.6 ± 49.3 U/L; lipase, 70.3 ± 60.6 U/L; creatine kinase, 443.9 ± 182.2 U/L; lactate dehydrogenase, 880.4 ± 293.6 U/L; alkaline phosphatase, 177.5 ± 116.6 U/L; amylase, 917.6 ± 314.3 U/L; glutamate dehydrogenase, 7.3 ± 4.0 U/L; total protein, 45.2 ± 8.1 g/L; uric acid, 459.2 ± 254.3 µmol/L; and bile acids, 46.3 ± 20.5 µmol/L) were determined. The results obtained can be used as reference values, because there are no established values previously reported for adult white storks.

Effect of various dietary fat supplementations on liver lipid and glycogen of high-yielding dairy cows in the peripartal period

In a model experiment, Holstein-Friesian dairy cows were fed on a corn-silage-based diet supplemented with 11.75 MJ NE1 per day of calcium soaps of palm oil fatty acids (CAS) or hydrogenated triglyceride (HTG) or without fat supplementation (control). All diets were fed to the cows over a period from 21 +/- 3 days (d) prior to the expected calving to d 100 +/- 5 postpartum. On d 25 (basal sample) and d 14 prepartum as well as on d 5 and 25 postpartum liver samples were collected by percutaneous biopsy. Total lipid content, fatty acid composition and glycogen of liver tissues were determined. At d 5 postpartum, both control and CAS cows had higher liver lipid (P < 0.05) and lower glycogen (P < 0.05) concentrations than cows in the HTG group. No significant (P < 0.05) differences were detected in liver fat content among the groups at d 14 prepartum or d 25 postpartum. The glycogen concentration slightly decreased in the liver of cows in each treatment group from d 14 prepartum to d 5 postpartum; however, this decrease was more intensive in both the control and CAS groups than in the HTG group. The variations in liver lipid concentrations were accompanied by significant changes in the proportion of C16:0, C16:1n-7, C18:0, C18:1n-9, C18:2n-6 and C20:4n-6 fatty acids in the liver lipids. The results show that HTG supplementation exerted more advantageous effects on liver lipid and glycogen metabolism than did CAS supplementation.

The hematology of captive Bobtail lizards (Tiliqua rugosa): blood counts, light microscopy, cytochemistry, and ultrastructure.

INTRODUCTION Bobtail lizards (Tiliqua rugosa) are native to Australia. The only previous study on the hematology of this species documented just 6 animals. OBJECTIVES The aims of this study were to characterize the light microscopy, ultrastructure and cytochemistry of blood cells, and evaluate CBCs of captive Bobtail lizards. METHODS Over 2 consecutive summers, heparinized venous blood was collected from the ventral coccygeal vein of 46 clinically healthy, captive indoor- or outdoor-housed adult Bobtails. Complete blood cell counts and smear evaluations were performed, and cytochemical stains and transmission electron microscopy were used to further characterize blood cells. RESULTS The eosinophils of this species were uniformly vacuolated: a unique feature not previously reported in reptiles. Heterophils were the predominant leukocyte, with fewer lymphocytes, azurophilic and nonazurophilic monocytes, occasional eosinophils, and basophils. Thrombocytes were frequently clumped. Slight polychromasia (0-15% of erythrocytes) was typically present. Hemogregarine parasites were seen on some smears. The range of CBC results was often wide. The PCV ranged from 11% to 38%. Total plasma proteins by refractometry were between 3.5 and 7.8 g/dL. Hemoglobin ranged between 2.6 and 12.6 g/dL by the modified hemoglobin-hydroxylamine method. Manual RBC count was 0.35-1.27 × 106 /μL, and WBC count was 2.86-22.66 × 103 /μL. Bobtail lizards housed outdoors had lower PCVs than indoor-housed animals. Bobtails with hemogregarine infections had lower PCVs than noninfected lizards. CONCLUSIONS Ranges for CBC data were often very wide, influenced by preanalytic and analytic factors. Hemogregarine infection is associated with a decreased PCV, suggesting that some hemogregarine species are pathogenic in this population.

Transudate or exudate: can lactate dehydrogenase activity in canine and feline effusions help to differentiate between the 2?

BACKGROUND Lactate dehydrogenase (LDH) activity is often measured in human effusions to help in differentiating between transudates and exudates. Few studies have been performed using effusion samples from animals. OBJECTIVES The purpose of the study was to determine whether LDH can be used to differentiate between transudative and exudative effusions in dogs and cats (including postmortem samples), and whether there is a difference between different laboratory methods of LDH measurement. METHODS Lactate dehydrogenase activity was measured in canine and feline effusions that were submitted to the Murdoch University Veterinary Hospital Clinical Pathology Laboratory over approximately 12 months using 2 wet and one dry chemistry methods, including 10 effusions collected postmortem. Results were compared to classification using traditional methods for effusion types. RESULTS Lactate dehydrogenase activity was significantly higher in exudates than in transudates, significantly different depending on the method of measurement, and significantly higher in all effusions collected postmortem. An LDH effusion:serum ratio of < 0.5 was associated with transudates. There was no significant difference between samples collected into EDTA or plain serum tubes, in frozen and thawed samples, or after storage at 4°C for 3-7 days. CONCLUSIONS Measurement of LDH activity may be useful in helping to differentiate between transudates and exudates in cats and dogs. The method of measurement must be known and kept consistent if cutoff values are to be used. The LDH activity was increased in all effusions collected from animals after death, potentially invalidating its use postmortem.

Comparison of a qualitative canine C-reactive protein test to a quantitative test and traditional markers of inflammation — Short communication

Qualitative tests for C-reactive protein (CRP) are available for use in dogs, and provide a rapid in-house method of detecting acute inflammation. The aim of this study was to compare results from a qualitative CRP lateral flow test (Teco CRP FASTest) to those obtained from a quantitative CRP ELISA and to traditional methods of detecting inflammation, including total leukocyte and neutrophil numbers, presence of immature neutrophils and a left shift, presence or absence of toxic changes in neutrophils and plasma fibrinogen concentration in whole blood and serum samples collected from 113 client-owned dogs. More dogs had CRP FASTest positive results than had quantitatively increased CRP (ELISA) or increases in traditional methods used for measuring inflammation. Few dogs had increases in markers of inflammation but no elevated CRP. The qualitative CRP FASTest was found to be a sensitive test for detecting increased CRP concentration and was positive more frequently than were traditional markers of inflammation.

Glycogenic induction of thyroid hormone conversion and leptin system activation in the liver of postpartum dairy cows

In the regulation of energy metabolism, the liver plays an important role in the reinforcement of energy production. In periparturient cows the energy homeostasis turns into a negative energy balance that may shift the physiological regulation of energy balance towards pathological processes. Propylene glycol (PG), as a complementary source of energy used in the nutrition of dairy cows, alters systemic thyroid hormone economy; however, the exact mechanism through which highly glycogenic feed supplements impact liver metabolism is little known. Previous studies showed that only leptin receptors are expressed in the liver of cows, and now we report that leptin mRNA is expressed in the liver of cows as well. The present results show that the mRNA of leptin and its receptors are differentially modulated by the increased energy content of the feed consumed. Simultaneous changes in hepatic type I deiodinase activity suggest that hepatic modulation of the leptin system by PG supplementation may be mediated by an increased local thyroxine-triiodothyronine conversion. Since PG supplementation with simultaneous T4-T3 turnover and increased hepatic leptin- and short-form leptin receptor mRNA were not associated with a significant change in hepatic total lipid levels, it is suggested that the leptin system, directly or indirectly modulated by thyroid hormones, may represent a local defence mechanism to prevent fatty liver formation.

Rate of lipid peroxidation in brain and liver tissues and the total antioxidant status of blood plasma in developing chicks.

Age-related changes of tissue lipid peroxidation (LPO) of liver and brain, as well as plasma antioxidant capacity of broiler chicken cockerels were investigated. Tissue LPO was characterised by the spectrophotometric assessment of thiobarbituric acid reactive substances (TBARS). Plasma antioxidant power was evaluated by the measurement of total antioxidant status (TAS). Newly hatched broiler chicks had similar TAS value (1.19 mmol/l) as newborns of mammalian species. Significant changes (p < 0.05) were observed in the time course of all parameters. Tissue TBARS concentration was higher in the brain than in the liver at hatching, while the latter organ was found to have more effective antioxidant defence during embryonic life. The concentration of TBARS increased up to the 10th day in the liver but only up to the 21st day in the brain, and the former was accompanied by an approximately 50% decrease of plasma antioxidant capacity. This suggests that the liver plays an important role in forming the antioxidant defence mechanisms of the blood plasma in broiler chicks.