Suitability of poultry litter ash as a feed supplement for broiler chickens

An experiment was conducted to evaluate poultry litter ash (PLA) at graded levels (0, 25, 50, 75, and 100%) as a dietary substitute for dicalcium phosphate (dicalP) for broiler chickens, where PLA was substituted for dicalP on a wt/wt basis. A decreased BW gain was observed at 21 d from PLA at the 100% substitution rate when compared with the 25% substitution rate. No effects on BW gain, feed consumption, or FCR were incurred by study termination at 41 d, and the 100% substitution rate of dicalP did not cause any detrimental effects on the live performance in market age broilers. Although femur ash percentages decreased with increasing levels of PLA, bone integrity was not compromised by the addition of PLA to the diet. Dry matter digestibility of dietary Ca (26.32–58.65%) and P (30.23–42.68%) increased with increasing levels of PLA (0–100%), respectively, inferring that the Ca and P component of the diet was more efficiently used as the level of PLA increased. In conclusion, PLA resulting from the combustion of poultry litter can be used as a P and Ca source for broilers.     

Replacement of canola meal with Moringa oleifera leaf powder affects performance and immune response in broilers

Moringa oleifera is known as a miracle tree due to its amazing nutritional and therapeutic properties. Considering its nutritional value, Moringa oleifera leaf powder can be used as a non-conventional ingredient in poultry diets. This study was conducted to investigate the effect of the replacement of canola meal (CM) with Moringa oleifera leaf powder (MOLP) on growth performance, blood hematology, and immune response in broilers. Two-hundred-twenty one-day-old Hubbard broiler chicks were reared in one group for a wk (adaptation period). At 8 d of age, 150 chicks of similar body weight (±5g) were selected and randomly divided into 15 experimental units, each comprising 10 chicks. These experimental units were further allocated to 5 treatment groups that were fed Ration A (control), B, C, D, and E, containing 8% CM and 0% MOLP, 6% CM and 2% MOLP, 4% CM and 4% MOLP, 2% CM and 6% MOLP, and 0% CM and 8% MOLP, respectively. The experimental diets were fed to the broilers for a period of 31 d. The results of the present study suggest that replacement of CM with MOLP as a vegetable protein source can enhance the immune response to Newcastle disease and infectious bursal disease vaccination without any change in weight gain, body organ weight, and blood hematology in broilers. The results also indicate that replacement of CM with MOLP results in higher feed intake with some negative effects on FCR in broilers.     

Effect of poultry litter biochar diet inclusion on feed manufacture and 4- to 21-d broiler performance

Decreasing diet cost and minimizing environmental impact are current issues that can affect the success of poultry production. In the eastern United States, much concern has been generated surrounding eutrophication of the Chesapeake Bay due to nitrogen and phosphorus leaching from land application of litter. Gasification of poultry litter and feeding the resultant poultry litter biochar (PLB) may be an alternative to traditional land application of litter. In addition, PLB may provide a cost-effective source of essential nutrients for poultry by the partial or complete replacement of rock phosphorus in poultry diets, and may also provide a mechanism for improving feed manufacture variables. The objectives of this study were to assess effects of diet incorporation of PLB on feed manufacture and pellet quality (Study 1) and subsequent feeding effects on broiler performance and tibia ash (Study 2). Seven diets were formulated to compare the replacement of rock phosphorus with PLB. Inclusion of PLB was high, 6.2 or 6.9%, in order to maximize rock phosphorus replacement but also to assess potential detriments. Four diets were chosen to generate replicated feed manufacture and pellet quality data. The addition of PLB to diets was shown to improve pellet quality (P < 0.05). Diets containing PLB decreased live weight gain and FCR; however, a positive yet modest contribution to bone mineralization was demonstrated (P < 0.0001). Therefore, PLB contains available phosphorus and calcium; however, the bioavailability of these minerals relative to rock phosphorus was not equivalent. Furthermore, the particular PLB tested decreased broiler performance.     

Evaluation of a Feed-Grade Enzyme in Broiler Diets to Reduce Pododermatitis

Nutritional and management interventions are needed to reduce the incidence of pododermatitis in poultry. In this study, enzyme (Allzyme Vegpro) supplementation of corn-soybean meal-based broiler diets was evaluated in an effort to reduce total N and NH₃ production and its effect on pododermatitis in broiler chickens. A total of 1,600 mixed-sex chicks were raised on floor pens in a design involving 2 × 2 × 2 arrangement of protein level [high or low], protein source [all vegetable (Veg) or vegetable plus animal (Veg + Ani)], and enzyme [with or without enzyme supplementation (0.06%)], on a 4-stage feeding program (4 replicate pens/treatment; 50 birds/pen). In addition to live performance, the feet were scored for incidence of lesions on all birds on 28, 42, and 57 d of age, and the severity was recorded as none, mild, and severe. Pooled gut samples were collected at 57 d of age to determine viscosities of fore- and hindgut contents. Pooled litter samples were analyzed for moisture, total N, and NH₃ production at 14, 28, 42, and 57 d of age. Live performance of birds did not vary among the treatments (P > 0.05). The incidence of pododermatitis was significantly affected by protein source at 42 d (P < 0.05), with birds fed all-vegetable diets showing higher incidence and severity than those fed vegetable plus animal diets. At 57 d of age, birds reared on all-vegetable diets with enzyme supplementation showed a lower incidence of mild footpad lesions compared with other treatments. Enzyme supplementation reduced viscosity of the gut contents irrespective of the protein level or protein source. Higher levels of litter NH₃ were observed with high-protein diets (28 and 42 d), all-vegetable diets (28 d), and with enzyme supplementation (28 and 42 d). In this study, enzyme supplementation had little effect on litter total N and NH₃ production levels, but reduced viscosity of the gut contents and severity of pododermatitis in older birds.     

Litter Moisture and Footpad Dermatitis as Affected by Diets Formulated on an All-Vegetable Basis or Having the Inclusion of Poultry By-Product

Chicken feet (paws) are valuable products in the Asian market. Foot dermatitis, mostly caused by litter condition, can affect the foot skin tissue leading to downgrades and reduced market value. In this study, a diet having animal by-products was compared with 2 all-vegetable diets formulated with corn, soybean meal, and toasted soybean with or without corn gluten meal. A total of 1,200 birds were placed in 24 pens with new pine shavings as litter. Each treatment had 8 replications. Birds were fed the experimental diets up to 40 d of age. Starting at 21 d of age, 10 birds per replication were labeled and submitted to weekly evaluations of foot dermatitis. Litter samples were also collected weekly to determine percentage of moisture. In general, litter moisture and incidence and severity of foot dermatitis increased as broilers aged. Inclusion of corn gluten meal consistently reduced the incidence and severity of footpad dermatitis, which occurred in parallel with the reduction in litter moisture. Litter moisture from birds fed a diet with the inclusion of poultry by-product was similar to that obtained with corn gluten meal; however, benefits from reductions in foot dermatitis were not seen. It is concluded that feed formulation can affect litter moisture and the incidence and severity of foot dermatitis. Birds fed all-vegetable diets based exclusively on corn and soybean meal have an increased potential to develop footpad dermatitis as well as to produce excreta with greater percentages of moisture when compared with those fed diets with inclusions of poultry by-product or corn gluten meal.     

Effects of a New Recombinant Phytase on the Performance and Mineral Utilization of Broilers Fed Phosphorus-Deficient Diets

An experiment was conducted with Arbor Acres broiler chickens that were fed 3 experimental diets—a control diet containing an adequate level of available phosphorus (AP) and 2 diets that were deficient in AP but supplemented with phytase at a level of either 500 or 750 phytase units/kg—to assess the effects of a novel microbial phytase supplement in broilers fed AP-deficient diets on growth performance and mineral utilization. Similar average daily gain, feed intake, and feed efficiency (P > 0.05) were obtained among broilers fed different diets. Compared with broilers fed the control diet, broilers fed diets with phytase had greater (P < 0.05) retention of Ca, P, and Zn. Moreover, the levels of Cu, Zn, Mg, and Mn in the tibia bone at 28 d of age, and Zn and Mn at 42 d of age in birds fed diets with phytase exceeded (P < 0.05) those of birds fed the control diet. Supplementation of phytase increased Zn and Mg contents in the plasma at 42 d of age. Birds responded similarly to phytase supplemented at a level of 500 or 750 phytase units/kg in terms of growth performance, mineral retention, and mineral content in the serum and bone. Therefore, with the supplementation of this novel phytase, it is possible to reduce the dietary levels of P and other minerals to below the recommended levels of the Feeding Standard of Chicken in P. R. China (ZB B 43005-86).     

Growth performance and carcass characteristics of male broilers fed diets varying in digestible threonine to lysine ratio from 21 to 49 days of age

Two experiments were conducted to ascertain digestible Thr to Lys ratio of male broilers from 21 to 35 d of age (experiment 1) and 35 to 49 d of age (experiment 2) based on growth performance and processing yields. In both experiments, 2 diets (dilution and summit; 3,108 kcal ME/kg and 18.2% CP in experiment 1; 3,163 kcal ME/kg and 17.2% CP in experiment 2) consisting of corn, soybean meal, poultry by-product meal, and peanut meal formulated to be surfeit in limiting amino acids with exception of digestible Lys and Thr were mixed at various proportions to create 8 titration dose-response diets. Digestible Lys was formulated to contain 95% of the requirements from 21 to 35 and 35 to 49 d of age. In each experiment, gradient treatment structure was arranged in a randomized complete block design. Calculated digestible Thr to Lys ratios ranged from 0.512 to 0.806 in approximately increments of 0.040 (1,600 Hubbard × Cobb 500 broilers; experiment 1) and 0.552 to 0.793 in approximately increments of 0.035 (3,000 Ross × Ross 708 broilers; experiment 2). In experiment 1, digestible Thr to Lys ratio for male Hubbard × Cobb 500 broilers was estimated at 0.68 and 0.67 for BW gain and feed conversion from 21 to 35 d of age. In experiment 2, digestible Thr to Lys ratio of Ross × Ross 708 was determined at 0.68 and 0.63 for feed conversion ratio with quadratic and linear broken-line models, respectively. Meat weights and yields were not affected by the dietary treatments in either experiment. These data indicate that a digestible Thr to Lys ratio of 0.68 can optimize growth performance of broilers from 21 to 35 and 35 to 49 d of age.     

The effects of poultry meal source and ash level on nursery pig performance

Weanling pigs (total of 560) were used in two experiments to determine the effects of poultry meal in nursery diets on pig performance. In Exp. 1,210 barrows and gilts (initially 7.4 kg and 21 +/- 2 d of age) were fed one of five diets, which included a control diet with no specialty protein products or (as-fed basis) the control with 2.5 or 5.0% fish meal, or 2.9 or 5.9% poultry meal (11.8% ash). Poultry meal replaced fish meal on an equal lysine basis. Overall (d 0 to 28), pigs fed diets containing fish meal had greater (P < 0.01) ADG than pigs fed poultry meal. Increasing fish meal tended to have increased (quadratic, P < 0.07) ADG, with the greatest improvement observed in pigs fed the diet containing 2.5% fish meal. Pigs fed diets containing fish meal had improved (P < 0.01) G:F compared with pigs fed diets containing poultry meal. In Exp. 2, a total of 350 barrows and gilts (initially 8.9 kg and 22 +/- 2 d of age) were fed one of seven experimental diets, which included a control diet with no specialty protein products, or the control with 2.5 or 5.0% fish meal, 2.9 or 5.8% low-ash (10.9%) poultry meal, and 3.1 or 6.2% high-ash (13.5%) poultry meal. Poultry meal replaced fish meal on an equal lysine basis. Overall (d 0 to 15), there were no differences in ADG and ADFI (P = 0.14); however, pigs fed diets containing fish meal or poultry meal had improved (linear, P < 0.01) G:F compared with pigs fed the control diet. Pigs fed diets containing low-ash poultry meal had greater (P < 0.01) G:F compared with pigs fed diets containing high-ash poultry meal. Based on these data, quality control specifications, such as ash content, need to be considered when using poultry meal as an animal protein replacement in diets for nursery pigs.     

Effect of supplemental zinc source and corn particle size on 40-day broiler performance

Zinc (Zn) supplementation source and particle size of feed ingredients are two factors that can affect poultry performance and should be considered for proper feeding of poultry. The objective of the current study was to assess the effects of Zn supplementation source and corn particle size on broiler performance, breast yield, and tibia Zn concentration. Treatments were arranged in a 5 × 2 factorial randomized complete block design with the main effects Zn treatment and corn particle size (550 micron vs. 1,050 micron). Zinc treatments included a basal diet (no added Zn), 80 mg/kg Zn sulfate, and 3 diets with 40 mg/kg Zn sulfate + 40 mg/kg of either Zn-glycine amino acid (AA) chelate (Zn-gly), Zn-AA complex (Zn-AA), or Zn bis(-2-hydroxy-4-methylthio)butanoic acid (Zn-HMTBA). A total of 8 replications per treatment were fed to 23 broilers per pen from d one to 40. A Zn treatment x corn particle size interaction was observed for ending bird weight (EBW; P < 0.05) demonstrating that feeding small particle corn produced larger broilers except when supplemental Zn was not included. Broilers fed small particle corn or diets supplemented with Zn consumed the most feed (P < 0.05); however, FCR was decreased (P < 0.05) by 1.9 points for broilers fed large particle corn diets. Tibia Zn concentration was higher (P < 0.0001) for Zn supplemented diets, but no other treatment effects were observed. In conclusion, Zn supplement source had little effect on broiler performance; however, Zn supplementation per se optimized performance.     

Effect of dietary nucleotide supplementation on performance and development of the gastrointestinal tract of broilers

1. Two experiments were conducted to determine the effects of dietary nucleotide supplementation on broiler performance, and physical and morphological development of the gastrointestinal tract.

2. Experiment 1: A total of 180 one-d-old male chicks were placed in battery brooders in 3?×?6 replicate pens containing 10 chicks each. Chicks were randomly assigned to one of the three dietary treatments; a maize-soyabean meal based diet supplemented with 0, 0·25, and 0·50% Torula yeast RNA (as a source of nucleotides) from 0 to 16?d of age.

3. Experiment 2: A total of 1344 one-d-old male chicks were placed in floor pens and reared on recycled wood shavings (two flocks) under a high stocking density (0·068?m²/bird). Chicks were randomly assigned to one of the 4 dietary treatments (0, 0·25% Torula yeast RNA, 2% and 6% Nupro®) for the starter period (0 to 14?d of age) with 6 replicate pens containing 56 chicks each. All the birds were fed on the same common grower diet with no supplementation of nucleotides from 15 to 32?d of age.

4. Experiment 1: Supplementing the diets with up to 0·50% Torula yeast RNA did not affect broiler performance, or relative intestinal tract weight and length of broilers at any periods measured.

5. Experiment 2: From 0 to 14?d of age, broilers fed on the diets supplemented with 0·25% Torula yeast RNA and 2 and 6% Nupro® were significantly heavier and had improved feed conversion (feed:gain) ratios as compared with the birds fed on the control diet. Supplementing the starter diet only with 2% Nupro® supplementation significantly improved body weight (BW) gain as compared with the control diet over the entire experiment (0 to 32?d of age). Broilers fed on the diets supplemented with 2 and 6% Nupro® from 0 to 14?d of age had better feed conversion (feed:gain) ratios over the entire experiment (0 to 32?d of age) as compared with the birds fed on the control diet, even though the birds were only fed on the diets supplemented with Nupro® from 0 to 14?d of age. The broilers fed on the diets supplemented with 0·25% Torula yeast RNA and 2% Nupro® had higher villus height and an improved villus height-to-crypt depth ratio as compared with birds fed on the control or 6% Nupro® diet at 14?d of age.

6. It is generally assumed that nucleotides are not an essential nutrient; thus there is no need to supplement the diets of broilers reared under normal conditions. However, dietary nucleotide supplementation may be important to maintain maximum growth performance when birds are exposed to stress conditions, such as high stocking density combined with dirty litter.     

Effects of feeding cracked corn and concentrate protein pellets on broiler growth performance

Typically, in a vertically integrated poultry (broiler or turkey) operation, maintaining adequate feed manufacturing production proves to be a challenge. To evaluate an alternative management strategy, 2 studies were conducted to examine the effects of feeding broilers cracked corn and a concentrated pellet on broiler growth performance from 0 to 41 d of age. Cracked corn (0, 25, 50, 75, or 100%) was used to replace the corn fraction in the diet for all 3 stages of growth. Cracked corn and concentrate pellets were blended together to be isonitrogenous and isocaloric among all treatments, so only feed form would differ. Experiment 1 diets included a control (0% cracked corn) and experimental diets (25, 50, 75, or 100%) in which cracked corn directly replaced the ground corn fraction. Overall (0 to 41 d), a linear decrease (P < 0.001) for ADG and ADFI and a linear increase (P < 0.003) for FCR was observed as cracked corn levels increased. In experiment 2, a “step-up” feeding program of cracked corn was evaluated with dietary treatments including the following: 1) control (0% cracked corn throughout feeding), 2) 0% cracked corn (0 to 17 d) and 25% (18 to 41 d), 3) 0% cracked corn (0 to 17 d) and 50% (18 to 41 d), 4) 25% cracked corn (0 to 41 d), and 5) 50% cracked corn (0 to 41 d). Overall (0 to 41 d), ADG for treatment 1, 2, and 4 was greater than 3 and 5 (P < 0.05). Feed conversion ratio was superior for treatments 2 and 4 (P < 0.05) in comparison with treatments 3 and 5. Up to 25% of the dietary corn can be fed to the broiler as cracked corn from 0 to 41 d without a negative response on growth performance.     

The effect of dietary lysozyme with EDTA on growth performance and intestinal microbiota of broiler chickens in each period of the growth cycle

Lysozyme is a potential replacement for antibiotics in the poultry industry. Two trials were conducted using new or used litter to determine the effect of 100 ppm lysozyme in feed on growth performance and intestinal microbiota of broiler chickens in each period of the growth cycle. The new litter trial and used litter trial were each analyzed as a one-way analysis of variance with length of time in which 100 ppm lysozyme was fed to the birds as the main factor (no lysozyme d zero to 35; positive lysozyme d zero to 4; positive lysozyme d 5 to 14; positive lysozyme d 15 to 24; positive lysozyme d 25 to 35; positive lysozyme d zero to 35; positive virginiamycin d zero to 35). Effects of lysozyme were not detected under clean conditions (P > 0.05). When used litter was provided, growth performance was not improved by lysozyme (P > 0.05). However, feeding lysozyme to birds from d 5 to 14 and throughout the trial reduced the number of E. coli in the ileum compared with feeding virginiamycin (positive lysozyme d 5 to 14 and zero to 35, and virginiamycin d zero to 35: 1.7 × 10⁴ cfu g⁻¹, 1.9 × 10⁴ cfu g⁻¹ and 9.3 × 10⁴ cfu g⁻¹, respectively) to birds (P < 0.05). Dietary lysozyme at 100 ppm can change intestinal microbiota of broiler chickens.     

Evaluation of different water flow rates of nipple drinkers on broiler productivity

Watering systems utilized in broiler production can impact bird performance. Many companies have increased water flow rates (WFR) in their nipple drinkers (ND) system during brooding above the manufacturers recommended level, then make adjustments in WFR during the grow period. This has increased moisture and early caking problems in litter. The objective of this study was to determine how birds perform on different WFR rates during brood and grow periods while observing litter condition. Seven WFR treatments were evaluated for broilers reared from 1 to 42 d age: 50 mL/min, 75 mL/min, 100 mL/min, 120 mL/min, 50 mL/min 1 to 7 d increasing to 75 mL/min 8 to 42 d, 75 mL/min 1 to 7 d increasing to 100 mL/min 8 to 42 d, and 100 mL/min 1 to 7 d increasing to 120 mL/min 8 to 42 d. Chicks were identified and randomly allocated in a randomized complete block design. BW, cumulative feed consumption (FC), FCR (feed:BW), litter moisture (%), and litter moisture under the ND were determined weekly to 42 d. Mortality (MO) was recorded daily. Birds tended to have heavier BW on d 35 when (P = 0.08) on the higher WFR (75, 100, and 120 mL/min) in comparison to birds on the lowest WFR (50 mL/min). No differences were observed for FC, FCR, or MO. Birds on treatments with higher WFR (100 and 120 mL/min) and treatments which were increased to higher WFR (75 to 100 mL/min and 100 to 120 mL/min) utilized greater amounts of water as compared to birds receiving lower WFR (50 and 75 mL/min). The 100 and 120 mL/min WFR resulted in higher percent litter moisture (P ≤ 0.01) under the ND but decreased at the end of the growing period. In conclusion, as birds become heavier, they attempt to utilize larger amounts of water from ND with greater WFR without any beneficial effect on bird performance. As WFR increase, litter moisture under the ND will initially increase but then decrease as the birds age.     

Effect of Spray-Dried Plasma Form and Duration of Feeding on Broiler Performance During Natural Necrotic Enteritis Exposure

The effect of duration of feeding (continuous or discontinued after d 14) and form (granular vs. powder) of spray-dried plasma (SDP) on performance and mortality of broilers using used litter was evaluated with 240 Ross × Ross 308 male broilers (6 broilers per pen, 8 pens per treatment). Dietary treatments were control (no SDP) or SDP as powder or granular included in the pellet and fed continuously (d 0 to 35) or discontinued after d 14. During the experiment, broilers developed necrotic enteritis, and tissue cultures were positive for Escherichia coli and Salmonella, resulting in 50% mortality on control broilers. Addition of SDP to the feed improved (P < 0.05) average daily gain, feed intake, and feed efficiency for each period of the study (d 0 to 14, 15 to 28, 29 to 35, and 0 to 35). Continuous feeding of SDP improved (P < 0.05) average daily gain, feed intake, and feed efficiency from d 15 to 35 compared with broilers fed SDP to d 14. Liveability was improved (P < 0.05) in broilers consuming SDP either for 14 d or continuously throughout the experiment compared with control broilers. Spray-dried granular plasma was more effective than spray-dried powder plasma from d 0 to 14. The results of this experiment confirmed that SDP improved broiler growth rate, feed intake, feed efficiency, and minimized enteric challenge associated with necrotic enteritis with maximal protection afforded by continuous feeding. The response to SDP was independent of age of the broiler.     

Feed endoxylanase type and dose affect arabinoxylan hydrolysis and fermentation in ageing broilers

Despite the general use of endoxylanases in poultry feed to improve broiler performance, the abundance of different endoxylanase products and the variable response to their application in the field prevent a clear understanding of endoxylanase functionality in vivo. To gain insight into this functionality, we investigated the impact of endoxylanase type (Belfeed from Bacillus subtilis versus Econase XT from Nonomuraea flexuosa) and dose (10, 100, 1,000 mg/kg) in combination with broiler age on arabinoxylan (AX) hydrolysis and fermentation in broilers (Ross 308) fed a wheat-soy based diet. In a digestibility trial and a performance trial, a total of 1,057 one-day-old chicks received the control diet or 1 of the 6 endoxylanase supplemented wheat-soy based diets with, respectively, 5 replicate cages and 8 replicate pens per dietary treatment per trial. The AX content and structure, the AX digestibility values and the short-chain fatty acids produced were analysed at the level of the ileum, caeca and excreta at d 11 and 36. Endoxylanase supplementation resulted in a more extensive solubilisation of wheat AX and a reduction in the intestinal viscosity compared to the control (P < 0.05). A high endoxylanase dose was, however, required to obtain increased hydrolysis of the dietary AX along the gastrointestinal tract against the control (P < 0.001). Depending on the type of endoxylanase, a pool of AX with distinct physicochemical properties was created. The B. subtilis endoxylanase created a large pool of soluble AX in the ileum, thereby increasing ileal viscosity compared to broilers fed an endoxylanase from N. flexuosa (P < 0.001). The N. flexuosa endoxylanase mainly triggered caecal AX fermentation in young broilers, by delivering easily fermentable AX substrates with a low degree of polymerisation (P = 0.03). The effects were particularly present in young broilers (d 11). From this study, it is clear that the type and dose of endoxylanase added to wheat-soy based diets determine the nature of AX substrates formed. These, in turn, affect the intestinal viscosity and the interplay between the dietary AX compounds and microbiota, hence dictating AX digestion at young broiler ages and performance outcomes towards slaughter age.     

Post-pellet liquid application fat disproportionately coats fines and affects mixed-sex broiler live performance from 16 to 42 d of age

The effect of 2 fat application sites (FAS) and 2 levels of fines on feed manufacturing parameters and broiler live performance from 16 to 42 d was studied. The FAS included mixer-added fat (MAF) and post-pellet liquid application (PPLA) of fat. While the MAF diets had all fat added to the diet prior to pelleting, the PPLA diets were pelleted with 0.5% MAF, and the remaining 3.5% fat was added subsequent to pellet cooling. The levels of fines included 0 and 30%. A total of 32 pens was placed with 8 males and 8 females (mixed-sex) in each pen. Broiler chicks were fed a common crumbled starter for approximately 16 d and then transitioned to one of the 4 dietary treatments. The PPLA pellets were more durable than were MAF pellets (P < 0.01), but required more energy to pellet (P < 0.01). When adding liquid fat post pellet to the diets with 30% fines, the fines absorbed more liquid fat and exhibited a greater gross energy when compared to pellets (P < 0.01). Male broilers consuming the PPLA diets were 50, 97, and 120 g heavier than male broilers consuming the MAF diets at 28, 35, and 42 d, respectively (P < 0.01). Female broilers consuming the PPLA diets with 30% fines were 71 and 90 g heavier than female broilers consuming the MAF diets with 30% fines at 28 and 35 d, respectively (P < 0.05). It was concluded that the females may have benefited from consuming high-energy-density fines present in the PPLA diets with 30% fines when compared to females consuming MAF diets with 30% fines because the additional fat that coated the fines offset the negative energy associated with prehension of the fines.     

Growth response of broilers to spray-dried plasma in pelleted or expanded feed processed at high temperature

A series of 4 experiments evaluated effects of mash conditioning temperature from a pellet mill or expander on performance of broilers fed pelleted diets containing spray-dried plasma (SDP). All experiments utilized Ross x Ross 308 male broilers randomly assigned to their respective treatments (6 or 10 broilers/pen and 8 or 10 pens/treatment). Treatments in Exp. 1 consisted of a control (0% SDP), SDP coated postpelleting, or SDP blended into the meal prepelleting. Experiment 2 and 3 included the same 3 treatments as in Exp. 1 but with additional treatments of SDP blended into the meal and conditioned at 90 or 95 degrees C before pelleting. In Exp. 4, treatments consisted of a control (0% SDP) or SDP blended into the meal and pelleted (85 degrees C conditioning temperature) or expanded (149 degrees C final effective temperature) and then pelleted. Corn-soybean meal-based diets were formulated to be equal in lysine and ME in all experiments. Pelleted diets were conditioned for 15 s at 85 degrees C, and expanded diets were conditioned at 95 degrees C, 29.7 MJ/t, 13.95 kg/cm2 cone pressure, exit temperature of 149 degrees C, and then pelleted through a 4 x 32-mm die. In Exp. 1, ADG and feed intake were improved (P < 0.05) for broilers fed SDP from d 1 to 28 of age, with greater BW at d 42. In Exp. 2, both in early (d 1 to 28 of age) phases, and overall (d 1 to 42 of age), broilers fed SDP had improved (P < 0.05) gain and efficiency. In Exp. 3, ADG, feed intake, efficiency of gain, and BW were improved (P < 0.01) for broilers fed SDP from d 1 to 21 of age, regardless of conditioning temperature. In Exp. 4, broilers fed SDP had improved (P < 0.05) gain, BW, and feed intake regardless of processing method. Overall, the results of all of the experiments demonstrated that pellet conditioning temperature from 85 to 95 degrees C and expander temperatures to 149 degrees C did not impair the positive growth effects of SDP in pelleted or expanded broiler feed.     

Effects of catfish meal blend inclusion in broiler feeds on live performance and carcass yield attributes

This study was designed to investigate whether a catfish meal blend, formulated into broiler feed as a protein supplement, would influence broiler growth and meat yield when included in the diet at industry-acceptable levels. A catfish meal blend was fed at an inclusion rate of 7.5% of the diet to broilers raised to 42 d on a 3-feed program. This treatment was compared with broilers raised on a corn-soybean meal control diet (no animal protein products) and a diet with 7.5% poultry by-product meal. Each animal protein product was formulated into the diets based on a nutritional matrix and was not substituted for another ingredient. The broilers were raised with 50 birds per pen (10 replicate pens per treatment). Five males and 5 females per pen were processed and deboned at 42 d to compare carcass and meat yields. Body weights at 21 d were highest for birds fed the catfish meal blend, with the corn-soybean meal control treatment being the lowest and the poultry by-product meal treatment being intermediate. No significant differences were recorded after 21 d, and no differences were seen in period gains from 21 to 35 or 35 to 42 d. Feed conversion at 21 d favored birds in those treatments fed animal protein products; however, no significant differences were seen at 35 or 42 d. No significant differences were noted in mortality during any of the production periods. Chilled carcass, fillet, and tender yields were not significantly affected by feeding either of the animal protein products. In conclusion, the catfish meal blend included in broiler feeds at an industry-acceptable level (7.5%) showed no adverse effects on broilers grown to 42 d. No health effects were recorded and live performance parameters were not reduced in comparison with the other treatments.     

Use of Digestible Amino Acids and the Concept of Ideal Protein in Feed Formulation for Broilers

The objective of this study was to evaluate diet formulation based on digestible amino acids (DAA), the formulation of low protein diets supplemented with synthetic amino acids, and L-Thr supplementation to increase the Thr:Lys ratio from 67:100 to 70:100. Two experiments were carried out with Hubbard male broilers from 3 to 6 wk of age. In experiment 1, corn-soybean meal diets containing 20% CP were used. In experiment 2, 20% CP diets were formulated with corn, soybean meal, wheat bran, feather meal, and meat meal. In both experiments, body weight gain and economic evaluations were better for broilers fed diets formulated on DAA. Carcass yields and carcass composition were not significantly affected by formulation procedures. In experiment 2, birds fed diets based on DAA had improved feed efficiency compared with those fed total amino acids (TAA). In experiment 1, a reduction of CP from 20 to 18.2% did not affect broiler performance. It did, however, result in fatter carcasses, lower percentages of breast meat, and lower economic evaluation. In both experiments, performance and economic evaluation were not affected by the Thr:Lys ratio. In experiment 1, however, abdominal fat and carcass fatness were reduced, and, in both experiments, carcass protein level was higher with a Thr:Lys ratio of 70:100 than with 67:100 ratio (P < 0.05).     

Dietary glycine and threonine interactive effects in broilers

Little information is available regarding the interaction of dietary Thr and Gly on the potential metabolic sparing effects, live production, or breast meat yield of broilers. To test these potential interactions, 432 one-day-old Ross 308 male broilers were fed a common diet up to 21 d of age, and then fed 1 of 6 experimental diets. A factorial arrangement of treatments consisted of 3 dietary levels of standardized digestible Thr (0.57, 0.61, and 0.65%) in combination with 2 levels of total Gly + Ser (1.55 and 1.65%). Experimental diets were fed from 21 to 42 d of age, with live performance, carcass traits, and free blood plasma levels of Gly, Ser, and Thr serving as evaluation criteria. Interactions (P ≤ 0.05) were observed for BW gain, feed consumption, carcass and breast meat weight, and carcass yield, all showing improvements with increasing dietary Thr in combination with low dietary Gly + Ser treatments. Circulating plasma Gly, Ser, and Thr were affected by their respective dietary status.