Effect of methionine chelated Zn and Mn and corn particle size on Large White male turkey live performance and carcass yields.

Most turkey research has been conducted with a regular corn particle size set through phase-feeding programs. This study's first objective was to determine the effect of increasing corn particle size through the feed phases on performance, processing yield, and feed milling energy usage in Large White commercial male turkey production. Zinc (Zn) and manganese (Mn) are essential microminerals for animals' healthy growth. The source in which these elements are supplied to the bird will determine their bioavailability, effect on bird growth, and subsequent environmental impact. This study's second objective was to measure both inorganic and chelated Zn and Mn sources on turkey performance, turkey carcass processing yields, and subsequent litter residues. Twelve hundred Nicolas Select male poults were randomly assigned to 48 concrete; litter-covered floor pens. The experimental design was a completely randomized block design with a 2 × 2 factorial arrangement of 2 sources of minerals (organic blend vs. inorganic) formulated to match breeder recommendations and 2 types of corn mean particle size (coarse corn [1,000-3,500 µm] vs. fine corn [276 µm]). The ASABE S319.4 standard was used to measure corn mean particle size. Bird performance, carcass processing yield, litter content of Zn and Mn, and pellet mill energy consumption were analyzed in SAS 9.4 in a mixed model. There was a reduction of pellet mill energy usage of 36% when coarse corn was added post-pelleting. Birds fed increasing coarse corn mean particle size were 250 g lighter on average in body weight (BW) than birds fed a constant control mean particle size. No difference was found in feed intake (FI) or feed conversion ratio (FCR). Birds fed methionine chelated Zn and Mn blended with inorganic mineral sources were 250 g heavier on average than birds fed only an inorganic source of minerals. In addition, feeding an organic blend of Zn and Mn resulted in greater breast meat yield. Litter from birds fed the control corn mean particle size, and inorganic minerals had a higher concentration of Zn in the litter but were not different when the chelated Zn/Mn were fed. In conclusion, increasing the corn mean particle size and adding it post pellet could save money during feed milling; however, birds might have a slightly lower BW. A combination of inorganic and chelated Zn and Mn may improve performance and increase total breast meat yields.

Effects of functional oils on the growth, carcass and meat characteristics, and intestinal morphology of commercial turkey toms.

Two experiments were conducted to evaluate the effects of functional oils containing cashew nutshell and castor oil on turkey performance and intestinal morphology. In experiment 1, 585 hatchlings were randomly placed in 15 replicate floor pens, (13 poults/pen) with recycled litter and provided feed and water ad libitum. Birds were randomly assigned to 3 dietary treatments from 1 to 12 wk: nonmedicated control, 0.15% functional oils, and 66-ppm monensin. From wk 13 to 20, each initial treatment group was further divided into 3 treatments-control (no additive), 0.15% of functional oils, or 20 ppm of virginiamycin to produce 9 different treatments, 5 replicate pens per treatment. Data on feed weights were collected weekly, and body weight bi-weekly. At termination (20 wk), birds were euthanized, and their meat was processed to determine mass of carcass sections and meat quality, while intestinal samples were collected for histology. In experiment 1, toms fed monensin or functional oils were 10.5 and 4.5% heavier (P < 0.05), respectively, than the controls at 12 wk. Birds fed monensin had a 4% improvement (P < 0.05) in feed conversion as compared to the other treatments. Neither virginiamycin nor the functional oils affected bird performance when fed from 13 to 20 wk. The jejunum villi surface area at 3 wk was most enhanced (P < 0.05) for the poults fed monensin. Supplementation with functional oils significantly reduced leg yield and thiobarbituric-acid reactive substances of white meat after 7 D of storage (P < 0.05). There were no effects on performance or carcass characteristics in experiment 2. While additional confirmatory studies are needed, functional oils in the diet of turkey toms may be a viable alternative to antibiotic growth promotants.

Dietary amino acids under hypoxic conditions exacerbates muscle myopathies including wooden breast and white stripping.

The occurrence of wooden breast (WB) and white striping (WS) of broiler breast myopathies may be associated with least-cost feed formulations and the inclusion of greater amounts of synthetic amino acids. Two experiments were conducted to evaluate the effects of supplemental glutamine (Gln-/+, 0 and 1%) and arginine (Arg-/+, 0 and 0.25%) in a 2 × 2 factorial arrangement. Experiment 1 consisted of 8 replicates using 32 pens and focused on live performance to 44 d of age, carcass yield, and meat quality evaluations at 45 d of age. Live performance parameters including feed intake, BW gain, mortality, and feed conversion were evaluated. Post-harvest carcass yield, breast muscle quality (including WB and WS), proximate analysis, and mineral analysis of breast muscle and tibia bone were also evaluated. Experiment 2 comprised 4 replicates using 8 pens with weekly measurements of blood physiology and muscle myopathy development from 21 to 45 d of age. Broilers fed supplemental Gln and Arg (Gln+/Arg+) produced broilers with greater BW and improved FCR. The WB and WS severity increased with Gln+ diets, while only WB increased using Arg+ diets. Weekly observations revealed the greatest increase in WB myopathies occurred between 28 to 35 d, while WS significantly increased one week later (35 to 42 d). When comparing broilers of similar BW at 45 d, Gln+ diets resulted in greater WS scores and percentage breast muscle fat. Further analysis of WB and WS scores (independent of treatment affect) revealed that increased myopathy scores were associated with increased blood CO2, H2CO3, and reduced O2 with increased meat pH, moisture content, and Ca concentration. These results indicated that increased muscle Ca is associated with increased WB, while increased dietary glutamine and lack of oxygen may have resulted in a reverse flux of the citric acid cycle and reduced electron transport chain activity resulting in increased WS.

Enrichment of the amnion with threonine in chicken embryos affects the small intestine development, ileal gene expression and performance of broilers between 1 and 21 days of age.

The effects of in ovo feeding with threonine (Thr) on intestinal morphology, ileal gene expression and performance of broiler chicken between 1 and 21 d of age (d) were assessed. On day 17.5 of incubation, fertile eggs were randomly allotted to 5 treatments of Thr injection in the amniotic fluid (0; 1.75; 3.5; 5.25; 7%, corresponding to 17.5; 35; 52.5 and 70 mg Thr/mL). After hatch, chicks were given a commercial corn-soybean diet up to 21 d. Daily feed intake (FI), body weight (BW), and food conversion ratio (FCR) were measured from 1 to 7, 14, and 21 d of age. The ileal gene expression of mucin (MUC2), peptide transporter (PepT1), and aminopeptidase enzyme (APN) were evaluated on day of hatch and at 21 d, as well as intestinal morphometric traits. In ovo feeding with threonine significantly increased final weight (FI) and weight gain (WG) and decreased FCR in the period from 1 to 21 d. Threonine levels affected beneficially the villus height, vilo: crypt ratio and villus area on day of hatch and at 21 d. At hatch, all Thr levels increased the expression of MUC2 and PepT1 compared to the control group. APN expression also increased, but for the lowest and the highest threonine levels (1.75 and 7%). At 21 d, there was no effect of threonine on the expression of MUC2, PepT1, and APN. In conclusion, in ovo threonine feeding beneficially affected the morphological and functional development of the intestinal mucosa, which ensured improved performance of chicks at hatch and at 21 d.

Effects of supplemental L-methionine on growth performance and redox status of turkey poults compared with the use of DL-methionine.

This study was conducted to test the effects of dietary supplementation of feed grade L-Met on growth performance and redox status of turkey poults compared with the use of conventional DL-Met. Three hundred and eighty five newly hatched turkey poults were weighed and allotted to 5 treatments in a completely randomized design and the birds were fed dietary treatments for 28 d, including a basal diet (BD), the BD + 0.17 or 0.33% DL-Met or L-Met (representing 60, 75, and 90% of the requirement by National Research Council (NRC) for S containing AA, respectively). Increasing Met supplementation from 0 to 0.33% increased (P < 0.05) weight gain (690 to 746 g) and feed intake (1,123 to 1,248 g) of turkey poults. Supplementing L-Met tended (P = 0.053) to reduce feed to gain ratio (1.70 to 1.63) compared with DL-Met. The relative bioavailability of L-Met to DL-Met was 160% based on a multilinear regression analysis of weight gain. Supplementing Met regardless of its sources decreased (P < 0.05) malondialdehyde (3.29 to 2.47 nmol/mg protein) in duodenal mucosa compared with birds in the BD. Supplementing L-Met tended (P = 0.094) to decrease malondialdehyde (1.27 to 1.16 nmol/mg protein) and increase glutathione (3.21 to 3.45 nmol/mg protein) in the liver compared with DL-Met. Total antioxidant capacity, protein carbonyl, and morphology of duodenum and jejunum were not affected by Met sources. In conclusion, dietary supplementation of 0.33% Met to a diet with S containing AA meeting 60% of the NRC requirement enhanced weight gain, feed intake, and redox status by reducing oxidative stress in the gut and liver of turkey poults during the first 28 d of age. Use of L-Met tended to enhance feed efficiency and was more effective in reducing oxidative stress and increasing glutathione in the liver compared with the use of DL-Met. The use of L-Met as a source of Met replacing DL-Met seems to be beneficial to turkey poults during the first 28 d of age.

Effect of natural betaine and ractopamine HCl on whole-body and carcass growth in pigs housed under high ambient temperatures.

Betaine is an osmolyte that helps to maintain water homeostasis and cell integrity, which is essential during heat stress. We hypothesized that supplemental betaine can improve growth during heat stress and may further improve the response to ractopamine. Two studies were conducted to determine: 1) the effects of betaine in combination with ractopamine; and 2) the optimum betaine level for late finishing pigs during heat stress. Heat stress was imposed by gradually increasing temperatures over 10 d to the target high temperature of 32°C. In Exp. 1, pigs ( = 1477, BW = 91.6 ± 3 kg) were assigned within BW blocks and sex to 1 of 4 diets arranged in a 2 × 2 factorial RCB design (68 pens; 20 to 23 pigs/pen). Treatments consisted of diets without or with ractopamine (5 mg/kg for 21 d followed by 8.8 mg/kg to market) and each were supplemented with either 0 or 0.2% of betaine. Betaine reduced ( ≤ 0.05) BW (123.1 vs. 124.3 kg), ADG (0.780 vs. 0.833 kg/d), and ADFI (2.800 vs. 2.918 kg/d), but did not impact carcass characteristics. Ractopamine increased ( < 0.01) BW (125.5 vs. 121.9 kg), ADG (0.833 vs. 0.769 kg/d), G:F (0.295 vs. 0.265), HCW (94.1 vs. 90.0 kg), carcass yield (74.8 vs. 73.8%), loin depth (63.6 vs. 60.0 mm), and predicted lean percentage (53.2 vs. 51.7%) and reduced ADFI (2.822 vs. 2.896 kg/d, = 0.033) and backfat depth ( < 0.001; 20.2 vs. 22.5 mm). In Exp. 2, pigs ( = 2193, BW = 95.5 ± 3.5 kg) were allocated within BW blocks and sex to 1 of 5 treatments in a RCB design (100 pens; 20 to 24 pigs/pen). Treatments consisted of diets with 0, 0.0625, 0.125, 0.1875% of betaine, and a positive control diet with ractopamine, but not betaine. Betaine tended to decrease carcass yield quadratically ( = 0.076; 74.1, 73.5, 73.8, and 73.9 for 0, 0.0625, 0.125, 0.1875% of betaine, respectively), but did not impact other responses. Ractopamine improved ( < 0.001) BW (121.6 vs. 118.5 kg), G:F (0.334 vs. 0.295), carcass yield (74.7 vs. 73.8%), loin depth (61.7 vs. 59.0 mm), and predicted lean percentage (53.2 vs. 52.6%), and reduced backfat (18.7 vs. 20.4 mm). Collectively, data indicate that under commercial conditions, betaine did not improve performance of pigs housed under high ambient temperatures, regardless of ractopamine inclusion. Ractopamine improved whole-body growth and especially carcass growth of pigs raised under high ambient temperatures. The ability of ractopamine to stimulate growth during heat stress makes it an important production technology.

Effects of dietary coarsely ground corn and 3 bedding floor types on broiler live performance, litter characteristics, gizzard and proventriculus weight, and nutrient digestibility.

The effects of zero or 50% dietary coarsely ground corn (CC) in pelleted and screened grower and finisher diets on broilers reared on 3 bedding floor types (plastic net [NET], new pine wood shavings litter [NEW], or old pine wood shavings litter [OLD]) on broiler live performance, litter characteristics, gizzard and proventriculus weight, and apparent ileal digestibility (AID) were studied in a 2 × 3 factorial arrangement of treatments. Fine corn was produced with a hammermill (271 µm) and CC with a roller mill (1145 µm). Utilization of CC reduced milling cost by 9.47 cents per MT with similar nutrient content of screened pellets. The 50% CC treatment exhibited improved (P ≤ 0.05) feed intake at 42 d (2.5%) and 49 d (3.0%), and BW (5.4%) and FCR from 28 d (1.4%). Birds on NEW litter exhibited improved (P < 0.05) BW at 28 and 35 d and 42 d FCR as compared to NET and 49 d FCR compared to NET and OLD. The 50% CC treatment exhibited increased (P < 0.05) gizzard weight but decreased proventriculus weight at 49 d. NEW litter birds exhibited increased (P ≤ 0.05) gizzard weight at 28 d and 49 d and decreased proventriculus weight as compared to NET at 49 days. The 50% CC treatment exhibited decreased (P ≤ 0.05) litter moisture at 35 and 42 d, litter N at 35 and 49 d, and litter pH at 49 days. OLD litter birds exhibited greater (P < 0.05) litter N at 14, 35, and 49 d, as well as litter moisture, pH, and ammonia concentration at 49 days. The 50% CC group also exhibited improved AID of nitrogen (P < 0.05). Broilers fed pelleted and screened diets containing 50% CC exhibited improved live performance and reduced litter moisture while use of NEW litter resulted in a somewhat similar effect, which indicated that consumption of NEW litter also facilitated gastric development and function.

Effects of dietary supplementation of the osmolyte betaine on growing pig performance and serological and hematological indices during thermoneutral and heat-stressed conditions.

The present study was designed to evaluate the effects of dietary betaine on pig performance and serological and hematological indices during thermoneutral and heat-stressed conditions. Individually housed pigs ( = 64; 39.0 ± 1.5 kg BW) were assigned within weight blocks and sex to 1 of 8 treatments. Treatments consisted of 2 environmental conditions (thermoneutral or heat-stressed) and 4 levels of betaine (0, 0.10, 0.15, and 0.20%). Room temperatures followed a daily pattern with a low of 14°C and a high of 21°C for the thermoneutral environment and a low of 28°C and a high of 35°C for the heat-stressed environment. Experimental diets were fed from d -7 (7 d prior to imposing temperature treatments; constant 21°C) until 28. Respiration rate and rectal temperature were measured on d 0, 1, 2, 3, 7, 14, 21, and 28, and blood samples were collected on d 3 and 28. Heat stress reduced ( ≤ 0.008) ADG (0.710 vs. 0.822 kg/d) and ADFI (1.81 vs. 2.27 kg/d) and increased G:F ( = 0.036; 0.391 vs. 0.365). Betaine tended to quadratically increase G:F ( = 0.071; 0.377, 0.391, 0.379, and 0.366 for 0, 0.10, 0.15, and 0.20% betaine, respectively), regardless of environment. Heat stress increased ( ≤ 0.001) respiration rate (48 vs. 23 breaths/30 s) and rectal temperature (39.47 vs. 38.94°C) throughout d 1 to 28. Betaine at 0.10% reduced rectal temperature in heat-stressed pigs but not in control pigs (interaction, = 0.040). Heat stress increased serum cysteine and triglycerides and reduced Ca, alkaline phosphatase, and lipase, regardless of day of sampling ( ≤ 0.048). Heat stress increased serum creatine phosphokinase (CPK) and K and reduced osmolarity, Na, urea N, methionine, homocysteine, the albumin:globulin ratio, and blood eosinophil count on d 3 but not on d 28 (interaction, ≤ 0.013). Heat stress increased serum Mg, globulin, creatinine, amylase, and γ-glutamyltranspeptidase and reduced , the urea N:creatinine ratio, alanine aminotransferase, NEFA, hemoglobin, hematocrit, and red blood cells on d 28 but not on d 3 (interaction, ≤ 0.034). Betaine increased serum osmolarity and NEFA and reduced CPK and K on d 3 but not on d 28 (interaction, ≤ 0.060) and increased serum creatinine and reduced amylase on d 28 but not on d 3 (interaction ≤ 0.057). Heat stress reduced growth, disturbed ion balance, and increased markers of muscle damage. Betaine had a minor impact on alleviating heat stress with the possible exception of early days of heat exposure. The beneficial effect of betaine was diminished by pig adaptation.

Effects of feed form and dietary coarse ground corn on broiler live performance, body weight uniformity, relative gizzard weight, excreta nitrogen, and particle size preference behaviors.

In this 14-d cage study, the effects of feed form (mash and crumble) and 6 coarse ground corn ( CC: ) inclusions [0, 10, 20, 30, 40, and 50% CC that replaced fine corn ( FC: )] on broiler live performance, BW uniformity, gizzard weight, excreta nitrogen, and particle size preference were investigated. The geometric mean diameter by mass ( DGW: ) of mash diets increased from 422 µm to 431, 471, 509, 542, and 640 µm, respectively, as the percentage of CC increased. Feed intake and BW were decreased by CC and mash at 7 d. Interactions between feed form and CC were observed for feed conversion ratio ( FCR: ) at 7 d of age (P < 0.01), and feed intake (P < 0.05), BW (P < 0.01), and gizzard weight (P < 0.01) at 14 d of age. Feed intake for all CC inclusions in crumble diets was similar and exceeded (P < 0.01) that of mash diets at 14 d. Among mash diets, the 10 and 30% CC feed intake was greater (P < 0.05) than 40 and 50% CC with 0 and 20% CC intermediate. Crumble diets produced a similar BW but greater 14-d BW than mash diets (P < 0.01). Within mash diets, 40 and 50% CC produced a smaller BW (P < 0.01). The FCR at 7 d of CC inclusions in crumble diets was improved (P < 0.01) versus the same CC in mash diets. Within mash diets, 40% CC performed poorer than 0, 10, 20, and 30% CC diets with 50% CC diet intermediate (P < 0.01). Crumble diets improved FCR at 14 d, but CC worsened FCR. Gizzard weight at 14 d was not affected by CC in crumble diets, while it increased with CC in mash diets (P < 0.01). Excreta nitrogen was increased (P < 0.01) by crumble diets. These data demonstrated that pelleting and crumbling reduced the impact of CC, produced a more consistent feed intake, and reduced selective feeding, and that CC stimulated gizzard weight in a linear manner in mash diets.

Effects of dietary coarsely ground corn and litter type on broiler live performance, litter characteristics, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and intestinal morphology.

The objectives of this study were to evaluate the effects of the dietary inclusion of 2 coarsely ground corn (CC) levels (0 or 50%) in diets of broilers reared on 2 litter types (new wood shavings or used litter) on live performance, litter characteristics, gastrointestinal tract (GIT) development, apparent ileal digestibility (AID) of energy and nitrogen (N), and intestinal morphology. No interaction effects between CC level and litter type were observed on live performance. No litter effect was observed on live performance. Dietary inclusion of 50% CC increased BW at 35 d (P<0.01) and improved cumulative feed conversion ratio (FCR) at 35 and 49 d of age (P<0.01). The 50% CC treatment increased absolute and relative gizzard weight (P<0.01) and decreased jejunum unit weight (g/cm) (P<0.01). The new litter treatment (litter N) increased absolute and relative proventriculus weight (P<0.05) but did not affect gizzard weight. An interaction effect between CC level and litter type was observed for litter N, where the 50% CC treatment reduced litter N regardless of litter type (P<0.01), but litter N was reduced by new litter only among birds fed 0% CC (P<0.05). The 50% CC inclusion increased litter pH (P<0.05) and improved the AID of energy and N by 6.8% (P<0.01) and 3.5% (P<0.05), respectively. The 50% CC treatment increased jejunum villi tip width (P<0.05) and villi surface area (P<0.01), and decreased the muscularis layer thickness (P<0.01), whereas new litter increased jejunum villi and ileum villi height (P<0.05), jejunum villi surface area (P<0.01), and the ratio of jejunum villi height to crypt depth (P<0.01). This study showed that birds fed pelleted and screened diets containing 50% CC exhibited improved BW, FCR, and AID of energy and N, in conjunction with altered morphology of the GIT and intestinal mucosa. Litter type affected some GIT traits and functions but did not affect live performance.

Evaluation of litter type and dietary coarse ground corn inclusion on broiler live performance, gastrointestinal tract development, and litter characteristics.

Two 49 d floor pen studies were conducted to evaluate the effects of litter type and dietary coarse ground corn (CC) inclusion on broiler live performance, gastrointestinal tract (GIT) development, and litter characteristics. Experiment 1 was a 2×2 factorial arrangement of 2 genders (male or female) and 2 CC levels (0 or 50%). From 15 to 35 d, the addition of CC decreased feed intake (P<0.01) and BW gain (P<0.05) of males but not females. The inclusion of CC decreased feed intake (P<0.01) and BW gain (P<0.01) from 0 to 49 d but improved adjusted feed conversion ratio (AdjFCR) from 35 to 49 d (P<0.05). Male broilers exhibited better live performance than females during the study as evidenced by greater feed intake (P<0.01) and BW gain (P<0.01), and improved FCR (P<0.01), but with increased mortality (P<0.05). The inclusion of CC increased relative gizzard weight (P<0.01) and decreased relative proventriculus weight (P<0.01) at 49 d. Experiment 2 was a 2×2 factorial arrangement of 2 CC levels (0 or 50%) and 2 litter types (ground old litter or new wood shavings litter). The inclusion of CC decreased feed intake throughout the experiment without affecting final BW when only males were used and improved FCR after 25 d (P<0.01). New litter improved FCR from 1 to 14 d (P<0.01). At 49 d, the birds fed the CC diet had reduced excreta nitrogen (P<0.05) and litter moisture (P<0.05). In conclusion, 50% CC inclusion initially produced negative effects on live performance that became positive as BW increased. The effects of CC became evident at an earlier age for males. New litter had only a marginal benefit on broiler live performance.

Effect of dietary coarsely ground corn on broiler live performance, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and digesta particle size distribution and retention time.

Dietary structural material has been reported to improve broiler live performance and gastrointestinal tract (GIT) function. In this 50 d cage study, the effects of coarsely ground corn (CC) inclusion on broiler live performance, GIT development, apparent ileal digestibility (AID) of energy and nitrogen (N), and digesta particle size distribution and retention time were investigated. This study included 3 CC inclusions (0, 25, and 50% fine corn [FC] replaced by CC), with 6 replicate cages of 10 birds per treatment. The feed conversion ratio (FCR) at 35 and 42 d was improved (P<0.01) as the dietary inclusion of CC increased without effect on feed intake. The 50% CC diet increased absolute and relative gizzard weight at 42 d of age as compared to diets with 0 and 25% CC (P<0.01). Dietary CC increased absolute proventriculus weight at 28 d of age (P<0.05). A numerically lower gizzard digesta pH (P<0.08) was observed at 28 d but not 42 d of age, and there was no difference in proventriculus, jejunum, or ileum digesta pH at 28 or 42 d of age. The 25 and 50% CC treatments increased the digesta retention time at 30 and 45 d of age (P<0.05 and P<0.01, respectively). The 25 and 50% CC treatments improved AID of energy by 7.1 and 8.2%, respectively, when compared with the 0% CC treatment, and they improved AID of N by 12.2 and 12.4%, respectively (P<0.01). The digesta particles in the jejunum exhibited a similar distribution, with a dgw (geometric mean diameter by mass) of 218, 204, and 181 µm when 0, 25, of 50% CC diets were consumed, respectively. In conclusion, birds fed pelleted and screened diets that contained 25 and 50% CC exhibited increased BW, improved FCR, and increased AID of energy and N, which was probably due to enhanced gizzard development and greater digesta retention time.

Effects of trypsin inhibitor and particle size of expeller-extracted soybean meal on broiler live performance and weight of gizzard and pancreas.

Soybean meal (SBM) is a co-product that remains after the oil is removed from whole soybeans by either solvent extraction or mechanically pressing soybeans using an expeller. Expeller-extracted soybean meal (ESBM) contains more fat and less protein than solvent-extracted soybean meal (SSBM), but has higher trypsin inhibitors (TI) that limit its inclusion in poultry diets. We hypothesized that increasing the particle size of ESBM could enhance chick tolerance to dietary TI. The experiment consisted of a 2 × 6 factorial arrangement of 2 ESBM particle sizes (coarse, 1,300 µm, and fine, 530 µm) and 6 TI levels (6, 9, 12, 15, 18, and 21 TIU/mg). A total of 672 male broiler chicks was randomly assigned among the 12 treatment combinations with 8 replicates per combination. The birds were provided with 1 kg/bird of starter diet in a crumble form. The pancreas and gizzard were excised and weighed at 16 d of age and organ weights relative to BW calculated. Feed consumption, BW, and feed conversion ratio (FCR) were determined at 7 and 14 d of age. Increasing TI level produced a quadratic effect (P < 0.01) on BW and FCR at 14 d of age. The best performance was obtained when chicks were fed diets containing ESBM at intermediate TI levels. Increasing the particle size of the ESBM from 530 to 1,300 µm improved BW and feed intake (P < 0.01) without affecting FCR. The relative weight of the pancreas increased linearly as TI level increased (P < 0.001). The results of this study indicated that chicks performed better when fed coarse ESBM at an intermediate TI level.

Effects of Clostridium butyricum on growth performance, immune function, and cecal microflora in broiler chickens challenged with Escherichia coli K88.

This study was conducted to investigate the effects of Clostridium butyricumon growth performance, immune function, and cecal microflora in broiler chickens challenged with Escherichia coli K88. Three hundred sixty 1-d-old broiler chickens were randomly divided into 4 treatments: negative control (NC) birds were fed a basal diet and not challenged with E. coli K88; positive control (PC) birds were fed a basal diet and challenged with E. coli K88; C. butyricum treatment (CB) birds were fed a diet containing 2 × 10(7) cfu C. butyricum/kg of diet and challenged with E. coli K88; and colistin sulfate treatment (CS) birds were fed a diet containing 20 mg of colistin sulfate/kg of diet and challenged with E. coli K88. Birds fed CB had greater (P < 0.05) BW than the PC birds from 3 to 21 d postchallenge. Birds fed CB had greater (P < 0.05) serum IgA and IgY at 14 d postchallenge, greater (P < 0.05) serum IgM at 21 d postchallenge, and greater (P < 0.05) mucosal secreted IgA at 3 and 7 d postchallenge than the PC birds. Birds fed CB had greater concentrations of serum complement component 3 at 14 d postchallenge, and greater (P < 0.05) concentrations of serum complement component 4 at 3, 7, and 14 d postchallenge than the PC birds. Birds in the CS or CB treatments had less cecal E. coli population at 3, 7, and 21 d postchallenge, and less cecal Clostridium perfringens counts at 21 d postchallenge compared with the PC birds. The CB treatment increased (P < 0.05) the population of cecal Lactobacillus at 3 d postchallenge and the number of cecal Bifidobacterium at 3, 14, and 21 d postchallenge in comparison with the PC treatment. The results indicate that dietary supplementation of CB promotes growth performance, improves immune function, and benefits the cecal microflora in Escherichia coli K88-challenged chickens.

Evaluation of soybean meal source and particle size on broiler performance, nutrient digestibility, and gizzard development.

Although there have been several reports concerning the effects of particle size of cereal grains on productive performance of poultry, there is limited information about the effects of soybean meal (SBM) particle size on broiler performance. The objective of the present experiments was to evaluate the effects of SBM source and particle size on broiler performance, gizzard weight, and nutrient digestibility. The first experiment was a 2 × 2 factorial arrangement of 2 SBM sources: expeller-extracted (ESBM) and solvent-extracted (SSBM), and 2 particle sizes: coarse grind, 971 µm, and fine grind, 465 µm. The second experiment was a 2 × 2 factorial arrangement of 2 ESBM particle sizes: coarse grind, 1,290 µm, and fine grind, 470 µm, and 2 corn particle sizes: coarse grind, 1,330 µm, and fine grind, 520 µm. In the first experiment, there was an interaction (P < 0.05) between SBM source and particle size on BW at 49 d of age. No differences in BW were observed when birds were fed coarse SSBM or ESBM, whereas birds fed diets containing fine ESBM exhibited lower BW than birds fed diets containing fine SSBM. In the second experiment, fine-grind ESBM (P < 0.05) and corn (P < 0.01) produced greater 19-d BW than did coarse grind. A significant interaction (P < 0.01) between ingredient type and particle size revealed that chicks fed coarse particles of corn or ESBM exhibited higher protein digestibility compared with chicks fed only fine particles. Corn particle size had a greater effect on gizzard weight than ESBM particle size. Birds fed diets that contained coarse corn had larger gizzards than birds fed fine corn (P < 0.01), but differences in gizzard weight were not observed when birds were fed coarse or fine ESBM. Particles greater than 1,300 µm depressed BW but improved protein digestibility.

Metabolic profiling of late-term turkey embryos by microarrays.

The last stages of embryonic development are crucial for turkeys as their metabolism shifts to accommodate posthatch survival and growth. To better understand the metabolic change that occurs during the perinatal period, focused microarray methodology was used to identify changes in the expression of key genes that control metabolism of turkey embryos from 20 d of incubation (E) until hatch (E28). Gene expression patterns were evaluated in liver, pectoral muscle, and hatching muscle and were associated with measured embryonic growth and tissue glycogen concentration. Within the studied period, the expression of 60 genes significantly changed in liver, 53 in pectoral muscle, and 51 in hatching muscle. Genes related to lipid metabolism (enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, 3-hydroxymethylglutaryl-CoA reductase, acetyl-CoA carboxylase, lipoprotein lipase, and thyroxine deiodinase) had reduced expression between E22 and E26, corresponding to the period of expected limited oxygen supply. In contrast, genes related to opposing pathways in carbohydrate metabolism, such as glycolysis and gluconeogenesis (hexokinases, glucose-6 phosphatase, phosphofructokinases, glucose 1-6 phosphatase, pyruvate kinase, and phosphoenolpyruvate carboxykinase), or glycogenesis and glycogenolysis (glycogen synthase and glycogen phosphorylase) had rather static expression patterns between E22 and E26, indicating their enzymatic activity must be under posttranscriptional control. Metabolic survey by microarray methodology brings new insights into avian embryonic development and physiology.

By-product of Tropical Vermicelli Waste as a Novel Alternative Feedstuff in Broiler Diets.

Two experiments were conducted to determine physical and chemical properties of vermicelli waste (VW) and effect of VW inclusion levels on growth performance of broilers. In experiment 1, VW samples were randomly collected from vermicelli industry in Thailand to analyze nutritional composition. Vermicelli waste contained 9.96% moisture, 12.06% CP, 32.30% crude fiber (CF), and 0.57% ether extract (EE), as DM basis. The ratio of insoluble:soluble non-starch polysaccharide (NSP) was 43.4:8.9. A total of 120 chicks (6 pens per treatment and 10 chicks per pen) were fed a corn-soybean meal-based diet or 20% VW substituted diet to determine the apparent metabolizable energy corrected for nitrogen retention (AMEn) of VW. The AMEn of VW was 1,844.7±130.71 kcal/kg. In experiment 2, a total of 1,200 chicks were randomly allotted to 1 of 4 dietary treatments for 42-d growth assay. There were 300 chicks with 6 pens per treatment and 50 chicks per pen. The dietary treatments contained 0%, 5%, 10%, or 15% VW, respectively. All diets were formulated to be isocaloric and isonitrogenous. From 0 to 18 d of age chicks fed VW diets had higher (p<0.001) feed conversion ratio (FCR) compared with those fed the control diet. No difference was observed during grower and finisher phase (19 to 42 d). Chicks fed VW diets had lower relative weight of abdominal fat (p<0.001) but higher relative weight of gizzard (p<0.05) than those of chicks fed the control diet. Increasing VW inclusion levels increased ileal digesta viscosity (p<0.05) and intestinal villus height of chicks (p< 0.001). For apparent total tract digestibility assay, there were 4 metabolic cages of 6 chicks that were fed experimental treatment diets (the same as in the growth assay) in a 10-d total excreta collection. Increasing VW inclusion levels linearly decreased (p<0.05) apparent total tract digestibility of DM and CF.

Effects of probiotic, Clostridium butyricum, on growth performance, immune function, and cecal microflora in broiler chickens.

Four hundred and fifty 1-d-old male Lingnan Yellow broiler chickens were used to investigate the effects of Clostridium butyricum on growth performance, immune function, and cecal microflora. The birds were randomly assigned to 5 treatments and offered the same antibiotic-free basal diets for 42 d. The treatments were as follows: no addition (control), 1 × 10(7) cfu C. butyricum/kg of diet (CB1), 2 × 10(7) cfu C. butyricum/kg of diet (CB2), 3 × 10(7) cfu C. butyricum/kg of diet (CB3), and 10 mg of colistine sulfate/kg of diet (antibiotic). Birds fed either CB2 or antibiotic had greater overall BW than those in the control group. During d 1 to 7, d 21 to 42, and d 1 to 42, birds fed either CB2 or CB3 or the antibiotic diet had greater ADG compared with those in the control group. No significant differences were observed in BW or ADG among the CB2, CB3, and antibiotic groups. Birds fed the CB2 or CB3 diet had greater concentrations of IgA and IgG in the serum from d 14 to 42 and greater IgM in the serum from d 21 to 42 than those in the control group. Birds fed the CB3 diet had a greater concentration of complement component 3 in the serum than those in the control group from d 7 to 42. Dietary C. butyricum decreased (P < 0.05) Escherichia coli in cecal contents on d 14 and 42, and both CB2 and CB3 decreased (P < 0.05) cecal Salmonella and Clostridium perfringen from d 14 to 42 compared with the control. Broilers fed either CB2 or CB3 had greater cecal Lactobacillus and Bifidobacterium counts from d 21 to 42, and birds fed C. butyricum had greater cecal C. butyricum counts during the whole period compared with those in the control group. The results indicate that C. butyricum promotes growth performance and immune function and benefits the balance of the intestinal microflora in broiler chickens.

Effect of chito-oligosaccharide on growth performance, intestinal barrier function, intestinal morphology and cecal microflora in weaned pigs.

A total of 180 weanling pigs (21 ± 3 d of age; 5.98 ± 0.04 kg) were used to investigate the effect of chito-oligosaccharide (COS) on growth performance, intestinal barrier function, intestinal morphology, and cecal microflora. Based on initial BW, gender and litter, the pigs were given 5 treatments during a 14-d feeding experiment, including a basal diet (control), 3 diets with COS supplementation (200, 400, or 600 mg/kg), and a diet with colistin sulfate (CSE) supplementation (20 mg/kg). Six randomly selected pigs from each treatment were used to collect serum, duodenal, jejunal, ileal, and cecal samples on d 7 and 14 postweaning. From d 1 to 7 postweaning, pigs fed COS or CSE had greater ADG and ADFI compared with the control pigs. From d 1 to 14, diets with either 400 or 600 mg/kg COS, or 20 mg/kg CSE increased (P < 0.05) ADG and G:F compared with the control diet. No significant differences were observed in ADG, ADFI, and G:F between the pigs fed COS and CSE. Pigs fed either 400 or 600 mg/kg COS, or 20 mg/kg CSE had less (P < 0.05) diamine oxidase (DAO) in the serum, but greater concentration of (P < 0.05) DAO in jejunal mucosa, than the control pigs on d 7 postweaning. Treatments did not affect villous height and crypt depth of the duodenum, jejunum, or ileum. Pigs fed COS at 400 mg/kg had greater (P < 0.05) concentration of Bifidobacteria and Lactobacilli in the cecum than pigs fed the control diet and CSE diet on d 7 postweaning. Supplementation of COS or CSE decreased (P < 0.05) the population of cecal Staphylococcus aureus compared with the control diet on d 7 postweaning. The number of cecal Bifidobacteria in pigs fed 600 mg/kg COS was greater (P < 0.05) than that of pigs fed the control diet or CSE diet on d 14 postweaning. No significant differences were observed in Escherichia coli counts in the cecum among treatments. The present results indicate that dietary supplementation of COS at 400 or 600 mg/kg promotes growth performance and improves gut barrier function, increases the population of Bifidobacteria and Lactobacilli, and decreases S. aureus in the cecum of weanling pigs.

Mechanistic modeling of turkey growth response to genotype and nutrition.

Along with the fast genetic improvement, nutritional and environmental effects on poultry growth performance have made it necessary to develop growth models that have the flexibility to adapt to different genotypes and growing conditions. A mechanistic simulation model of energy and nutrient utilization in growing turkeys is presented herein. The model consists of simulating the average homeorhetic and homeostatic regulations associated with the utilization of circulating glucose, fatty acid, AA, and acetyl-CoA for protein and lipid retention in carcass, viscera, and feathers in a turkey population. Homeorhesis plays a major role in the control of protein and lipid turnover for the definition of genetic potential and feed intake, whereas homeostasis adjusts growth rate through protein and lipid turnover rates and, therefore, BW gain and feed intake to the growing conditions. Also, homeostasis enables the maintenance of a dynamic balance state during all the growing period through the control of circulating nutrient concentration. The model was developed and calibrated with experimental data that described energy utilization in male and female growing turkeys. Then, the ability of the model to adapt to genotypes and to predict the average response of a turkey population to dietary energy was evaluated. Model calibration showed simulations of energy and nutrient utilization that fitted well with the experimental data because ME was satisfyingly partitioned into heat production and energy retention as protein and lipid, and nutrient intake accurately partitioned BW gain into carcass, viscera, and feathers. The evaluation of the model was also satisfactory because BW gain and feed-to-gain ratio were globally in accordance with the observations in different male and female genotypes, in spite of an overestimation of the feed-to-gain ratio during the first weeks of age. Model evaluation showed that the BW gain and feed intake response of growing turkeys to dietary energy was accurately predicted. The model can therefore be used in different growing conditions as it is capable of simulating the growth of different turkey genotypes fed under changing environmental and nutritional contexts.