Effects of nanosized zinc oxide and γ-polyglutamic acid on eggshell quality and serum parameters of aged laying hens

In order to increase zinc (Zn) absorption and improve eggshell quality, diets for aged laying hens were supplemented with different Zn sources and the effects on egg production, eggshell quality and serum parameters were recorded. Seventy-five 64-week old brown layers were individually caged and randomly allotted to five treatment groups: an un-supplemented Control and four groups, where the following Zn sources were added to the diets, ZnO (group ZnO), Zn-methionine (group Zn-Met), nanosized ZnO (group nanoZnO) and γ-PGA-nano ZnO (group γ-PGA-nanoZnO). The Zn level was maintained at 80 mg/kg in the supplemented diet, while the Control group received Zn at 40 mg/kg diet. The results indicated that the average daily feed intake was highest in group nanoZnO (p < 0.05), whereas further performance parameters were not influenced by treatments. Eggshell thickness was increased in group γ-PGA-nanoZnO (p < 0.05). Zn content in eggshells and Zn concentration in serum were increased in groups Zn-Met, nanoZnO and γ-PGA-nanoZnO (p < 0.05). Serum ghrelin concentration was significantly elevated in all Zn-supplemented groups, but further increased in groups nanoZnO and γ-PGA-nanoZnO (p < 0.05). Carbonic anhydrase activity was highest in group γ-PGA-nanoZnO and lowest in group Zn-Met (p < 0.05). Compared to the Control and group ZnO, supplementation of γ-PGA-nanoZnO and nanoZnO increased serum IgG levels (p < 0.001). In conclusion, dietary supplementation of nanoZnO and γ-PGA-nanoZnO increased Zn content in eggshells, serum Zn concentration, ghrelin and IgG levels of aged layers when compared to regular ZnO. Compared to Zn-Met, the serum carbonic anhydrase activity and ghrelin levels were also increased. Thus, nanosized ZnO alone or mixed with γ-PGA has positive effects on the Zn status of aged layers.     

Nutrient utilisation,growth performance and blood metabolites in Murrah buffalo calves (Bubalus bubalis) divergently selected for residual feed intake

The aim of this study was to evaluate differences in efficiency of feed utilisation between buffalo calves with low and high residual feed intake (RFI) by comparing feed intake, nutrient digestibility, growth traits and blood metabolites. Eighteen male Murrah buffalo calves (aged 4–6 months; 70 ± 1.0 kg body weight) were fed ad libitum with a total mixed ration for 120 d. Based on linear regression models involving dry matter intake (DMI), average daily gain (ADG) and mid-test metabolic body size, calves were assigned into low and high RFI groups. The RFI varied from ?0.33 to +0.28 kg DM/d with an average RFI of ?0.14 and 0.14 kg DM/d in low and high RFI calves, respectively. Calves had a mean DMI of 1.9 and 2.4 kg/d and an ADG of 0.5 and 0.6 kg/d in low and high RFI groups, respectively. Low RFI calves ate 19.0% less DM each day and required significantly less metabolisable energy for maintenance compared with high RFI calves (12.5 vs. 16.7 MJ/d). Nutrient digestibility and nitrogen balance did not differ among low and high RFI calves. In more efficient animals (low RFI calves) higher (p < 0.05) plasma level of growth hormone, insulin-like growth factor-1 (IGF-1), triiodothyronine (T₃) and lower concentration of thyroxin hormone were detected. No significant differences in levels of insulin, hydroxyproline, plasma and urine creatinine, total protein and albumin between high and low RFI groups were found. Blood metabolites showed significant (p < 0.05) differences at initial and final stages of study in both groups. At final stage of study, RFI showed negative correlations with growth hormone, IGF-1, T₃, urine creatinine and albumin. Low RFI buffalo calves are more efficient in feed utilisation and the differences in blood metabolites are probably due to differences in feed intake and body metabolism.     

Effects of Dietary Supplementation of Zinc Oxide and Zinc Methionine on Layer Performance,Egg Quality,and Blood Serum Indices

The objective of this study was to evaluate the effectiveness of dietary zinc oxide (ZnO) and zinc methionine (Zn-Met) supplementation on layer performance, quality of egg, some blood constituents, and oxidative status in blood of laying hens. A total of 120 laying hens (Hisex Brown) 22-week-old were indiscriminately allotted into five groups of 24 hens with six replications (four birds/replicate). A complete randomized design experiment was performed including control (basal diet), two levels of ZnO (50 and 100 mg/kg basal diet), and two levels of Zn-Met (50 and 100 mg/kg basal diet) through 22 to 34 weeks of age. Supplementation of 100 mg of Zn-Met significantly (P = 0.001) increased feed intake compared to other treatment groups. The groups supplemented with 50 mg of ZnO and 100 mg of Zn-Met reported the significantly higher egg production rate (P = 0.002) and egg mass (P < 0.001) compared to other treated groups. All traits of egg quality were not statistically (P < 0.05 or 0.01) affected by ZnO or Zn-Met supplementation except shell thickness, Haugh unit score, and yolk to albumin ratio. Dietary supplementation of either ZnO or Zn-Met did not affect the oxidative parameters in serum except the activity of Cu-Zn-SOD. Serum triglyceride, total cholesterol, and LDL cholesterol (low-density lipoprotein) were significantly (P < 0.05) affected by Zn supplementation, while HDL cholesterol (high-density lipoprotein) did not affect. Compared to the control group, supplementation of ZnO or Zn-Met increased serum content of zinc with no differences among supplemental zinc doses. It could be concluded that dietary inorganic (ZnO) and organic (Zn-Met) supplemented up to 50 and 100 mg/kg, respectively, can be used as effective supplements to improve productivity of laying hens, serum zinc level, lipid profile (triglyceride and LDL cholesterol), and activity of Cu-Zn-SOD.     

Aus der Versuchsstation für Tierernährung,Perchtoldsdorf/Wien

This study aimed to compare the effects of organic (proteinate) and inorganic (sulphate) copper (Cu) and zinc (Zn) supplements, in presence or absence of a mannan oligosaccharide (MOS) supplement, on mineral solubility and digestibility in pigs. Twenty-eight barrows (25 ± 4 kg) assigned randomly to four treatment groups were fed a corn-wheat-soya bean meal diet with 10 mg/kg of Cu and 100 mg/kg of Zn supplied as organic or inorganic supplement, and supplemented or not with 0.1% MOS. After an adaptation period, total faeces and urine were collected for a period of 6–7 days. Pigs were then euthanatised and digesta from ileum and caecum were collected. Apparent digestibility was calculated in ileum and caecum using titanium dioxide. The organic mineral supplement improved total (faecal) digestibility and retained/ingested ratio of Cu (p < 0.05) while reducing apparent digestibility of Zn in the ileum (p < 0.05) without effect on total digestibility of Zn. Solubilities of Cu and Zn in liquid fraction of ileum and caecum were not affected by mineral sources. Although MOS supplement increased Cu solubility in the ileum (p < 0.05), it had no effect on digestibility of Zn and Cu in ileum, caecum and faeces, retained/ingested ratio of Zn and Cu, or pH and volatile fatty acid concentration in ileal and caecal digesta. In conclusion, organic mineral supplement improved total digestibility and retained/ingested ratio of Cu in pigs but this cannot be attributed to its solubility in ileal and caecal digesta. The MOS supplement did not interfere with digestibility or dietary utilisation of Zn and Cu in pigs fed above the Zn and Cu requirements.     

über den Einfluß von Diäthylstilboestrol und anderer Wirkstoffe auf den Stoffwechsel männlicher Ratten

The presented study aimed at investigating the residual feed intake (RFI) of Sahiwal calves, nutrient utilisation as affected by RFI and its relationship with methane (CH₄) emissions and some blood metabolites. Eighteen male Sahiwal calves (10–18 months of age; mean body weight 133 kg) were fed ad libitum with a total mixed ration. After calculating RFI for individual calves (?0.40 to +0.34 kg DM/d), they were divided into three groups with low, medium and high RFI, respectively. Dry matter intake (DMI) was higher (p < 0.05) in Group High RFI, whereas digestibility of all nutrients except crude protein and ether extract was significantly higher in Group Low RFI. Nitrogen balance was also significantly higher in Group Low RFI (20.2 g/d) than in Group High RFI (17.0 g/d). Average daily gain and feed conversion ratio were similar among the groups. With exception of glucose, concentrations of all measured blood metabolites were higher in Group High RFI (p < 0.05). Compared with Group High RFI, the CH₄ emission of Group Low RFI was significantly lower (on the basis g/d and g/kg DMI by 11% and 19%, respectively). Furthermore, the CH₄ emission [g/d] was significantly correlated with RFI (r = 0.77). Because higher feed efficiency and less CH₄ production were observed in Group Low RFI, it was concluded that RFI can be used as a measure of feed efficiency, which has a potential to select Sahiwal calves for lowered CH₄ emissions.     

Effects of feeding high-quality hay with graded amounts of concentrate on feed intake,performance and blood metabolites of cows in early lactation

Dairy cows are commonly fed energy-dense diets with high proportions of concentrate feedstuffs to meet the increased energy needs of early lactation. However, feeding large amounts of concentrates may cause rumen acidosis and impact cow health. The hypothesis tested was that the energy supply and metabolic health of early-lactation Simmental cows can be maintained when high-quality hay rich in water-soluble carbohydrates (WSC) and crude protein (CP) is fed, despite the proportion of concentrates in the diet being reduced or even excluded. Twenty-four Simmental cows were allocated to one of four feeding groups beginning 10 d before the expected calving date, until 28 d thereafter. The feeding groups were 60CH (60% conventional fibre-rich hay plus 40% concentrate feed), 60HQH (60% high-quality hay plus 40% concentrate feed), 75HQH (75% high-quality hay plus 25% concentrate feed) and 100HQH (100% high-quality hay). The fibre-rich hay and high-quality hay differed in WSC content (110 g vs. 198 g of dry matter (DM)), neutral detergent fibre (646 g vs. 423 g of DM) and CP (65 g vs. 223 g of DM). Individual feed intake and milk production were monitored daily, and blood samples were collected weekly. Dry matter intake (DMI) and milk yield increased post partum, but 4 weeks post partum, the DMI of cows fed 100HQH only reached a daily mean DMI of 18.6 kg, whereas the DMI of the other groups averaged 21.9 kg (p < 0.046). The negative energy balance was less pronounced in cows fed 75HQH since they showed similar milk yields to the cows fed 60CH and 100HQH, but their energy intake was higher. Concentrations of milk components were similar across rations 60CH, 60HQH and 75HQH, as were most of blood parameters. Cows fed 100HQH responded to the energy deficit post partum with a higher ratio of non-esterified fatty acids to cholesterol and a higher concentration of ß-hydroxybutyrate (significant in comparison to cows fed 75HQH, p < 0.05). In conclusion, feeding high-quality hay with a WSC content of 20% in DM has the potential to decrease the proportion of concentrates in dairy cow feeding in early lactation, but cannot fully replace their supplementation due to a limited rumen capacity for forage intake.     

Effects of keratinase supplementation of corn-soybean meal based diets on apparent ileal amino acid digestibility in growing pigs and serum amino acids,cytokines, immunoglobulin levels and loin muscle area in nursery pigs

Two experiments were conducted to evaluate effects of keratinase for growing and nursery pigs. In Exp. 1, six pigs (32.3 ± 2.8 kg body weight), fitted with a simple T-cannula at the distal ileum, were assigned to one of two 3 × 3 Latin squares involving three periods and three diets including a basal diet and the same diets supplemented with 0, 0.05 or 0.1% keratinase. Dietary keratinase supplementation increased the apparent ileal digestibility of crude protein (CP), arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, alanine, glutamic acid and proline (p < 0.05). Digestibility coefficients did not differ between pigs fed 0.05 and 0.1% keratinase. In Exp. 2, 24piglets weaned at 30 ± 2 d of age were used in a 2 × 2 factorial design experiment with two CP concentrations (19 vs. 22%) and two levels of keratinase supplementation (0 vs. 0.05%). Keratinase supplementation increased (p < 0.05) average daily gain, serum arginine concentration and loin muscle area but decreased (p < 0.05) serum interleukin-10 concentrations. The reduction in dietary CP level decreased (p < 0.05) serum urea nitrogen concentrations, isoleucine, serine and proline concentrations, but increased serum arginine concentrations. Few interactions between keratinase supplementation and dietary CP concentration were observed. This study indicated that dietary keratinase supplementation improved apparent ileal amino acid digestibility for growing pigs and had a positive effect on weight gain, immune response and loin muscle area for nursery pigs.     

Influence of feeding a fish oil-containing diet to young,lean, adult dogs: effects on lipid metabolites,postprandial glycaemia and body weight

The aim of this study was to determine the effect of feeding a fish oil (FO)-containing diet on lipid and protein metabolism, postprandial glycaemia and body weight in young, lean, adult dogs. Eight female Beagles were randomly assigned to one of two isonitrogenous and isoenergetic diets, Control or FO, in a crossover design. At the beginning of the experiment and at 30 and 60 d, a baseline blood sample was collected and the dogs then were fed their daily ration. Nitrogen balance began at 07:00 h on day 63 of each experimental period and ended at 07:00 h on day 69. On day 66 of each period, a single dose (7.5 mg/kg) of ¹⁵N-glycine was administered orally to each dog via gelatin capsule. Postprandial glycaemia did not differ between treatments or among sampling days within treatment. Cholesterol concentration was increased (p < 0.05) on the Control treatment throughout the experiment when compared to values of day 0. Dogs fed the FO treatment had higher plasma triglyceride and ghrelin concentrations than those fed the Control treatment. Body weight and food intake did not differ between dietary treatments. Faecal excretion was increased (p < 0.05) in the FO treatment. Dry matter digestibility was decreased (p < 0.05) and fat digestibility tended (p < 0.10) to decrease in the FO treatment. Overall, feeding a FO-containing diet showed a protective effect against the rise of plasma cholesterol and it increased plasma ghrelin concentration. However, FO supplementation did not appear to affect protein metabolism or postprandial glycaemia in adult lean dogs.     

Effects of dietary cellulase and xylanase addition on digestion,rumen fermentation and methane emission in growing goats

The objective of this study was to evaluate the effectiveness of supplementation of cellulase and xylanase to diets of growing goats to improve nutrient digestibility, utilisation of energy and mitigation of enteric methane emissions. The experiment was conducted in a 5 × 5 Latin square design using five goats with permanent rumen fistulae and five treatments consisted of two levels of cellulase crossed over with two levels of xylanase plus unsupplemented Control. The cellulase (243 U/g) derived from Neocallimastix patriciarum was added at 0.8 and 1.6 g/kg dry matter intake (DMI) and the xylanase (31,457 U/ml) derived from Aspergillus oryzae was fed at 1.4 and 2.2 ml/kg DMI. There were no differences in apparent digestibility of organic matter, neutral detergent fibre, acid detergent fibre and rumen fermentation parameters (i.e. ammonia-nitrogen [N], volatile fatty acids) among all treatments. Dietary cellulase and xylanase addition did not influence energy and N utilisation. But compared to xylanase addition at the higher dose, at the low xylanase dose the retained N, the availability of retained N and digested N were increased (p < 0.01). Moreover, enzyme addition did not affect the enteric methane emission and community diversity of ruminal methanogens. The present results indicated that previous in vitro findings were not confirmed in ruminant trials.     

Effects of nickel supplementation on nutrient utilization,mineral balance,haematology and antioxidant status of crossbred dairy calves

BackgroundNickel has been identified as an important newer trace mineral playing essential role in animals however, its precise mechanism of action in the body is yet to be determined. Interaction of Ni with other essential minerals is suggested in reports limited to lab animals and needs to be explored further in large animals.AimThis study was conducted to study the influence of Ni supplementation at different levels, on minerals and health status of crossbred dairy calves.MethodTwenty-four Karan Fries crossbred (Tharparkar × Holstein Friesian) male dairy calves were selected based on body weight (137.09 ± 5.68) and age (10.78 ± 0.61) and were divided into 4 treatment groups (n = 6) given basal diet supplemented with 0 (Ni0), 5 (Ni5), 7.5 (Ni7.5) and 10 (Ni10) ppm Ni/kg of DM. Nickel was supplemented in the form of nickel sulphate hexahydrate (NiSO₄.6 H₂O) solution. To ensure the intake of the required amount of nickel by each animal, the calculated quantity of solution was mixed with 250 g concentrate mixture and offered individually to the calves. The calves were fed total mixed ration (TMR) consisting of green fodder, wheat straw and concentrate mixture in the ratio of 40:20:40 and the nutritional requirements were met according to NRC (2001) guidelines. Growth performance was recorded at fortnightly interval whereas, plasma minerals, haematology, antioxidant and immunity parameters were studied at monthly interval during the 150-day experimental period. Nutrient utilization and mineral balances were estimated with the help of a metabolism trial conducted at the end of feeding trial.ResultsSupplementation of Ni exhibited no influence on dry matter intake (DMI), body weight, average daily gain (ADG) and nutrient digestibility of dairy calves. However, the absorption and balance of minerals such as Ni, Fe, Cu, Zn and their respective plasma concentration increased (P < 0.05) with Ni supplementation and highest values were observed in calves fed 10 mg Ni/kg DM. The red blood cell (RBC) count, haemoglobin (Hb) concentration, haematocrit (HCT) and activity of superoxide dismutase (SOD) and catalase antioxidant enzymes showed highest increase (P < 0.05) in calves supplemented with Ni at level of 10 mg/kg DM as compared to other treatment groups. However, white blood cell (WBC) count, glutathione peroxidase (GPx), total antioxidant status (TAS), total immunoglobulins and IgG plasma concentration remained unaltered with addition of different levels of Ni in the diet of calves.ConclusionsThe supplementation of Ni at level of 10 mg/kg DM shows a positive effect on status of trace minerals such as Fe, Cu, Zn and improves the physiological conditions and health status of crossbred dairy calves indicated by improved haematology and antioxidant parameters.     

Comparative effect of different dietary inulin sources and probiotics on growth performance and blood characteristics in growing–finishing pigs

The study was focused on assessment of the effect of an extract of long-chain inulin (LCI) and dried tubers of Jerusalem artichoke (JA) and a multispecies probiotic preparation as well as a combination thereof on growth performance and blood parameters of fattening pigs. In total, 144 pigs (initial body weight 30.0 ± 0.5 kg) were used in a 98-d experiment. The six dietary treatments consisted of the control diet (Con), diet Con supplemented with probiotics (ConP) and four diets supplemented with LCI or JA alone or with probiotics (diets LCIP and JAP). Throughout the fattening period, there was a beneficial effect of the probiotic supplementation to the inulin-containing diets and the average daily gain (ADG) was increased by supplementation of probiotics in combination with inulin sources (p < 0.05). At the end of the fattening period, ADG and feed conversion ratio (FCR) were higher after supplementation of LCI only (p < 0.05). Compared with group ConP, in groups LCI and JA, the ADG and FCR were improved (p < 0.05). Only in the first fattening stage, the addition of the prebiotics and/or probiotics had an impact on the level of white blood cells and some biochemical indices in pigs. In younger animals, probiotic or LCI supplementation increased the IgG level (p < 0.05). There was also an interaction between the probiotics and JA resulting in increased IgG and IgA concentrations (p < 0.05). In the finishing period, LCI addition increased the IgM level (p < 0.05), whereas JA addition increased IgG and IgM levels as well (p < 0.05). In conclusion, both dietary sources of inulin and probiotic supplementation can improve the fattening performance and health status of growing pigs.     

Determination of endogenous faecal phosphorus loss in goats

Four black Liuyang wether goats were fed with corn stover and concentrate formulated to contain four levels of dietary phosphorus (P), including 0.129, 0.140, 0.162 and 0.180% of P. In a 4 × 4 Latin square experiment the endogenous faecal P loss was determined by the regression technique and the substitution method. Treatment effects on faecal and urinary P output, apparent P digestibility and P retention, and saliva P secretion were not significant. A linear relationship was observed between apparent faecal digestible P (Y, g/kg DMI) and P intake (X, g/kg DMI), which was described by the equation: Y = 0.4799X ?0.9209, r² = 0.9869, (p < 0.05). The true P digestibility determined by the regression technique and the substitution method amounted to 48.0 and 48.9%, respectively; the recorded endogenous faecal P losses were 0.92 and 0.93 g/kg DMI, respectively. The study demonstrated the potential of the regression method as well as the substitution method for estimation of true P digestibility and endogenous faecal P losses in goats.     

Effect of Zinc Source on Performance, Zinc Status, Immune Response, and Rumen Fermentation of Lactating Cows

Two experiments were conducted to examine the effect of zinc (Zn) source on the performance, Zn status, immune response, and rumen fermentation of lactating cows to find the most available Zn source for dairy production. In Experiment 1, a total of 30 multiparous Holstein cows were randomly allocated by body weight and milk yield to one of five treatments in a completely randomized design. Cows were fed a total mixed ration (TMR) with no Zn addition (containing 37.60 mg?Zn/kg TMR by analysis), and the basal TMR supplemented with 40 mg?Zn/kg TMR from either Zn sulfate or one of three organic Zn chelates with weak (Zn-AA W), moderate (Zn-Pro M), or strong (Zn-Pro S) chelation strengths, respectively for 55 days. In Experiment 2, the in vitro rumen fermentation method was used in a completely randomized design involving a 4?×?3 factorial arrangement of treatments. The four Zn sources were the same as those used in Experiment 1, and the three supplemental Zn levels in the rumen fluid were 0, 10, and 20 μg/mL, respectively. The feed intake, milk composition, and somatic cell count (SCC) were unaffected (P?>?0.05) by treatments. However, the milk yield was increased (P?<?0.05) by addition of Zn from both the Zn-AA W and Zn-Pro S. Plasma Zn level at the end of the experiment was increased (P?<?0.05) by addition of Zn from all three organic sources. Serum antibody titers on day 21 after vaccination with foot and mouth disease (FMD) vaccine were increased (P?<?0.05) by both supplemental Zn-AA W and Zn-Pro S. The organic Zn sources with different chelation strengths supplemented at the added Zn level of 10 μg/mL were more effective (P?<?0.05) in improving the rumen fermentation than Zn sulfate, with the most effective being Zn-AA W. In conclusion, Zn source had no influence on the feed intake, milk composition, and SCC; however, both the Zn-AA W and Zn-Pro S were more effective than Zn-Pro M and Zn sulfate in enhancing the rumen fermentation, Zn status, and humoral immune response as well as improving milk yield of lactating cows. The improved milk production might be attributed to the improved rumen fermentation, Zn status, and immune function.     

Effects of Different Sources and Levels of Zinc on Growth Performance,Nutrient Digestibility,and Fur Quality of Growing-Furring Male Mink (<Emphasis Type="Italic">Mustela vison</Emphasis>)

The objective of this study was to investigate the effects of different sources and levels of zinc (Zn) on growth performance, nutrient digestibility, serum biochemical parameters, and fur quality in growing-furring male mink. Animals in the control group were fed a basal diet with no Zn supplementation. Mink in the other nine treatments were fed the basal diet supplemented with Zn from either grade Zn sulfate (ZnSO₄·7H₂O), Zn glycinate (ZnGly), or Zn pectin oligosaccharides (ZnPOS) at concentrations of either 100, 300, or 900 mg Zn/kg dry matter. One hundred and fifty healthy 15-week-old male mink were randomly allocated to ten dietary treatments (n = 15/group) for a 60-day trial from mid-September to pelting in December. Mink in the Zn-POS groups had higher average daily gain than those in the control group (P < 0.05). Zn source slightly improved the feed/gain (P = 0.097). N retention was increased by Zn addition (P < 0.05). Mink supplemented with dietary Zn had higher (P < 0.05) pancreas Zn level than the control group. Fur length was greater (P < 0.05) in ZnGly and ZnPOS groups compared with the control. In addition, fur length and fur density increased (linear, P < 0.05) with Zn supplementation in the diet. In conclusion, our data show that dietary Zn addition improves growth performance by increasing nitrogen retention and fat digestibility in growing-furring mink and Z-POS is equally bioavailable to mink compared to ZnGly.     

Effects of dietary inclusion of Moringa oleifera leaf meal on nutrient digestibility,rumen fermentation,ruminal enzyme activities and growth performance of buffalo calves

This study was conducted to investigate the impact of dietary inclusion of Moringa oleifera leaf meal (MLM) as a substitution for soybean meal on nutrient digestibility, rumen fermentation, rumen enzyme activity, blood metabolites, growth-related hormones, and growth performance of buffalo calves. Thirty buffalo calves eight to nine months of age with an average body weight of approximately 153.7 ± 0.97 kg were randomly distributed through three dietary treatments (ten calves/treatment). MLM inclusion rates were 15% (M15) and 20% (M20), replacing soybean meal by 50 and 75% in the concentrate mixture, respectively. The results indicated that, digestibility of dry matter, organic matter (OM), and crude fiber (CF) increased significantly (p < 0.05) with MLM inclusion, while the digestibility of crude protein (CP) and ether extract (EE) reduced significantly (p < 0.05) with MLM addition. Dietary supplementation with MLM significantly affected (p < 0.001) rumen fermentation by reducing ruminal enzymes, ruminal ammonia-N, total protozoa, and acetate/propionate ratio and increasing acetic, propionic, and butyric acids and total volatile fatty acid concentrations (p < 0.001). Furthermore, dietary inclusion of 15% MLM significantly improved (p < 0.001) final body weight, dry matter intake of feed, daily weight gain, feed conversion efficiency, blood metabolites, and plasma insulin growth factor-I (IGF-I). It can be concluded that MLM is a multi-purpose protein supplement that provides some nutritional and therapeutic advantages when replacing 50% of soybean meal. Dietary supplementation of 15% MLM improved rumen fermentation, growth performance, blood metabolites, plasma IGF-I and mitigated ammonia and methane without any adverse effects in growing buffalo calves.     

Antioxidant properties of chromium and zinc

The effects of chromium (chromium picolinate, CrPic) and zinc (ZnSO₄H₂O) supplementation on serum concentrations of malondialdehyde (MDA) (an indicator of lipid peroxidation) and serum status of some antioxidant vitamins and minerals of laying hens (Hy-Line) reared at a low ambient temperature (6.8°C) were evaluated. One hundred twenty laying hens (Hy-Line; 32 wk old) were divided into 4 groups, 30 hens per group. The hens were fed either a basal diet or the basal diet supplemented with either 0.4 mg Cr/kg of diet, 30 mg Zn/kg of diet, or 0.4 mg Cr plus 30 mg Zn/kg of diet. Digestibility of nutrients (dry matter [DM], organic matter [OM], crude protein [CP], and ether extract [EE]) increased by supplementation of chromium and zinc (p<0.05). Supplemental chromium and zinc increased serum vitamins C and E but decreased MDA concentrations (p<0.05). Additionally, supplemental chromium and zinc caused an increase in the serum concentrations of Fe, Zn, Mn, and Cr (p < 0.05). The present study showed that low ambient temperature causes detrimental effects on the digestibility of nutrients and antioxidant status and that such detrimental effects caused by low ambient temperature can be alleviated by chromium and zinc supplementation, particularly when Cr and Zn were simultaneously included into the diet. Data obtained in the present study suggest that such supplementation can be considered as a protective management practice in a diet of laying hens for alleviating negative effects of cold stress.     

Parameters of fermentation and rumen microbiota of Nellore steers fed with different proportions of concentrate in fresh sugarcane containing diets

The objective of this study was to evaluate the effect of a fresh sugarcane-based diet and different roughage-to-concentrate ratios (70:30, 60:40, 40:60 and 20:80) on the rumen microbiota associated with rumen fermentation parameters and the intake and apparent digestibility of nutrients in Nellore steers. Eight rumen-cannulated Nellore steers (331 ± 8 kg BW) were distributed in a double 4 × 4 Latin square design balanced for the control of the residual effect. The ruminal pH decreased (p < 0.01) and the concentrations of N–NH₃, isovaleric and valeric acids increased linearly (p < 0.05) with an increase dietary concentrate level. Furthermore, an increased concentrate proportion reduced the population of Fibrobacter succinogenes and Ruminococus flavefaciens (p < 0.01) and increased the population of Selenomonas ruminantium and Megasphaera elsdenii (p < 0.01). The protozoa count revealed a predominance of the genus Entodinium. The synthesis of microbial N [g/d] and the efficiency of microbial synthesis [g of microbial N/kg of organic matter apparently digested in the rumen] increased as the proportion of concentrate was increased (p < 0.05). Therefore, it can be concluded that an increasing proportion of concentrate in sugarcane-containing diets enhances the synthesis of microbial protein and does not alter the fibre digestibility, although the population of fibre fermenting bacteria was reduced.     

Influence of feeding sunflower seed and meal protected against ruminal fermentation on ruminal fermentation,bacterial composition and in situ degradability in sheep

ABSTRACT

The effects of treating sunflower seed (SS) and meal (SM), as well as of a mixture of both feeds (SSM; 45:55) with a solution of malic acid (1 M; 400 ml/kg feed) and heating for protection against ruminal degradation were studied. Four rumen-fistulated sheep were fed two mixed diets composed of oat hay and concentrate (40:60) and differing only in the concentrate, that contained either a mixture of untreated SS and SM (control diet) or treated SS and SM (MAH diet). A crossover design with two 24-d experimental periods was used, and each period included 10 d of diet adaptation, 9 d for in situ incubations of SS, SM and SSM, and 5 d for measuring ruminal fermentation characteristics and rumen emptying. From day 6 onwards a solution of (¹⁵NH₄)₂SO₄ was continuously infused into the rumen of each sheep to label ruminal bacteria. Feeding the MAH diet did not affect either ruminal pH or concentrations of total volatile fatty acids and NH₃-N, but decreased (p ≤ 0.01) the molar proportions of acetate and propionate and increased those of butyrate (p< 0.001). Organic matter and lipid contents of ruminal bacteria were lower whereas both N content and ¹⁵N enrichment were greater (p ≤ 0.05) in MAH-fed sheep. The in situ effective degradability (ED) of different fractions of SS, SM and SSM were calculated from the ruminal rates of particle comminution and passage, and values were corrected for microbial contamination. The MAH treatment decreased the ED of most fractions for all feeds and increased the supply of by-pass crude protein (CP) by 19.1% and 120% for SS and SM, respectively, and that of fat by 34% for SS. The MAH treatment also increased the in vitro intestinal digestibility of the by-pass CP for both SS (from 60.1% to 75.4%) and SM (from 83.2% to 91.0%). The simultaneous heating of both feeds (SSM) reinforced the protective effect of the MAH treatment and increased the by-pass CP without altering its intestinal digestibility, increasing the intestinally digested CP content by 16.8% compared with the value estimated from the results obtained for MAH-treated SS and SM incubated independently. These results indicate that the MAH treatment was effective to protect sunflower protein against rumen degradation and increased its intestinal digestibility.     

Effects of combined α-galactosidase and xylanase supplementation on nutrient digestibility and growth performance in growing pigs

Two experiments were conducted to investigate the effect of combined supplementation of α-galactosidase and xylanase on nutrient digestibility and growth performance in growing pigs. Experiment 1 had a 2 × 2 Latin square design, where eight barrows (45.0 ± 0.52 kg body weight [BW]) were fitted with a simple T-cannula in the distal ileum and received a basal diet without or with supplementation of α-galactosidase (12 U/kg diet) and xylanase (15 AXC/kg diet) within two periods of 10 d. The apparent ileal digestibility (AID) and apparent total tract digestibility of nutrients, pH, viscosity of digesta and digestive enzyme activities were assessed. In Experiment 2, a total of 432 growing pigs (initial BW 44.7 ± 0.66 kg) were allocated to four treatments. Diets were based on corn and soybean meal and had a normal or reduced nutrient level (reduced by 0.42 kJ digestible energy [DE] per kg and 0.8% crude protein). Both diets were offered without or with supplementation of α-galactosidase and xylanase. The growth performance was assessed within a 43-d feeding period, where at the end, biochemical serum indices were estimated. In Experiment 1, the enzyme-supplemented diet had a greater contents of DE and DE/gross energy ratio (p < 0.05), and a higher AID of Arg, raffinose, stachyose and arabinoxylan (p < 0.05). In Experiment 2, the low nutrient level caused lower daily gain (p < 0.05), which was partially compensated by enzyme addition. Enzyme addition also increased the serum concentration of Lys (p < 0.05). Moreover, it appears that the tested enzyme supplementation could increase dietary DE, serum total amino acid concentrations and decrease serum urea nitrogen.     

Reciprocal combinations of alfalfa hay and corn silage in the starter diets of Holstein dairy calves: effects on growth performance,nutrient digestibility,rumen fermentation and selected blood metabolites

Adding corn silage (CS) instead of alfalfa hay (AH) to the finely ground starter diet would improve calf performance if feed intake or feed efficiency is increased. We investigated the effects of replacing AH with CS in the starter diet on nutrient intake, digestibility, growth performance, rumen fermentation and selected blood metabolites in Holstein calves. Newborn male calves (n = 30; 3 days of age; 40.2 ± 1.28 kg BW) were assigned randomly to three groups receiving starter diets containing chopped AH (10% dry matter (DM) basis; AH diet), CS (10% DM, CS diet) or their combination (each at 5% level; AHCS diet). The starter diets had the same nutrient composition but differed in DM content (91.2%, 87.5% and 83.8% for AH, AHCS and CS, respectively). The calves were weaned on day 50, and the study continued until day 70. Nutrient intake, BW (at weaning and at the end of the study) and body measurements were not affected by the diet. During the post-weaning period, average daily gain tended to be greater on CS than on AH diet. Feed efficiency was greater in CS than in AH or AHCS calves during the post-weaning period. Digestibility of neutral detergent fiber was greater in AHCS and CS compared with AH during the post-weaning period. Concentration and profile of volatile fatty acids and ruminal fluid pH were not affected by the diet. Replacing AH with CS in the starter diet had no effect on feed intake, growth performance and general health of the calves. These results indicate that AH and CS can be used interchangeably in dairy calf starter diets until 70 days of age, allowing dairy producers more choices in selecting the feed ingredients.