Effect of hops β-acids (Humulus lupulus) on performance and intestinal health of broiler chickens

To evaluate a novel feed additive, hops β-acids, a pen trial using 1,440 one-day-old broiler chickens, in a randomized design with 6 treatments and 6 replicates of 40 birds/pen, was conducted. The experimental treatments were a negative control (NC) basal diet, a positive control (PC) basal diet supplemented with zinc 30 mg/kg of bacitracin, and 4 additional treatments consisting of the basal diet supplemented with 30, 60, 120, and 240 mg/kg of hops β-acids in a microencapsulated form. All birds were vaccinated against coccidiosis by eye drops. Productive performance, jejunum morphology, andClostridium spp. count in jejunum and cecum contents were evaluated. At 21 d of age, the birds fed the PC, 30, or 60 mg/kg of β-acids had the same weight gain of those fed the NC, whereas the highest level of β-acids decreased the gain. In addition, feed intake was decreased and FCR was improved in all treatments when compared with the NC. At 42 d, compared with the NC, the treatments containing 30 or 240 mg/kg of β-acids and the PC resulted in improved FCR. No differences were found for other performance variables. No difference was observed among the treatments on villus length, crypt depth, and villus-to-crypt ratio. Except for one sample, all others had negative results forClostridium spp. based on the methodology of sulphite reduction. In this study, we demonstrated positive effects of supplementation of hops β-acids on productive performance of broilers, and the best results were obtained with addition of 30 mg/kg.     

Effect of organic acids–essential oils blend and oat fiber combination on broiler chicken growth performance,blood parameters,and intestinal health

This study evaluated the effect of organic acids–essential oils blend with or without oat hulls (OH) on growth performance, organ weights, blood parameters, gut morphology, microbiota, and short-chain fatty acids (SCFA) in broiler chickens. Day-old broiler chickens were randomly allocated to 4 dietary treatments consisting of 1) a corn-soybean meal-wheat based diet (BAS), 2) BAS + 0.05% bacitracin methylene disalicylate (BMD), 3) BAS + protected organic acids–essential oils at 300 g/1,000 kg of feed (OE), and 4) BAS + protected organic acids–essential oils at 300 g/1,000 kg of feed + 3% OH (OEOH), in 8 replicate groups. Feeding was in starter (d 0 to 14), grower (d 14 to 24), and finisher (d 24 to 36) phases. Body weight (BW), feed intake (FI), feed conversion ratio (FCR), and mortality were determined weekly. On d 36, 8 chickens per treatment were sampled for blood biochemistry, organ weights, cecal SCFA production, and microbiota. Treatments had no effect on FI and FCR at all phases. Both OE and OEOH treatments reduced (P < 0.001) the body weight gain of birds at the starter phase. Birds fed the OEOH treatment had higher (P < 0.001) gizzard weight, while those offered the BMD diet showed a tendency (P = 0.08) to have higher cecal weight. Birds in the OEOH treatment recorded increased ileal villus height and villus height-to-crypt depth ratio, as well as reduced duodenal crypt depth, while birds in the OE treatment had increased jejunal villus height and villus height-to-crypt depth ratio. Both OEOH and OE treatments increased the number of goblet cells produced in the duodenum and jejunum. Treatments had no effect on SCFA concentrations. Birds in the OE treatment recorded the lowest concentration of blood urea (P = 0.05) and cholesterol (P < 0.05). Both OE and OEOH treatments increased (P < 0.05) the relative abundance of potentially beneficial bacteria in the genus Firmicutes_unclassified, Ruminococcus, Turicibacter, and Erysipelotrichaceae_unclassified, while reducing (P < 0.001) the relative abundance of potentially harmful Coprobacillus. Conclusively, both protected organic acids–essential oils blend and its combination with oat fibers show potential as tools to achieve antibiotics reduction in broiler production.     

Effect of calves’ supplementation on performance, nutritional and behavioral characteristics of their dams

The effects of supplementation of beef calves on weight gain, intake and digestibility of pasture, milk production and composition of their dams, and behavior of the pair cow–calf were assessed. Fifty-five beef cows with an initial average body weight of 449?±?8 kg and their respective offspring, with an initial average body weight of 138?+?3 kg and aged between 90 and 150 days, were used. Animals were submitted to an experimental period of 112 days. The experimental treatments consisted of: control?=?mineral mixture only, plan 1?=?high protein and high carbohydrate multiple supplement, plan 2?= high protein and low carbohydrate multiple supplement, plan 3?=?low protein and high carbohydrate multiple supplement, and plan 4?=?low protein and low carbohydrate multiple supplement. About 25 and 12.5 % of the protein requirements were supplied by the high and low protein supplements, respectively, and 15 and 7.5 % of total digestible nutrient requirements by the high and low carbohydrate supplements, respectively. Grazing behavior, performance, milk production, milk composition, intake, and digestibility of the cows were not affected (P?>?0.05) by the supplementation of the calves. The supplemented calves had greater (P?<?0.05) performance (as measured by final body weight, average daily gain, and final body condition score), intake and idle time, and lower (P?<?0.05) grazing time, but supplementation did not affect (P?>?0.05) suckling time and suckling frequency. It can be concluded that supplementation affects the behavior and feed intake of calves. However, it does not affect the suckling time and suckling frequency of calves. Additionally, performance, milk production, nutritional characteristics, and behavior of their dams are not affected.     

Effect of β-glucosidase on the meat quality and digestibility in broilers

This study investigated the effects of supplementary β-glucosidase on the carcass composition, meat quality, weight of digestive organ and apparent digestibility in male broilers. Two hundred and forty male, 1-day avine broiler chicks were randomly allocated into four treatment groups and fed with corn-soya bean meal supplemented with 0 (control), 0.6, 1.2 and 1.8 U/g of β-glucosidase respectively. The results showed that there were no significant differences (p > 0.05) among groups in carcass composition (percentages of eviscerated yield, half-eviscerated yield, muscle yield of breast and leg). However, adding 0.6 U/g β-glucosidase to the diet not only altered the meat quality by decreasing the drip loss ratio (p < 0.05) and relative lightness (L*) value (p < 0.01), increasing relative redness (a*) value (p < 0.01), but also significantly decreased the pancreas to body weight ratio (p < 0.05), however, with little effect on liver, proventriculus and gizzard to body weight ratio (p > 0.05). The length and width of duodenum villus were not affected by the addition of β-glucosidase, but the coefficients of total tract apparent digestibility of protein and fat increased by 9.02% (p < 0.05) and 7.40% (p < 0.01) respectively; the parameters of ash were not affected by β-glucosidase addition (p < 0.05). This study provided valuable information for evaluation of the effect of supplementary β-glucosidase on the meat quality and digestibility of broilers.     

Effect of supplementation with n-3 polyunsaturated fatty acids and/or β-glucans on performance,feeding behaviour and immune status of Holstein Friesian bull calves during the pre-and post-weaning periods

Background: Previous research in both calves and other species has suggested n-3 polyunsaturated fatty acids(PUFA) and β-glucans may have positive effects on immune function. This experiment measured performance,behaviour, metabolite and immunological responses to pre-weaning supplementation of dairy bull calves with n-3 PUFA in the form of fish oil and β-glucans derived from seaweed extract. 44 Holstein Friesian bull calves, aged 13.7± 2.5 d and weighing 48.0 ± 5.8 kg were artificially reared using an electronic feeding system. Each calf was offered5 L(120 g/L) per day of milk replacer(MR) and assigned to one of four treatments included in the MR,(1) Control(CON);(2) 40 g n-3 PUFA per day(FO);(3) 1 g β-glucans per day(GL) and(4) 40 g n-3 PUFA per day 1 g/d β-glucans(FOGL) in a 2 × 2 factorial design. Milk replacer and concentrate was offered from d 0–62(pre-weaning),while concentrate provision continued for a further 31 d post-weaning period. Individual daily feed intake and feeding behaviour was recorded throughout, while bodyweight and blood analyte data were collected at regular intervals.Results: Overall mean concentrate DMI from d 0–93 was 1.39, 1.27, 1.00 and 0.72 kg/d for CON, FO, GL and FOGL calves, respectively(SEM = 0.037; P 0.0001). Calves supplemented with GL were significantly lighter(P 0.0001) at both weaning(d 62) and turnout to pasture(d 93) than un-supplemented calves, with a similar effect(P 0.0001)evident for calves receiving FO compared to un-supplemented contemporaries. Supplementation with GL reduced the number of unrewarded visits where milk was not consumed(P 0.0001) while supplementation with FO increased mean drinking speed(P 0.0001). Supplementation with GL resulted in greater concentrations of haptoglobin(P = 0.034), greater serum osmolality(P = 0.021) and lower lymphocyte levels(P = 0.027). In addition,cells from GL supplemented calves exhibited a lower response than un-supplemented contemporaries to both Phytohaemagglutinin A stimulated IFN-γ(P = 0.019) and Concanavalin A stimulated IFN-γ(P = 0.012) following in vitro challenges.Conclusions: Pre-weaning supplementation of bull calves with either n-3 PUFA or β-glucan resulted in reduced voluntary feed intake of concentrate and consequently poorer pre-weaning calf performance. There was no evidence for any beneficial effect of either supplementation strategy on calves' immune responses.     

Acceptability,growth performance and nutritional status of chickens fed cassava leaf meal (CLM)–based diets

Tropical Animal Health and Production - This study evaluated the effect of feeding cassava leaf meal–based diets on feeding behavioural patterns, growth performance parameters and nutritional...     

Effect of dietary protein,essential and non‐essential amino acids on the performance and carcase composition of male broiler chickens

1. The present study was conducted to determine the possibility of using low‐protein broiler diets supplemented with synthetic amino acids. The effects on performance, carcase composition and nitrogen retention were evaluated.)

2. A starter diet was given, ad libitum, from 7 to 21 and a finisher diet from 21 to 42 d of age. Body weight, weight gain, food intake and food conversion (FC) were determined at 3 and 6 weeks of age. Abdominal fat deposition (AFD), carcase yield, carcase fat and protein and nitrogen retention were determined at 6 weeks of age. During the starter period chicks were given a 231 g/kg crude protein (CP) diet and a low protein diet supplemented with synthetic amino acid, a: to National Research Council recommendations, b: to the concentration of the control diet, and c: in agreement with the pattern of body composition. Glutamic acid and glycine were added to some diets as sources of non‐essential amino acids (NEAA). All diets contained 12.62 MJ metabolisable energy (AME_n)/kg. The diets administered between 3 and 6 weeks were comparable to the starter diets, except that they contained more AME_n (12.85 MJ/kg) and less protein.

3. Performance equal to that of high protein controls was obtained with birds fed a low protein diet supplemented with synthetic essential and NEAA to the amounts in the control diet or based on the amino acid profile of body protein. This was not achieved with low protein diets supplemented with synthetic amino acids to the amounts recommended by NRC.

4. Without altering performances, the efficiency of protein utilisation of birds fed on low protein diets was superior to that of birds fed on the commercial control diet and their nitrogen excretion was reduced by 26%. The percentage carcase yield and protein was unaffected by the dietary regimen but carcase fat content and AFD increased as the protein content of the diet decreased.

5. These results show that it is possible to obtain the same performances with low protein diets supplemented with synthetic amino acids, using an ideal amino acid balance. However, low protein diets result in a higher carcase fat content.     

Effects of single or combined dietary supplementation of β-glucan and kefir on growth performance,blood characteristics and meat quality in broilers

1. This study was conducted to evaluate the effects of dietary β-glucan and kefir (a fermented milk product) on growth performance, blood profiles, relative organ weight and meat quality in broilers.

2. A total of 375 day-of-hatch mixed sex ROSS 308 broilers (BW of 46 ± 0.1 g) were used in a 5-week experiment and randomly allotted to one of the following dietary treatments: (1) NC, basal diet; (2) PC, basal diet + 40 mg/kg of avilamycin; (3) B, NC + 0.1% β-glucan; (4) K, NC + 0.1% kefir; (5) BK, NC + 0.1% β-glucan + 0.1% kefir.

3. During weeks 0–3, broilers in B, K and BK treatments had higher body weight gain (BWG) than those in NC treatment. During weeks 4–5, BK treatment had a higher BWG than NC treatment. Overall, broilers given PC, K and BK diets had higher BWG than those given NC diet. The feed efficiency ratio (FCR) was improved by PC treatment.

4. Relative liver weight was increased by B treatment, whereas the relative weight of breast meat and gizzard was higher in BK group than that in NC group. Broilers given PC, B and BK diets had greater breast meat redness value and reduced drip loss at d 5 and d 7. The cooking loss was also reduced by B and BK treatments compared with NC treatment.

5. In conclusion, the results suggested that inclusion of 0.1% β-glucan and 0.1% kefir, either individually or combined, would improve growth performance and benefit meat quality in broiler chickens.     

Quantitative effects of pelleting on performance,gastrointestinal tract and behaviour of meat‐type chickens

1. In an attempt to quantify the effects of “degree” of pelleting, two experiments were conducted. Diets were prepared by mixing together a mash composed mainly of maize (experiment 1) or sorghum (experiment 2) with soft pellets, or soft pellets mixed with hard pellets.

2. The pelleting degrees (PDs) were as follows: 0 mash; 0·5 mixture of soft pellets and mash 1 to 1; 1 soft pellets pelleted once; 1·5 mixture of soft and hard pellets 1 to 1; 2 hard pellets pelleted twice.

3. In experiment 2, the weight and length of the digestive organs were determined as well as digestive enzyme activities. In both experiments, the behaviour recorded was eating, standing, sitting and drinking.

4. Food intake and body weight gain were related to the degree of pelleting in a curvilinear manner. PD had a positive effect up to a peak (1 to 1·5 PD), after which its effect decreased. Food efficiency was not related to PD. In experiment 1, food efficiency of PDs 1 to 2 were superior to PDs 0 to 0·5 and in experiment 2, PDs 1·5 to 2 were superior to PD 0.

5. The relative weight of the gizzard was reduced by pelleting, whereas pelleting increased the relative weight of abdominal fat. The content of the crop was not affected by PD, whereas that of the proventriculus was lowest in the PD 2 group. Gizzard content was inversely related to PD. Pelleting reduced the length of the jejunum and ileum: which were shortened by about 15% with PDs 1 to 2, as compared to PD 0. The weight/length ratio of the jejunum and ileum tended to increase with increasing PD to a peak at PD 1·5, and to decrease thereafter.

6. Trypsin activity in the pancreas and amylase activity in the intestinal content were reduced by pelleting.

7. Chicks fed pelleted diets were less active: they ‘sat’ more and spent less time eating than their mash‐fed counterparts.     

Effects of oregano essential oil with or without feed enzymes on growth performance,digestive enzyme,nutrient digestibility,lipid metabolism and immune response of broilers fed on wheat–soybean meal diets

1.?The study was conducted to determine the effects of dietary supplementation of enzyme and oregano essential oil at two levels, alone or together, on performance, digestive enzyme, nutrient digestibility, lipid metabolism and immune response of broilers fed on wheat–soybean meal based diets.

2.?The following dietary treatments were used from d 0 to 21. Diet 1 (control, CONT): a commercial diet containing no enzyme or oregano essential oil, diet 2 (ENZY): supplemented with enzyme, diet 3 (EO250): supplemented with essential oil at 250 mg/kg feed, diet 4 (EO500): supplemented with essential oil at 500 mg/kg feed, diet 5 (ENZY + EO250): supplemented with enzyme and essential oil at 250 mg/kg, and diet 6 (ENZY + EO500): supplemented with enzyme and essential oil at 500 mg/kg.

3.?Birds fed on diets containing ENZY, EO250 and ENZY + EO250 had significantly higher weight gain than those given CONT diet from d 0 to 7. No significant effects on feed intake, feed conversion ratio, mortality, organ weights except for jejunum weight and intestinal lengths was found with either enzyme or essential oil, alone or in combination, over the 21-d growth period. The supplementation of essential oil together with enzyme decreased jejunum weight compared with essential oil alone.

4.?Supplementation with enzyme significantly decreased viscosity and increased dry matter of digesta, but did not alter pH of digesta. There was no effect of essential oil alone at either concentration on viscosity, dry matter or pH of digesta. A significant decrease in viscosity of digesta appeared when essential oil was used with together enzyme.

5.?The supplementation of essential oil at both levels with or without enzyme significantly increased chymotrypsin activity in the digestive system, and improved crude protein digestibility.

6.?The higher concentration of essential oil with and without enzyme significantly increased serum total cholesterol concentrations. No significant effect on immune response was found with either enzyme or essential oil, alone or together.

7.?Enzymes and essential oil had different modes of actions. The supplementation of enzyme with essential oil in diets is likely more effective in view of performance, nutrient digestibility, enzyme activities and immune system.     

Effect of dietary digestible lysine level on growth performance,blood metabolites and meat quality of broilers 23–38 days of age

This study was done to evaluate the effects of different dietary digestible lysine (dig Lys) levels on growth performance, blood metabolites, carcass and breast yield, and breast meat quality of broilers 23–38 days of age. Three hundred 23-day-old Cobb-500 male broiler chickens were allocated to a completely randomized design with five treatments (finisher diet containing 0.88%, 0.94%, 1.00%, 1.06% and 1.12% dig Lys) and six replicates of 10 birds each. Feed intake (FI) was not affected by different dietary dig Lys levels. Weight gain (WG) linearly increased and feed conversion ratio (FCR) linearly decreased with an increasing dietary dig Lys levels. With increasing dietary dig Lys levels, carcass and breast yield and breast meat hue angle (h^*) linearly increased, but abdominal fat decreased quadratically, whereas breast meat lightness (L^*) and ether extract composition linearly decreased. Dietary dig Lys levels did not show any significant effect on serum metabolites, breast meat cooking loss and water holding capacity. Based on the linear broken-line regression models, the weight gain, feed conversion ratio and breast yield were optimized when dietary dig Lys levels were 0.95%, 1.01% and 1.02% respectively. It is concluded that Lys requirements vary according to what productive parameter is taken for optimization. A minimum of 1.02% dig Lys concentration in the finisher diet is suggested to optimize breast yield, feed efficiency and performance in broiler chickens.     

Effect of storage duration on egg quality,embryo mortality and hatchability in FUNAAB-ɑ chickens

Effect of extended storage on egg quality, embryo mortality and hatchability in FUNAAB-ɑ chickens was determined. Hatchable eggs (n = 288; weighing 53.2 ± 4.67 g) collected from a flock of FUNAAB-ɑ layer breeder hens aged 32 weeks were stored in egg tray with broad end up under 16 ± 1.5°C for either 0, 4, 8, 12, 16 or 20 d. Before incubation, eight eggs from each group were evaluated for internal and external quality traits. Remaining eggs were set in an incubator and transferred into hatcher on embryonic day 18. Data collected were subjected to one-way analysis of variance. Egg weight loss (EWL; p < .001), surface area (p < .001), yolk diameter (p < .001), inner and outer blastoderm diameters (p < .05) and dead in germ (DIG; p < .001) increased with storage duration while yolk height (p < .001), yolk index (p < .001), albumen weight (p < .05), albumen height (p < .05), albumen index (p < .01), Haugh's unit (HU; p < .05), fertility (p < .001), hatchability of set (HATCHS; p < .001) and fertile eggs (p < .05) decreased. Weight losses of 0, 1.2, 2.2, 3.4, 4.6 and 6.1% were recorded in egg stored for 0, 4, 8, 12, 16 and 20 days respectively. Eggs stored beyond 8 days exhibited higher DIG and lower HATCHS. Shell percentage in 4 days storage (11.4%) was lower (p < .05) than in 16 days storage (13.4%). Shell thickness was similar in eggs stored for 0 to 12 days, but 8 days storage (0.60 mm) had thinner (p < .01) shell than day 16 (0.71 mm) and day 20 (0.73 mm) storage. Internal quality unit (IQU) was higher (p < .05) in fresh eggs (180.4) than in 12 days (167.8) and 20 days (167.8) stored eggs. Extended storage of FUNAAB-ɑ eggs caused EWL, surface area shrinkage, lowered HU and IQU, loss of yolk and albumen quality, increased blastoderm diameters and DIG, and decreased egg fertility and HATCHS from day 8 forward. Storing FUNAAB-ɑ eggs beyond 8 days reduced quality parameters; therefore, other mitigating factors are recommended when storing beyond 8 days.     

Studies on acid oils and fatty acids for chickens. III. Effect of chemical composition on metabolisable energy of by‐products of vegetable oil refining

1. Fourteen by‐products of oil refining, selected for their variability in free fatty acid and unsaponifiable contents, were analysed chemically with the objective of relating the determined ME values of the products to chemical composition by means of multiple linear regression analysis. Refined sunflower oil was included as a reference fat.

2. Twenty‐one 2‐week‐old chicks were used to determine fat digestibilities and AMEn values of diets, using the total collection method. Fats were included in a wheat‐soyabean meal diet at 100 g/kg. Multiple linear regression analysis was used to express the ME values of fats as functions of the parameters measured (moisture, gross energy, impurities, unsaponifiables, non eluted material, free fatty acid content, unsaturated: saturated ratio, peroxide value, TBA test).

3. The ME of the fat products lay in the range 12.62 to 24.35 MJ/kg, and 29.26 MJ/kg for refined sunflower oil. Free fatty acid content of the fats was shown to be a poor predictor of their ME values, whereas non eluted material (NEM) of the fat products showed a good correlation with their ME. A regression equation could be derived (R² = 0.6548; SEE = 2–0064) with the unsaturated: saturated ratio (U:S) and NEM. An ME prediction equation based on the U:S, NEM and unsaponifiable content is also proposed (R² = 0–7168; SEE= 1.9058).     

Effect of the administration program of 2 β-adrenergic agonists on growth performance and carcass and meat characteristics of feedlot ram lambs

The aim of the study was to determine the effects of 3 feeding dose programs of the β-adrenergic agonists (β-AA) ractopamine hydrochloride (RH) or zilpaterol hydrochloride (ZH) for the final 30 d before slaughter on growth performance and carcass and meat characteristics of feedlot ram lambs. Eighty-four Dorper × Katahdin ram lambs (30.0 ± 1.6 kg) were blocked by BW and randomly assigned to pens (4 lambs per pen and 3 pens per treatment). Pens within a block were assigned randomly to 1 of 7 dietary treatments: 1) control (CTL) = diet without β-AA; 2) RH constant (RHC) = 20.0 mg/kg of RH, d 1 to 30; 3) RH increasing (RHI) = 10.0 mg/kg, d 1 to 10; 20.0 mg/kg, d 11 to 20; and 30.0 mg/kg, d 21 to 30; 4) RH decreasing (RHD) = 30.0 mg/kg, d 1 to 10; 20.0 mg/kg, d 11 to 20; and 10.0 mg/kg, d 21 to 30; 5) ZH constant (ZHC) = 6.0 mg/kg of ZH, d 1 to 30; 6) ZH increasing (ZHI) = 3.0 mg/kg, d 1 to 10; 6.0 mg/kg, d 11 to 20; and 9.0 mg/kg d 21 to 30; and 7) ZH decreasing (ZHD) = 9.0 mg/kg, d 1 to 10; 6.0 mg/kg, d 11 to 20; and 3.0 mg/kg, d 21 to 30. Overall, β-AA supplementation reduced DMI (P < 0.001) compared with CTL lambs, but lambs fed RHI and ZHI programs had greater (P < 0.05) total BW gain, ADG, and G:F. Carcass weight was improved (P < 0.05) by RHI and ZHI programs, but dressing percentage was enhanced (P < 0.05) by only ZHC or ZHI treatments. Fat thickness and yield grade were reduced (P < 0.05) by ZH or RH regardless of feeding program. Most LM characteristics (pH, moisture loss, and chemical composition) were not different among treatments (P > 0.05), with the exception of fat content that was reduced (P < 0.001) in lambs fed β-AA, and diameter of muscle fibers that was increased (P < 0.05) by ZHI treatment. Constant and increasing doses of ZH reduced (P < 0.05) the a* value of LM and semitendinosus muscles, with no effects on L* or b* values. The mass of liver was reduced (P < 0.05) in ZHI-treated lambs compared with CTL lambs, and plasma urea concentration was reduced (P < 0.05) by RH or ZH administration regardless of feeding program, although there were no other differences in organ mass weight (P ≥ 0.35) or blood metabolites (P ≥ 0.16). Increasing doses of RH or ZH augmented the growth performance response without negative effects on organ mass weight or blood metabolites. Although a ZHI program improved carcass characteristics, the increased LM fiber diameter of lambs fed ZHI program could be unfavorable because of the potential negative effect on tenderness.     

Effect of dietary α -tocopherol concentration on performance and some immune responses in broiler chickens fed on diets containing oils from different sources

1. An investigation was carried out into the effects of dietary α-tocopherol (α-T) concentration and source of supplemental oil on performance, activity of anti-oxidative enzymes and some immune responses in broilers from day-old to 41 d of age. 2. Three dietary concentrations of α-T (10, 50 and 100 mg/kg) with three sources of supplemental oil (sunflower - SFO, palm - PMO and safflower - SAO) were provided using a 3 × 3 experimental design. 3. Body weight gain and food conversion efficiency were not affected by either interaction or concentrations of α-T and sources of oil in diet. 4. Concentrations of total protein, globulin, triglycerides and cholesterol in sera increased significantly with dietary α-T concentration irrespective of the source of oil. Significantly higher concentration of serum albumin was evident in broilers fed on the SFO-based diet and the concentration of globulin was higher in groups fed on those diets containing PMO and SAO. 5. The lipid peroxidation (LP), measured as MDA release, decreased with the concentration of α-T in a dose-related manner with SFO- and SAO-based diets, although not with the PMO-based diet. With different oil sources, LP was significantly lower with the PMO-based diet compared to the others. Activities of glutathione peroxidase and RBC catalase increased and heterophil: lymphocyte ratio was reduced with concentration of α-T for each source of oil tested. 6. Assays for humoral and cell-mediated immune responses indicated no effect of the source of dietary supplemental oil or interaction, although an increasing concentration of dietary α-T improved cell-mediated immune responses. 7. It is concluded that sunflower oil, palm oil and safflower oil can be used as sources of oil for broiler diets without having any effect on performance, immune responses or the activity of anti-oxidizing enzymes. Higher concentrations of dietary α-tocopherol (50 or 100 mg/kg) reduced lipid peroxidation activity and enhanced activities of anti-oxidative enzymes, they also improved the cell-mediated immune responses in commercial broilers.     

Effects of increasing dried distillers’ grains with solubles and non-starch polysaccharide degrading enzyme inclusion on growth performance and energy digestibility in broilers

Two experiments were conducted to examine the effects of non-starch polysaccharide degrading enzyme on broiler performance and ileal nutrient digestibility in diets containing dried distillers’ grains with solubles, as well as evaluate non-starch polysaccharide degrading enzyme inclusion in low energy diets with dried distillers’ grains with solubles on performance and carcass yield. Experiment 1 was a 4 (dried distillers’ grains with solubles level of 0, 5, 10, and 15%) x 2 (with and without enzyme) factorial design in battery-reared broilers for 21 d; body weights and feed intake were determined weekly. On day 22, ileal contents were collected to determine digestibility of energy and nitrogen. The second experiment was a 48 d floor pen trial utilizing three dietary treatments: positive control, negative control (positive control, negative control less 132 kcal/kg ME), and a negative control + non-starch polysaccharide degrading enzyme inclusion. Diets included dried distillers’ grains with solubles at 2.5 to 10%. In Experiment 1, BW decreased (P < 0.05) with 15% dried distillers’ grains with solubles inclusion as compared to the control. The FCR was also increased (P < 0.05) with 15% dried distillers’ grains with solubles inclusion as compared to all other diets through 14 d. Inclusion of dried distillers’ grains with solubles reduced (P < 0.05) ileal digestible energy at 10 and 15% inclusion and inclusion of non-starch polysaccharide degrading enzyme increased (P < 0.05) ileal digestible energy. Increased energy and nitrogen digestibility coefficients (P < 0.05) were observed at all dried distillers’ grains with solubles inclusion levels with non-starch polysaccharide degrading enzyme inclusion except for the 10% inclusion rate. In Experiment 2, non-starch polysaccharide degrading enzyme in the negative control diet increased BW compared to the negative control at all observed time points at each phase (P < 0.05). Additionally, non-starch polysaccharide degrading enzyme in the negative control diet reduced mortality corrected FCR through the grower phase. Non-starch polysaccharide degrading enzyme inclusion in the negative control diet resulted in comparable live weights, carcass weights, breast filets, and tenders to the positive control diet; however, fat pad was reduced compared to the positive control (P < 0.05). These data confirm that elevated levels of dried distillers’ grains with solubles in starter diets can negatively impact digestibility and performance of broilers and the inclusion of an non-starch polysaccharide degrading enzyme can increase nutrient digestibility and improve broiler performance in low energy dried distillers’ grains with solubles containing diets.     

Transient stray voltage: Is it detrimental to growth performance,health status and welfare of market pigs?

The effects of transient stray voltage associated with an alternating current were evaluated in growing-finishing pigs from 9 to 22 weeks of age. Seventy-two pigs were assigned to 9 blocks of 8 animals each. In each block, the following treatments were randomly distributed: a constant voltage differential created between the feeder or drinker and the metallic floor (woven wire), at a level of 0 volt plus 2-volt pulses (0 V–2 V), 2 volts plus 3-volt pulses (2 V–5 V), 5 volts plus 3-volt pulses (5 V–8 V), and a control treatment without any voltage differential (0 V–0 V). The constant voltage was applied 24 h per day. The pulses of 3 s duration were in the form of an increase in the amplitude of the constant 60-Hz signal. One pulse appeared every 20, 40 and 100 s during the hour following feed distribution and every 60, 120 and 300 s during the rest of the day. The animals were fedad libitum and received fresh feed twice per day. Once during the 2-week periods at 9–10, 13–14, 17–18 and 21–22 weeks of age, the behaviour of the pigs was recorded during the hour following the two daily feed distributions. Animal weights and blood samples were taken every 2 weeks, from 9 to 21 weeks of age. No significant effect of transient stray voltage on any of the variables measured for the feeding, drinking, sitting or lying activities was found (p>0.05). At 9–10 weeks of age, the number of rooting bouts was higher for the 5 V–8 V treatment (p=0.03) and the number of events of butting the penmate was higher for the 2 V–5 V treatment (p=0.05). Although the water and feed intake did not differ between treatments (p0.39), the average daily gain of the control group was lower than that of treated groups (p=0.04) at 9 and 10 weeks of age, while the pigs submitted to a 2 V–5 V treatment had a higher daily gain than the pigs in the other treatment groups (p=0.05) at 17 and 18 weeks of age. Finally, the frequency of gastric ulceration and the metabolic profile were not affected by the treatments (p>0.05) except for the CO₂ and total protein concentrations (p0.04), where treatment effects were inconsistent among ages. Consequently, under the experimental conditions of the present study, no major impact of transient stray voltage on the health, growth or welfare of fattening pigs was observed.