Dietary inclusion level effects of distillers dried grains with solubles on broiler meat quality

Performance, fatty acid composition, and liver fatty acid metabolism markers of broilers fed genetically modified soybean DP-3Ø5423-1

Several genetically modified (GM) plants have been produced and approved by regulatory agencies worldwide for cultivation and commercialization. Soybean and its by-products are major components of poultry diets and approximately 74% of world production is obtained from GM soybean events. The aim of this study was to evaluate the nutrient composition of DP-3Ø5423-1 extruded full-fat soybean meal (FFSBM) and near isoline non-GM control FFSBM included in broiler diets. Also assessed were their effects on bird performance, body composition, intestinal morphology, tissue fatty acid profile, and mRNA abundance of fatty acid metabolism markers. A total of 480 Ross 308 d of hatch birds were randomly allocated to 24 floor pens in a 2 × 2 factorial arrangement with diet and gender as main factors. Birds were fed diets containing 20% of either DP-3Ø5423-1 or control FFSBM for 35 d. Data were subjected to a 2-way ANOVA using the GLM procedure of JMP (Pro13). No significant interaction (P > 0.05) was observed between treatment groups in terms of performance and carcass composition. Morphological measurements of the jejunum and ileum were not influenced by the SBM treatments. Dietary addition of the DP-3Ø5423-1 FFSBM resulted in higher monounsaturated fatty acid composition of the thigh muscle and abdominal fat. Moreover, dietary treatment had no significant impact on the mRNA abundance of metabolic markers ACCα, FAS, MTTP, SREBP1, PPARα, PPARγ, AMPK-α1, SOD, CAT, and GPx in the liver. In conclusion, our results showed that DP-3Ø5423-1 extruded FFSBM is nutritionally equivalent to non-GM near-isoline counterpart with a comparable genetic background as evidenced by feed analyses except for fatty acid composition. Furthermore, the findings of this study clearly indicate that the examined DP-3Ø5423-1 FFSBM yields similar bird performance as conventional FFSBM.

The effects of Moringa peregrina seed meal, autoclaving, and/or exogenous enzyme cocktail on performance, carcass traits, meat quality, and blood lipids of broilers

The effects of Moringa peregrina seed meal (MPSM), autoclaving, and/or enzyme cocktail addition on performance, profitability, carcass traits, meat quality, and blood lipids of broilers between 1 and 35 d of age were investigated. Seven experimental diets were employed: the control 0% MPSM, 10% raw MPSM, 10% autoclaved MPSM (at a temperature of 120°C and 1 kg/cm² pressure for 30 min), 10% raw MPSM supplemented with enzymes at 0.1 or 0.2 g/kg feed, and 10% autoclaved MPSM supplemented with the same previous enzymes and doses. Each diet was fed to 8 replicates with 5 broilers in each. At the end of the experiment, 3 broilers from each replicate were randomLy chosen to determine carcass traits, meat quality, and blood lipids. Findings at 35 d of age indicated that all 10% raw MPSM treatments with or without enzymes addition impaired growth, feed conversion (FCR), and profitability (p < 0.05), but increased feed intake (p < 0.05) and did not affect mortality when compared with the control group. The 10% autoclaved MPSM treatments with or without enzymes addition increased feed intake (p < 0.05) when compared with the control group, inducing growth equal to the control group (p > 0.05), and improving FCR and profitability. Enzymes addition to raw MPSM did not produce positive effects (p < 0.05), and no additive effect was observed when autoclaving and enzymes addition were combined (p > 0.05) as compared to the autoclaving group. Carcass traits, meat quality, and blood lipids were not significantly affected by MPSM, autoclaving, and enzymes addition. However, intestine, cecum, and gizzard percentages increased (p < 0.05) with all 10% raw MPSM treatments, while all 10% autoclaved MPSM treatments could return these values (p > 0.05) to the control group, except with gizzard, which exhibited less improvement. Additionally, all autoclaved groups had lower meat pH measured 24 h postmortem (p <0.05) compared to the control group. In conclusion, autoclaved MPSM can be included in broilers' diets at a 10% level without negative effects on performance, carcass traits, meat quality, and blood lipids. This indicates that autoclaving alone is adequate.

Evaluating the impact of feeding dried distillers grains with solubles on Boer goat growth performance, meat color stability and antioxidant capacity

A total of 72 male Boer goat kids (21.7 ± 0.5 kg) were fed for 21 d with 3 kids per pen and 12 pens per treatment. Dietary treatments were: 0% inclusion of dried distillers grains with solubles (DDGS; 0% DDGS) or 33% DDGS inclusion (33% DDGS) and were provided ad libitum. Goats and feeders were weighed weekly to collect body weights (BW) and determine feed disappearance in order to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). At the conclusion of the feeding study, a subset (n = 30; 2–3 goats from each pen representing six6 pens per treatment) of goats were harvested, carcasses evaluated, and loins were fabricated into 2.54 cm chops. Goat chop discoloration was evaluated by trained panelists and measured for L*, a*, and b* values on days 0, 4, 7, and 10 under retail display conditions. Samples were collected and analyzed for lipid oxidation, fatty acid profile, and hydrophilic and lipophilic antioxidant capacity. No evidence of differences was observed for final BW, ADFI, G:F, and carcass characteristics (P > 0.05). However, goats fed the 0% DDGS diet had greater ADG compared with those fed a diet containing 33% DDGS (P = 0.05). Overall, visual evaluation of discoloration, L*, a*, and b* as well as lipid oxidation data confirmed that feeding 33% DDGS to goats had no effect on goat chop discoloration and lipid oxidation (P > 0.10). However, all chops demonstrated a display effect, which they increased in visual discoloration and lipid oxidation and decreased in a* and b* values (P < 0.01) over the entirety of the 10-d period of retail display, regardless of the dietary treatments. As expected, feeding 33% DDGS to goats decreased relative percentage of multiple and total monounsaturated fatty acids, but increased relative percentage of multiple and total polyunsaturated fatty acids (PUFA; P < 0.05). The antioxidant capacity measurements showed no treatment difference in the hydrophilic portion (P > 0.10), but chops from the 33% DDGS treatment had greater lipophilic antioxidant activity compared with the 0% DDGS chops (P < 0.05). In conclusion, including 33% DDGS to the diet may negatively impact goat growth performance, but did not impact any carcass characteristics. Feeding a diet with 33% DDGS resulted in an increase in the PUFA content of goat chops but did not appear to impact meat color or lipid oxidation. The supposed negative consequence from increased PUFA is likely counterbalanced by the increased antioxidant capacity in the lipid component of meat, resulting in no difference in meat shelf-life.

Effect of feeding corn distillers dried grains with solubles naturally contaminated with deoxynivalenol on growth performance, meat quality, intestinal permeability, and utilization of energy and nutrients in broiler chickens

The objective of this experiment was to investigate the effect of feeding corn distillers dried grains with solubles (DDGS) naturally contaminated with deoxynivalenol (DON) on growth performance, meat quality, intestinal permeability, and utilization of energy and nutrients in broiler chickens. Two trials (growth and metabolism trials) were conducted. In the growth trial, a total of four hundred 7-day-old Ross 308 broiler chicks were allotted to 1 of 5 dietary treatments with 8 replicates in a completely randomized design. The diets were formulated to contain 5 inclusion levels of 0, 5, 10, 15, or 20% DON-contaminated DDGS in diets and were fed to birds for 21 d. Results indicated that increasing inclusion levels of DON-contaminated DDGS decreased (linear, P < 0.01) BW gain and feed efficiency of broiler chickens. The relative organ weights of the liver and breast were decreased (linear and quadratic, P < 0.05) by increasing inclusion levels of DON-contaminated DDGS in diets. The transepithelial electrical resistance values as a measure of intestinal permeability were decreased (linear, P < 0.05) by increasing inclusion levels of DON-contaminated DDGS in diets. In the metabolism trial, a total of twenty four 22-day-old Ross 308 broiler chickens were allotted to 1 of 3 dietary treatments consisting of 0, 10, or 20% inclusion of DON-contaminated DDGS in diets. Each treatment had 8 replicates. Increasing inclusion levels of DON-contaminated DDGS in diets decreased (linear and quadratic, P < 0.05) ME_n (AME_n and TME_n) and apparent total tract retention of nitrogen and acid-hydrolyzed ether extract in diets. In conclusion, feeding diets containing more than 10% DON-contaminated DDGS to broiler chickens has negative effects on growth performance, intestinal permeability, and utilization of energy and nutrients in diets. Therefore, it is suggested that if DDGS is contaminated with DON, inclusion level of DDGS should be limited, possibly at less than 5.0% in broiler diets.

Meat quality, fatty acid profile, and sensory attributes of spent laying hens fed expeller press canola meal or a conventional diet

This study evaluated the effects of feeding an expeller press canola meal (EPCM) supplement (20%) on the carcass, meat, and sensory quality characteristics of spent laying hens. Thirty EPCM-based and thirty conventionally (soybean based) fed Lohmann Brown-Elite spent laying hens were obtained from a commercial egg farm. Carcass, portions, physical quality, proximate composition, fatty acids, and sensory quality were determined. EPCM-fed hens had higher (P ≤ 0.05) drum yield, breast bone weights and percentages, but lower (P ≤ 0.05) thigh and breast meat yields. Conventionally fed hens had higher (P ≤ 0.05) thaw losses, skin yellowness (b*), Chroma values and breast fat content with lower (P ≤ 0.05) cooking losses, skin redness (a*) and hue angle values, as well as breast Warner-Bratzler shear force values (N) (15.43 ± 0.600 vs. 12.37 ± 0.411). Palmitic acid, stearic acid, heneicosanoic acid, palmitoleic acid, saturated fatty acids (SFA) (34.0 ± 0.56 vs. 38.7 ± 0.71), n-6:n-3 polyunsaturated fatty acids (PUFA) ratio (5.5 ± 0.13 vs. 7.2 ± 0.28), atherogenic index, thrombogenic index, delta-5 desaturase, elongase index, and thiosterase index were lower (P ≤ 0.05) for EPCM-fed hen breast meat. Myristic acid, lignoceric acid, nervonic acid, alpha-linolenic acid, docosahexaenoic acid (DHA), PUFA:SFA ratio (0.7 ± 0.05 vs. 0.9 ± 0.02), n-3 PUFA (3.4 ± 0.31 vs. 5.1 ± 0.17), hypocholesterolemic:Hypercholesterolaemic, stearoyl-CoA desaturase 16, and stearoyl-CoA desaturase 18 were higher (P ≤ 0.05) for EPCM-fed hen breast meat. Metallic flavor was decreased (P ≤ 0.05) for EPCM-fed hen breast meat. Generally, effects of EPCM supplementation were observed to have an effect on the carcass, physical quality, proximate composition, fatty acids, and health indices. The sensory profiles did not differ between EPCM and conventionally fed spent laying hen breast meat (except for metallic flavor). The EPCM improved the nutritional profile of spent laying hen meat with low intramuscular fat, low n-6:n-3 PUFA ratio, and favorable lipid health indices.

Dietary sources and levels of selenium supplements affect growth performance, carcass yield, meat quality and tissue selenium deposition in broilers

This study examined the effects of sources and levels of selenium (Se) on performance, carcass parts yield, meat quality and tissue Se concentration in broilers. A total of 960 one-day-old male broilers were divided into 8 treatments in a 4 × 2 factorial arrangement. Chicks were penned in groups of 20 with 6 pens per group. Selenium sources were sodium selenite (SS), Se enriched yeast (SY), DL-selenomethionine (SM) and nano-selenium (NS) and dietary supplemental Se levels were 0.1 and 0.3 mg/kg diet. The average daily gain (ADG), average daily feed intake (ADFI), feed:gain ratio, mortality, and carcass parts yield were not affected by dietary treatments. The level of 0.3 mg/kg Se decreased lightness and increased yellowness of the breast and thighs (P < 0.001). Nano-selenium improved yellowness, redness and meat quality (P < 0.05). The interactive effects of sources and the levels of Se affected Se retention (P < 0.001). Inorganic Se showed poor retention compared to other sources of Se; and NS showed equal retention with the organic sources. With consideration to meat quality responses, NS had a more significant positive effect compared to SS as an inorganic source of Se. Overall, NS and organic sources of Se resulted in better meat quality compared with the inorganic source. Moreover, the highest Se retention percentage was achieved by supplementation of NS followed by organic sources at 0.1 mg/kg compared to SS.

Effect of feeding larvae meal in the diets on growth performance, nutrient digestibility and meat quality in broiler chicken

Larvae meal has been reported as a suitable alternative protein source to fish meal and soybean meal. It contains necessary essential amino acids required in poultry feeding. A feeding trial was conducted to assess the effects of feeding different levels of larvae meal on broiler performance, nutrient digestibility, carcass and meat quality, and bacterial count. Day-old male broiler chicks (216) were raised for 42 days. Birds were weighed and randomly allotted into 6 dietary treatments consisting of 6 replicates (pens) per treatment and 6 birds in each replicate. The dietary treatments were supplemented with earth larvae meal by 0% (control group), 2%, 4%, 6%, 8% and 10%. The feed and drinking water were provided ad lib. The findings showed that body weight, average daily gain and total weight gain for group of birds fed 0% larvae meal significantly decreased compared to those chickens fed 8% and 10% larvae meal. A higher crude protein digestibility was found in birds fed with larvae meal. Control group had the highest Enterobacteriaceae count compared to the other treatments. Larvae meal supplementation improved the growth performance, nutrient digestibility and meat quality of broiler chicken and decreased excreta Enterobacteriaceae counts.

Investigating Meat Quality of Broiler Chickens Fed on Heat Processed Diets Containing Corn Distillers Dried Grains with Solubles

The present study investigated the effects of feed form and distiller’s dried grain with solubles (DDGS) on meat quality and fatty acids profile of broiler chickens. A total of 720 broilers (Ross 308; average BW [body weight] 541±5.7 g) were randomly allotted to six treatments. Birds were fed three different feed forms (mash; SP, simple pellet; EP, expanded pellet) and DDGS (0 or 200 g kg^–1) in a 3×2 factorial arrangement. The addition of DDGS and EP to the diet resulted in increased shear force of breast meat. Moreover, DDGS inclusion in the diet reduced the concentration of stearic acid and behenic acid in thigh meat. Pelleting (SP and EP) of the diets increased palmitic acid content in the thigh, whereas the linolenic acid content decreased. The breast mass was higher with EP and SP diets than with the mash diet. Feed processing led to increased pectoralis muscle and drum mass compared to mash-fed chickens. In conclusion, our results demonstrated that EP decreased thigh linolenic acid and meat shear force. In addition, DDGS supplementation in broiler hampers meat quality by increasing the shear force.

Effects of corn dried distillers' grains with solubles on performance, egg quality, yolk fatty acid composition and oxidative status in laying ducks

The study investigated the effects of increasing content of corn distillers' dried grains with solubles (DDGS) in the diets of laying ducks on oxidative status, laying performance, egg quality, and egg yolk fatty acid composition. Longyan females (1080) with similar BW at 17 wk of age were randomly assigned to 6 treatment groups, each consisting of 6 replicates of 30 birds. The basal diet (I) was a typical corn-soybean ration while the experimental diets (II to VI) substituted corn DDGS for soybean meal and wheat bran and a small reduction of corn. The level of substitution in diets (II to VI) was 6%, 12%, 18%, 24% and 30%. The experiment lasted for 18 wk. Average egg weight decreased linearly as the level of corn DDGS inclusion increased (P < 0.001). Haugh unit, albumen weight, and proportion declined as linear responses to corn DDGS substitution (P < 0.05), but yolk color linearly increased (P < 0.001); the proportions of oleic (C18:1) and total monounsaturated fatty acids in egg yolk linearly decreased with increasing corn DDGS and many of the key polyunsaturated fatty acids (PUFAs) like linoleic (C18:2n-6), arachidonic (C20:4n-6) and α-linolenic (C18:3n-3) acids linearly increased (P < 0.001), but not those of eicosapentaenoic (C20:5n-3) and docoshexaenoic (C22:6n-3) acids. The PUFAs n-6/n-3 ratio linearly increased with increasing corn DDGS level (P < 0.001). Increasing corn DDGS linearly increased hepatic expression of GPX1, HO-1, and Nrf2 and hepatic activity of GSH-Px and the liver content of MDA (P < 0.001). There were no treatment effects on egg production, egg mass, feed conversion ratio, eggshell thickness, strength, and yolk cholesterol content (P > 0.05). In conclusion, the current study indicates that the use of corn DDGS is possible as a replacement, primarily for soybean meal at levels up to 18% in the diets of laying ducks without affecting laying performance, egg quality, and antioxidant status. Increasing amounts of corn DDGS linearly increased egg yolk concentrations of key fatty acids like like C18:2n-6 and C18:3n-3 and the antioxidant enzyme activity of GSH-Px through the Nrf2 pathway to avoid oxidative stress.

Production of Barbari Bread (Traditional Iranian Bread) Using Different Levels of Distillers Dried Grains with Solubles (DDGS) and Sodium Stearoyl Lactate (SSL)

Bread is one of the oldest foods known throughout history and even though it is one of the principal types of staple around the world, it usually lacks enough nutrients, including protein and fiber. As such, fortification is one of the best solutions to overcome this problem. Thus, the objective this study was to examine the effect of three levels of distillers dried grains with solubles (DDGS) (0%, 10% and 20%) in conjunction with three levels of SSL (sodium stearoyl lactate) (0%, 2% and 5%) on physical and chemical properties of Barbari bread (traditional Iranian bread). To the best of our knowledge, this is the first study to evaluate DDGS and Sodium Stearoyl-2-Lactilate (SSL), as sources of fortification in Barbari bread. The results showed that incorporation of 20% of DDGS and 0% SSL caused a significant increase in the amount of fiber and protein. As for the physical attributes, using higher amount of DDGS caused a darker color, and as for the texture parameters, the highest firmness was measured when 10% DDGS and 5% of SSL were used. Different Mixolab and Rapid Visco Analyzer (RVA) parameters also were measured with varying results. The findings of this study show that DDGS can be a valuable source of fiber and protein, which can be used as a cost effective source to fortify cereal-based products.

Effects of corn distillers dried grains with solubles on performance, oxidative status, intestinal immunity and meat quality of Chinese Yellow broilers

The study assessed the effects of different dietary levels of corn distillers dried grains with solubles (DDGS) on performance, oxidation status, intestinal immunity and meat quality in Chinese Yellow broilers aged from 1 to 63 days. Lingnan male hatchings (1440) were randomly assigned to six treatments, each consisting of six replicates of 40 birds. The basal diet (I) was a typical corn-soya bean ration while the experimental diets (II to VI) partially substituted corn DDGS for soya bean meal. The level of substitution in starter, grower and finisher diets was as follows: II, 2%, 4% then 6%; III, 4%, 8% then 12%; IV, 6%, 12% then 18%; V, 8%, 16% then 24%; VI, 10%, 20% then 30%. Average daily feed intake and feed-to-gain ratio increased as linear responses to corn DDGS substitution from 1 to 21 days (p < 0.001). The plasma content of triglycerides and liver content of malondialdehyde increased as linear responses to corn DDGS substitution (p < 0.05). There was a linear decrease (p < 0.001) in jejunal abundance of IL-6 transcripts, with a substantial reduction to approximately 25% those of broilers fed the control diet, and a quadratic effect existed for secretory immunoglobulin A (sIgA) (p < 0.001). In addition, increased dietary corn DDGS caused favourable changes in selected functional properties of the meat: drip loss at 24 and 96 h increased as linear response to corn DDGS substitution (p < 0.001). Further, meat colour L* values decreased and a* values increased linearly in response to increasing corn DDGS (p < 0.05). In conclusion, diet IV (6%, 12% then 18% corn DDGS) in Chinese Yellow broiler diets had no negative effects on performance, antioxidant capacity and meat quality. This level of inclusion also appeared to promote sIgA secretion and enhance anti-inflammatory status.

Improving productive performance and mitigating harmful emissions from laying hen excreta via feeding on graded levels of corn DDGS with or without Bacillus subtilis probiotic

An experiment that included some inclusions of corn distillers dried grains with solubles (DDGS) with or without supplementation of probiotic bacteria to Hi-sex Brown laying hen diets was conducted to evaluate the impacts on performance, egg quality, blood metabolites and nitrogen and phosphorus excretion in the manure. A total of 216 twenty-two-week-old Hi-sex Brown laying hens were randomly divided into eight treatment groups in a factorial design (4 × 2) experiment, which included four levels of DDGS (0, 50, 100 and 150 g/kg diet) plus two levels of Bacillus subtilis probiotic (0 or 1000 mg/kg diet, with a concentration of 1.5 × 108 CFU/g of dried product). The experimental period extended from 22 to 34 weeks of age. The results showed that linear increase in DDGS level up to 150 g/kg improved (p ≤ 0.01) the values of feed consumption, egg shape index and yolk colour compared to the control and other treatment groups. Inclusion of dietary DDGS up to 150 g/kg in layer diets led to a significant decrease in egg mass and a significant increase in Haugh unit score compared to other groups. In the bacillus group, the values of feed conversion, egg weight and egg mass enhanced by 6.45, 3.27 and 7.60% respectively compared with the control diet. Total protein, albumin, triglycerides, cholesterol, calcium and ammonia in serum were significantly (p ≤ 0.01) influenced by DDGS inclusion. The excreted nitrogen decreased by 8.62 and 4.31% in hens fed 50 or 100 g/kg of DDGS respectively, while excreted phosphorous decreased by 3.33, 7.22 and 10.56% in hens fed 50, 100 or 150 g/kg of DDGS respectively as compared to the control group. It could be concluded that increasing DDGS inclusion level in the diet up to 10% and the supplementation of probiotic bacteria improved the productive performance of laying hens and mitigated the harmful emissions from chicken manure; this means better production within environmentally friendly conditions.

Effect of different feed supplements on selected quality indicators of chicken meat

The aim of the study was to evaluate the effect of different feed additives (bee pollen extract, propolis extract, and probiotic) on meat quality of broiler chickens. A total of 180 one day-old broiler chicks of mixed sex (Ross 308) were randomly divided into 3 groups. Dietary treatments were as follows: basal diet, free of supplements (control group; C);  basal diet  plus 400 mg bee pollen extract per 1 kg of feed mixtures and 3.3 g probiotic preparation added to drinking water (group E1); basal diet  plus 400 mg propolis extract per 1 kg of feed mixtures and 3.3 g probiotic preparation added to drinking water (group E2). In the experiment, the probiotic preparation based on Lactobacillus fermentum (1.109 CFU.g-1 of bearing medium) was used. Fattening period lasted for 42 days. Feed mixtures were produced without any antibiotic preparations and coccidiostatics. Meat quality was evaluated by following technological properties: cooling, freezing and roasting loss; colour parameters based on CIELab system; and shear force. Both dietary supplementations led to decrease in cooling (p ≤0.05) and freezing (p ≥0.05) losses compared with control. On the contrary, the supplemented diet tended to increase roasting losses (p ≤0.05) and shear force values in thigh muscle (p ≤0.05). Significantly higher L* values (p ≤0.05) in breast and thigh muscles, as well as the b* values in thigh muscle, were found when broiler chickens were fed the supplements, especially bee pollen extract and probiotics. In addition, the supplements improve redness (a*) of meat. The redness of breast muscle appeared to be the most affected (p ≥0.05) by propolis extract plus probiotics supplementation, while thigh muscle had the highest value (p ≤0.05) in bee pollen extract plus probiotics supplemented group. These findings suggested that the supplements have a beneficial effect on quality of chicken meat due to positive changes in most of quality indicators investigated in the study.

Effect of feeding diets containing barley, wheat and corn distillers dried grains with solubles on carcass traits and meat quality in growing rabbits

The effect of dietary inclusion of distillers dried grains with solubles (DDGS) on carcass and meat quality of longissimus muscle was studied in 100 growing rabbits from 28 to 59days old. Diets with no DDGS (C), barley (Db20), wheat (Dw20) and corn (Dc20) DDGS at 20% and corn (Dc40) DDGS at 40% were formulated. No effects on most of the carcass traits, texture and water holding capacity were found. Barley and corn DDGS led to a higher dissectible fat percentage. Meat redness was higher with Dw20 and pH was higher with Dw20 and Db20 than with Dc20. Protein and saturated fatty acids concentration declined as corn DDGS level increased. Dc40 led to the lowest saturated/unsaturated fatty acid ratio, atherogenic index and thrombogenic index. In conclusion, dietary inclusion of these DDGS at 20% did not affect most of the carcass and meat quality traits in rabbits.

Effects of protein source and nutrient density in the diets of male broilers from 8 to 21 days of age on their subsequent growth, blood constituents, and carcass compositions

The effects of protein source and amino acid (AA) and AME levels in the diets of male broilers from 8 to 21 d of age on subsequent growth and blood and carcass traits were investigated in the current study. Fourteen Ross × Ross 708 male broiler chicks were randomly allocated to each of 80 floor pens arranged in a randomized complete block design. Each diet contained 1 of 2 dietary protein sources (high inclusion of distillers dried grains with solubles or high inclusion of meat and bone meal), 1 of 2 AA densities (moderate or 10% higher), and 1 of 2 AME densities (2,998 or 3,100 kcal/kg). Experimental diets were fed from 8 to 21 d of age, and common diets from 1 to 7 and 21 to 55 d of age. The higher AME density in high inclusion of meat and bone meal diets increased serum triglyceride and cholesterol levels on d 20. The dietary inclusion of high inclusion of distillers dried grains with solubles or lower levels of AA increased high-density lipoprotein cholesterol on d 20. Feeding the high-AA-density diet decreased feed intake without affecting BW gain, which resulted in a lower feed conversion ratio (FCR). A high-AME-density diet lowered feed intake but increased BW gain, which resulted in a lower FCR from 8 to 21 d of age. Feed intake, BW gain, FCR from 21 to 54 d of age, and carcass weight on 42 and 55 d of age were not affected by treatments from 8 to 21 d of age. However, early dietary manipulation from 8 to 21 d of age affected fat and meat yield at 42 and 55 d of age. Moreover, a high-AME diet decreased feed cost per carcass weight gain from 8 to 55 d of age. In conclusion, high AA or AME densities during the grower phase, from d 8 to 21 of age, may improve growth during the grower feeding phase, but may also affect meat yield during the latter grow-out phases. Furthermore, high-AME diets from 8 to 21 d of age may save on feed costs for meat production.

The effects of conjugated linoleic acid on growth performance, carcass traits, meat quality, antioxidant capacity, and fatty acid composition of broilers fed corn dried distillers grains with solubles

This study investigated the effects of dietary supplementation with conjugated linoleic acid (CLA) on the growth performance, carcass traits, meat quality, antioxidant capacity, and fatty acid composition of broilers fed corn dried distillers grains with solubles (DDGS). Four hundred eighty 1-d-old broilers were randomly assigned to 4 groups, consisting of 6 replicates with 20 broilers each. Broilers were allocated 1 of 4 diets and fed for 49 d in a 2 × 2 factorial design. The dietary treatments consisted of 2 levels of DDGS (0 or 15%) and 2 levels of CLA (0 or 1%). The results of growth performance analyses showed that dietary supplementation with 1% CLA, 15% DDGS, or both in broilers had no significant effects on ADG, ADFI, and feed/gain (P > 0.05). Dietary supplementation with 15% DDGS did not significantly affect meat color values, drip loss percentage, pH value at 15 min, crude fat content, or shear force value (P > 0.05). Diets supplemented with 15% DDGS decreased the proportions of saturated fatty acids (P < 0.05) and monounsaturated fatty acids but increased the proportion of polyunsaturated fatty acids of the thigh meat (P < 0.05). Diets supplemented with 1% CLA significantly decreased the abdominal fat percentage (P < 0.05). Supplementation with 1% CLA increased the crude fat content and decreased the color (b*) value and shear force value of the breast meat (P < 0.05). Diets supplemented with 1% CLA increased the total superoxide dismutase activity of the serum, breast meat, and liver, and decreased the malondialdehyde content of the serum and breast meat (P < 0.05). Supplementation with 1% CLA decreased the proportion of monounsaturated fatty acids and increased the proportion of saturated fatty acids (P < 0.05). Accumulation of CLA in the thigh meat was significantly increased (P < 0.05) with increasing CLA level in the diet. In conclusion, dietary supplementation with 1% CLA had positive effects on meat quality, antioxidant capacity, and fatty acid composition of broilers, although it had no significant effect on growth performance.

Broiler genetic strain and sex effects on meat characteristics

A randomized complete block design within a factorial arrangement of treatments was used to evaluate the effect of strain and sex on carcass characteristics, meat quality, and sensory acceptability. Two broiler strains were reared: a commercially available strain (strain A) and a strain currently in the test phase (strain B) that has been genetically selected to maximize breast yield. Broilers were harvested in a pilot scale processing plant using commercial prototype equipment at 42 d of age. Carcasses were deboned at 4 h postmortem. The left half of each breast was evaluated for pH, color, cooking loss, shear force, and proximate analysis. The right side of each breast was used for consumer acceptability testing. Thigh meat was evaluated for proximate composition. No interactions were observed throughout the study. Male broilers had a higher (P < 0.05) live BW, carcass weight, and breast weight and lower (P < 0.05) dressing percentage and breast meat yield when compared with females. Broilers from strain B presented a higher (P < 0.05) breast yield and dressing percentage than those broilers corresponding to the commercially available broiler strain. At 24 h postmortem, female broilers presented a lower ultimate pH and higher Commission internationale de l'éclairage yellowness values (ventral side of the pectoralis major) when compared with male broilers. On average, no differences existed (P > 0.05) among treatments with respect to pH decline, cooking loss, shear values, and proximate composition. In addition, no differences (P > 0.05) existed among breast meat from the different strains with respect to consumer acceptability of appearance, texture, flavor, and overall acceptability, but breast meat from strain B was slightly preferred (P < 0.05) over that of strain A with respect to aroma. However, breast meat from both strains received scores in the range of "like slightly to like moderately." Overall data suggest that all treatments yielded high quality breast and thigh meat and strain cross did not present variability in terms of consumer acceptability.