Ways to minimize bacterial infections, with special reference to Escherichia coli, to cope with the first-week mortality in chicks: an updated overview

On the commercial level, the poultry industry strives to find new techniques to combat bird's infection. During the first week, mortality rate increases in birds because of several bacterial infections of about ten bacterial species, especially colisepticemia. This affects the flock production, uniformity, and suitability for slaughter because of chronic infections. Escherichia coli (E. coli) causes various disease syndromes in poultry, including yolk sac infection (omphalitis), respiratory tract infection, and septicemia. The E. coli infections in the neonatal poultry are being characterized by septicemia. The acute septicemia may cause death, while the subacute form could be characterized through pericarditis, airsacculitis, and perihepatitis. Many E. coli isolates are commonly isolated from commercial broiler chickens as serogroups O₁, O₂, and O₇₈. Although prophylactic antibiotics were used to control mortality associated with bacterial infections of neonatal poultry in the past, the commercial poultry industry is searching for alternatives. This is because of the consumer's demand for reduced antibiotic-resistant bacteria. Despite the vast and rapid development in vaccine technologies against common chicken infectious diseases, no antibiotic alternatives are commercially available to prevent bacterial infections of neonatal chicks. Recent research confirmed the utility of probiotics to improve the health of neonatal poultry. However, probiotics were not efficacious to minimize death and clinical signs associated with neonatal chicks' bacterial infections. This review focuses on the causes of the increased mortality in broiler chicks during the first week of age and the methods used to minimize death.

Potential of Spirulina platensis as a feed supplement for poultry to enhance growth performance and immune modulation

Increase in drug resistance as well as ineffective immunization efforts against various pathogens (viruses, bacteria and fungi) pose a significant threat to the poultry industry. Spirulina is one of the most widely used natural ingredients which is becoming popular as a nutritional supplement in humans, animals, poultry and aquaculture. It contains protein, vitamins, minerals, fatty acids, pigments, and essential amino acids. Moreover, it also has considerable quantities of unique natural antioxidants including polyphenols, carotenoids, and phycocyanin. Dietary supplementation of Spirulina can beneficially affect gut microbial population, serum biochemical parameters, and growth performance of chicken. Additionally, it contains polyphenolic contents having antibacterial effects. Spirulina extracts might inhibit bacterial motility, invasion, biofilm formation, and quorum sensing in addition to acting directly on the bacterium by weakening and making the bacterial cell walls more porous, subsequently resulting in cytoplasmic content leakage. Additionally, Spirulina has shown antiviral activities against certain common human or animal viruses and this capability can be considered to exhibit potential benefits against avian viruses also. Spirulan, a calcium-rich internal polysaccharide of Spirulina, is potentially responsible for its antiviral effect through inhibiting the entry of several viruses into the host cells, boosting the production of nitric oxide in macrophages, and stimulating the generation of cytokines. Comparatively a greater emphasis has been given to the immune modulatory effects of Spirulina as a feed additive in chicken which might boost disease resistance and improve survival and growth rates, particularly under stress conditions. This manuscript reviews biological activities and immune-stimulating properties of Spirulina and its potential use as a dietary supplement in poultry to enhance growth, gut health and disease resistance.

Quantitative estimates of the optimal balance between digestible lysine and the true protein contents of broiler feeds

Typical poultry feed formulation models have been developed for meeting the minimum specifications of the essential amino acids (EAAs), ignoring the importance of providing precise levels of the non-essential amino acids (NEAAs) that are required for maximum performance. Including true protein (TP) values in these models in relation to EAAs can most accurately account for the requirements of all amino acids (AAs) in the ration (essential, non-essential and excess EAAs). Data from recent research reports on the digestible lysine (dLys) requirements for maximum weight gain and minimum feed conversion ratio (FCR) were compiled from the literature. dLys requirements and the TP contents of the feeds were recalculated based on common ingredient composition values. Broken-line linear (BLL) and broken-line quadratic (BLQ) models were fitted to the data and compared. The dLys requirements of broilers (g/kg diet) for body weight gain (BWG) and FCR were found to increase linearly as a function of the true and crude protein contents of the diet. These relationships were not affected by either age or sex. As chickens aged, the dLys requirements decreased. However, the dLys requirement to TP ratio did not change with age for BWG or FCR. For maximum BWG and minimum FCR, the dLys requirements were estimated from the prediction models to be 4.92% ± 0.51 and 5.58% ± 0.70 of the TP level of the diet, using the BLL models, respectively. The good linear relationship between the dLys requirement and TP level allows the prediction of the variables from each other for use in feed formulation to represent the requirements of both EAAs and NEAAs. The dietary dLys requirements were estimated to be lower using the BLL vs. the BLQ models. TP was a better predictor of dLys requirements than crude protein (higher R(2) values).

Estimation of the maximum safe level of feed ingredients by spline or broken-line nonlinear regression models

The use of non-linear regression models in the analysis of biological data has led to advances in poultry nutrition. Spline or broken-line nonlinear regression models are commonly used to estimate nutritional requirements. One particular application of broken-line models is estimating the maximum safe level (MSL) of feed ingredients beyond which the ingredients become toxic, resulting in reduced performance. The objectives of this study were to evaluate the effectiveness of broken-line models (broken-line linear or BLL; and broken-line quadratic or BLQ) in estimating the MSL; to identify the most efficient design of feeding trials by finding the optimal number of ingredient levels and replications; and to re-estimate the MSL of various test ingredients reported in the nutrition literature for comparison purposes. The Maximum Ingredient level Optimization Workbook (MIOW) was developed to simulate a series of experiments and estimate the MSL and the corresponding descriptive statistics (SD, SE, CI, and R2). The results showed that the broken-line models provided good estimates of the MSL (small SE and high R2) with the BLL model producing higher MSL values as compared to the BLQ model. Increasing the number of experimental replications or ingredient levels (independently of each other) reduced the SE of the MSL with diminishing returns. The SE of the MSL was reduced with increasing the size (total pens) of the simulated experiments by increasing either the number of replications or levels or both. The evaluation of MSLs reported in the existing literature revealed that the multiple range procedure used to determine the MSL in several reports can both overestimate and underestimate the MSL compared to the results obtained by the broken-line models. The results suggest that the broken-line linear models can be used in lieu of the multiple range test to estimate the MSL of feed ingredients along with the corresponding descriptive statistics, such as the SE of the MSL.

Nutritive value and the maximum inclusion level of pennycress meal for broiler chickens

Two experiments were conducted to evaluate the nutritive value and maximum safe level (MSL) of pennycress meal (PM) for broiler chicks. In experiment 1, a total of 480 chicks was fed either mash or crumbled diets containing zero, 5, 10, or 15% PM for 18 d (8 diets; 6 replications per diet). In experiment 2, a total of 660 chicks was fed mash diets containing zero, 3, 6, 9, 12, or 15% of either PM or canola meal (CM; a comparative reference) for 14 d (11 diets; 6 replications per diet). Analytical results show that PM is a good source of protein (∼31% CP) and it is very comparable to CM (∼36% CP). However, it contains higher erucic acid (∼1.68 vs. < 0.021%), glucosinolates (sinigrin) (∼63.5 vs. <0.163 μmol /g), and crude fiber (18.60 vs. 9.27%) compared to CM. In experiment 1, increasing PM from zero to 15% resulted in linear reductions (P < 0.05) in FI, BWG, and FCR at 10 days. Above 10%, performance responses were affected for FI and BWG at 18 d, respectively. An estimated MSL of 10% PM based on orthogonal contrast was optimal for satisfactory FI and BWG. The MSL as estimated by broken-line linear (BLL) and broken-line quadratic (BLQ) models was 9.12 ± 0.50 and 7.0 ± 1.27%, respectively. In experiment 2, growth performance at 14 d was reduced above 9% due to PM inclusion. CM inclusion did not affect growth performance at 14 d, suggesting 15% to be safe. The MSL for maximum growth performance varied depending on the statistical analysis as follows: 12% by orthogonal contrast and LSD, 15% by the Scheffé test, 10.84 ± 0.57 by BLL, and 8.61 ± 1.29 by BLQ. In conclusion, PM can be included in broiler starter diets as a protein source but its inclusion should be limited to no more than 8.5%. Different statistical procedures give different MSL and this should be considered when interpreting the data.

Origanum vulgare Essential Oil Modulates the AFB1-Induced Oxidative Damages, Nephropathy, and Altered Inflammatory Responses in Growing Rabbits

The current study was performed to investigate the toxic effects of aflatoxin B1 (AFB1) through the evaluation of kidney function tests and histopathological examination of renal tissues, targeting the therapeutic role of Marjoram (Origanum vulgare essential oil-OEO) in improving health status. Forty-eight New Zealand Whites growing rabbits (four weeks old) weighing on average 660.5 ± 2.33 g were randomly and equally distributed into four groups, each of which had four replicas of three animals as the following: Control group (only basal diet), AFB1 group (0.3 mg AFB1/kg diet), OEO group (1 g OEO/kg diet) and co-exposed group (1 g OEO/kg + 0.3 mg AF/kg diet). Our study lasted eight weeks and was completed at 12 weeks of age. The results revealed that OEO decreased the toxic effects of AFB1 in rabbit kidneys by substantially reducing the cystatin C levels in the AFB1 group. Additionally, OEO decreased oxidative stress and lipid peroxidation levels in the co-exposed group. Moreover, OEO reduced DNA damage and inflammatory response in addition to the down-regulation of stress and inflammatory cytokines-encoding genes. Besides, OEO preserved the cytoarchitecture of rabbits' kidneys treated with AFB1. In conclusion, O. vulgare essential oil supplementation ameliorated the deleterious effects of AFB1 on the rabbits' kidneys by raising antioxidant levels, decreasing inflammation, and reversing oxidative DNA damage.

Antrodia cinnamomea polysaccharide improves liver antioxidant, anti-inflammatory capacity, and cecal flora structure of slow-growing broiler breeds challenged with lipopolysaccharide

Lipopolysaccharides (LPS) induces liver inflammatory response by activating the TLR4/NF-κB signaling pathway. Antrodia cinnamomea polysaccharide (ACP) is a medicinal mushroom that can protect from intoxication, liver injury, and inflammation. Nevertheless, the effect of ACP on the liver antioxidant, anti-inflammatory capacity and cecal flora structure of LPS-challenged broilers remains unclear. The aim of this experiment was to investigate the effects of ACP on the anti-oxidative and anti-inflammatory capacities of the liver, and cecal microbiota in slow-growing broilers stimulated by LPS. A total of 750 slow-growing broilers (9-day-old) were assigned to five treatments with 6 replicates of 25 chicks per replicate: a control diet, the chicks were fed a control diet and challenged with LPS. Dietary treatments 3 to 5 were the control diet supplemented with 100, 200, 400 mg/kg ACP challenged with LPS, respectively. The groups of 100 mg/kg ACP supplementation significantly increased liver index, pancreas index, and bursa of Fabricius index (P < 0.05). The GSH-Px content of LPS-challenged broilers was lower than that of the control group (P < 0.001), but the content of MDA increased (P < 0.001). Feeding with 100 mg/kg ACP resulted in increased the activity of T-AOC, GSH-Px, and T-SOD, and decreased MDA content (P < 0.05). The activity of TNF-α, IL-1β, and IL-6 of the LPS group increased, but these indicators were decreased with supplemental 100 mg/kg ACP (P < 0.05). Dietary application of ACP up to 100 mg/kg down-regulated (P < 0.05) the expression of TLR4/NF-κB pathway in the liver induced by LPS. The results of 16S rRNA demonstrated that feeding with 100 mg/kg ACP can change the diversity and composition of the gut microbiota, and restrained the decline of beneficial cecal microbiota (typically Lactobacillus, Faecalibacterium, and Christensenellaceae R-7 group) in the challenged LPS group (P < 0.05). Conclusively, feeding a diet with 100 mg/kg ACP may have beneficial effects on liver damage and the bacterial microbiota diversity and composition in the ceca of LPS-stressed slow-growing broiler breeds, probably because of its combined favorable effects on antioxidants and cytokines contents, and restoration the decline of beneficial cecal microbiota.

Effects of Betaine Supplementation on Live Performance, Selected Blood Parameters, and Expression of Water Channel and Stress-Related mRNA Transcripts of Delayed Placement Broiler Chicks

This study examined the effect of supplemental betaine on live performance, selected blood parameters, and gene expression of water channel proteins (Aquaporins, AQP) of broiler chicks delayed in placement for 48 h post-hatch. In total, 540 newly-hatched male broiler chicks were obtained from a local hatchery and were randomly allotted to one of five treatments with nine replicates per treatment (12 chicks per replicate). Chicks were either placed immediately, control; held for 48 h post-hatch with no access to feed or water, Holdnull; held for 48 h with free access to drinking water only, HoldW; held for 48 h with free access to drinking water supplemented with 1 ml per L of betaine solution (40% betaine), HoldB1; or held for 48 h with free access to drinking water supplemented with 2 ml per L of betaine solution (40% betaine), HoldB2 group. The results showed that post-hatch holding for 48 h depressed feed intake and body weight gain during the entire 15 d study period with no beneficial effect of supplemental betaine. Chicks in the HoldB2 group had elevated serum glucose, triglycerides, and aspartate aminotransferase 48 h post-hatch. Early water deprivation directly affected the brain proopiomelanocortin (POMC) and hepatic glucocorticoid receptors (GR) expression and induced significant changes in various aquaporins (AQP1, AQP2, AQP4, and AQP9). In conclusion, betaine supplementation to chicks held for 48 h post-hatch resulted in some changes in blood biochemical indices with no effects on performance during the first 15 days of life. The results suggest that betaine supplementation could ameliorate the stressful effects of water deprivation on POMC and GR expression and maintain cellular osmosis through interactions with variable aquaporins expression, particularly the AQP1 and AQP2. Further investigations are required to investigate the molecular mechanisms underlying the selective regulatory expression of different aquaporins in relation to betaine supplementation.

Interactive effects of dietary amino acid density and environmental temperature on growth performance and expression of selected amino acid transporters, water channels, and stress-related transcripts

Exposure to heat stress (HS) is one of the challenges facing the broiler industry worldwide. Various nutritional strategies have been suggested, such as altering dietary concentrations of some nutrients. Thus, we evaluated feeding different amino acid (AA) densities on live performance, Pectoralis (P.) muscles, and expression of selected AA transporters, water channels, and stress-related transcripts in a fast-growing broiler strain. Ross 308 chicks (n = 576) were randomly assigned to 4 dietary treatments (24 reps, 6 chicks per rep), differing in AA density (110, 100, 90, and 80% of a breeder's AA specifications). During 24 to 36 days of age, half of the birds were kept at a thermoneutral (TN) temperature of 20°C, whereas the other half were subjected to HS at 32° C for 8 h daily, making the treatment design a 4 × 2. The results revealed no interaction between housing temperature and AA density on growth performance or P. muscles weights. Feeding 80% AAs depressed BWG, FCR, and P. muscles at 36 d (P < 0.001). There was an interaction (P < 0.001) between AA density and temperature on the expression of all examined genes. Reducing the AA density beyond 100% upregulated the expression of AA transporter (CAT1, B⁰AT, b^0,+AT, SNAT1, LAT1), HSP70, HSP90, glucocorticoid receptor (GR), and AQP3 in the TN birds’ jejunum. Whereas in the HS birds, inconsistent expressions were observed in the jejunum, of which CAT1, B⁰AT, and LAT1 were markedly downregulated as AA density was reduced. In P. major of TN birds, reducing AA density resulted in upregulating the expression of all AA transporters, HSP70, GR, and AQP1, while downregulating HSP90 and AQP9. In contrast, AA reduction markedly downregulated CAT1, B⁰AT, and LAT1 in the P. major of HS birds. These findings indicate that the dietary AA level alters the expression of various genes involved in AA uptake, protein folding, and water transport. The magnitude of alteration is also dependent on the housing temperature. Furthermore, the results highlight the importance of adequate AA nutrition for fast-growing chickens under HS.

Effects of protected complex of bio-factors and antioxidants on growth performance, serum biochemistry, meat quality, and intestinal antioxidant and immunomodulatory-related gene expressions of broiler chickens

One-day-old male broiler chickens (Ross 308) were assigned to 3 dietary treatments in a completely randomized design with 8 replicates per treatment, and 4 birds per replicate. The control group was fed a basal control diet, and the 2 test groups were fed the basal control diet supplemented with 150 and 300 mg/kg of protected complex of biofactors and antioxidants [P(BF+AOX)], respectively. The P(BF+AOx) is a combination of vitamins, L-tryptophan and biofactors such as fermentation extracts (Jefo Nutrition Inc., Saint-Hyacinthe, QC, Canada). Dietary P(BF+AOX) did not affect growth performance and breast meat quality (water holding capacity, cooking loss, shear force, and texture profile analysis), but the addition of 150 mg/kg of P(BF+AOX) decreased the relative weight of liver, heart, and spleen (P < 0.05). The addition of 150 mg/kg of P(BF+AOX) tended to increase (P = 0.051) the cold carcass yield. The addition of 150 and 300 mg/kg of P(BF+AOX) decreased (P = 0.002) the cooler carcass shrink, but the relative weight of fat pad increased (P = 0.032) in chickens fed 300 mg/kg P(BF+AOx) than in those of birds fed the control diet. On the other hand, the addition of 300 mg/kg of P(BF+AOX) decreased (P = 0.041) the serum level of uric acid compared with those of birds fed the basal diet. Broiler chickens fed diets supplemented with 150 mg/kg of diet had higher (P < 0.05) mRNA expressions of jejunal SOD1 and interleukins 6 and 10 (IL-6, IL-10). The findings suggest that P(BF+AOX) could be considered as a functional nutrient in broiler diets up to a concentration of 150 mg/kg because of its favorable effects on maintaining intestinal barrier function as well as carcass traits, while excess levels (300 mg/kg) had exhibited superior effect on the serum level of uric acid compared with those of birds fed the control diet.

Comparison of formulation costs for poultry feeds based on crude protein versus the digestible lysine to protein ratio

Abstract The objective of this study was to determine the influence of using dLys:TP instead of crude protein recommendations of commercial poultry breeding companies to meet the chicken’s need for dietary essential and non-essential amino acids. The ingredient composition matrix used in the feed formulation was compiled from Feedstuffs Magazine. The rations were formulated using a linear feed formulation program to meet the minimum cost, with crude protein or dLys: TP of 5.58%. Using the dLys to TP ratio versus CP minimums for the model diets chosen, formula costs were changed from +$10.96 to -$4.26 per ton of feed. The magnitude of the changes was dependent on the imbalance present in the feeds from using the breeder management guide recommendations and ingredient prices. Through the use of dLys: TP, it is possible to improve the feed formulation process, assuring the birds get adequate EAA and NEAA without being wasteful and reducing environmental pollution.

Effects of adding nano-emulsified plant oil and probiotics to drinking water during different periods besides sex on processing characteristics, physicochemical properties, and meat quality traits of broiler chickens

Introduction

High-quality meat is one of the consumer demands. Therefore, several studies have concluded that supplementing broilers with natural additives can improve meat quality. This study was carried out to evaluate the effects of nano-emulsified plant oil (Magic oil^®) and probiotic (Albovit^®) as water additives (at the rate of 1 ml/L and 0.1 g/L, respectively) during different growing periods on processing characteristics, physicochemical properties, and meat quality traits of broilers chickens.

Methods

A total number of 432-day-old Ross broiler chicks were randomly assigned to one of six treatment groups according to the growing periods in which magic oil and probiotics were added to drinking water, each with nine replicates and eight birds per replicate (4♂ and 4♀). On day 35, birds' processing characteristics, physicochemical properties, and meat quality traits were examined.

Results and discussion

The results showed that treatments had a significant (P < 0.001) impact on cooking loss, cohesiveness, and chewiness. The male broiler chickens had higher (P ≤ 0.05) initial lightness, initial whiteness index, water holding capacity, shear force, live weight, hot and chilled carcass weights, as well as lower gizzard and neck percentages than females. The interactions between treatments and sex showed a significant (P < 0.001) impact on cooking loss, shear force, hardness, springiness, and chewiness. In conclusion, supplementing male broiler chickens with Magic oil and probiotic, particularly from 0-30 days of age had favorable meat chewiness as a result of lower cohesiveness and hardness higher springiness, and the most convenient cooking loss value. Magic oil and probiotic, especially in males, is advisable to be supplemented in water of growing broilers chicken programs from 0 to 30 days of age. Moreover, further studies under commercial conditions are recommended to locate the most favorable combination of Magic oil/probiotic supplements for the best processing characteristics and meat quality attributes outcomes.

Effect of gum Arabic as natural prebiotic on intestinal ecosystem of post-hatched broiler chicks

The purpose of the current study was to investigate the effects of gum Arabic supplementation on short-chain fatty acids, cecal microbiota, immune-related gene expression, and small intestinal morphology in post-hatched broiler chicks. On the day of hatching, four hundred thirty-two commercial male broiler chicks were randomly allocated into six treatments with twelve cages as replicates of six chicks each for 24 days. Dietary treatments (T1 to T6) were supplemented with 0.0, 0.12, 0.25, 0.50, 0.75, and 1.0% gum Arabic to the basal diet, respectively. Performance parameters, short-chain fatty acid concentration, quantification of microbiota and immune response gene expression (pre-inflammatory cytokines, mucin-2, and secretory immunoglobulin A), and histomorphometry of the small intestine were measured. According to our results, daily weight gains in T2 and the production efficiency index increased in T2 to T4, whereas daily feed intake decreased in T2, T3, T5, and T6, but feed conversion ratio improved. Concentration of lactate, acetate, butyrate, and total short-chain fatty acid increased in T2, T3, T5, and T6. Propionate ‎in T2 T3, T4, and T6 and format in T2, T5, and T6 also increased. Lactobacillus spp. quantitatively increased from T3 to T6, whereas Bacteroides spp. decreased in T3 and T5. Other microbiota quantitatively showed no effect of dietary supplements. IL-1β, TNF-α, and MUC-2 decreased in T2 to T6 and IL-12 in T3, whereas INF-Y increased in T4 to T6 and SIgA in T4. All histometeric parameters of the duodenum, jejunum, and ileum improved with dietary supplementation. We conclude that the administration of gum Arabic resulted in an improvement in overall performance, fermentation metabolites, and modification of microbiota and immune response with improved histomorphometry in the intestines of young chicks.

Does slaughter age affect amino acids and fatty acids profiles and health and nutritional values of male and female ROSS 308 broiler chicken breast muscle?

Chemical composition, amino acids (AAs), and fatty acid (FAs) profiles, and health and nutrition values of breast muscle of ROSS 308 broiler chickens were studied after being slaughtered at 28, 35, 42, and 49 d of age (n = 126 males and 126 females/slaughter age). The slaughter age significantly affected some AAs levels including glutamic acid, valine, isoleucine, histidine, and leucine, and some FAs level including capric acid, tetradecanoic acid, eicosanoic acid, total saturated fatty acids, 9-pentadecenoic acid, hexadecatetraenoic acid, α-linolenic acid, stearidonic acid, linoleic acid, dihomo-γ-linolenic acid, arachidonic acid, adrenic acid, omega 6, sum polyunsaturated fatty acids (Ʃ PUFAs), and unsaturation index. Subsequently, the slaughter age significantly affected some health indexes including the n-6/n-3 ratio, thrombogenic index, hypocholesterolemic/hypercholesterolemic ratio, and health-promoting index. Valine, leucine, isoleucine, histidine, and glutamic acid levels increased with increasing slaughter age until 35 d of age and then decreased with increasing slaughter age until 49 d of age. Moreover, the health indices of fatty acids were best at slaughter age of 35 d, followed by 49 d, and the lowest health-promoting indices were at 42 d, followed by 28 d. The sex did not affect (P ˃ 0.05) all the evaluating parameters including chemical composition, amino acid and fatty acid profiles, and related health indices. There was no significant interaction effect between sex and slaughter age in all evaluating parameters except in stearidonic acid level. In conclusion, amino acids and fatty acids profiles and health and nutritional values of male and female ROSS 308 broiler chicken breast muscle can be affected by slaughter age. The study provides valuable insights into the nutritional value of meat, including its composition, amino acid, and fatty acid profiles, and associated health indices, for both male and female fast-growing ROSS 308 broiler chickens, as the slaughter age increases.