Sex-related differences of bone properties of pelvic limb and bone metabolism indices in 14-month-old ostriches (Struthio camelus).

1. Sex-related differences of long pelvic limb bones and serum bone metabolism indices were evaluated in 14-month-old female (N = 7) and male (N = 7) ostriches of similar body weights. 2. Densitometric parameters of femur, tibia and tarsometatarsus were determined using quantitative computed tomography (volumetric bone mineral density, calcium hydroxyapatite density and mean volumetric bone mineral density) and dual energy X-ray absorptiometry (bone mineral density and bone mineral content) methods. Geometrical parameters such as cortical bone area, cross-sectional area, second moment of inertia, mean relative wall thickness and cortical index were determined in the midshaft of bones. Mechanical properties of bones (maximum elastic strength and ultimate strength) were evaluated using three-point bending test. Serum concentrations of free amino acids, osteocalcin, N-terminal propeptide of type I procollagen, C-terminal telopeptides of type II collagen and total antioxidative capacity were also determined. 3. Bone weight and relative bone weight of all bones were significantly higher in males than in females. Significantly lower values of trabecular bone mineral density and calcium hydroxyapatite density were found in the trabecular bone of tibia in males. The highest number of the sex-related differences was observed in the tarsometatarsus where bone length, bone mineral content, cortical bone area, cross-sectional area and ultimate strength were higher in males. Serum concentrations of taurine, hydroxyproline, valine and isoleucine were significantly higher in males. 4. Higher loading of the tarsometatarsus in comparison to femur and tibia may be an important factor interacting with sex hormones in regulation of bone formation and mineralisation processes. Sex-related differences of bone properties were associated with increased serum concentration of selected amino acids in males.

Microbiological quality of milk sold directly from producers to consumers.

The aim of this study was to determine the microbiological quality of raw cow milk from direct sale points. Raw cow milk samples were collected from 5 randomly selected direct sale points for microbiological evaluation. The samples were analyzed to determine total aerobic bacterial count, somatic cell count (SCC), counts of Enterobacteriaceae, Enterococcus, Escherichia coli, and Staphylococcus, and presence of Salmonella, Listeria monocytogenes, and inhibitory substances. The mean counts of total aerobic bacterial in samples from all direct sale points were between 9.2×10(4) and 3.6×10(7) cfu/mL. Milk samples collected from 5 direct sale points revealed counts Enterobacteriaceae ranging from 6.4×10(1) to 1.7×10(6) cfu/mL. Escherichia coli were detected in 12 milk samples with counts ranging from 5.0×10(0) to 1.1×10(2) cfu/mL. Staphylococcus spp. bacteria were found in all milk samples, at counts ranging from 1.6×10(3) to 5.1×10(4) cfu/mL. Listeria monocytogenes bacteria were detected in 1 sample, and SCC in all samples ranged from 78,000 to 1,730,000/mL. The examined samples did not contain Salmonella rods or inhibitory substances. In the samples examined in this study, international hygiene standards were exceeded for total aerobic bacterial count (n=48) as well as for SCC (n=19). Two milk samples contained pathogenic bacteria (Listeria monocytogenes and Staphylococcus aureus) that pose a potential hazard for consumer health.

Effects of increased stocking density and heat stress on growth, performance, carcase characteristics and skeletal properties in turkeys.

Effects of increased stocking density and heat stress on growth, feed conversion, carcase characteristics and skeletal system properties in turkeys were determined. One-day-old males (n=1674) were divided into two weight-matched groups exposed to different environmental conditions. Controls were reared at a stocking density of 2.8 birds/m(2) and at thermo-neutral temperature (TnT group), while the experimental group was exposed to heat-stress (HSID group) and reared at a stocking density of 3.4 birds/m(2) and ambient temperature increased by 5°C. At 28 days of age, 27 birds from each group were sacrificed, while at 126 days of age, 54 birds from each group were slaughtered. Increased stocking density and ambient temperature during the first four weeks of life increased the body weight (BW) of turkeys and weight, length, volume, vertical internal and horizontal external diameters of the tibia in the HSID group compared with the TnT group (P<0.05). In turkeys older than four weeks, increased stocking density and ambient temperature significantly decreased daily feed intake, final BW and relative weight of drumstick muscle by 4.7 per cent, 4.0 per cent and 3.3 per cent, respectively (P<0.05). The weight, length, volume, vertical and horizontal diameters, cross-sectional area, second moment of inertia, volumetric bone mineral density, maximum elastic strength and ultimate strength of bones were significantly lower in turkeys in the HSID group (P<0.05) at 126 days compared with turkeys in the TnT group at the same age. These results indicate that, up to four weeks of age, turkeys tolerate increased stocking density and heat stress better than birds between 5 and 18 weeks of age.

Assessment of extent of apoptosis and DNA defragmentation in chilled semen of stallions during the breeding season.

The objective of the study was to assess apoptosis and DNA defragmentation in equine semen diluted and chilled to +4°C. Semen was collected from nine fertile stallions, including four Arabian thoroughbreds and five coldbloods. Examinations were carried out immediately after semen collection (0) and at five storage times (24, 48, 72, 96 and 120 h). The basic semen evaluation was performed in terms of volume, sperm concentration, viable sperm percentage, progressive motility and morphology. Using flow cytometry, DNA defragmentation and cell membrane integrity of spermatozoa were determined. The results of basic tests did not demonstrate significant differences amongst stallions, except for progressive sperm motility, which was significantly higher (p < 0.05) in the semen of Arabian stallions. In the semen of the same stallions, a significant decrease in the percentage of alive spermatozoa was observed at 72, 96 and 120 h of storage, whereas a significant increase in the number of spermatozoa with DNA defragmentation was found after 24 h storage. In the semen of coldblood stallions, significantly reduced live spermatozoa percentage was observed at 96 and 120 h, while increased DNA defragmentation was observed at 48 h. These findings demonstrated that the semen of Arabian stallions chilled to +4°C retained original characteristics until 24 h of storage, whereas in coldbloods, these were preserved up to 48 h of storage.

Effects of dietary calcium content and vitamin D source on skeletal properties in growing turkeys.

1. The aim of the study was to investigate the effects of feeding fast growing turkeys with differentiated dietary calcium (Ca) content, and the partial replacement of vitamin D(3) in the feed with 25-hydroxycholecalciferol (25(OH)D(3)), on skeletal properties. 2. One-day-old Big-6 male turkeys (n = 1008) were randomly divided into 4 groups, and two subgroups were created within each group. The groups were differentiated with 4 levels of Ca provision in the feed, namely 85% of the National Research Council (NRC) recommendation (Group Ca(1)); 95% as above (Group Ca(2)); 105% as above (Group Ca(3)); and 115% as above (Group Ca(4)). The first subgroup received the recommended dosage of cholecalciferol (vitamin D(3) subgroup) in the feed, while in the second subgroup (Hy-D subgroup), half of the dosage of cholecalciferol was replaced with 25(OH)D(3). At the ages of 4, 8, 12 and 20 weeks, 7 turkeys from each subgroup were randomly selected and killed to obtain the right tibia for densitometric, geometric and mechanical analyses. 3. This study showed advantageous effects of increased calcium supply in the diet on skeletal system properties, that were increased and produced the most desirable traits in turkeys receiving 95%, 105% and 115% of the NRC calcium recommendation. Benefits resulting from administration of 25(OH)D(3) in the diet were also obtained in the skeletal formation of turkeys, and the most advantageous effects were present in the group receiving 105% of recommended dietary Ca. 4. Effects on the metabolic response of the skeleton of turkeys to manipulation of dietary calcium content and vitamin D(3) source were the most evident in the groups between 4 and 12 weeks of life, and demonstrated a limited ability to induce a positive influence on bone properties at advanced stages of the production cycle by alteration of these dietary factors.

Alpha-ketoglutarate protects the liver of piglets exposed during prenatal life to chronic excess of dexamethasone from metabolic and structural changes.

Glucocorticoids play a role in the origin of the features of the metabolic diseases. Alpha-ketoglutarate (AKG) is defined as glutamine homologue and derivative, conditionally an essential amino acid. In the liver, glutamine serves as a precursor for ureagenesis, gluconeogenesis and acute phase protein synthesis The aim of the study was to determine the effect of AKG administered to piglets prenatally exposed to dexamethasone, on the structure of the liver and its metabolic function. Sows were administered with dexamethasone (3 mg/sow/48 h) from day 70 of pregnancy to the parturition, and then after the birth, the piglets were divided into the group administered with AKG (0.4 g/kg body weight) or physiological saline. Biochemical markers, lysozyme and ceruloplasmin serum activities, concentrations of selected free amino acids, macro- and microelements and histomorphometry of the liver tissue were determined. The total cholesterol concentrations in the sows and their newborns from the Dex groups were higher by 72% and 64%, respectively, compared with the control groups. Triacylglycerol concentration was higher by 50% in sows from the Dex group and 55% in the new-born piglets. Alpha-ketoglutarate administered to the piglets after prenatal influence of dexamethasone lowered the total cholesterol concentration by 40%, and enhanced aspartate by 41%, serine by 76%, glutamate by 105%, glutamine by 36%, glycine by 53% and arginine by 105%, as well as methionine and cystathionine, but increased the sulphur concentration compared with the control (p < 0.01). Intracellular space D decreased after AKG administration in comparison with the piglets from Dex/Control group not treated with AKG. Postnatal administration of AKG had a protective effect on liver structure, and lowered the total cholesterol concentration in piglets prenatally exposed to dexamethasone, and also influenced selected macro- and microelement serum concentrations and amino acids plasma concentration.

Effect of ß-hydroxy-ß-methylbutyrate (HMB) administration on volumetric bone mineral density, and morphometric and mechanical properties of tibia in male turkeys.

This study was performed to investigate the effects of ß-hydroxy-ß-methylbutyrate (HMB) administration on skeletal system properties in turkeys. Thirty-two males were randomly divided into two groups at the age of 35 days of life. The first group included control turkeys (n = 16) treated with placebo, while the second group of birds (HMB group; n = 16) was administered orally with calcium salt of HMB during the last 15 weeks of life. The turkeys were sacrificed at the age of 20 weeks and tibia was isolated for analysis of bone geometrical parameters, volumetric bone mineral density (vBMD) and mechanical properties. Furthermore, assessment of free amino acid concentrations in plasma was performed. The results showed a 6.3% increase of vBMD of tibia in response to HMB treatment (p < 0.01). Cross-sectional area, second moment of inertia, maximum elastic strength and ultimate strength of tibia were significantly increased in HMB-treated turkeys by 21.3%, 49.0%, 27.2% and 28.3%, respectively (p ≤ 0.01). ß-hydroxy-ß-methylbutyrate administration increased plasma concentrations of proline,glutamate, leucine, isoleucine, valine, alanine, aspartate, phenylalanine and cysteic acid (p < 0.05). These results indicate that long-term administration of HMB improves vBMD, and geometrical and mechanical properties of skeletal system in turkeys, and that these effects are associated with improved plasma amino acid concentrations.

The long-term effect of alpha-ketoglutarate, given early in postnatal life, on both growth and various bone parameters in pigs.

The long-term effect of alpha-ketoglutarate (AKG) given for 21-24 days post-partum, on the skeleton of commercial pigs, was investigated. In experiment A, 12 pigs were given AKG [0.1 g/kg of body weight (b.w.) per day per os], while 12 controls were administered vehicle. At day 169, the left and right femur, humerus and sixth ribs were analysed for mechanical and geometrical properties and quantitative computed tomography. In experiment B, 32 piglets were divided equally into an AKG group (0.3 g/kg of b.w. per day) or a control group. Blood, taken at days 24 and 53 was analysed for plasma 17 beta-oestradiol. The main bone effect of AKG was to increase bone length in the sixth rib (7.3%, p < 0.01), ultimate strength (23%, p < 0.05), Young s modulus (52%, p < 0.001) and maximum elastic strength (31%, p = 0.056) compared with controls. In both experiments, AKG preferentially increased the growth of female piglets, whilst for male piglets AKG had the opposite effect. In addition, AKG elevated plasma 17 beta-oestradiol levels compared to those of controls at the end of the period of treatment (20%, p = 0.002). It is concluded that AKG has long-term effects on rib properties when given early in postnatal life whilst it elevates plasma 17 beta-oestradiol levels only so long as it is being administered.

Effect of maternal dexamethasone and alpha-ketoglutarate administration on skeletal development during the last three weeks of prenatal life in pigs.

BACKGROUND: The effect of dexamethasone (Dex) on postnatal bone formation processes is known to decrease the synthesis of collagen and bone matrix, but the effect of alpha-ketoglutarate (AKG) is to induce positive effects on growth and skeletal development during postnatal life. However, the effects of Dex and AKG treatment on the prenatal processes of skeletal development have not been investigated so far. OBJECTIVE: The aim of this study was to determine the effect of Dex and AKG administered separately or simultaneously to sows during the last three weeks of pregnancy on the skeletal development in fetuses. METHODS: Immediately after birth blood samples were collected from non-suckling piglets for alkaline phosphatase and osteocalcin determinations, and the humeri were isolated. Bone mineral density (BMD) and bone mineral content (BMC) of humeri and the geometric and mechanical properties were evaluated. RESULTS: Dex and AKG administered separately to pregnant sows during the last 24 days of prenatal life decreased BMD, BMC, and geometric and mechanical parameters of humeri in the newborns. Simultaneous administration of Dex and AKG significantly increased the analyzed properties of humeri. CONCLUSION: The bone mineral density and mechanical and geometric properties of humeri indicate an inverse effect of maternal separate or simultaneous administration of AKG and Dex to sows on bone development during the last 24 days of prenatal life.

Effects of alpha-ketoglutarate on bone homeostasis and plasma amino acids in turkeys.

The objective of the study was to evaluate the effect of denervation and alpha-ketoglutarate (AKG) administration on the development of osteopenia in the turkey radius. At 22 d of age, all turkeys were subjected to neurectomy of the right radius. Control turkeys were given a saline solution into the crop each day for 97 d. Experimental turkeys were given 0.4 g of AKG/kg of BW into the crop each day. After 98 d, BW was not affected by the AKG treatment. Volumetric bone mineral density of the radius was measured by quantitative computed tomography. Mechanical properties were tested using a 3-point bending test. Cross-sectional area, second moment of inertia, and mean relative wall thickness were measured as well. Amino acid concentrations were assessed with the use of ion-exchange chromatography. Denervation had a negative effect on all bone characteristics that were measured except bone length. The AKG had a positive effect on all bone characteristics except bone length. Plasma concentrations of proline and leucine were increased by AKG, whereas concentrations of taurine and glutamine were decreased. The turkey radius appears to be a good model for studying osteopenia because its development can be affected by treatments such as denervation and AKG administration.

Long-term denervation of the humerus in turkeys as an experimental model for osteopenia.

The aim of this study was to evaluate the influence of long-term denervation on volumetric bone mineral density, and geometrical and mechanical properties of the humerus in turkeys. The experiment was conducted from d 22 after hatching until wk 17 of life. All experimental birds (male turkeys) were randomly divided into 2 weight-matched groups. The first group of turkeys served as the control group and underwent a sham operation on the right wing, and the second group was subjected to surgical denervation of the right humerus. The denervation was performed by neurectomy of the radialis and the mediano-ulnaris nerves in the region of the proximal epiphysis of the humerus. All the left wings within both groups were surgically untouched. The left humerus served as the control bone to the right humerus in both investigated groups. Effect of denervation of humerus was determined in terms of geometrical and mechanical properties and quantitative computed tomography. The denervation of the humerus in turkeys significantly decreased volumetric bone mineral density, and geometrical and mechanical properties of this bone, when compared with the results obtained in humerus from the sham-operated or surgically untouched wings. However, no significant differences between right and left humerus were observed when analyzing all of the investigated parameters in the sham-operated group of turkeys. It is concluded that long-term denervation of humerus in turkeys induces osteopenia and may serve as a new experimental model for investigating factors that affect skeletal homeostasis in poultry and other vertebrates.

Alpha-ketoglutarate treatment early in postnatal life improves bone density in lambs at slaughter.

This study has investigated the long-term effect on skeletal development of a short postnatal period of oral alpha-ketoglutarate (AKG) administration, a compound known to regulate the synthesis of proline, which in turn is important for collagen production. Male lambs born to Shropshire ewes were used in this study. Lambs were randomly assigned to either an AKG-treated group or a control group receiving an equal volume of distilled water. AKG-treated lambs received 0.1 g/kg body weight orally from the first 14 days of postnatal life. Lambs were slaughtered at approximately 130 day of life and a body weight of 43-49 kg. Plasma samples, collected from lambs at days 14 and 130, were analyzed for IGF-1 concentration using sheep-specific RIA kits. Bone development was determined on the femur in terms of geometrical and mechanical properties and quantitative computed tomography (QCT). Trabecular bone density, cortical bone density, and the mechanical properties of the bones were significantly higher for AKG-treated compared with control lambs. However, neither plasma IGF-1 concentration nor the geometrical properties of the bones were significantly influenced by AKG treatment. It is concluded that early postnatal treatment of lambs with AKG positively affects bone strength, an effect that does not appear to be mediated by an increased plasma IGF-1 concentration.