Refining dietary metabolisable energy and crude protein levels in relation to duck performance and behaviour.

1. The study evaluated the effect of dietary metabolisable energy (ME) content and crude protein (CP) level on the growth performance and behaviour of ducks.2. A total of 720, Cherry Valley ducks were allocated to 36 pens in groups of 20 birds. For the initial period, from 1 to 21 d age, six diets, containing a standard (SME), low (LME) and high (HME) ME of 12.14, 11.93 and 12.35 MJ/kg, and standard (SCP) or high (HCP) CP contents of 210 or 220 g/kg diet, respectively, were mixed. For the period from 22 to 42 d age, the diets contained ME of 12.98 (SME), 12.77 (LME), 13.19 (HME) MJ/kg and the levels of CP were 170 (SCP) or 180 (HCP) g/kg, respectively.3. An ME by CP interaction was seen from 1 to 21 d age in ducks fed HME + HCP diet, which had greater weight gain than those fed LME + SCP (P < 0.05). Compared to LME + SCP, dietary HME decrease feeding but increased walking behaviour compared to LME + SCP and SME + SCP (P < 0.05). High CP in LME and SME diets increased drinking behaviour (P < 0.05), but there was no change in HME diet. Compared to LME, feeding HME reduced ground pecking (P < 0.05). Feeding HME reduced feeding behaviour (P < 0.05) from 22 to 42 d age. During the same period, standing behaviour was reduced in HCP + LME (P < 0.05). Drinking was reduced in LME + SCP compared to SME + HCP and HME + HCP (P < 0.05).4. A diet formulated with HME and HCP is effective for enhancing growth performance of ducks aged 1-21 d and saving time for feeding or ground pecking, which may induce spending more time on other activities.

Sunflower and rapeseed meal as alternative feed materials to soybean meal for sustainable egg production, using aged laying hens.

1. This study assessed the impact of replacing two thirds of a soybean meal (SBM) based diet with an alternative protein (AP) based diet (sunflower and rapeseed meal), when fed to end of production Hy-Line Brown laying hens.2. Diets were fed in seven cages, each containing six birds aged from 75 to 83 weeks old. Measured variables included bird performance, egg production, quality variables of fresh eggs, total tract digestibility of dry matter (DMD), neutral detergent fibre (NDFD), fat (FD), and nitrogen corrected apparent metabolisable energy (AMEn).3. No significant differences were observed (P > 0.05) for egg production, egg composition or egg quality. However, birds fed the AP diet had darker yolks (P < 0.05), possibly linked to natural pigments in AP.4. The SBM diet had higher AMEn, DMD and NDFD (P < 0.05), although FD was higher in the AP diet (P < 0.05).5. Diets based on AP sources can be fed to aged laying hens without deteriorating productive performance, providing care is taken in formulating diets (e.g. amino acid levels, balance etc). Using AP sources may reduce reliance on SBM associated with land use change, contributing towards sustainability for the egg industry.

The effect of different wheat varieties and exogenous xylanase on bird performance and utilization of energy and nutrients.

The aims of the present study were to first, determine the xylan fractions of 10 different wheat cultivar samples and their response to treatment by the same commercial xylanase enzyme preparation. Second, use information obtained to select 5 of the wheats for use within a feeding experiment to determine whether the rate of xylan release can be used to predict the feeding value of the wheats when diets have been supplemented with xylanase. Treatment of 10 different wheat varieties by the same enzyme resulted in varying levels of hydrolysis. Soluble xylan content ranged from 7.85 to 14.40 and 3.20 to 5.13 (mg/g) when treated with and without xylanase, respectively. Oligosaccharide content ranged from 0.34 to 1.58 and 0.05 to 0.54 (mg/g) when treated with and without xylanase, respectively. Five of the 10 wheats were then selected based on the determined xylan fractions to use within a feeding experiment. A total of 360 male Ross 308 broilers were randomly allocated to 60 raised floor pens. A soybean meal (SBM) balancer feed was formulated to contain 12.07 MJ/kg apparent metabolizable energy (AME) and 392.9 g/kg crude protein (CP). Five diets were prepared by mixing 630 g/kg of each of the 5 experimental wheats with 370 g/kg of the balancer. Each diet was split into 2, one of which was supplemented with 100 g/MT of Econase XT (223,000 BXU/g), resulting in a total of 10 diets. The birds were fed the diets from 0 to 28 d of age. Wheat cultivar had an effect (P = 0.044) on feed intake (FI), while the addition of xylanase increased (P < 0.05) weight gain (WG) and improved feed conversion ratio (FCR). Various interactions were observed (P < 0.05) between wheat cultivars and xylanase for AME and nutrient utilization. This study suggests that wheats treated with the same xylanase, differ in their susceptibility to release soluble xylan and oligosaccharides, which may partially explain the varying performance and nutrient digestibility responses noted in the literature.

Refining the metabolisable energy value of field beans for turkeys.

1. This study examined the feeding value of ten UK grown field bean (Vicia faba L. var. minor) cultivar samples from the same harvest year on nitrogen corrected apparent metabolisable energy (AMEn) and nutrient retention coefficients when fed to young female turkeys.2. A balancer feed (BF) was formulated to contain 12.39 MJ/kg ME and 269 g/kg crude protein. Ten nutritionally complete, mash diets were prepared by mixing 200 g/kg of each ground field bean cultivar with 800 g/kg of the BF, totalling eleven diets. Diets were fed to female BUT Premium turkeys from 40 to 50 d of age. Each diet was fed to eight raised floor pens, housing two birds, following randomisation. The AMEn was determined by the total collection technique over the last 4 d of the study. Relationships were examined between AMEn, chemical composition and quality variables of the field bean samples.3. The overall determined AMEn value of the beans ranged from 7.72 MJ/kg DM to 9.87 MJ/kg DM, giving an average AMEn of 8.80 MJ/kg DM (P < 0.05). The soluble non-starch polysaccharide (NSP) content of the beans negatively correlated with their determined AMEn (r = -0.730; P < 0.05). Bean flour lightness-darkness degree (L*) correlated positively with the AMEn (r = -0.643; P < 0.05)4. A positive correlation was observed between the degree of yellowness-blueness of bean flour and condensed tannins content (r = 0.696; P < 0.05). Step-wise regression indicated that soluble NSP + L* of field beans provided explanatory variables suitable for estimating the AMEn value for turkeys (r2 = 0.737; P < 0.05).

Feeding dihydroquercetin in wheat-based diets to laying hens: impact on egg production and quality of fresh and stored eggs.

1. This study assessed the impact of dietary dihydroquercetin (DHQ) in wheat-based diets on egg production, composition and quality when fed to laying hens. A total of 80 Hy-Line Brown hens were allocated to 20 enriched layer cages, over two tiers, in groups of four birds.2. Two wheat-based diets were used in the study. A basal diet, meeting the nutrient requirement of the hens, containing 11.56 MJ/kg AME and 172 g/kg crude protein, was mixed and split into two parts. One part was fed as prepared to the control group of birds. The second diet was made by adding 1.5 g DHQ per kg basal diet and fed to the treatment group of birds. This level was relatively high and extended the data on levels normally fed. The diets were fed in a meal form and did not contain any coccidiostat, antimicrobial growth promoters or other similar additives. Each diet was fed to hens in 10 replicate cages for 4 weeks, from 22 to 26 weeks of age, following randomisation.3. Subsequently, eggs were investigated to determine the impact of dietary DHQ on the quality variables of fresh and 28-d stored eggs.4. Overall, feeding 1.5 g/kg dietary DHQ for 4 weeks did not affect (P > 0.05) egg production or the quality of fresh and stored eggs. Any observed egg quality changes (P < 0.05) confirmed the expected effects of egg storage.

Feeding guanidinoacetic acid to broiler chickens can compensate for low dietary metabolisable energy formulation.

1. This study compared the responses of broilers to diets supplemented with the same level of guanidinoacetic acid (GAA) but formulated to have different N-corrected apparent metabolisable energy (AMEn) contents. The study involved 1280, one-day-old Ross 308 broilers, in 64 pens comprising 32 pens of males and 32 pens females, (20 birds in each) aged from 0 to 42 d.2. Commercial AME levels of 12.55 MJ/kg, 12.97 MJ/kg and 13.18 MJ/kg in the starter, grower and finisher diets, respectively, were set for the positive control (PC) feed. Four dietary treatments were prepared: PC (as above); negative control 1 (NC; PC - 0.21 MJ ME /kg); NC1 + 0.06% GAA; NC2 (PC - 0.42 MJ ME/kg + 0.06% GAA). Each diet was provided in 16 pens (eight male and eight female), following randomisation.3. Overall, birds fed NC1 had lower feed intakes (FI) compared to birds fed the PC and NC2+ GAA, lower weight gain (WG) compared to all the other diets and lower final body weight than birds fed the GAA diets (P < 0.05). There was a diet x sex interaction (P = 0.039), whereby feeding NC+GAA to female birds improved feed efficiency compared to being fed NC2 and NC1+ GAA, but not in males. Birds fed diets with GAA had a higher poultry efficiency factor (P < 0.001) than those fed NC1.4. There were no effects of treatment or sex on litter moisture, footpad score, white striping, wooden breast, AMEn, dry matter and fat retention (P > 0.05). However, the diet NC1+ GAA had 11.2% higher nitrogen retention coefficient compared to the NC1 diet (P = 0.038).5. Overall, the results implied that lower performance induced by a reduction of dietary AMEn in the range of 0.21 to 0.42 MJ/kg was more than compensated by supplementing 600 g/t GAA to the feed.

The effect of selenium source on the oxidative status and performance of broilers reared at standard and high ambient temperatures.

1. This study investigated the oxidative status of broilers fed diets containing selenium (Se) from 14 to 35 d of age and reared at two different constant temperatures. Measurements of oxidative status included blood glutathione peroxidase (GSH-Px) and plasma total antioxidant status (TAS). Other variables included feed intake (FI), weight gain (WG), feed conversion ratio (FCR), Se levels in breast and liver tissue, jejunal villus morphometry, percentage weight of organs in relation to body weight; apparent metabolisable energy adjusted for nitrogen (AMEn); dry matter retention (DMR); fat retention (FR) and nitrogen retention (NR).2. The experiment started at 14 d of age, when 240 birds were randomly allocated to 48 pens (12 pens in four rooms). Treatments included a control diet 1 (SFC; 209.4 g/kg CP and 12.98 MJ/kg ME and no added Se containing saturated fat); diet 2 (SFSe) the control plus 12.605 mg/kg Se additive; diet 3 (USFC) was a second control diet (208.2 g/kg CP and 13.10 MJ/kg ME with no added Se containing unsaturated fat as rapeseed oil); diet 4 (USFSe) was the latter control plus 12.605 mg/kg Se additive. Two rooms were kept at a standard temperature of 20°C (ST) and two rooms were kept at high temperature of 35°C (HT).3. A temperature x Se interaction existed for GSH-Px in birds reared at ST (P < 0.05), and these birds had the highest levels of Se in liver tissue (P < 0.05). Fat x Se interactions were evident in breast tissue with highest levels in USFSe (P < 0.05). Adding Se improved jejunal VH: CD in USFSe fed birds (P < 0.001).4. Birds reared at ST had higher FI and WG than those reared at HT (P < 0.001), and had lower FCR than those reared at HT (P < 0.05). AMEn (MJ/kg DM) and FR were higher in birds fed USF diets, and lowest in birds fed SF (P < 0.50 and P < 0.001 respectively). NR was highest in birds raised at ST (P < 0.50).5. Broiler growth performance was reduced by HT. Oxidative status and Se in liver tissue was improved by adding Se in both diets.

The effect of feeding different sources and levels of selenium on growth performance and antioxidant status of broilers raised at two different temperatures.

1. This study examined the effects of different dietary sources and levels of selenium (Se) on growth performance, hepatic and breast meat Se content, glutathione peroxidase (GSH-Px) activity and total antioxidant status (TAS) in blood, when fed to broilers from 14 to 35 d of age and reared at two different temperatures (20°C and 35°C). 2. Five hundred and sixty male Ross 308 broilers were reared in a single floor pen and fed the same proprietary starter diet from 0 to 14 d age (229.9 g/kg CP and 12.67 MJ/kg ME, without Se supplementation). 3. The experiment started at 14 d age, and the birds randomly assigned to 112 raised-floor pens (0.36 m2 area, 5 birds/pen). Each of the seven experimental diets were offered to birds in 16 pens within four rooms. Two rooms were at 20°C and two rooms were maintained at 35°C. The experimental diets were fed from 14 to 35 d age and contained 214.9 g/kg CP and 13.11 MJ/kg ME. The experimental diets were as follows; control diet containing background Se only (0.189 mg/kg; C); low level sodium selenite (0.376 mg/kg; LSS): high level sodium selenite (0.558 mg/kg; HSS); low level commercial B Traxim® Se (0.244 mg/kg) (LBT); high level B Traxim® Se (0.448 mg/kg; HBT); low level selenised yeast (0.290 mg/kg; LSY); high level selenised yeast (0.487 mg/kg; HSY). 4. Birds consumed more when raised at 20°C compared to birds reared at 35°C (P ≤ 0.05). Birds fed lower Se level reared at 35°C had higher weight gain versus those fed higher Se level (P < 0.05). Birds fed SY had the lowest feed intake, weight gain and FCE (P < 0.05). The greatest GSH-Px activity was observed in birds fed SS diets (P < 0.001). There were interactions between diet x level for TAS, which were highest in birds fed LBT compared to birds fed HBT (P < 0.05). Breast Se content was higher in birds fed HSY compared to LSY (P < 0.001). The highest hepatic Se was seen in birds fed SY and lowest in C (P < 0.001). 5. Birds fed BT diets showed similar levels of Se to those birds fed inorganic Se, and similar levels of GSH-Px to birds fed SY. Further comparative work with broilers fed BT and other Se supplemented diets may elucidate the findings from this report.

Effect of feeding different sources of selenium on growth performance and antioxidant status of broilers.

1. This study was conducted to determine the effect of different sources of selenium (Se) on breast and liver tissue deposition, apparent metabolisable energy (AME), growth performance and antioxidant status of broilers, measured as Se content in liver and breast tissues and glutathione peroxidase (GSH-Px) in blood, when used in 0-35 d broiler chicken diets. 2. A total of 200 male Ross 308 broilers were used in the feeding trial, which comprised two dietary phases, a starter from 0 to 21 d and finisher from 21 to 35 d of age. Four treatments with 10 replications each were used. A control diet (C) was formulated that was sufficient in protein and energy (230 and 215 g/kg of crude protein and 12.67 and 13.11 MJ/kg of metabolisable energy, respectively), for both phases, but contained background Se only from the feed ingredients. Diet 2 (IS) was supplemented with 10.35 g/t inorganic, elemental source of Se. Diet 3 (SY) was supplemented with 136.36 g/t selenised yeast, an organic source derived from Saccharomyces cerevisiae. Diet 4 (SS) was supplemented with 0.666 g/t sodium selenite, an inorganic source. 3. Birds fed the SY diet consumed less and weighed less than those fed IS or C (P < 0.05; 0-35 d of age), but there was no difference compared to birds fed SS diets. There were no differences in FCR or dietary AME between broilers fed different Se sources. All diets containing supplementary Se increased concentrations in the liver and breast muscle, and for GSH-Px levels in blood compared to birds fed the C diet (P < 0.001). Birds fed SY diets had greater Se levels in liver and breast tissues compared to birds fed any of the other diets (P < 0.001). 4. Diets supplemented with Se had variable effects on broiler growth performances and antioxidant status. Feeding Se from a yeast source has higher transfer into breast tissues. Feeding different sources and levels of Se to birds in a more challenging situation to induce oxidative stress may bring more conclusive results.

Nutrient content and digestibility of different batches of wheat distillers dried grains with solubles for laying hens.

1. Four batches of wheat distillers dried grains with solubles (DDGS) produced by a single production plant were used to investigate variation in digestible energy (DE) and nutrient digestibility for laying hens. 2. A total of 144 Hy-Line Brown laying hens were allocated to eight treatment groups in replicates of six. Experimental diets were prepared by replacing the basal feed with either 150 g/kg or 300 g/kg of each batch of DDGS. 3. Chemical analysis of the DDGS showed variation between the different batches. Largest coefficients of variation were observed for starch (0.546) and total soluble non-starch polysaccharides (NSP; 0.276). 4. Digestible energy and the nutrient digestibility of each diet was measured using the ileal collection technique. Data were statistically analysed as a blocked 2 × 4 factorial design analysis of variance (ANOVA). 5. Variability between the different diets were observed for digestible energy and the digestibility of certain nutrients (P < 0.05). 6. The observed differences in energy utilisation and nutrient digestibility in laying hens suggested that the feeding quality of diets containing different wheat DDGS batches produced by a single production plant may still have large variation.

Effect of wheat distillers dried grains with solubles and exogenous xylanase on laying hen performance and egg quality.

Despite the rapid increase in the use of wheat distillers dried grains with solubles (DDGS) within the poultry sector, little information is available on how the long-term feeding of this by-product will affect the performance of laying hens. This experiment examined the effect of wheat DDGS, with and without exogenous xylanase on dietary apparent metabolizable energy (AME), total tract dry matter retention (DMR), nitrogen retention (NR), fat digestibility (FD) coefficients, feed intake (FI), bodyweight gain (BWG), eggs laid, mean egg weight, egg mass output, and egg quality characteristics including albumin height (AH), Haugh units (HU), yolk color, eggshell strength, and thickness. A total of 320 Hy-Line brown laying hens were randomly allocated to 80 enriched layer colonies (groups of 4). A total of 2 control wheat-soybean meal-based diets were formulated to contain 11.60 MJ/kg. One of the diets contained 300 g/kg wheat DDGS, while the other was DDGS free, with a respective crude protein content of 171.1 g/kg and 166.5 g/kg. Both diets were divided by 2 and half of them were supplemented with 2,500 U/kg of xylanase, resulting in 4 diets in total. Data was analyzed as a 2 × 2 factorial arrangement of treatments with analysis of variance (ANOVA). Diets were fed ad libitum from 17 to 43 wk of age and data was collected from 23 to 43 wk. The inclusion of wheat DDGS reduced (P < 0.001) dry matter retention (DMR), FI, BWG, eggs laid, mean egg weight, and egg mass. However, xylanase supplementation improved AME and NR in diets containing wheat DDGS and FD in diets without DDGS (DDGS × xylanase, P < 0.05) and tended to improve (P < 0.10) BWG and egg mass output. For egg quality measurements, the inclusion of DDGS improved (P = 0.046) HU values, eggshell strength (P < 0.001), and increased (P < 0.001) yolk color intensity. This experiment showed xylanase can be used to improve the AME and NR of DDGS-based diets. However, the long-term feeding of 300 g/kg wheat DDGS negatively impacts the productive performance of hens.

Nutrient availability of different batches of wheat distillers dried grains with solubles with and without exogenous enzymes for broiler chickens.

Wheat distillers' dried grains with solubles (DDGS) are being used increasingly in the poultry feed industry but their nutritional value is variable. The aim of this experiment was to examine the effect of batch to batch variation of wheat DDGS produced by the same manufacturer on the growth performance, dietary N corrected apparent metabolizable energy (AMEn), energy conversion ratio (ECR), total tract dry matter retention (DMR), nitrogen retention (NR) and fat digestibility (FD) coefficients when fed to broilers in complete diets with and without enzyme supplementation. Six UK wheat DDGS samples, produced by a single manufacturer, were used in a broiler experiment. Six diets containing 150 g/kg of each selected wheat DDGS sample were mixed. Each diet was then split into two batches and one of them was supplemented with commercial enzyme preparation, providing 1220 units xylanase and 152 units of ß-glucanase/kg diet, resulting in 12 experimental diets. Each diet was fed ad libitum to five pens of two male Ross 308 broilers from 7 to 21 d old. Enzyme supplementation improved dietary AMEn, DMR, NR (P < 0.001) and FD (P < 0.05) compared to non-supplemented diets. There was DDGS sample by enzyme interaction (P < 0.05) on daily weight gain and ECR. The results suggest that the variability in AMEn of DDGS samples produced from a single manufacturer is greater than expected compared to the variability of whole wheat samples but substantially lower than expected from wheat DDGS samples from different EU manufacturers. This experiment has shown that the variation in feeding value of wheat DDGS may be explained by the variability in polysaccharide contents.