Poultry Science Journal
Volume:12 Issue: 2, Summer -Autumn 2024

The gut serves in the digestion of foods, the absorption of nutrients, and the maintenance of the host's health. Intestinal flora maintains a healthy gut by interacting with intestinal cells and inhibiting pathogens from adhering to the gut wall. Probiotics are widely used to regulate intestinal microflora, prevent and treat intestinal disorders,, and promote growth by replacing antibiotics in poultry. The current paper focuses on the effects of probiotics on gut health in general and stress factors that affect probiotic survivability from handling to the host animal's distal intestinal tract. We also go through the various ways of dealing with these stressful factors and methods adopted for industrial use. The use of encapsulation to preserve probiotics has been proven to be effective. The encapsulation strategy directly benefits stability by providing a physical barrier to safeguard them from unfavorable environments. Probiotics have been encapsulated using a variety of approaches. Here, we also discuss the effects of encapsulation on probiotic stability during different stages from processing to animal gut. Choosing the appropriate encapsulating process and encapsulating material during is crucial for producing the best microcapsule as an additive for animal feed, which ultimately improves the animal's intestinal health.

This study aimed to estimate the growth parameters of Muscovy ducks. The superiority of the study offers insightful information on the Muscovy duck growth curve, makes quantitative comparisons easier, allows for predictive capacities, and quickly finds problems. A total of 40 Muscovy ducks called “Rambon” were used in the study, consisting of 12 males and 28 females. Body weight was weighed periodically every two days from the day-old ducks (DOD) until 60 days of age. The data was analyzed by using Gompertz and Logistic models. The growth curves were analyzed, and parameters such as adult body weight (A), integral constant (B), and growth rate (K) were determined. Inflection points were also identified. Body weight (Wi) and age at the inflection (Ai) point using Gompertz were 1060.95 g and 46.34 d; 613.41 g and 30.52 d; 712.56 g and 36.81 d, respectively for males, females, and the unsexed. By using Logistic model, the Wi and Ai for males were 934.60 g and 41.46 d, females were 670.52 g and 32.96 d, and unsexed were 739.11 g and 36.56 d. Results showed that the Gompertz model generally outperformed the Logistic model, with lower AIC, BIC, MSE values and slightly higher R2 for all sex groups, indicating superior fit and predictive accuracy. These findings offer valuable insights into Rambon Muscovy duck growth dynamics, aiding in breeding and production strategies to enhance economic efficiency and sustainability. Farmers can utilize these models to optimize feeding schedules and make informed decisions about slaughtering, ultimately improving Muscovy duck production.

The aim of the current study was to estimate the genetic and environmental parameters for weekly egg weights using a random regression model in wild and white Japanese quails. The base population included 300 wild and white Japanese quails, with a mating ratio of 1:2 (one male with two females). Four mating groups including pure and cross-breeding methods, were considered to produce the next generation. Eggs were collected and numbered based on their sire and dam. At the fifth week of age, 508 female quails were transferred to the laying cages. The data on egg weight was recorded from the seventh to fifteenth week of age. Nine random regression models were analyzed to determine the best orders of Legendre polynomials. The model with first and second-order Legendre polynomials for additive genetic and permanent environmental effects, respectively, indicated the lowest AIC value and was chosen as the appropriate model. The heritability estimates and the ratios of the permanent environment to the phenotypic variance of weekly egg weights ranged from 0.09 to 0.35 and from 0.08 to 0.51, respectively. The effect of permanent environmental factors on the average weight of laid eggs decreased with increasing laying weeks, followed by an increase in the additive genetic effect on the occurrence of this trait. The estimates of genetic and phenotypic correlations between weekly egg weights varied from 0.59 to 0.98 and from 0.21 to 0.51, respectively. As a result, because of higher heritability estimates for later ages, selection to improve weekly egg weight is better performed based on at least the fifth week of the laying period onward. In conclusion, due to high positive genetic correlations among weekly egg weights, the selection basis of each weekly part record can lead to improving the consecutive weekly egg weights.

A total of 210 one-day-old male Ross 308 broilers were used to investigate the effect of butyric acids glycerides (BAG) and eugenol (EU) on growth performance, intestinal morphology, blood metabolites and bacteriological examination in broilers under necrotic enteritis challenge. Dietary treatments consisted of 2 supplemental BAG levels (0 and 0.2%) and 3 EU levels (0, 500, and 1000 ppm) in a 2×3 factorial arrangement with five replicates and six birds in each group. The treatment groups were as follows: 1) basal diet, negative control group (NC); 2) basal diet + C. perfringens, positive control group (PC); 3) PC + 0.2% butyric acid glycerides (BAG); 4) PC + 500 ppm of eugenol (EU500); 5) PC + 1000 ppm of eugenol (EU1000); 6) PC + 500 ppm of eugenol +0.2% butyric acid glycerides (EU500+BAG); 7) PC + 1000 ppm of eugenol +0.2% butyric acid glycerides (EU1000+BAG). The addition of EU1000 and EU1000+BAG in the diet of challenged chickens increased the body weight compared to the PC group (P < 0.05). Also, adding EU at 500 or 1000 ppm + 0.2% BAG in the diet significantly increased the digestibility of dry matter and organic matter of challenged birds compared to the NC and PC control groups. The lowest cholesterol was observed for the challenged groups that supplemented EU1000+BAG compared to NC and PC controls. Supplementation in the diet with high or low-level EU and 0.2% BAG increased the carcass weight compared to the PC group (P < 0.05). The Thymus, spleen, and bursa of Fabricius weight in the PC group decreased compared to the NC birds (P < 0.05). Counts of the Lactobacillus subgroup were not affected by treatments, but C. perfringens in NC birds was higher compared to the PC group (P < 0.05). Generally, our results showed that adding 1000 ppm EU+0.2% BAG effectively controlled experimental Eimeria and C. perfringens coinfection.

A dose-response experiment with seven dietary energy levels (2500, 2650, 2800, 2950, 3100, 3250 and 3400 kcal of MEn/Kg) was implemented to study the effects of dietary energy level on growth performance and carcass characteristics of Japanese quails from 2 to 5 weeks of age. Three hundred and thirty-six 14-day-old Japanese quails were randomly divided into 7 dietary treatments, containing six replicates with eight males and females per each, and the birds were grown up to 5 weeks of age. At 35 d of age, weight gain, feed intake and feed conversion ratio (FCR) of quails from each pen were measured or calculated, and one quail (male one) that had similar body weight to the average of the replication weight was selected and slaughtered to evaluate the yields of carcass parts. The results showed that with an increase in dietary MEn levels feed intake, crude protein intake, FCR  and crude protein intake:gain (g/g) of quails decreased significantly (P < 0.05). The highest and the lowest dietary MEn levels resulted in a decrease in body weight gain and metabolizable energy intake (kcal/b). The highest rate of weight gain belonged to moderate dietary energy levels (2800 and 2950 kcal/kg). The results of the experiment revealed that metabolizable energy intake to weight gain, as well as some carcass characteristics such as edible carcass, thighs and breast percentages and giblets (liver, heart and gizzard percentages), were not affected by different dietary energy levels. With increasing dietary energy from 2500 to 2950 kcal MEn/Kg, the weight gain of quail increased and above 2950 kcal/Kg decreased significantly (p=0.0058). Based on broken line regression analysis, between two and four weeks of age, the metabolizable energy requirement of growing quails was 2831 and 2799 Kcal/kg for optimal weight gain and FCR, respectively, when protein level in the diet was 24 percent.

A total of 200 day-old COBB-500 chicks were randomly allocated into four dietary treatments with five replications and ten birds per replicate for 28 days to select the most effective forms of plantain herb for broiler performance and meat quality. The control diet (CL-D) and different forms of plantain diets were based on corn-soybean meal that was iso-caloric and iso-nitrogenous. The different forms of plantain diets were fresh plantain-diet (FP-D): CL-D + fresh-plantain, shade-dried plantain-diet (SP-D): CL-D + shade-dried plantain powder, and blanched-dried plantain-diet (BP-D): CL-D + blanched-dried plantain powder. Plantain herb was given at a 1.0% dry matter basis. Daily feed consumption and weekly body weight were noted, whereas blood samples were taken and a meat panel test was confirmed by specialists in meat on day 28. Birds given the different forms of plantain diets revealed a 6-10% greater body weight gain compared to the CL-D (P < 0.05). Plantain diets in different forms showed a 3–6% better feed, crude protein, and metabolizable energy conversion ratio compared to the CL-D (P < 0.05), but no difference was observed between BP-D and SP-D (P > 0.05). Compared to the CL-D, birds fed the different forms of plantain diets reduced serum triglyceride and total cholesterol by 4–11% and 6–9%, respectively (P < 0.05). Birds that were fed the different forms of plantain diets had a lower meat ether extract and a greater meat saturation index (redness) than the CL-D (P < 0.05). Compared to the CL-D, birds fed the redifferent forms of plantain diets showed better meat juiciness, tenderness, and acceptance (P < 0.05). Therefore, fresh plantain demonstrated superior broiler performance and improved meat quality,  whereas both blanched-dried and shade-dried plantain powder might be considered for inclusion in feed formulations to enhance broiler performance and meat quality.

This study aimed to explore the impact of incorporating hemp seed oil (Cannabis sativa L.) at 1.5% and 3% levels in broiler diets on broiler performance, carcass yield, weights of some internal organs, and some blood parameters. In total, 132 day-old broiler chicks (Ross 308) were utilized, with the control group (C) receiving a basal diet without supplementation. Experimental groups included 1.5% hemp seed oil (HOA) and 3% hemp seed oil (HOB) added to the basal diet. The 42-day experiment concluded with the total average live weight (LW) for control, HOA, and HOB groups reaching 2637.90, 2647.81, and 2665.68 g, respectively. Average live weight gains (LWG) were 2595.03, 2605.16, and 2622.54 g; average feed intake (FI) amounted to 4044.25, 3880.78, and 3900.36 g, and feed conversion ratio  (FCR) values were 1.56, 1.50, and 1.49, respectively. While LW, LWG, and FI values did not differ significantly between groups (P > 0.05), the addition of hemp seed oil notably improved FCR (P < 0.05). Relative carcass rates and weights of carcass, heart, pancreas, and spleen were similar across groups (P > 0.05). However, liver weight was lowest in the HOA group, and the bursa of Fabricius weight was lowest in the C group (P < 0.05). No statistical differences were observed in serum glucose, albumin, triglyceride, and total cholesterol parameters among groups (P > 0.05). Total protein, HDL-c, non-HDL-c, LDL-c, TAC, and TOC values were significantly influenced by hemp seed oil (P < 0.05). In conclusion, the data suggest that adding up to 3% hemp seed oil to broiler diets can have notable effects on feed conversion ratio and serum biochemical parameters, offering critical health benefits, particularly in improving serum lipid profiles. However, the antioxidant properties of hemp seed oil were found to be weak.

This study aimed to compare the efficacy of probiotic (Pro), curcumin (Cur), and sodium bentonite (SB) to alleviate the toxic effects of aflatoxin B1 (AFB1) on performance, egg quality, intestinal morphology, gut microbiota, and hepatic gene expression in laying Japanese quails. A total of 420 37-day-old laying quails were randomly allocated into 7 treatment groups, with 6 replicates, each of 10 quails for 7 weeks. The treatments were: 1) Control, 2) Control + AFB1 (100 μg/kg), 3) Control + AFB1 + Pro (0.5 g/kg), 4) Control + AFB1 + Cur (100 mg/kg), 5) Control + AFB1 + SB (3 g/kg), 6) Control + AFB1 + Pro (0.5 g/kg) + Cur (100 mg/kg), 7) Control + AFB1 + Pro (0.5 g/kg) + SB (3 g/kg). The addition of dietary supplements, especially the combination of Pro + Cur or SB, ameliorated the adverse effects of AFB1-contaminated diets on egg production, egg weight, and feed conversion ratio (FCR). The dietary inclusion of supplements resulted in higher shell thickness and shell weight compared to the control + AFB1 group (P < 0.05). Villus height, villus height: crypt depth and villus surface area of the jejunum were increased by dietary inclusion of Pro, Cur, and SB in contaminated diets. However, the effects on these parameters were more pronounced in birds that received a combined of Pro + Cur (P < 0.05). The combined supplementation of Pro + Cur or SB in AFB1-contaminated diets synergistically increased the lactic acid bacteria (LAB) in the ileum and reduced the coliform and C. perfringens counts in the ileum and cecum, respectively (P < 0.05). Serum hepatic indices were improved by Pro, Cur, and SB, but a further increase in antioxidant enzymes and reduction in AST and MDA were observed by combination of Pro + Cur (P < 0.05). Increased expression of AHR1 and CYP1A1 genes due to AFB1 was alleviated by supplements. However, there was a synergistic effect of Pro + Cur in the down-regulation of these genes. Overall, these results showed that although dietary Pro, Cur, and SB may ameliorate the toxicity of AFB1, the synergistic effects of Pro + Cur or SB may further mitigate the AFB1-induced toxicity.

In ovo injection of camel lactoferrin (cLF36) as an antimicrobial peptide was applied in Ross 308 fertile eggs and tested in 320 post-hatched chickens challenged with Clostridium perfringens (Cp). In 8 treatments and five replicates of 8 birds each, performance, jejunum morphometry and ileal microbial counts of chickens were assayed. Feed intake and feed conversion ratio of the chickens affected by treatments. Together with the positive control group under the Cp (10 8 cfu/g) challenge and the negative control group under the antibiotic (AB) challenge, the highest villi length was observed. The highest crypt depth was related to the treatment with the Cp challenge and the lowest value was related to the in ovo injection of cLF36 group and combined Cp and AB challenges. The number of Clostridium spp. in the ileal contents increased in the chickens challenged with Cp (P < 0.05). The greatest change was observed in the treatment with injection of cLF36 during the embryonic period and challenge with Cp and the lowest value was related to negative control treatment. In addition, the difference between treatments with cLF36 in ovo injection during the embryonic period and challenge with or without Cp challenge was significantly increased. In the groups under the Cp challenge, the population of E. coli was numerically increased. Based on the obtained results, cLF36, derived from camel milk, could change some of the indices in performance. It caused morphological changes in the villi of ilium and caused a decrease the microbial counts of Clostridium spp., similar to the AB group in the chickens challenged with Cp. Our research attempts to create a new window for in ovo administration of cLF36, according to its beneficial effects in the present study, can be introduced as a candidate for growth-promoting antibiotics.

Heat stress has adverse effects on the health and performance of broilers. This study was conducted to investigate the protective effects of black seed (BS) supplementation on broilers subjected to heat stress (HS). A total of 500 (day-old) Ross-308 male broiler chicks were randomly assigned into five groups with five replicated pens (20 broilers per pen): thermoneutral (TN), heat stress (HS), and HS with a diet supplemented with three different levels of black seed (Nigella sativa) powder (BSP (at rates of 5g/kg (BSP-5), 10 g/kg (BSP-10), and 15 g/kg (BSP-15. Exposure to HS reduced feed intake, and weight gain and elevated feed conversion ratio (FCR), mortality (P < 0.05). Also, low antioxidant enzyme activity (such as glutathione peroxidase, superoxide dismutase, and catalase) and high malondialdehyde levels in serum, liver, and spleen were observed in the birds of the heat stress group compared to the TN treatment (P < 0.05). Moreover, HS elevated interleukin-6 and tumor necrosis factor-α and lowered interleukin-10 levels in serum, liver, and spleen (P < 0.05). In addition, heat stress causes an increase in ALT, AST, ALP, triglycerides, and cholesterol levels compared to the TV group (P < 0.05). Compared with the HS group, broilers in the BSP-10 group had a higher body weight gain, a lower feed conversion ratio, and mortality (P < 0.05). Broilers in the BSP-10 and BSP-10 groups showed higher levels of antioxidant enzyme activities and lower malondialdehyde in serum, liver, and spleen compared to the HS group. BSP supplementation at 10 and 15 mg/kg reduced TNF-α and interleukin-6 levels and enhanced interleukin-10 in serum, liver, and spleen compared to the HS group. Additionally, BSP supplementation at 15 mg/kg reduced the effect of the heat stress on ALT, AST, ALP, triglycerides, and cholesterol compared to the HS group. Obtained results showed that BSP in diet during heat stress may have a role in the reduction of the changes exerted by heat stress in broiler chickens.

A factorial experiment with a completely randomized design was carried out to examine the effects of reducing dietary crude protein (CP) and incorporating threonine, arginine, valine, isoleucine, and tryptophan synthetic amino acids supplements (SAA) on broiler chickens. The experiment involved 180 Ross 308 broilers divided into six treatments with six replicates each. The experimental treatments were as follows: 1- Standard diet, 2- Standard diet + SAA, 3- Diet with 2% reduced CP, 4- Diet with 2% reduced CP + SAA, 5- Diet with 4% reduced CP, and 6- Diet with 4% reduced CP + SAA. The 4% CP reduction diet decreased body weight gain in the starter and finisher periods (P < 0.05). The 4% lower CP also decreased feed intake in the grower, finisher and whole of the experiment (P < 0.05), and the same effect was observed for the 2% reduced CP diet only in the grower and entire experiment (P < 0.05). The same negative effects of lower dietary CP were also found for feed conversion ratio (FCR) (P < 0.05). The SAA supplements improved weight gain in the starter and the whole experimental period (P < 0.05). Feed intake did not show any change following SAA incorporation; however, SAA had a significant positive effect on FCR (P < 0.05). The only significant effect of experimental factors on small intestine morphology was a higher villus thickness in birds fed 2% less CP compared to the control (P < 0.05). The lower dietary CP led to increased serum cholesterol, triglyceride and HDL-c concentrations (P < 0.05). The serum total protein and albumen in the group fed 2% less CP was higher than the two other groups (P < 0.05). The only effect of SAA was an increased serum HDL level (P < 0.05). The results suggest that SAA supplementation could compensate for the negative effects of 2% but not the 4% lower dietary CP.

This experiment was conducted to determine total amino acid (AA) content and standardized ileal digestible (SID) amino acid content of 6 different origins of fish meal (FM) and subsequently determine equations that estimate total and SID amino acid contents from chemical composition as well as SID amino acid contents from its total AA. In order to conduct this study, a total of 210 one-day-old male broiler chicks were randomly assigned to 7 dietary treatments consisting of 6 semi-purified diets containing each of FM as the only source of dietary protein (200 mg of crude protein/g diet) and one nitrogen-free diet in order to determine ileal endogenous amino acids (IEAA) flow. Birds were allowed ad libitum access to a corn-soybean meal starter diet until ten days, a grower diet from 11 to 23 days, and then experimental diets from 24 to 28 days of age. The total content of Lys and Met among the various samples significantly differed from 1.52 to 2 and 0.59 to 0.77%, respectively (P < 0.05). This difference was observed among the other total and SID amino acids. In this study the accuracy and precision of the models were tested by the adjusted coefficient of determination (R2) value, P-value regression coefficients, and standard error of prediction (SEP). The SEP of the developed regression equations for the predicting SID amino acids of FM were from 0.009 (for Met) to 0.056 (for Arg).