Effects of dietary oleuropein supplementation on growth performance,serum lipid concentrations and lipid oxidation of Japanese quails

An in vivo experiment was conducted to compare the effects of dietary supplementation with oleuropein and/or α‐tocopheryl acetate on growth performance, serum lipid concentrations and lipid oxidation of Japanese quail meat during refrigerated storage. Performance and slaughtering parameters were not affected by dietary treatments. The diets supplemented with oleuropein at the levels of 150 or 200 mg/kg were more effective in delaying lipid oxidation in breast and thigh meats compared with the control diet. The dietary inclusion of neither vitamin E nor oleuropein at different levels did not significantly affect the fatty acid compositions of the breast meat compared with the control diet. The diets supplemented with oleuropein at the levels of 150 or 200 mg/kg had significantly the highest polyunsaturated fatty acid and omega‐3 fatty acid contents in thigh meat compared with the vitamin E diet. The ratio of omega‐6 fatty acids to omega‐3 FAs in thigh meat of quails fed diet supplemented with vitamin E at the level of 200 mg/kg was equivalent to those of quails fed the diets supplemented with oleuropein at the levels of 100 and 150 mg/kg . The results showed that the dietary oleuropein supplementation at 150 mg/kg level may be used in quail diets enriched with the polyunsaturated fatty acids of vitamin E as a natural antioxidant.     

Effect of vitamin A on the oxidative stability of broiler meat during storage: Lack of interactions with vitamin E

1. An experiment was carried out with male broiler chicks to evaluate the combined effect of two concentrations of vitamin A (1.032 and 10.32 mg retinyl acetate/kg diet) and two concentrations of vitamin E (0 and 150 mg a‐tocopheryl acetate/kg diet) on the oxidative stability of the drumstick meat of broiler chickens. The experimental diets were fed from 1 to 42 d of age. The oxidative stability, evaluated by thiobarbituric acid reactive substances (TBARS) values, was determined after 125 d of storage at — 18°C.

2. TBARS values were very low and not significantly affected by dietary vitamins A and E or their combinations. However, the TBARS values in the meat of birds fed on the vitamin E‐free diets, but not on the vitamin E‐supplemented diets, were markedly increased after using an accelerated test of oxidation of the meat lipids by incubation. This resulted in a significant (P< 0.001) difference from vitamin E supplementation. Vitamin A, alone or in combination with vitamin E, did not affect TBARS values found after incubation.

3. It is concluded that vitamin A at the concentrations used had no effect on the oxidative stability of the meat, in contrast to the protective effect of vitamin E, and that there is no interaction between the effect of these two vitamins on meat stability.     

Effect of monensin and vitamin E on milk production and composition of lactating dairy cows

Feeding unsaturated oils to lactating dairy cows impair ruminal biohydrogenation (BH) of unsaturated fatty acids (USFA) and increase ruminal outflow of BH intermediates such as trans‐10, cis‐12 CLA that are considered to be potent inhibitors of milk fat synthesis. Supplementing lactating dairy cow’s rations containing plant origin oils with monensin and/or vitamin E may minimise the formation of trans‐10 isomers in the rumen, thereby preventing milk fat depression. Therefore, this study was conducted to evaluate the effects of monensin and vitamin E supplementation in the diets of lactating dairy cows containing whole cottonseed, as the main source of FA on feed intake, milk production and composition, milk fatty acid profile, efficiency of nitrogen (N) utilisation, efficiency of net energy (NE) utilisation and nutrients digestibilities. Four multiparous Holstein lactating dairy cows (86 ± 41 days in milk) were assigned to a balanced 4 × 4 Latin square design. Each experimental period lasted 21 days with a 14 days of treatment adaptation and a 7 days of data collection. The control diet was a total mixed ration (TMR) consisted of 430 g/kg forage and 570 g/kg of a concentrate mixture on dry matter (DM) basis. Cows were randomly assigned to one of the four dietary treatments including control diet (C), control diet supplemented with 150 mg of vitamin E/kg of DM (E), control diet supplemented with 24 mg of monensin/kg of DM (M) and control diet supplemented with 150 mg of vitamin E and 24 mg of monensin/kg of DM (EM). Dry matter intake (DMI) ranged from 19.1 to 19.5 kg/d and was similar among the dietary treatments. Dietary supplementation with vitamin E or monensin had no effect on milk production, milk fat, protein and lactose concentrations, efficiency of utilisation of nitrogen and net energy for lactation (NE_L). Digestibility of DM, organic matter (OM), crude protein (CP) and ether extract (EE) was not affected by the dietary treatments. Digestibility of neutral detergent fibre (NDF) was higher in cows fed with the M and EM diets in relation to those fed the C and E diets. The concentrations of C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C15:0, trans‐10‐16:1, cis‐9‐16:1, 17:0, 18:0, trans‐11‐18:1, cis‐9‐18:1, cis‐9, trans‐11 conjugated linoleic acid (CLA), trans‐10, cis‐12 CLA, and 18:3n‐3 FA in milk fat were not affected by the dietary supplementations. While feeding the M diet tended to decrease milk fat concentration of C16:0, the milk fat concentration of C18:2n‐6 FA tended to be increased. Dietary supplementation with vitamin E or monensin had no effect on milk fat concentrations of saturated, unsaturated, monounsaturated, polyunsaturated, short chain and long chain FA, but feeding the M diet numerically decreased milk fat concentration of medium chain fatty acids (MCFA). The results showed that vitamin E and/or monensin supplementations did not improve milk fat content and did not minimise the formation of trans‐10 FA isomers in the rumen when whole cottonseed was included in the diet as the main source of fatty acids.     

Assessment of α-tocopheryl acetate supplementation,addition of salt and packaging on the oxidative stability of raw turkey meat

1. One-day-old turkey poults (n=14) were randomised into 2 groups (n=7) and fed diets containing 20 (E20) and 600 (E600) mg all-rac-α-tocopheryl acetate/kg food for 21 weeks prior to slaughter. Two batches were formed from E20 meat (E20) and E20 plus 10 g salt/kg (E20S). Two similar batches were formed from E600 meat (E600) and E600 plus 10 g salt/kg (E600S). 2. The effects of α-tocopheryl acetate supplementation and salt addition on the oxidative stability of raw turkey patties was investigated during aerobic and vacuum-packaged refrigerated (4°C) storage. 3. Dietary α-tocopheryl acetate supplementation reduced TBARS (thiobarbituric acid reacting substances) numbers for raw overwrapped and vacuum-packaged turkey leg and breast patties. 4. Dietary α-tocopheryl acetate had the greatest influence on TBARS numbers for raw overwrapped turkey leg patties. 5. The addition of 10 g salt/kg increased TBARS numbers for overwrapped and vacuum-packaged turkey leg and breast patties. 6. Vacuum-packaged patties remained more oxidatively stable than similarly treated overwrapped patties throughout the experimental period.     

Effect of a dietary supplementation with linseed oil and selenium to growing rabbits on their productive performances,carcass traits and fresh and cooked meat quality

The present experiment tested a dietary supplementation with linseed oil and selenium to growing rabbits. The basal diet (B) contained 3% sunflower oil, while it was substituted with 3% linseed oil in the experimental feed (S). The selenium (Se) content of the two diets was 0.10 vs. 0.46 mg/kg. Rabbits were fed with B diet from the age of 18 days. One group was fed with the B diet until 11 weeks of age (group B), whereas the experimental groups were fed with S diet for 1, 2, 3 or 4 weeks (groups S1, S2, S3 and S4, respectively), before slaughtering (11 weeks of age). Live performance and carcass traits of rabbits, fatty acid (FA) profile and selenium content of their hind leg (HL) and Longissimus thoracis et lumborum (LTL) meat were considered in this study. In addition, the effect of two different cooking methods on the nutritional value of the enriched HL meat was also assessed. The tested dietary supplementation only minimally affected the live performance and carcass traits of rabbits. The S supplementation significantly reduced the Σ n‐6 FA and increased the Σ n‐3 FA of the HL meat and LTL meat, compared to the B diet (p < 0.001); thus, n‐6/n‐3 ratio was improved (p < 0.001). In addition, HL meat and LTL meat of S fed rabbits were significantly enriched in Se reaching a twofold increase in both meat cuts (p < 0.01). Therefore, the S supplementation improved the functional value of the rabbit meat. The heat treatment affected cooking loss, Se and vitamin E contents as well as the oxidative status of the HL meat (p < 0.001), with the different cooking methods providing different results. In addition, even if the beneficial C20:5 n‐3 and C22:6 n‐3 decreased with cooking, the n‐6/n‐3 ratio remained unaffected.     

Effects of commercial premix vitamin level on sternum growth,calcification and carcass traits in meat duck

The present study was conducted to investigate the effects of dietary vitamin level on sternum growth, calcification and carcass traits in meat duck. A total of 432 1‐d‐old mixed‐sex Cherry Valley ducks (216 males and 216 females) were randomly allocated and fed low‐vitamin level diet (70% NRC vitamin regimen), high‐vitamin level diet (DSM vitamin regimen) or medium‐vitamin level diet (50% low‐vitamin level diet and 50% high‐vitamin level diet). Sternum and serum were harvested after 49 d of feeding. Compared with the low‐vitamin level group, dietary high‐vitamin level increased body weight (BW) at d 49 (p = 0.029) but did not alter all parameters of carcass trait (p > 0.05). Medium‐ and high‐vitamin level increased sternum defatted weight, density, ash and calcium (Ca) concentration (p < 0.05). Meanwhile, the medium and high‐vitamin level group significantly decreased the relative proportions of the keel cartilage at 49 d (p < 0.05) and decreased the sternum length and height (p < 0.05) in meat ducks at 49 d. Likewise, high‐vitamin level improved serum Ca and phosphate (P) content (p < 0.05) and declined serum Alkaline phosphatase (ALP) activity (p = 0.003) compared with the low‐vitamin level group. Our study indicates that high‐vitamin level did not affect the examined carcass traits; however, high‐vitamin level improved growth performance and sternum calcification.     

Vitamin C Overcomes the Detrimental Effect of Vanadium on Brown Eggshell Pigmentation

Phosphorus supplementation from poor quality feed-grade sources may introduce excessive levels of vanadium (V) into the diets of laying hens. Vanadium in the diet of chickens has been shown to be detrimental to egg production, albumen height, BW, and feed consumption. This study showed that dietary V also has a negative effect on the color of brown eggshells from commercial-type layers. Commercial-type brown egg layers were fed a cornsoybean meal basal diet supplemented with 0, 50, or 100 ppm of V as NH₄ VO₃ to determine the effect on shell pigmentation. Hens fed V at both dietary concentrations laid lighter colored eggs (less redness) after only 2 d. Another experimental group of the same type of hens that were fed lower V concentrations (0, 15, or 30 ppm) also had less shell pigmentation. After the detrimental “bleaching” effect on shell color was observed, these diets were supplemented with 1 of the following: no supplement, 100 ppm of vitamin C, 100 IU of vitamin E, or 100 ppm of β-carotene. Only vitamin C restored the eggshell color of eggs from hens fed both levels of V. When these same antioxidants were added as preventive agents to diets supplemented with 15 ppm of V before the effects of V were established, brown layers benefited again from 100 ppm of vitamin C but not from vitamin E or β-carotene.     

Effects of low protein diet and low protein diet supplemented with synthetic essential amino acids on meat quality of broiler chickens

We investigated the effects of a low crude protein (CP) diet and a low CP diet supplemented with synthetic essential amino acids (EAA) on the meat quality of broiler chickens. Twenty‐one‐day‐old chickens were assigned to one of three diets: control, low CP (LCP), or low CP supplemented with EAA (ELCP). The chickens received these diets for 10 days. The shear force value (SFV) and free glutamate content of the Pectoralis major muscle were measured as indicators of the meat toughness and taste. The collagen and crude fat content of the muscle and the cross‐sectional area of myofibers were measured to evaluate the effects of the LCP and ELCP diets on meat toughness. The SFV of the ELCP group was 47% lower than that of the control group (P < 0.01). However, the LCP diet did not affect the SFV. The collagen and crude fat content were not affected by the dietary treatment. The cross‐sectional area was lower in the LCP and ELCP groups (P < 0.05) than the control group. The free glutamate content of muscle was not affected by the dietary treatment. Thus, a low CP diet supplemented with EAA is an effective means of producing tender meat.     

Effect of Dietary Vitamin E on Cortisol and Glucose Responses to Handling Stress in Juvenile Beluga Huso huso

Abstract

An 8-week feeding experiment was conducted to investigate the effect of dietary vitamin E on the physiological response to handling stress in juvenile beluga Huso huso. Fish were fed six experimental diets supplemented with 0, 25, 50, 100, 200, or 400 mg Dl-all-rac-α-tocopherol acetate/kg diet. At the end of the experiment, the fish in each tank were subjected to acute handling and air exposure stress. Cortisol and glucose were measured as the primary hormonal and secondary metabolic responses to the stressors, both before and 3 h after application of the stressors. The growth parameters and feed utilization rates were significantly lower in fish fed the diet not supplemented with vitamin E than in fish fed diets supplemented with vitamin E. Cortisol concentration was not affected by dietary treatment but glucose concentration was. Fish fed vitamin E at 0, 25, 100, and 400 mg/kg diet had higher concentrations of glucose than those fed vitamin E at 50 and 200 mg/kg. However, fish fed diets with 50 and 200 mg/kg exhibited higher growth rates. These results indicate that dietary vitamin E has some effect on plasma glucose but no effect on plasma cortisol. In general, when the stressors were applied to belugas, the glucose and cortisol responses were relatively low. This may be due to higher resistance and lower physiological responses to these types of stressors by this species or by chondrosteans in general.

Received January 10, 2011; accepted August 4, 2011     

Excess dietary tryptophan mitigates aflatoxicosis in growing quails

A biological assay was carried out to evaluate the impact of dietary tryptophan (TRP) in aflatoxin B₁‐contaminated diets (AFB₁‐D) on performance, blood parameters, immunity, meat quality and microbial populations of intestine in Japanese quails. Six experimental diets were formulated to include two levels of dietary TRP; 2.9 (moderate high: MH‐TRP) and 4.9 g/kg (excess: Ex‐TRP); and three levels of AFB₁ (0.0, 2.5, and 5.0 mg/kg). Each experimental diet was fed to the one of the six groups of birds from 7 to 35 days of age in a completely randomized design with 2 × 3 factorial arrangement. Decrease in feed intake, body weight gain and gain:feed in birds fed 5.0 mg/kg AFB₁‐D was restored to the control level by 4.9 g TRP/kg of the diet. The hepatic enzymes in blood were elevated in quails fed on AFB₁‐D but attenuated by 4.9 g TRP/kg of the diet (Ex‐TRP; p ≤ .01). High serum uric acid in birds challenged with AFB₁ significantly decreased by Ex‐TRP (p ≤ .01). The skin thickness to 2,4‐dinitro‐1‐chlorobenzene challenge suppressed by AFB₁ but increased by Ex‐TRP diet (p ≤ .02). The AFB₁ increased the malondialdehyde in meat, whereas TRP efficiently diminished malondialdehyde production (p ≤ .01). The greatest drip loss and pH in meat were observed in the birds fed 5.0 mg/kg AFB₁‐D but Ex‐TRP augmented the adverse effects of AFB₁ (p ≤ .01). The Ex‐TRP reduced the total microbial and Escherichia coli counts (p ≤ .01). The adverse effect of AFB₁ on ileal Lactic acid bacteria was completely prevented by Ex‐TRP (p ≤ .03). This study showed that tryptophan supplementation could be considered as a powerful nutritional tool to ameliorate the adverse effects of AFB₁ in growing quails.     

Effects of nutritional level of concentrate‐based diets on meat quality and expression levels of genes related to meat quality in Hainan black goats

The present study investigated the effects of the nutritional levels of diets on meat quality and related gene expression in Hainan black goat. Twenty‐four goats were divided into six dietary treatments and were fed a concentrate‐based diet with two levels of crude protein (CP) (15% or 17%) and three levels of digestive energy (DE) (11.72, 12.55 or 13.39 MJ/kg DM) for 90 days. Goats fed the concentrate‐based diet with 17% CP had significantly (P < 0.05) higher average daily gains (ADG) and better feed conversion rates (FCR). The pH _24h value tended to decrease (P < 0.05) with increasing DE levels. The tenderness of Longissimus dorsi muscle (LD) and Semimembranosus muscle (SM) reduced with increasing CP levels (P < 0.05). With increasing DE levels, tenderness was increased (P < 0.05). The heart fatty acid‐binding protein (H‐FABP) mRNA expression levels in LD and SM increased with increasing DE levels (P < 0.05), but decreased with increasing CP levels (P < 0.05). The calpastatin (CAST) and μ‐calpain mRNA expressions levels in LD and SM were affected significantly (P < 0.05) by CP and DE levels in the diet. Therefore, the nutritional levels of diets affect meat quality and expression levels of genes associated with meat quality in Hainan black goats.     

Comparison of effects of dietary olive oil,tallow and vitamin E on the quality of broiler meat and meat products

1. The effect of dietary fat and vitamin E supplementation on quality attributes (drip loss, oxidative stability, sensory quality) in chicken meat and meat products was investigated. Broiler chicks were fed on diets containing tallow (60 g/kg) or olive oil (60 g/kg) at a basal (30 mg/kg diet) or supplemental (200 mg/kg diet) concentration of alpha-tocopheryl acetate for 8 weeks. The alpha-tocopherol content and fatty acid composition of breast and thigh meat was determined. Drip loss was determined in breast fillets. Lipid oxidation (thiobarbituric acid-reacting substances/TBARS) and sensory quality (warmed-over flavour development/WOF) were assessed in minced thigh meat during storage. 2. Dietary olive oil increased the ratio of monounsaturated to saturated fatty acids (MUFA/SFA) in the diets. In breast and thigh, this resulted in approximately a two-fold increase in the MUFA/SFA ratio. Supplemental alpha-tocopherol increased the alpha-tocopherol content of muscles. 3. Dietary fat did not influence drip loss in thawed breast fillets during refrigerated storage, but supplemental alpha-tocopherol reduced drip loss. 4. TBARS and WOF development in minced thigh meat patties were also reduced by supplemental alpha-tocopherol following frozen storage, or cooking and refrigerated storage. Storage stability was not adversely affected by dietary fat. 5. Overall, the results showed that increasing the monounsaturated profile of chicken meat lipids did not adversely affect quality characteristics. Dietary alpha-tocopherol supplementation was a more important factor in the determination of broiler meat quality.     

Effects of alpha-tocopheryl acetate supplementation and salt addition on the oxidative stability (TBARS) and warmed-over flavour (WOF) of cooked turkey meat.

1. Day-old turkey poults (n = 14) were randomly divided into 2 groups (n = 7) and fed diets containing 20 (E20) and 600 (E600) mg all-rac-alpha-tocopheryl acetate/kg food for 21 weeks prior to slaughter. Following slaughter, breast and leg meat was removed and 4 batches of patties were produced from each. Two of the batches were formed from E20 meat (E20) and E20 plus 1% salt (E20S). Two similar batches were formed from E600 meat (E600) and E600 plus 1% salt (E600S). 2. Patties were fried, cooled and overwrapped with high oxygen-permeable film. Overwrapped patties were displayed in a 4 microC cabinet under fluorescent light (616 lux). Lipid oxidation (TBARS numbers) was determined on d 0, 2, 4, 6, 8 and 10, while taste panels to assess warmed-over flavour (WOF) were carried out on d 0, 2 and 4 of refrigerated (4 degrees C) display. 3. In the case of both leg and breast meat, E600 patties were the least susceptible of the 4 treatment batches to lipid oxidation. Salt had the effect of promoting lipid oxidation, with E20S and E600S patties having higher TBARS numbers than the corresponding patty batches where salt was absent. 4. Taste panel results showed that leg and breast patties formed from the meat of turkeys given alpha-tocopheryl acetate enriched diets developed significantly (P < 0.05) less WOF than those formed from control turkey meat on d 2 and 4 of refrigerated (4 degrees C) display. Patties containing 1% salt generally exhibited a greater degree of WOF than patties without salt. 5. A linear relationship was observed between TBARS numbers and WOF percentages for all batches of leg and breast patties.     

Vitamin E and organic selenium enhances the antioxidative status and quality of chicken semen under high ambient temperature

1. The effects of supplemental dietary vitamin E and organic selenium (Se), and their combination, on improving semen quality characteristics and antioxidative status were investigated in cockerels exposed to high ambient temperature.

2. A total of 36 Egyptian local cross males, 40 weeks old, were housed individually in cages in an open-sided building (average daily temperature ranged from 33 to 36°C and relative humidity from 60 to 70%). Birds were divided randomly into 4 experimental treatments (n?=?9 each): (1) control (basal diet without any supplementation with vitamin E or Se); (2) vitamin E (basal diet +200?mg α-tocopherol acetate/kg diet); (3) Se (basal diet +0·3?mg organic Se/kg diet); and (4) vitamin E?+?Se (basal diet +200?mg α-tocopherol acetate/kg diet +0·3?mg organic Se/kg diet).

3. Under heat stress conditions, inclusion of vitamin E and/or organic Se in the diets enhanced the semen quality traits, including the spermatozoa count and motility, and reduced the percentage of dead spermatozoa.

4. A combination of 200?mg/kg vitamin E with 0·3?mg/kg organic Se reduced the thiobarbituric acid reactive substance concentration in seminal plasma samples to about 28% of the controls; and also enhanced the seminal plasma glutathione peroxidase activity by two-fold compared with controls.

5. It was concluded that dietary vitamin E in combination with organic Se has a synergistic effect in minimising lipid peroxidation and improving the antioxidative status in seminal plasma of the domestic fowl, which probably translated into enhanced spermatozoa count, motility and reduced percentage of dead spermatozoa under heat stress conditions.     

Changes in diarrhea,nutrients apparent digestibility,digestive enzyme activities of weaned piglets in response to chitosan‐zinc chelate

A total of 120 weanling barrows weighing 6.11 ± 0.20 kg were randomly allotted to four treatments with three replications (i.e. pen) of ten piglets per replicate. Pigs were received corn‐soybean basal diet (control) or the same basal diet supplemented with the following sources of zinc: (i) 100 mg/kg of Zn as ZnSO₄; (ii) 100 mg/kg of Zn as chitosan‐Zn chelate (CS‐Zn); and (iii) 100 mg/kg of Zn as ZnSO₄ mixed with chitosan (CS + ZnSO₄). The results showed that CS‐Zn could highly improve average daily gain and average daily feed intake than those of ZnSO₄ or CS+ ZnSO₄ (P < 0.05). The pigs fed dietary CS‐Zn had lower diarrhea incidence and higher apparent digestibility of crude protein than those of the pigs fed dietary ZnSO₄ (P < 0.05). The protease activities in duodenal content of the pigs receiving CS‐Zn diets was higher than that of the pigs fed dietary ZnSO₄ or CS + ZnSO₄ (P < 0.05). The amylase activity in duodenal content of the pigs fed dietary CS‐Zn was higher than that of the pigs receiving ZnSO₄ diets or basal diets (P < 0.05). These results indicated that dietary CS‐Zn showed different bioactivities from ZnSO₄ or CS + ZnSO₄ in reducing the incidence of diarrhea, improving activities of digestive enzymes and growth performance of weaned pigs.     

UV‐light and dietary vitamin D and their effects on ionized calcium and 25‐OH‐D plasma concentrations in captive gentoo penguins (Pygoscelis papua)

In this study, the effect of ultraviolet (UV) light and dietary vitamin D on calcium metabolism in permanently indoor‐housed gentoo penguins (Pygoscelis papua ) was investigated. The study consisted of three periods, each completed with blood samples to analyse plasma concentrations of 25‐OH‐D, 1,25‐(OH)₂‐D, ionized (iCa) and total calcium (tCa). During the first study period (D), animals were housed under routine conditions without UV‐light and fed a diet of different fish species, supplemented with 1,000 IU vitamin D per animal and day. The following study period (Baseline) of 28‐day duration consisted of the same diet without any vitamin D supplementation and without UV‐light. During the study period (UVB) artificial UV‐light was added for 3 weeks. The vitamin D content of fish was measured by high‐performance liquid chromatography. It varied between fish species and between facilities, ranging from no measurable content in capelin (Mallotus villosus ) to 7,340 IU vitamin D/kg original matter (OM) in herring (Clupea spp). The average dietary vitamin D content was 311 IU/kg OM at facility 1 and 6,325 IU/kg OM at facility 2, resulting in a vitamin D intake per animal and day without supplementation of 130 IU (25.5 IU/kg body weight BW) and 2,454 IU (438.2 IU/kg BW) respectively. The supplementation of vitamin D elevated significantly the plasma concentrations of 25‐OH‐D by an intraindividual difference of 15 (range ?2 to 59) nmol/L and tCa by 0.1 (0.0–0.3) mmol/L only at facility 2. The exposure to UV‐light raised the blood concentrations of tCa at facility 2 by 0.15 (0.1–0.2) mmol/L, and of iCa and tCa for females at facility 1 by 0.23 (0.13–0.41) mmol/L and 1.8 (1.1–2.5) mmol/L respectively. No significant influence of the study periods (D) and (UVB) was found for the concentrations of 1,25‐(OH)₂‐D at both facilities.     

Dietary supplementation of 25-hydroxycholecalciferol increases tibial mass by suppression bone resorption in meat ducks

Leg problems often result from the rapid weight gain and poor bone quality in modern ducks, leading to a high risk of fractures and continuous pain. We hypothesized that improving bone quality in combination with delaying weight gain via a low nutrient density (LND) diet probably reverses these skeletal abnormalities. Studies indicated that 25-hydroxycholecalciferol (25-OH-D₃), a vitamin D₃ metabolite, is effective in treating bone-related disorders. Therefore, Exp. 1 evaluated the effects of 25-OH-D₃ on tibial mass of meat ducks. Male meat ducklings were fed a standard nutrient density diet (containing a regular vitamin regimen) without or with 25-OH-D₃ at 0.069 mg/kg for 35 d. The results showed that 25-OH-D₃ supplementation improved the mineral content, microarchitecture and mechanical properties of tibias, and this companied by a decreased serum bone resorption marker and a concomitant decrement in osteoclast-specific marker genes expression. Subsequently, Exp. 2 was conducted to examine the impacts of 25-OH-D₃ incorporating an LND diet on tibial quality of ducks under 2 different vitamin regimens (regular and high). Ducklings were allocated to a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes and without or with 25-OH-D₃ at 0.069 mg/kg in LND diets. The high premix had higher levels of all vitamins except biotin than the regular premix. The results demonstrated that high vitamin diets exhibited more significant effects than regular vitamin diets on inhibiting bone turnover and increasing minerals deposition. Tibial mineral content, microarchitecture, and strength of birds under the regular vitamin regimen were increased by 25-OH-D₃ supplementation; However, these positive effects were not observed in ducks under the high vitamin regimen. To conclude, 25-OH-D₃ supplementation improves tibial mass by suppressing osteoclast-mediated bone resorption in meat ducks, and this positive impact only was observed in regular but not high vitamin regimen when birds fed an LND diet.     

Vitamin K deficiency in cats fed commercial fish-based diets

Clinical signs of vitamin K deficiency have been observed in cats offered two commercial canned diets high in salmon or tuna. Some of the queens and kittens offered these diets had died while survivors had increased coagulation times. Necropsies revealed hepatic and, or, gastrointestinal haemorrhages. Coagulation times of survivors returned to normal after vitamin K therapy. The purpose of this study was to induce a vitamin K deficiency in kittens and determine the dietary requirement. Kittens were offered vitamin K-deficient purified diets containing antibiotics and, or, substances inherent in canned fish diets that may have contributed to the deficiency. Clinical signs of vitamin K deficiency were not observed, even though one purified diet contained only 4 μg K₁/kg diet compared with 60 μg in the commercial tuna diet. Therefore, a minimum vitamin K requirement could not be determined using purified diets; nevertheless, canned commercial diets formulated primarily with fish should contain more than 60 μg K₁/kg diet.     

Effects of Moringa oleifera leaves as a substitute for alfalfa meal on nutrient digestibility,growth performance,carcass trait,meat quality,antioxidant capacity and biochemical parameters of rabbits

This contribution reports the effects of Moringa oleifera leaves (MOLs) meal on the growth performances, nutrient digestibility, carcass trait, meat quality, antioxidant capacity and biochemical parameters of growing New Zealand white rabbits. The MOL was substituted for alfalfa meal at levels of 0, 10%, 20% and 30% to obtain respective diets MOL0, MOL10, MOL20 and MOL30. Each treatment was replicated five times with 10 rabbits per replicate. Results showed the average daily weight gain (ADWG) and feed conversion ratio (FCR) of rabbits fed MOL20 diet were significantly better (p < 0.05) than those of other three dietary groups. Liver and spleen index of rabbits fed MOL20 and MOL30 diets was significantly higher (p < 0.05) than that of the groups fed with lower M. oleifera leaves (MOL0, MOL10). The meat drip loss of rabbits fed with diet MOL10 was significantly lower (p < 0.05) than that of rabbits fed other diets. All rabbits fed MOL dietary groups had lower (p < 0.05) shear force of longissimus dorsi than the group without M. oleifera leaves. No significant differences were found in the digestibility of crude fibre (CF), crude fat (EE), ash, crude protein (CP) and nitrogen‐free extract (NFE) among the dietary groups. Moringa oleifera leaves also have a significant impact on serum albumin (ALB), low‐density lipoprotein cholesterol (LDLC), triiodothyroxine (T₃) and tetraiodothyroxine (T₄) values and the activity of superoxide dismutase (SOD) and catalase (CAT) in serum and liver. The results indicated that M. oleifera leaves could be developed as a good feed source, and it not only could substitute for alfalfa meal well but also has a significant effect on growth performance, meat quality, antioxidant and biochemical parameters of rabbits.     

The effect of dietary vitamin E level on selenium status in rats

The effect of varying levels of dietary vitamin E on selenium status was determined using 40 Wistar rats with similar initial body weight. The rats were equally divided into four groups and fed the following dietary treatments (mg vitamin E/kg DM): 18 (control; C‐diet), 0 (0E‐diet), 9 (0.5E‐diet) and 36 (2E‐diet) for either 4‐week (Phase 1) or 8‐week (Phase 2) period. At the end of experiment, animals were slaughtered to measure vitamin E and selenium levels in the brain, liver, spleen, kidney, muscles and blood tissues. Dietary vitamin E levels did not affect feed and water intake and body weight. But whole‐blood selenium concentration in rats fed 0E‐diet was higher than in rats fed 2E‐diet after 4 weeks. Selenium level in muscle, spleen and brain was also higher (p < 0.05) in rats fed the 0E‐diet than in rats fed C‐diet after 4 weeks of feeding. On the other hand, selenium level in the muscle was lower (p < 0.05) in rats fed 0.5E‐diet than in those fed 0E‐diet after 4 weeks of feeding, but not after 8 weeks of feeding. Increasing dietary vitamin E level directly influenced selenium content of the spleen and brain after 8 weeks of feeding 2E‐diet. Moreover, the twofold increase in vitamin E intake resulted in a tendency to reduce whole‐blood selenium level and total selenium in the liver and kidney after 4 and 8 weeks. The results showed that the increasing dietary vitamin E level resulted in a tendency to reduce Se contents in some vital organs of the body such as the liver and kidney, suggesting their close compensatory interrelationship. Therefore, dietary vitamin E level directly influenced selenium metabolism in the animal body.