Broiler Experiment Research Articles

Growth, nutrient uptake, blood metabolites and bone properties in broilers consuming feed with mineral-enriched whole black soldier fly larvae

Abstract The recycling of minerals is crucial for the future circular agriculture. Black soldier fly larvae (BSFL) can accumulate minerals in their body. This study investigated the effects of adding mineral-enriched BSFL, grown on substrates containing sewage sludge recyclates (SSR), to broiler feed to reintroduce minerals from waste streams currently subject to regulatory restrictions back into the nutrient cycle. Feed, nutrient, mineral and heavy metal intake, growth, blood metabolites and immunoglobulins, bone characteristics and mineral status of broilers were studied in response to different mineral-enriched BSFL supplements. Eighty newly-hatched mixed-sex Ross 308 chicks were divided into four groups, with six replicate pens per group. BSFL used in the broiler experiment were grown either on a modified Gainesville fly diet (FD) (L-FD) or on FD supplemented with 4% of sewage sludge biochar (L-BCH), or on the FD supplemented with Single Superphosphate (SSP) SSR (L-SSP). All broilers were fed age-specific diets and either had no access to BSFL (CON) or received 15% of CON birds’ feed intake as defrosted BSFL from three different sources. Inclusion of 15% of mineral-enriched whole BSFL in broiler rations had no adverse effects on growth performance parameters, nutrient intakes, nutrient conversion efficiency, plasma metabolites and immunoglobulins (). Birds in BSFL supply groups had higher serum Ca concentrations than CON birds (). L-BCH supplied birds had a lower serum P than CON birds (). Tibial characteristics and mineral status of birds were not affected by larvae supply (). Heavy metal intake (manganese, iron, zinc, copper, arsenic, cadmium, lead, and mercury) of the birds was not affected by dietary treatments (). In conclusion, 15% of mineral-enriched-BSFL reared on SSP can be included in broiler diets for 42 experimental days without adverse effects on nutrient intakes, growth performance parameters and bone condition.

Effect of wheat coarseness and pellet quality on performance and particle size preference of broiler chickens fed diets based on wheat and maize

Recent broiler experiments have demonstrated that the macrostructure defined as the diameter and length of pellets can be larger, and that the tolerance for fines in the diet is higher than currently assumed. In a first experiment, broiler performance till 10 d of age was not affected when a 3 mm pelleted diet was replaced with a 5 mm pelleted and crumbled diet (35% particles > 3.6 mm). Preference tests indicated either no particle size preference, or a preference for particles > 2.8 mm. In a second experiment, reducing pellet quality of 5 mm pellets to increase the amount of fines had no effect on weight gain and FCR from 10 to 34 d of age, but when diets consisted of finely ground wheat as compared to coarsely ground wheat, the feed intake was higher and FCR was poorer. When offered feed with particles > 4.0 mm, 2.8 – 4.0 mm, 1.6 – 2.8 mm and < 1.6 mm, broilers ate more particles 1.6 – 2.8 mm than > 4.0 mm at 12 d of age, while no clear particle size preferences were observed at older ages. These data confirm that diets pelleted through a 5 mm die can be used even from day-old, and that broilers can handle a moderate reduction in pellet quality of 5 mm pellets without compromising performance. A high versatility of broiler chickens to particle size variations, and a preference for larger particles than currently assumed even at a very young age, may explain these results.

Effects of pre-heating of broiler breeder's eggs on hatchability, chick quality, overall performance, and welfare traits in broilers.

This study aimed to investigate the effects of varying pre-heating practices (12-h: PH12; 8-h: PH8; 4-h: PH4 and 0-h or no pre-heating: PH0) of broiler breeder's eggs prior to incubation on hatching, chick quality, overall performance, and welfare traits in broilers. A total of 960 eggs obtained from Ross 308 breeders at 45 weeks were used for pre-heating manipulations and 480 chicks for broiler experiment. Apparent fertility was higher in PH0 (94.6%) and PH4 (94.5%) treatments than in PH8 (91.6%) and PH12 (90.6%); hatchability of fertile and set eggs was higher in PH4 and PH12. PH4, PH8, and PH12 treatments significantly accelerated the average hatching time compared to PH0. General chick quality was not affected by pre-heating treatments. However, chick length was significantly lower in PH0 chicks than PH12. Pre-heating manipulations did not change the overall broiler performance. Welfare characteristics were similar among treatments, while only hock burn was better in PH8 broilers. In conclusion, pre-heating of broiler breeder eggs for 4 to 12 h improved hatching success by lowering embryonic mortality and shortened the average hatching time compared to no pre-heating, and did not cause any significant alteration in chick quality, overall performance, and welfare characteristics.

Description of 3 failed attempts to estimate the calcium equivalency of phytase for growth performance and tibia ash of broiler chickens when using graded dietary levels of limestone

Three broiler experiments were conducted to estimate the Ca equivalency of a novel phytase using direct and indirect methods. All 3 experiments employed 4 concentrations of limestone to create 4 reference diets, deficient in nonphytate P, with increasing dietary Ca. Phytase was supplemented to the lowest Ca reference diet at 350, 700, 1,400, or 2,800 FYT/kg in experiment (Exp.) 1 and Exp. 2 and at 500, 1,000, 2,000, or 4,000 FYT/kg in Exp. 3. Broilers were fed from d 8 to 10 and 20 to 24, 19 to 21, or 7 to 10 and 7 to 21 posthatching in Exp. 1, 2, or 3, respectively. Diet did not affect growth performance or tibia ash in Exp. 1. Reducing the dietary Ca linearly (P < 0.05) increased body weight gain (BWG) and feed intake (FI) in Exp. 2 or Exp. 3. Feed conversion ratio (FCR) was decreased (linear or quadratic, P < 0.05) as dietary Ca was reduced in Exp. 2 or Exp. 3 (d 7-21). Tibia ash percent linearly (P < 0.05) decreased as dietary Ca decreased in Exp. 3 but only from d 7 to 21 and phytase increased (linear or quadratic, P < 0.05) FI and BWG, and decreased FCR. In Exp. 1 (d 8-10) and Exp. 2, apparent ileal digestibility (AID), total tract retention, and apparent digested and retained Ca or P increased (linear or quadratic, P < 0.05) as dietary Ca decreased. Phytase increased (linear or quadratic, P < 0.05) AID and apparent digested and retained Ca or P in Exp. 1 or Exp. 2. Due to the nature of the effect of dietary Ca on performance or tibia ash, it was not possible to use the indirect method to estimate the Ca equivalence of phytase in the current experiments. The total and digestible Ca equivalence of phytase could be estimated using the direct method. These experiments highlight challenges to consider when designing experiments to estimate the Ca equivalency for phytase in the future.

Is relaxing broiler breeder growth restriction cost-effective?

Broiler breeders are subjected to feed restriction programs to control excessive growth. However, current levels of feed restriction and concomitant growth restriction are becoming severe, raising welfare and suboptimal reproductive performance concerns in underfed breeders. To circumvent the issue, our previous studies investigated the effects of new strategic growth curves, with various degrees of relaxed growth restrictions, on broiler breeders and their progeny's performance. The broiler breeder study was conducted with 40 Ross 708 broiler breeder pullets reared on 1 of 10 target growth trajectories using a precision feeding (PF) system. The growth trajectories were designed with 2 levels of the amount of prepubertal BW gain and 5 levels of pubertal growth timing. The prepubertal BW gain (g1) was estimated from the breeder-recommended standard BW gain (Standard g1) target, or 10% higher (High g1). The pubertal growth timing (I2) was advanced such that it happened at I2-0%=22.29 wk, I2-5%=21.16 wk, I2-10%=20.05 wk, I2-15%=18.94 wk, I2-20%=17.82 wk of age. Two broiler experiments with different maternal ages (35 and 42 wk) were conducted as the extension of the breeder experiment to evaluate the intergenerational effects of a reduced degree of maternal prepubertal phase growth restriction and earlier maternal pubertal phase growth on offspring growth and development. The current paper investigated the economic aspects of implementing the growth curves using the partial budget analysis. Increasing prepubertal BW gain by 10% and advancing the pubertal growth phase by 20% (scenario 10) could increase margin over feed and chick cost for the hatching egg producers by CDN$1.97/hen. For broiler chicken supply chain as a whole, the highest differential margin over feed and chick cost was for maternal growth scenario 10 from 42-wk-old hens. The latter margin over feed and chick cost was greater than that of breeder-recommended maternal growth (from 35-wk-old hens) by $0.1053/kg live chicken under the current economic situation.

Processing weights of chickens determined by dual-energy X-ray absorptiometry: 1. Weight changes due to fasting, bleeding, and chilling

The increasing breast weight of modern broilers highlights the convenience of studying the dynamics of processing weights across the grow-out period. For models predicting these traits to work with non-fasted live birds under longitudinal studies, it is necessary to determine the changes in the weights of birds due to fasting and bleeding and carcasses due to chilling. This study aimed to develop a model to predict the fasting weight loss of broilers, determine the weight changes due to bleeding and chilling, and assess the percentage of gizzard fat in the abdominal fat. Models were fitted to fasting BW loss data from literature. A bleeding BW loss value obtained in a pilot study was compared to literature. This one and a single-source percent gizzard in the abdominal fat value were used as reference values. Birds from two experiments were selected at different ages to determine the following variables: non-fasted and fasted BW, bled weight, unchilled and chilled carcass weights, and gizzard fat and abdominal fat pad weights. Predicted and reference values were compared to the observed data based on their 95% confidence intervals, and the fitted model and reference values were validated if no statistical differences were inferred. The fasting BW loss model was refitted to the data from experiments, and the estimates of the model fitted to both datasets were compared. The fasting BW loss followed a three-parameter exponential model with reducing values as the bird aged, and the predicted and observed values showed no statistical difference (P > 0.05). The reference bleeding BW loss (2.76%) and gizzard fat percentage (18%) values showed no difference (P > 0.05) to data from broiler experiments, and a chilling carcass weight gain of 2.79% was determined. The scale and relative growth rate estimates of the fasting BW loss model showed no difference (P > 0.05) between datasets, and the asymptote showed a possible but negligible difference. The fasting BW loss model, the bleeding BW loss coefficient, and the gizzard fat percentage were validated. The model and coefficients obtained herein will not only be applied to predict processing weights using Dual-Energy X-ray Absorptiometry but also may be used in other modeling approaches.

Assessment of crop usage in ad libitum fed birds and short-term phytase efficiency as affected by acid addition

ABSTRACT 1. A field assessment was performed to map the extent of crop usage and thus retention time in broiler chickens. In addition, a broiler experiment was carried out to study the short-term effect of acid addition on phytase efficacy in the crop. 2. In the field assessment, the crop content of 40 ad libitum fed broiler chickens from 4 different farms were sampled at 10, 20 and 30 d of age. The dry matter (DM) content varied from 0 to 32 g. 3. From 11 d of age, 120 individually caged chickens were intermittently fed a high phytate-P diet with either no addition or 500 FYT C. braakii-derived phytase added or both phytase and 1.4% formic acid added. Excreta were collected for assessment of phosphorus (P) retention. At 20 and 21 d of age, starved birds were fed for 1 h, and thereafter crop and gizzard contents were collected every 20 min until 140 min after start of the feeding. At 60 and 140 min, the contents from the jejunum and ileum were collected. 4. All diets reduced the concentration of phytate in the crop, however the combination of acid and phytase resulted in a higher degradation (P < 0.05) than the other diets from 20 min after the start of feeding. Simultaneously, the concentration of the smaller inositol phosphate isomers, such as inositol-5-phosphate, increased (P < 0.05). Phytase increased (P < 0.05) P retention, and the combination of acid and phytase increased jejunal P digestibility (P < 0.05) compared to the other diets. 5. The results indicated that lower pH in the crop due to acid addition improved phytase efficacy and increased P digestibility in the anterior digestive tract, even with short retention times.

Lactobacillus reuteri-derived extracellular vesicles maintain intestinal immune homeostasis against lipopolysaccharide-induced inflammatory responses\xa0in\xa0broilers

BackgroundLactobacillus reuteri strains are widely used as probiotics to prevent and treat inflammatory bowel disease by modulating the host’s immune system. However, the underlying mechanisms by which they communicate with the host have not been clearly understood. Bacterial extracellular vesicles (EVs) have been considered as important mediators of host-pathogen interactions, but their potential role in commensals-host crosstalk has not been widely studied. Here, we investigated the regulatory actions of EVs produced by L. reuteri BBC3, a gut-associated commensal bacterium of Black-Bone chicken, in the development of lipopolysaccharide (LPS)-induced intestinal inflammation in a chicken model using both in vivo and in vitro experiments.ResultsL. reuteri BBC3 produced nano-scale membrane vesicles with the size range of 60–250 nm. Biochemical and proteomic analyses showed that L. reuteri BBC3-derived EVs (LrEVs) carried DNA, RNA and several bioactive proteins previously described as mediators of other probiotics’ beneficial effects such as glucosyltransferase, serine protease and elongation factor Tu. In vivo broiler experiments showed that administration of LrEVs exerted similar effects as L. reuteri BBC3 in attenuating LPS-induced inflammation by improving growth performance, reducing mortality and decreasing intestinal injury. LrEVs suppressed the LPS-induced expression of pro-inflammatory genes (TNF-α, IL-1β, IL-6, IL-17 and IL-8), and improved the expression of anti-inflammatory genes (IL-10 and TGF-β) in the jejunum. LrEVs could be internalized by chicken macrophages. In vitro pretreatment with LrEVs reduced the gene expression of TNF-α, IL-1β and IL-6 by suppressing the NF-κB activity, and enhanced the gene expression of IL-10 and TGF-β in LPS-activated chicken macrophages. Additionally, LrEVs could inhibit Th1- and Th17-mediated inflammatory responses and enhance the immunoregulatory cells-mediated immunosuppression in splenic lymphocytes of LPS-challenged chickens through the activation of macrophages. Finally, we revealed that the reduced content of both vesicular proteins and nucleic acids attenuated the suppression of LrEVs on LPS-induced inflammatory responses in ex vivo experiments, suggesting that they are essential for the LrEVs-mediated immunoregulation.ConclusionsWe revealed that LrEVs participated in maintaining intestinal immune homeostasis against LPS-induced inflammatory responses in a chicken model. Our findings provide mechanistic insight into how commensal and probiotic Lactobacillus species modulate the host’s immune system in pathogens-induced inflammation.

Effect of crop retention time and acidification of the feed on phytase efficacy in broiler chickens

ABSTRACT 1. An in vitro test to study the effect of pH reduction on phytic acid degradation over time for four commercial phytases was conducted. Changing the pH level affected phytate degradation over time differently for the various phytases (P < 0.05). 2. The phytase with the largest response of pH reduction in the in vitro test and a feed pH level of 4.5 was chosen for the broiler experiment. The effect of intermittent feeding, addition of 500 FYT C. braakii-derived phytase and 1% formic acid were tested in a 2 x 2 x 2 factorial arrangement. Ten pens containing 10 birds each were fed each of the treatment combinations from 15 to 36 d of age. Ad libitum fed birds had two 4-h dark periods with 2-h light in-between, while intermittently fed birds in addition had restricted access to the feed through except for four 1-h and one 2-h feeding bouts. 3. In addition to assessing performance, excreta were collected on a pen basis. The tibia and contents from jejunum and ileum were collected from one bird per pen. In addition, crop contents were collected from the intermittently fed birds 80, 160 and 240 min after the start of feeding. 4. Phytase improved performance, ileal and jejunal P digestibility, P retention and tibia ash and P concentration (P < 0.001). Intermittent feeding increased jejunal P digestibility and P retention (P < 0.001), but ileal P digestibility increased only in the intermittently fed birds compared to the ad libitum fed birds without phytase addition (P = 0.025). Acidification increased jejunal P digestibility only in the ad libitum fed birds (P = 0.019). There was a considerable inositol hexakisphosphate degradation into lower isomers in the crop after 80 min for diets with phytase (InsP3 and 4:P < 0.001), and acidification further increased this degradation (InsP4:P = 0.007). After 160 min retention time, the effect of phytase and acidification was even higher with more significant (P < 0.05) interactions. 5. The current data showed that prolonged retention time in the crop combined with feed acidification increased phytase efficacy by improving the phytate degradation.

POULTRY OFFAL MEAL AS A PROTEIN SUPPLEMENT FOR LAYING HENS AND FINISHER BROILERS

Two experiments were conducted to determine the value of poultry offal meal (POM) as a protein supplement for layers and finisher broilers, respectively, at dietary levels of O, 10, 15 and 20%. In the layer experiment, body weights of layers increased with increasing dietary levels of POM. Treatments effects on feed intakes were not significant but egg production as well as feed efficiency were significantly (P &lt; 0.05) improved by POM. In the broiler experiment, feed intake, growth rate, feed efficiency ad weights of livers were significantly (P &lt; 0.05) higher at 15 and 20% POM dietary levels. Abdominal fat became significantly (P &lt; 0.05) higher as from 10% POM dietary level. Poultry offal meal (POM), the processed edible and inedible parts of poultry (viscera, feathers, beaks, blood, discarded eggs and dead birds), used in this study contained (on dry matter basis) crude protein 56.4%, crude fat 20.9%, total ash 7.7%, crude fibre 4.6%, metabolizable energy 3.18kcal/gm.

Growth performance of starter broilers fed processed cocoyam (Xanthosoma sagittifolium) as energy source in place of maize

Considering the inherent attributes of cocoyam (Xanthosoma sagittifolium), its appropriate utilization for chicken diets may enhance performance of starter broilers. The study was therefore, carried out to determine the growth performance of starter broilers fed processed cocoyam tuber meal as energy source in place of maize. Xanthosoma cocoyam corms were harvested, cleaned of soil and chopped into bits of about 0.2 cm. The chopped tannia was soaked in water in a large vat for 24 hours to reduce the ant nutrients and later on separated from the water and dried with microwave oven. The dried cocoyam was milled and then used. The proximate chemical composition showed that soaked cocoyam tuber meal contained 8.05% moisture, 91.95% dry matter, 10.08% ash, 2.01% crude protein, 1.60% ether extract, 3.80% crude fibre, 74.46% NFE and 3158.92Kcal/kg DM metabolizable energy. In the starter broiler experiment, five experimental diets were formulated such that, diet 1 (control) contained yellow maize as the main energy source, while soaked CTM was used to replace maize at levels of 15%, 20%, 25% and 30% respectively in the control diet. Each starter diet was fed to a group of 30 broiler chicks for 4 weeks using completely randomized design. Each treatment was further grouped into 3 replicates of 10 birds each. The broiler chicks were kept in deep litter and given feed and water ad libitum. Parameters measured included initial body weight, final body weight, feed intake, feed conversion ratio and cost of production. In the starter feeding trial, the group on 30% soaked CTM (30% SCYM) compared favorably with the control group (P&lt;0.05) and recorded the highest body weight gain. It appeared that, the starter broilers could tolerate high levels of soaked CTM in their diets. Cost of production (cost of feed x feed conversion ratio) was lowest for diet 5 (30% SCYM) N248.15 as against N281.86 for control diet in the starter feeding trial. CTM meal can be used to replace maize at 30% in the diets of starter broilers without affecting weight gain, feed intake and feed conversion ratio as indicated in the study.

Effect of low-temperature drying on the nitrogenous compounds and inositol phosphates in broiler chickens and cecectomized laying hen excreta.

We investigated how the chemical composition of broiler chicken and cecectomized laying hen excreta is affected by drying in a forced-air drying chamber at low temperatures. Excreta that was immediately frozen after voiding provided the reference values. The excreta were dried in drying chambers for 4hr, 6hr, and 12hr at 23°C or 33°C in the broiler experiment and 19°C or 29°C in the cecectomized laying hen experiment. The total N and inositol phosphate concentrations in the excreta of broiler chickens and cecectomized laying hens were not influenced (p>.050), except for one inositol tetrakisphosphate isomer (p=.026) in broilers. Compared to fresh excreta, drying did not affect the ammonia concentrations in the cecectomized laying hen experiment (p>.050), but the ammonia concentration was lower when dried for 12hr at 33°C in the broiler experiment (p=.002). Amino acid concentrations in cecectomized laying hen excreta decreased until 4hr of drying and then increased at both drying temperatures (p<.001). The results indicate that the applicability of drying poultry excreta at low temperatures in forced-air drying chambers to determine the chemical compound concentrations is trait-dependent. Future studies are necessary to investigate whether these results are also dependent upon the amount of excreta stored in the drying chambers.

Bio-efficacy of organic selenium compounds in broiler chickens

This study is aimed at comparing the bio-efficacy of different inorganic and organic Se compounds. Three broiler experiments (Exp1 = Ross PM3; Exp2 = Ross 308; and Exp3 = Ross 308) were performed, on the basis of Se tissue accretion, to define the bio-efficacy of Se sources. Birds were fed a control diet (negative control [NC]; no supplemental Se) and, depending on the study, the NC was supplemented with sodium selenite (SS), Se-yeast (35%, 56%, 65% or 72% of Se as selenomethionine (SeMet); SY35, SY56, SY65 and SY72), pure forms of selenocysteine (SeCys) (methylselenocysteine [MSeCys]; L-selenocystine [L-SeCys]), or pure form of organic Se (L-selenomethionine, L-SeMet or hydroxy-selenomethionine, OH-SeMet) at 0.3 mg Se/kg. In Exp 2, an additional treatment of SY65 + L-SeCys was also fed, with both sources added at 0.3 mg Se/kg. In Exp3, L-SeMet and OH-SeMet, were supplemented at 0.15, 0.30, 0.45 and 0.60 mg Se/kg. The results of Exp 1 (mg Se/kg muscle DM) were: NC, 0.56; SS, 0.73; MSeCys, 0.68; L-SeCys, 0.70; SY65, 1.52; OH-SeMet, 1.85 (p < .001); Exp 2 were: NC, 0.34; SS, 0.52; SY35, 0.84; SY65, 1.18; SY65 + L-SeCys, 1.22; OH-SeMet: 1.33 (p < .001); Exp 3 were: NC, 0.10; SS, 0.31; SY56, 0.88; SY72, 1.03; L-SeMet, 1.33; OH-SeMet, 1.33 (p < .01). The results of these three studies demonstrate that the bio-efficacy of organic Se supplements for chickens depends upon the proportion of SeMet, while dietary SeCys sources showed similar bio-efficacy as SS. Moreover, these data showed the high bio-efficacy of the pure form of organic Se and the bioequivalence between L-SeMet and OH-SeMet. Highlights Updated knowledge on the bioavailability of different Se compounds in broiler. Direct L-selenomethionine and hydroxy-selenomethionine comparison.

Sentetik ve Ticari Etlik Piliç Genotiplerinin Bazı Ekonomik Parametreler ve Ebeveyn Performansları Bakımından Karşılaştırılması

Bu çalışmada, ticari ana ve baba ebeveyn hatlarından geliştirilen sentetik ebeveynler ile ticari ebeveynler karşılaştırılmıştır. Denemede ticari hat (TK) 8520 dişi, 1275 erkek civciv ve sentetik hat (SH) 8584 dişi ve 1275 erkek civciv olmak üzere toplam 19654 adet hayvan kullanılmıştır. Etlik piliç denemesi TK grubundan 1044 (3x348) adet, SH grubundan ise 1029 (3x343) adet, toplam 2073 adet karışık cinsiyette civciv ile yürütülmüştür. TK ve SH grubu dişi ebeveynleri 23 haftalık büyütme döneminde sırası ile hayvan başına 9,91 ve 9,87 kg yem tüketmiştir. Aynı sıra ile %6,5 ve %7,3 oranında ölüm ve ayıklama oranı, %87 ve %85 üniformite ve 23. hafta sonunda 2846 ve 2753g canlı ağırlık ile tamamlamışlardır. Erkekler aynı sırayla %9,5 ve %10,8 oranında ölüm ve ayıklama oranı ile 23. haftalık yaşa kadar 11,1 ve 11,3 kg yem tüketmişlerdir. Dişi ebeveynler TK ve SH grubunda %5 yumurta verimine sırasıyla 26 ve 25. haftalık yaşta; pik yumurta verimine ise 35 ve 32. haftalık yaşta ulaşmışlardır. Ebeveynler TK ve SH sırası ile 50 haftalık yaşta %5,7 ve %6,0 ölüm ve ayıklama oranı, %84,5 ve %83,8 pik yumurta verimi, 129,0 ve 128,0 adet yumurta verimi, 116,8 ve 118,5 adet kuluçkalık yumurta verimi, 62,5 ve 60,0 g ortalama kuluçkalık yumurta ağırlığı saptanmıştır. Aynı sıra ile kuluçka randımanları %82,1 ve %80,6 olarak tespit edilmiştir. TK ve SH ebeveynlerinden elde edilen 39,7 ve 37,7 g ağırlığındaki etlik civcivler, 4429 ve 4372g yem tüketerek 42. günde 2481 ve 2375g canlı ağırlığa ulaşmışlardır. Etlik piliç denemesinde yemden yararlanma oranları sırasıyla 1,79 ve 1,80 olarak tespit edilmiştir. Araştırmada, etlik piliç üretimi için ticari ana ve baba hatlarından elde edilen sentetik yeni hatların kullanılabileceği sonucuna varılmıştır.

Efficient Expression of Xylanase by Codon Optimization and Its Effects on the Growth Performance and Carcass Characteristics of Broiler.

Simple SummaryThe aim of this work was to combine xylanase expression and broiler production. The xylanase (XynB) gene from Trichoderma reesei was optimized to increase its expression level in Pichia pastoris. The maximum activity of xylanase (optiXynB) secreted by P. pastoris pPICZaA-optiXynB was 1299 U/mL after 96 h induction. The recombinase was highly specific towards birchwood xylan, beechwood xylan, and oat-spelt xylan. Dietary 1000 and 1500 IU/kg optiXynB significantly increased (p < 0.05) final weight and body weight gain; dietary 500, 1000, and 1500 IU/kg optiXynB significantly increased (p < 0.05) pre-evisceration weight, dressed percentage, and eviscerated weight compared with the control group. Results suggested that the optiXynB from P. pastoris pPICZaA-optiXynB has great application in broiler production.The aim of the present study was to improve the expression level of Trichoderma reesei xylanase (XynB) in Pichia pastoris through a codon optimization strategy and evaluate its effects on the growth performance and carcass characteristics of broiler. According to the codon bias of Pichia genome, the XynB gene from T. reesei was optimized and synthesized by whole gene assembly to improve its expression level in P. pastoris. Approximately 180 target mutations were successfully introduced into natural XynB. The maximum activity of xylanase (optiXynB) secreted by P. pastoris pPICZaA-optiXynB was 1299 U/mL after 96 h induction. Purified recombinant optiXynB had the molecular weight of 24 kDa. The optiXynB presented highest activity in pH 5.0 and 50 °C. The recombinase was highly specific towards birchwood xylan, beechwood xylan, and oat-spelt xylan. In the broiler experiment, a total of 200 Arbor Acre broilers (one day old) were randomly allocated into four groups fed with basal diets containing 0 (control group), 500, 1000, and 1500 IU/kg optiXynB. Dietary 1000 and 1500 IU/kg optiXynB significantly increased (p < 0.05) final weight and body weight gain; dietary 500, 1000, and 1500 IU/kg optiXynB significantly increased (p < 0.05) pre-evisceration weight, dressed percentage, and eviscerated weight compared with the control group. Inclusion of optiXynB in broiler diets linearly increased final weight, body weight gain, breast muscle weight and leg muscle weight, but linearly decreased feed conversion rate (p < 0.05). Furthermore, inclusion of optiXynB in broiler diets linearly and quadratically increased pre-evisceration weight, dressed percentage, and eviscerated weight (p < 0.05). The recombinant optiXynB from P. pastoris pPICZaA-optiXynB was beneficial in improving growth performance and carcass characteristics of broilers.

Nutritional evaluation of conventional and increased-protein, reduced-fiber canola meal fed to broiler chickens

Experiments were conducted to evaluate conventional canola meal (Conv CM) and a new increased-protein reduced-fiber CM (Test CM). The Test CM contained higher levels of all digestible amino acids than the Conv CM as determined in 2 precision-fed rooster assays wherein Single Comb White Leghorn roosters were fasted for 24 h and then tube-fed 30 g of Conv CM or Test CM. Excreta were then quantitatively collected for 48 hours. All diets in 2 broiler experiments then were formulated to be equal in AMEn and digestible amino acids based on values from precision-fed rooster assays. In Experiment 1, diets were corn and soybean meal based and contained zero, 10, 20, 30 or 40% Conv CM from 2 to 21 d of age and zero, 10, 20 or 30% Conv CM from 21 to 37 d of age. In the starter phase of Experiment 1 (2 to 21 d), there was a significant negative effect (P < 0.05) on weight gain and feed intake for CM levels in excess of 10%. In Experiment 2, both Conv CM and the new Test CM were evaluated. For the starter phase (2 to 19 d), the diets contained no CM or 8% Test CM or 8% Conv CM. For the grower phase (20 to 44 d), the chicks were fed diets that contained either no CM or 8, 16, or 24% of Test CM (Diets 2 to 4) or the same levels of Conv CM (Diets 5 to 7). The Test CM diets contained less soybean meal and less added fat than the Conv CM diets. There were no significant differences among dietary treatments for growth performance for either phase of Experiment 2. These results indicate that the new Test CM has increased levels of digestible amino acids compared to Conv CM and that up to 24% of either type of CM could be fed to broiler chickens during the grower phase with no statistical differences (P < 0.05) in performance when diets were formulated to be equal in AMEn and digestible amino acids.

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

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

Does the effect of pelleting depend on the wheat sample when fed to chickens?

Experimental comparisons of the nutritional value of different wheat cultivars commonly use feeds in meal form even though the large-scale broiler producers use steam pelleted feeds. The aim of this experiment was to examine the effect of steam pelleting on the performance, dietary N-corrected apparent metabolisable energy (AMEn), total tract dry matter retention (DMR), nitrogen retention (NR) and fat digestibility (FD) coefficients, and digestive tract development of broilers fed four different wheat samples in complete diets. Four European wheat samples, with different chemical composition and endosperm characteristics, were used in a broiler experiment. The wheat samples were milled through a 5 mm screen and four basal feeds containing 670 g/kg of each selected wheat sample were mixed. The basal feeds were then split into two batches and one of them was steam pelleted resulting in eight experimental diets. Each diet was fed ad libitum to eight pens of two male Ross 308 broilers from 10 to 24 days of age. Feeding pelleted diets improved (P<0.001) feed intake and weight gain, and daily water intake of the birds. Pelleting also improved dietary AMEn and FD (P<0.001) and DMR (P<0.05). An interaction (P<0.05) was observed between wheat samples and steam pelleting for NR. Steam pelleting improved (P<0.05) NR in the wheat sample with high starch and protein and hard endosperm but not in the rest of the wheat samples. Similar interactions (P<0.05) were also observed between wheat sample and steam pelleting for gain to feed (G : F) and water to feed (W : F) ratios. Pelleting improved G : F ratio the greatest in the wheat sample with high starch and protein and hard endosperm. Feeding the same wheat sample also decreased (P<0.05) W : F but only in the mash diets. Regardless of the wheat sample the values of dietary AMEn did not differ (P>0.05). Feeding different wheat types and pelleting did not (P>0.05) change the development of the gastrointestinal tract of the birds. The study showed that there were differences between four wheat samples when they were fed in pelleted complete feed, but no differences were observed when fed in mash form complete diets. Research on the interaction between pelleting and wheat chemical and quality characteristics is warranted.

PRODUCTIVE PERFORMANCE AND BLOOD PLASMA CONSTITUENTS OF BROILER CHICKS FED DIETS SUPPLEMENTED WITH SOME NATURAL FEED ADDITIVES

A grower broiler experiment (from 1 to 5 weeks of age) was conducted to study the impact of various commercial feed additives on performance and economical efficiency of broiler chicks. These additives included commercial premixture of flavouring substance (Biostrong® 510), commercial enzyme preparation (Nutrikem dry® and symbiotic (Bio-gen®). A number of 120 Hubbard broiler chicks (1 week of age) were divided into 4 treatment groups (3 replicates of 10 chicks, each). Groups were assigned to 4 experimental diets: a basal diet of no additive (control), the basal diet supplemented with either 150 g/ ton Biostrong (T1), 500g/ton Nutrikem dry (T2) or 500 g/ton Bio-gen (T3).The results indicated that:1- Supplementation of Biostrong or Nutrikem recorded insignificant higher body weight gain by (8 and 3%, respectively) than the control or Bio-gen groups.2- Supplementation of Bio-gen recorded significant (P<0.05) higher feed intake and worst feed conversion (1.81) than those fed other dietary treatments, but numerically Biostrong and Nutrikem treatments (T1 and T2) represented the best feed conversion (being the same figure 1.54 g) compared with that fed control diet (1.65).3- Carcass characteristics parameters (dressing, giblets and abdominal fat %) and carcass parts % (breast, thigh, drumstick and wing %) showed insignificant figures when chicks fed different dietary treatments.4- Bone measurements (wet tibia weight and tibia width) showed insignificant figures, however tibia length and tibia Seedor index have significant differences for dietary treatments.5- Biostrong (T1) and symbiotic (T3) significantly improved the total protein, and globulin values compared with T2 group. However the T3 treatment and control have the best A/G ratio.6- Enzyme treatment (Nutrikem, T2) decreased plasma triglycerides cholesterol and LDL concentrations compared with other treatments (T1 and T3).7- Concerning economic evaluation, the best economical efficiency value was demonstrated when broiler chicks fed 150 g/ton Biostrong (T1) and the value was 21% more when compared with that of broiler chicks fed control diet.It could be concluded that supplementation basal diets with 150 g/ton Biostrong improved productive performance and enhanced economic efficiency of Hubbard broiler chicks.

Effect of broiler breeder feeding programme and feeder space change at photostimulation using maize- or wheat-based diets on broiler progeny growth performance and leg health

1. The aim of this study was to evaluate the effects of diet type, maternal feeding programme at 29 weeks of age and breeder feeder space change at photostimulation on broiler progeny performance and leg health at 6 weeks of age.2. Fast-feathering Cobb 500 broiler breeders were fed on either maize- or wheat-based diets that had been formulated to have similar nutrient composition during growing and layer phases. Two feeding programmes, fast or flow, were used from 14 to 29 weeks of age. At 22 weeks, 69 females from each pen were placed in a layer house where feeder space was either similar to that in rearing (6.3 to 6.5 cm/female) or was increased from 6.3 to 8.4 cm/female. Eggs produced at 32 and 44 weeks of age were collected and incubated for two broiler experiments. A total of 16 male and 16 female one-d-old chicks were placed in floor pens in two experiments, respectively, with 6 and 4 replicate pens. Broiler gait scores and leg problem prevalence were evaluated at 6 weeks of age.3. Data were analysed as a 2 × 2 × 2 factorial design with diet type, feeding programme and feeder space change as main factors.4. The wheat diet increased the probability of observing crooked toes in broiler progeny compared to the use of maize, but only when breeders were fed according to the fast feeding programme and given similar feeder space as during rearing.5. Breeders given more feeder space in the laying period produced progeny with more locomotion problems compared with those provided similar feeder space, but only when maize was used and the slow feeding programme was applied to the breeders.6. The maternal feeding programme interacted with other factors to influence progeny leg health, but it did not solely influence walking ability or leg problems of progeny.7. In conclusion, an increased probability of observing walking impairment of broiler progeny was detected when breeders were given greater feeder space at photostimulation rather than no change and fed according to the slow feeding programme using maize diets in breeders and progeny.