Ferenc Husvéth

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.

Composition of diet modifies colonization dynamics of Campylobacter jejuni in broiler chickens

To evaluate the impact of diet composition on colonization dynamics of Camp. jejuni and on related physiological parameters in the chicken intestine.

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.

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.

Effect of feeding different oils on plasma corticosterone in broiler chickens

A study was conducted to examine the effects of different oils on the plasma corticosterone concentrations of broiler chickens fed ad libitum or deprived of feed for 24 hours. A total of 36 Ross broilers were randomly assigned to one of three dietary treatments at 10 days of age and fed a grower diet supplemented with 60 g/kg soybean oil (rich in linoleic acid, C18:2n-6), linseed oil (rich in a-linolenic acid, C18:3n-3) or fish oil (rich in C14:0, C16:0, C16:1n-7, C20:1n-9; eicosapentaenoic acid and docosahexaenoic acid, EPA, C20:5n-3 and DHA, C22:6n-3), respectively, for 18 days. Dietary supplementation of fish oil resulted in lower (P < 0.05) baseline plasma corticosterone levels of chickens fed ad libitum for 18 days compared to soybean and linseed oil supplementations. Feed deprivation for 24 h induced a significant (P < 0.05) increase in corticosterone concentration in every treatment group compared to the ad libitum-fed birds. The hormone levels of feed-deprived birds did not differ significantly among groups fed diets supplemented with different oils.

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.

Nutritional modulation of intestinal drug-metabolizing cytochrome P450 by butyrate of different origin in chicken

Intestinal cytochrome P450 (CYP) enzymes play key role in the first pass metabolism of orally ingested xenobiotics, providing a primary metabolic barrier, being of special importance in maintaining animal health and production. This study was aimed to investigate how intestinal drug-metabolizing CYPs can be modulated by nutritional factors in broiler chicken. We investigated the effects of the natural growth promoter (n-)butyrate of different origin (feed supplementation of protected or non-protected forms and/or inducing caecal microbial production by supporting higher level of dietary non-starch polysaccharides [NSP]) on the activity of duodenal CYPs. To observe the connection between intestinal CYP activity and butyrate concentration, the distribution of differently originated butyrate was also assessed by measuring its concentration in various intestinal segments and different vessels of portal and systemic circulation. Butyrate of different origin showed varying distribution properties as being absorbed from different parts of the gastrointestinal tract. Intestinal CYP1A and CYP2H2 activities were increased by dietary butyrate supplementation and by the increased caecal microbial butyrate production, while CYP3A37 activity was minimally influenced by microbial butyrate only. The present study proved that both dietary and microbial butyrate could alter the activity of CYPs in the duodenal epithelium. Our findings suggest that intestinal CYPs could be induced not only by the intestinal luminal butyrate, but also from basolateral side, by the already absorbed butyrate. Such action of butyrate can be of special importance from food safety and pharmacotherapeutic point of view as it may modify the metabolism and intestinal kinetics of simultaneously applied xenobiotics.

Effects of butyrate on the insulin homeostasis of chickens kept on maize- or wheat-based diets

The aim of the present study was to investigate the effects of butyrate as a feed supplement on the expression of insulin signalling proteins as potent regulators of metabolism and growth in Ross 308 broiler chickens fed maize- or wheat-based diets. Both diets were supplemented with non-protected butyrate (1.5 and 3.0 g/kg of diet, respectively) or with protected butyrate (0.2 g/kg of diet); the diet of the control groups was prepared without any additives (control). On day 42 of life, systemic blood samples were drawn for analyses of glucose and insulin concentrations, and tissue samples (liver, gastrocnemius muscle and subcutaneous adipose tissue) were taken for Western blotting examinations. The expression of key insulin signalling proteins (IRβ, PKCζ and mTOR) was assessed by semiquantitative Western blotting from the tissues mentioned. The type of diet had a remarkable influence on the insulin homeostasis of chickens. The wheat-based diet significantly increased IRβ and mTOR expression in the liver as well as mTOR and PKCζ expression in the adipose tissue when compared to animals kept on a maize-based diet. IRβ expression in the liver was stimulated by the lower dose of non-protected butyrate as well, suggesting the potential of butyrate as a feed additive to affect insulin sensitivity. Based on the results obtained, the present study shows new aspects of nutritional factors by comparing the special effects of butyrate as a feed additive and those of the cereal type, presumably in association with dietary non-starch polysaccharide- (NSP-) driven enteric shortchain fatty acid release including butyrate, influencing insulin homeostasis in chickens. As the tissues of chickens have physiologically lower insulin sensitivity compared to mammals, diet-associated induction of the insulin signalling pathway can be of special importance in improving growth and metabolic health.

Effects of high ambient temperature on fish sperm plasma membrane integrity and mitochondrial activity — A flow cytometric study

Local extreme climatic conditions occurring as a result of global climate change may interfere with the reproduction of animals. In the present study fish spermatozoa were incubated at different temperatures (20, 25, 30 and 40 °C) for 10 and 30 minutes, respectively and plasma membrane integrity and mitochondrial membrane potential changes were evaluated with flow cytometry using SYBR-14/PI and Mitotracker Deep Red FM fluorescent dyes. No significant differences were found in plasma membrane integrity at either incubation temperatures or time points. Mitotracker Deep Red FM histogram profiles indicating mitochondrial activity showed significant (p < 0.001) alterations in all cases of higher (25, 30 and 40 °C) temperature treatments as compared to the samples incubated at 20 °C. Our results indicate that fish spermatozoa exposed to high temperatures suffer sublethal damage that cannot be detected with conventional, vital staining techniques.