Weight Gain Of Broilers Research Articles

The Impacts of Vegetables and Fruits by Products on Growth and Health of Broiler Chickens

Agro-industrial by-products, which are not intended for human consumption, can serve as substitutes for traditional animal feed ingredients in animal nutrition. This can result in the production of animal products without causing competition for land or exacerbating the food versus feed dilemma, ultimately promoting environmental and economic sustainability. Utilizing co-products as animal feed has the potential to reduce feeding costs while enhancing the productive parameters, quality, animal welfare and sustainability of animal products. Numerous studies have indicated that fruits and vegetables are considered as significant sources of bioactive compounds. The extensive process of industrialization leads to the creation of considerable amounts of by-products, giving rise to grave ecological concerns. Hence, such a scenario necessitates the formulation of innovative approaches for effectively utilizing the resultant wastes, ensuring the potential to fabricate novel products with enhanced value. The generated by-products, reveal similar or higher antioxidant activity. It is recognized that these secondary products comprise various bioactive substances and may have the ability to serve as nutraceuticals for poultry, promoting their health and overall wellness. This review aims to summarize the exploitation of fruit wastes, namely, apple, citrus, banana, mango, pineapple and grape as well as vegetable by-products which are derived from tomato and olive cultivation. These byproducts can be in supplementation or substitution format. Some of these byproducts presented the following results: The addition of 2% dried sweet orange pulp to the diet significantly increased feed intake and total weight gain in broilers and the inclusion of dried orange pulp in broiler diets was found to reduce serum triglycerides and cholesterol. Also, the including of 10% apple peel in the diet led to an increase in the weight of the gizzard and small intestine in chickens. Additionally, diets containing 5% and 10% apple peel waste resulted in higher levels of lipids and HDL (high-density lipoprotein) in the blood serum, while LDL (low-density lipoprotein) and malondialdehyde levels decreased. Moreover, the including of 10% banana peel in poultry feed led to improved feed efficiency, feed conversion and the quality of poultry eggs and meat. However, the inclusion of olive cake with phytase to broiler chickens’ diet presented an increase of growth parameters increased. The incorporation of 10% of OC with phytase also resulted a reduction in plasma cholesterol and triglycerides and an increase in plasma inorganic phosphorus.

Research Note: Xylooligosaccharide directly attenuates Salmonella Typhimurium colonization and its induction of impairments in intestinal barrier and growth performance of broilers

Xylooligosaccharide (XOS) is known as a prebiotic, however, it is unknown whether XOS can directly protect against bacterial infection. This study aimed to investigate the direct inhibitory effects of XOS on Salmonella Typhimurium colonization and the inductive impairments in gut health and growth performance in broilers. We first probed the inhibitory effects of XOS on S. Typhimurium adhesion and its induction of intestinal epithelial cell (IPEC-J2) injuries. Afterward, 168 one-day-old yellow-feathered broilers were randomly divided into 3 groups (7 replicates/group): negative control (NC, received a basal diet), positive control (PC, received a basal diet with S. Typhimurium challenge) and XOS group (PC birds+1,500 mg/kg XOS). All birds except those in NC were orally challenged with S. Typhimurium from 8 to 10 d of age. Parameters were analyzed on d 11. The results showed that XOS inhibited S. Typhimurium adhesion and the inductive injuries of IPEC-J2 cells by lowering (P < 0.05) certain adhesion-related genes expression of this bacterium. It also alleviated S. Typhimurium-induced increase (P < 0.05) in the expression of certain inflammatory cytokines and tight junction (TJ) proteins of IPEC-J2 cells. Supplementing XOS to S. Typhimurium-challenged broilers attenuated the elevations (P < 0.05) in S. Typhimurium colonization of ileal mucosa and its translocation to the liver and spleen, as well as increased (P < 0.05) certain TJ proteins expression of ileum. Besides, XOS addition normalized S. Typhimurium-induced impairments (P < 0.05) in ileal morphology, final body weight and average daily gain in broilers. Collectively, supplemental XOS directly suppressed intestinal colonization of S. Typhimurium by diminishing its adhesiveness and subsequently mitigated destructions in intestinal barriers, thus contributing to weaken growth retardation in challenged broilers. Our findings provide a new insight into the mechanisms of XOS limiting Salmonella infection in chickens.

Saving and productivity of broiler chickens for feeding an optimal dose of zinc proteinate

On the basis of conducted scientific research, it was set that the use of inorganic salts of trace elements in animal and poultry feed leads to environmental pollution with heavy metals due to their low biological availability for the animal organism. Therefore, in recent years, a number of investigations have been conducted to study the effectiveness of using organic trace elements in animal and poultry feed. The article deals with the results of a scientific and economic experiment on the investigation of the influence of domestically produced zinc proteinate in combination with zinc sulfate on indicators of preservation, growth intensity and feed conversion in broiler chickens. Broiler chickens of the control group were fed with a complete ration balanced in terms of necessary nutrients, in accordance with the age periods of the growth of the poultry, with the addition of 50 g per ton of zinc sulfate. Then, the broiler chickens of the research groups were received the same compound feed, but with the addition of 50 g and 30 g per ton of zinc proteinate compound feed. The live weight of broiler chickens of the research groups was significantly higher than the control. At the age of one week, it tended to increase in the chickens of the 2nd and 3rd research groups, and at the age of 14, 21, 28, 35 and 42 days, the live weight of the chickens of the 3rd research group exceeded the live weight of the poultry of the control group, respectively , by 15.8 g (Р &lt; 0.05); 37.0 (P &lt; 0.01); 96.8 (P &lt; 0.05); 115.9 (P &lt; 0.01) and 177.7 g (P &lt; 0.05), or by 4.7 %, 4.6, 7.6, 6.5 and 7.1 %, while the chickens of the 2nd research group at this time exceeded the control group chickens in terms of live weight, but were slightly behind the peers of the 3rd research group. The researched doses of zinc proteinate contributed to the increase in the preservation of poultry stock by 4–5 %, the average daily weight gain of broilers in the research groups compared to the control, respectively, by 5.1–7.2 %. The European index of efficiency of broiler chickens growing for zinc proteinate feeding was increased by 48.4 and 76.7 units compared to the control group which were fed with zinc sulfate and at the same time feed costs per 1 kg of growth was decreased by 2.4–3.2 %.

Сравнительная оценка эффективности кормовых добавок на основе торфосапропелевого концентрата при выращивании бройлеров

Abstract. Modern conditions for the development of poultry farming increase the impact of technological stress on the poultry body, which contributes to the development of immunodeficiency conditions in them. Against the background of immunodeficiency, diseases of various etiologies develop, which reduces the efficiency of the industry. To offset the negative result of technological and other types of stress, the search for effective means of domestic production is carried out, which is especially important in the conditions of priority use of alternative import-substituting means. The search for effective means that meet all the requirements of prevention remains to this day an urgent issue of practical veterinary medicine. Feed additives with a wide spectrum of action act as such agents. Often such feed additives act as adaptogens. In this regard, the purpose of this study was to compare the effectiveness of feed additives prepared on the basis of peat sapropel concentrate mixed with known mineral and probiotic components. The objectives of the study were: to evaluate the effectiveness of disease prevention; causes of morbidity and mortality; livestock safety and improving the quality of fattening. Methods. To assess the effectiveness of the tested domestic feed additives, clinical, pathomorphological, histological studies were carried out in accordance with the zoohygenic conditions of poultry keeping and statistical methods for evaluating the results obtained. As a result of the conducted studies on the preventive feeding of feed additives based on peat sapropel concentrate of domestic production, their immuno- and organoprotective effect was revealed. Scientific novelty. For the first time, a comparative assessment of various feed additives based on peat-sapropel concentrate for the prevention of stress, various diseases, livestock safety and live weight gain of broilers at macro- and microscopic levels was carried out.

The effect of micronutrient supplementation on bioavailability, antioxidants activity, and weight gain in response to Infectious Bursal Disease vaccination in commercial broilers

The effect of supplementing organic selenium and zinc on bioavailability, oxidative stress, weight gain in commercial broilers was studied. A total of 180-day-old chicks were divided into six groups: NSUV (Not supplemented, unvaccinated), NSV (Not supplemented, vaccinated), VS (vaccinated, supplemented selenium), VZ (vaccinated supplemented zinc), VSZ (vaccinated supplemented selenium and zinc), UVSZ (unvaccinated supplemented selenium and zinc). 1 mg/kg selenium and 60 mg/kg zinc were added to the feed of supplemented groups. The concentration of selenium (0.05 ± 0.00 mg/L) in VS and zinc (0.66 ± 0.13 mg/L) in VZ were lower on day 27 post-vaccination compared to day 10 (VS= 0.07 ± 0.01 mg/L; VZ= 1.46 ± 0.30 mg/L). Glutathione peroxidase and catalase concentrations were highest in the supplemented groups compared to unsupplemented groups on day 27 post vaccination, expressing a similar trend with the micronutrients. There was no difference (P ≥ 0.05) in the glutathione concentration between all groups except on day 27 post vaccination where SZV group was significantly higher (P=0.02) compared to the NSV group. Catalase concentration was significantly decreased in the NSV group compared to SZV (P=0.04) on day 27 post vaccination. The NSV group (1.64 ± 0.13 kg) weighed significantly lower (P=0.02) than the VSZ (2.00 ± 0.12 kg) in the fifth week, while on the sixth week, the SZV group gained the highest weight (2.04 ± 0.18 kg). The supplementation of organic selenium and zinc in broilers increased the serum micronutrients bioavailability, decreased oxidative stress, increased weight gain, thus, enhancing immunity in the broilers.

Effects of Dietary Supplemental Chlorogenic Acid and Baicalin on the Growth Performance and Immunity of Broilers Challenged with Lipopolysaccharide.

The objective of this study was to investigate the effects of dietary supplemental chlorogenic acid and baicalin (CAB) on the growth performance and immunity of broilers challenged with lipopolysaccharide (LPS). This study was designed as a factorial arrangement of 2 dietary CAB treatments × 2 LPS treatments. Birds challenged with or without LPS were fed with a basic diet (CON) and (LPS), the level of CAB diet containing 500 mg/kg CAB(CAB) and (CAB + LPS). The feeding trial lasted for 42 days. Results showed that there was a negative effect on average daily weight gain (ADG) and average body weight of broilers during the animal trial with LPS challenge. The levels of diamine oxidase (DAO), lysozyme (LYZ), immunoglobulin G (IgG), and IgA in the serum, the contents of IL-1β and TNF-α in the spleen were elevated with LPS treated. Additionally, LPS treatment tended to reduce the jejunal villi height (VH) and total superoxide dismutase (T-SOD) in the serum. Dietary supplemental 500 mg/kg CAB increased the body weight and ADG and improved the feed conversion ratio (FCR) during the trial period. In addition, dietary 500 mg/kg CAB elevated the ratio of VH to crypt depth in the jejunum and reduced the content of protein carbonyl. Beyond that, the levels of IgG and IgA in the serum and transforming growth factor (TGF-β) in the spleen were up-regulated with 500 mg/kg CAB supplementation. In conclusion, dietary CAB was beneficial for growth performance and immunity of broilers challenged with lipopolysaccharide.

Effects of lactic acid bacteria isolated from Tibetan chickens on the growth performance and gut microbiota of broiler.

Lactic acid bacteria (LAB) are organic supplements that have several advantages for the health of the host. Tibetan chickens are an ancient breed, which evolve unique gut microbiota due to their adaptation to the hypoxic environment of high altitude. However, knowledge of LAB isolated from Tibetan chickens is very limited. Thus, the purpose of this study was to assess the probiotic properties of Lactobacillus Plantarum (LP1), Weissella criteria (WT1), and Pediococcus pentosaceus (PT2) isolated from Tibetan chickens and investigate their effects on growth performance, immunoregulation and intestinal microbiome in broiler chickens. Growth performance, serum biochemical analysis, real-time PCR, and 16S rRNA sequencing were performed to study the probiotic effects of LP1, WT1, and PT2 in broiler chickens. Results showed that LP1, WT1 and PT2 were excellent inhibitors against Escherichia coli (E. coli ATCC25922), meanwhile, LP1, WT1, and PT2 significantly increased weekly weight gain, villus height, antioxidant ability and gut microbiota diversity indexes in broilers. In addition, LP1 and PT2 increased the relative abundance of Lactobacillus and decreased Desulfovibrio in comparison with T1 (control group). Additionally, oral LAB can reduce cholesterol and regulate the expression of tight junction genes in broiler chickens, suggesting that LAB can improve the integrity of the cecal barrier and immune response. In conclusion, LAB improved the growth performance, gut barrier health, intestinal flora balance and immune protection of broiler chickens. Our findings revealed the uniqueness of LAB isolated from Tibetan chickens and its potential as a probiotic additive in poultry field.

Beneficial Effects of Bacillus amyloliquefaciens D1 Soy Milk Supplementation on Serum Biochemical Indexes and Intestinal Health of Bearded Chickens.

This study investigated the effects of dietary supplementation with Bacillus amyloliquefaciens D1 (B. amyloliquefaciens D1) on growth performance, serum anti-inflammatory cytokines, and intestinal microbiota composition and diversity in bearded chickens. To investigate the effects of Bacillus amyloliquefaciensa and fermented soy milk, 7-day-old broilers were orally fed different doses of Bacillus amyloliquefaciens D1 fermented soy milk for 35 days, with the unfermented soy milk group as the Placebo group. This study found that B. amyloliquefaciens D1 fermented soy milk improved the intestinal microbiota of broilers, significantly increasing the abundance of beneficial bacteria and decreasing the abundance of harmful bacteria in the gut. B. amyloliquefaciens D1 fermented soy milk also significantly reduced the serum lipopolysaccharide (LPS) content. The body weight and daily weight gain of broilers were increased. In conclusion, the results of this study are promising and indicate that supplementing the diets of bearded chickens with B. amyloliquefaciens D1 fermented soy milk has many beneficial effects in terms of maintaining intestinal microbiota balance and reducing inflammation in chickens.

Physiological condition, gut morphology and immune responses of broilers supplemented with Moringa oleifera leaf extract, whey protein or their combination

To improve growth performance and health, the broiler industry has recently incorporated plant sources and dairy milk byproducts as feed additives. The aim of this study was to investigate the effect of dietary supplementation of Moringa oleifera leaf extract (MOLE) and whey protein concentrate (WPC) or their combination on production performance, physiological status, gut integrity and immune responses of broilers. A total of 364 day old broiler chicks were used and assigned according to a com-pletely randomized design with four dietary treatments, including CONT (basal feed as control), MOLE (basal feed + 1% MOLE), WPC (basal feed + 1% WPC), and MOLE-WPC (basal feed + 0.5% MOLE + 0.5% WPC). Daily weight gain and daily feed intake of broilers were higher in WPC and CONT groups (P&lt;0.05) compared to MOLE group. The low-density lipoprotein (LDL) were lower in CONT and WPC (P&lt;0.05) than in MOLE and MOLE-WPC groups. The serum glutamic oxaloacetic transaminase (SGOT) were lower in MOLE group (P&lt;0.05) than in MOLE-WPC. In comparison to the CONT and WPC groups, the villi height and ratio of villi to crypt depth in the duodenum were more favorable in the MOLE and MOLE-WPC groups. The lactose negative enterobacteria have a lower number (P&lt;0.05) in MOLE group. Histologically, the jejunum, ileum, and spleen were in better condi-tion in the MOLE and MOLE-WPC groups (P&lt;0.05) than in the other groups. In conclusion, supple-menting MOLE, WPC or their combination improved the gut integrity and immune organ, but had no appreciable impact on production performance and physiological status in broilers.

Lipopolysaccharide-induced immune stress negatively regulates broiler chicken growth via the COX-2-PGE2-EP4 signaling pathway.

Immune stress in broiler chickens is characterized by the development of persistent pro-inflammatory responses that contribute to degradation of production performance. However, the underlying mechanisms that cause growth inhibition of broilers with immune stress are not well defined. A total of 252 1-day-old Arbor Acres(AA) broilers were randomly allocated to three groups with six replicates per group and 14 broilers per replicate. The three groups comprised a saline control group, an Lipopolysaccharide (LPS) (immune stress) group, and an LPS and celecoxib group corresponding to an immune stress group treated with a selective COX-2 inhibitor. Birds in LPS group and saline group were intraperitoneally injected with the same amount of LPS or saline from 14d of age for 3 consecutive days. And birds in the LPS and celecoxib group were given a single intraperitoneal injection of celecoxib 15 min prior to LPS injection at 14 d of age. The feed intake and body weight gain of broilers were suppressed in response to immune stress induced by LPS which is an intrinsic component of the outer membrane of Gram-negative bacteria. Cyclooxygenase-2 (COX-2), a key enzyme that mediates prostaglandin synthesis, was up-regulated through MAPK-NF-κB pathways in activated microglia cells in broilers exposed to LPS. Subsequently, the binding of prostaglandin E2 (PGE2) to the EP4 receptor maintained the activation of microglia and promoted the secretion of cytokines interleukin-1β and interleukin-8, and chemokines CX3CL1 and CCL4. In addition, the expression of appetite suppressor proopiomelanocortin protein was increased and the levels of growth hormone-releasing hormone were reduced in the hypothalamus. These effects resulted in decreased expression of insulin-like growth factor in the serum of stressed broilers. In contrast, inhibition of COX-2 normalized pro-inflammatory cytokine levels and promoted the expression of Neuropeptide Y and growth hormone-releasing hormone in the hypothalamus which improved the growth performance of stressed broilers. Transcriptomic analysis of the hypothalamus of stressed broilers showed that inhibition of COX-2 activity significantly down-regulated the expression of the TLR1B, IRF7, LY96, MAP3K8, CX3CL1, and CCL4 genes in the MAPK-NF-κB signaling pathway. This study provides new evidence that immune stress mediates growth suppression in broilers by activating the COX-2-PGE2-EP4 signaling axis. Moreover, growth inhibition is reversed by inhibiting the activity of COX-2 under stressed conditions. These observations suggest new approaches for promoting the health of broiler chickens reared in intensive conditions.

Dietary threonine and lysophospholipid supplement in broiler chickens: effect on productive performance, carcass variables, cecal microbiota activity, and jejunal morphology.

The objective of this experiment was to investigate the efficacy of lysophospholipid (LPL) in combination with different levels of threonine (Thr) on productive performance, jejunal morphometric variables, cecal microbial population, and carcass characteristics of male broiler chickens. Four hundred 1-day-old male broiler chicks were distributed into eight experimental groups with five replicates, each of ten birds. Factors were two levels of 0 or 0.1% Lipidol as LPL supplement and four inclusion amount of Thr (100, 105, 110, or 115% of requirements) in the diets. During 1 to 35days, inclusion of LPL supplementation in diets improved the body weight gain (BWG) and feed conversion ratio (FCR) of broilers (P < 0.05). Besides, FCR was significantly greater in the birds fed with 100% Thr compared to the other inclusion rates of Thr (P < 0.05). The jejuna villus length (VL) and crypt depth (CD) were greater in the birds fed with LPL-supplemented diets (P < 0.05) while the greatest VH/CD and villus surface was observed in the birds fed with 105% of dietary Thr (P < 0.05). In cecal microbiota composition, Lactobacillus population was lower in broilers which received diet containing 100% Thr compared to the other group receiving more than 100% Thr (P < 0.05). In conclusion, inclusion of LPL supplements and amounts greater than Thr requirement in diet improved productive performance and jejunal morphology of male broiler chickens.

EFFICIENCY OF FEED ADDITIVE APPLICATION BASED ON BACTERIA OF THE GENUS BACILLUS

The article highlights the results of using a feed additive based on spore-forming bacteria of the genus Bacillus when growing broiler chickens. The addition of the studied additive to the diet of chickens in the first group at a dose of 0.5 and to the second group at a dose of 1 g/kg of feed increased the intensity of the bird's growth. In particular, the average daily weight gain of broilers in the experimental groups was, respectively, 11 and 11.8% higher than in the control group.&#x0D; At the same time, the yield of gutted broiler carcasses in the first and second experimental groups was higher, compared to the control group, by 245 and 275 g, respectively. Under these conditions, in the first experimental group with an average body weight of 2411.1 g, feed consumption during the experimental period was 4310 g/head, while feed conversion was 1.78. In the second experimental group with an average body weight of 2426.9 g, the feed consumption was 4253.3 g/head and the conversion was 1.75, while in the control group with an average body weight of 2178.4 g, the feed consumption was 4433.3 g/head, and the feed conversion was 2.03.&#x0D; When identifying microorganisms of the Enterobacteriaceae family, in the first research group were found: Escheriсhia coli, Escheriсhia fergusonii, Escheriсhia hermannii, Escheriсhia vulneris, Serratia odorifera; in the second experimental group: Escheriсhia coli, Escheriсhia fergusonii, Serratia odorifera, Kluyvera spp.; and in the control group: Escheriсhia terioteria enorita, Serratia oderofera cloacea, Shigella spp. Microorganisms of the genus Salmonella, and also Campilobacter and C. perfringens on day 42 in broilers of all groups were not detected.&#x0D; Therefore, the use of a feed additive based on spore-forming bacteria of the genus Bacillus leads to a decrease in feed conversion, an increase in the body weight of birds, and an increase in total and average daily weight gain, compared to the control group. Also was found the positive effect of feed additives on the qualitative and quantitative composition of the intestinal microflora, while the microflora of the bird is corrected in the direction of an increase in the normal flora and a decrease in pathogenic and conditionally pathogenic microflora.

Effects of Dietary Crude Protein and Protease Levels on Performance, Immunity Capacity, and AA Digestibility of Broilers

Exogenous proteases are promising to stimulate the application of low-protein diets for broilers. A total of 540 1-day-old Arbor Acres male broilers were randomly assigned to 9 groups with 6 replicates of 10 birds. A 3 × 3 factorial, completely randomized arrangement was used to evaluate the effects of dietary crude protein (CP) and protease levels on growth and slaughter performance, immunity capacity, and apparent ileal digestibility (AID) of amino acids (AA). Dietary CP levels were 20.0%, 19.5%, or 19.0% during the starter phase, and 18.0%, 17.5%, or 17.0% during the finisher phase. Protease levels were 0, 250, or 500 mg/kg in diets throughout the trial. The trial lasted for 42 days. Weight gain and feed efficiency of broilers decreased as dietary CP lowered, but improved with protease supplementation. Dietary CP and protease levels had few effects and interactions on carcass characteristics, immune organ indexes, and immunoglobulin concentrations. The AID of most AA was improved by dietary CP decrease or protease supplementation. In conclusion, reducing dietary CP decreased the performance and immune capacity of broilers but increased the AID of AA. Almost independent of dietary CP level, dietary protease addition improved the performance of broilers, probably through the enhancement of AA digestibility, and had no effect on carcass traits.

Effects of Probiotic and Organic Acids with Yeast Extract on Body Weight Gain and Hemato-Biochemical Parameters in Broilers

The research was conducted to observe the effect of a probiotic and organic acid with yeast extract on growth performance (body weight gain, meat yield percentage, and organ weight), hematological (Hb, ESR, and PCV) and biochemical parameters (Urea, Uric acid, and Creatinine) as an indication of kidney function. A total of 18 broiler chicks (Cobb-500) 7 days old were assigned to 3 treatment groups as group A (control group, n=6) was fed with standard commercial feed, and Group B (n=6) was fed with probiotics (Gut-pro®). Group C (n=6) was fed with probiotics, organic acids, yeast extract, and normal commercial ration. Chicks were reared for 35 days. Body weights were recorded weekly. Broilers were sacrificed by cervical dislocation and blood samples were collected for analysis. Serum samples were separated for biochemical tests. Whole meat, liver, viscera and skin were collected and weighed. Total body weight, weight of whole meat, liver, viscera and skin increased significantly (P ˂ 0.01) in birds of group C (organic acid with probiotics) and group B (probiotic) than that of the control group A. Packed cell volume and hemoglobin concentration were increased significantly (P ˂ 0.01) in birds of group B (probiotic) and group C (probiotic and organic acid with yeast extract) than that of the control group A. Erythrocyte Sedimentation Rate (ESR) increased significantly (P ˂ 0.01) in control group A than that of probiotic and organic acid-treated groups. Uric acid and Creatinine concentrations decreased significantly (P ˃ 0.01) in probiotic and organic acid-treated groups than in the control group. Urea levels in group B (probiotic) and group C (probiotic and organic acid with yeast extract) were similar to that of control group A.

Pengaruh Waktu Penggantian Ransum BR1 dengan BR2 terhadap Performa Broiler

This research aimed to find out how the effect of replacing BR1 with BR2 on broiler performance. The research method was experimental using a Completely Randomized Design (CRD) with 5 treatments consisted of R1: giving BR1 aged 1 to 35 days, R2: giving BR2 aged 1 to 35 days, R3: giving BR1 aged 1 to 7 days and giving BR2 aged 8 to 35 days, R4: giving BR1 aged 1 to 14 days and giving BR2 aged 15 to 35 days, R5: giving BR1 aged 1 to 21 days and giving BR2 aged 22 to 35 days. Each treatment was replicated 5 times. The observed variables were daily ration consumption, daily body weight gain, ration conversion. Data were analyzed by variance analysis, if there was an effect of treatment, it was continued with Duncan's Multiple Range Test. The conclusion of this research was that the replacement of BR1 to BR2 rations had a significant effect on daily ration consumption and ration conversion, but had no significant effect on daily body weight gain of broilers. Giving BR1 for 35 days resulted in the lowest daily ration consumption, daily body weight gain and ration conversion.

Embryonic thermal manipulation leads growth inhibition and reduced hepatic insulin-like growth factor1 expression due to promoter DNA hypermethylation in broilers

When broilers cannot adapt to a high-temperature environment through self-regulation, it will cause heat stress, resulting in a large number of deaths and substantial economic losses. Studies have shown that thermal manipulation (TM) during the embryonic stage can improve broilers' ability to resist heat stress later. However, different TM strategies produce different results on broilers' growth. In this study, yellow-feathered broiler eggs were selected and randomly divided into 2 groups between E10 and E18, which the control group was incubated at 37.8°C with 56% humidity, and the TM group was subjected to 39°C with 65% humidity. After hatching, all broilers were reared normally until slaughtered at 12 d of age (D12). During D1 to D12, body weight, feed intake, and body temperature were recorded. The results showed that TM significantly decreased (P < 0.05) the final body weight, weight gain, and average daily feed intake of broilers. Meanwhile, the serum levels of Triiodothyronine (T3) and free T3 were significantly decreased in the TM group (P < 0.05). The expressions of hepatic growth regulation-associated genes, growth hormone receptor (GHR), insulin-like growth factor1, and 2 (IGF1 and IGF2) were significantly down-regulated in the TM group (P < 0.05). In addition, TM altered hepatic DNA methylation, resulting in a significant increase (P < 0.05) in the methylation of the IGF1 and GHR promoter regions. The above results indicated that TM during the embryonic stage decreased the serum thyroid hormone level and increased the methylation level of the IGF1 and GHR promoter regions to down-regulate the expression of growth-related genes, resulting in early growth inhibition of broilers.

Improve the accuracy of chicken leg disease assessment by combination of gait score and X-ray scan

With the over-selection of broiler body weight (BW) and breast muscle weight (BMW), the incidence of leg disease has been gradually increasing, which has seriously affected the welfare and industrial economic development of broilers. In this study, we used gait score and X-ray to evaluate the leg health of fast large white- feather broiler chickens at the age of six to seven weeks. The combined use of the two methods improved the detection rate and accuracy of diagnosing chicken leg disease. Moreover, more than 70% of chickens with abnormal gait scores also appeared abnormal on X-ray. At the same time, the 40-d BW,42-d BMW, 28- to 40-d body weight gain (BWG) and tibial bone strength (BS) of the abnormal broilers were significantly lower than those of normal chickens. The 28- to 40-d feed conversion rate (FCR) significantly increased relative to normal chickens (P<0.05). The comprehensive application of this method would be more suitable for evaluating of commercial broiler leg diseases, and providing a more complete set of in vitro evaluation criteria for broiler leg diseases.

Supplementation of amylase or amylase + xylanase improves performance and metabolism of broilers fed with diets containing newly harvested maize

How supplementation with amylase or amylase + xylanase in newly harvested maize-based diets affects broiler nutrient metabolism and performance is unclear. Thus, this study evaluated whether the supplementation of amylase (CN) or amylase + xylanase (CAX) improves performance and metabolism of broilers fed with newly harvested maize-based diets during a 6-week production. The results showed that the body weight gain of broilers fed with CA or CAX diet was higher than that with the control (CN) diet at 1–21 d of age; however, an opposite trend was observed for feed/gain (p < 0.05). Furthermore, 150, 64 and 35 different metabolites were found between CA/CN, CAX/CN and CAX/CA, respectively. Overall, amylase supplementation improved broiler growth performance at 1–21 d of age, and the positive effects of amylase on nutrient utilization were mostly related to nicotinate, retinol and glutathione metabolism improvement. Moreover, CAX diet increased apparent metabolizable energy and growth performance of broilers at 22–42 d of age, and the difference might be related to sphingolipid, porphyrin and chlorophyll metabolism regulation. The findings prove amylase + xylanase supplementation is an effective method to improve the nutritional value of newly harvested maize for broilers.

Does the Use of Emulsifier or Lipase Improve Weight Gain and Feed Conversion in Broilers? A Systematic Literature Review and Meta-Analysis

Does the Use of Emulsifier or Lipase Improve Weight Gain and Feed Conversion in Broilers? A Systematic Literature Review and Meta-Analysis

Effect of Fermented Meat and Bone Meal–Soybean Meal Product on Growth Performance in Broilers

In this study, we screen the proteolytic activity of Bacillus species in meat and bone meal (MBM) and investigate the effects of fermented MBM–soybean meal products (FMSMPs) on the growth performance of broilers. In Trial 1, FMSMPs were fermented using four strains—Bacillus siamensis M3 (M3), B. velezensis M5 (M5), B. subtilis M6 (M6), and B. subtilis M20 (M20)—all of which presented more total peptides and higher degrees of hydrolysis (DH) than Bacillus subtilis var. natto N21 (N21). In Trial 2, 280 0-day-old Arbor Acres broilers, with equal numbers of both sexes, were randomly assigned into 5% fish meal (FM), MBM–soybean meal (MSM, as control), and N21, M3, M5, M6, and M20 FMSMP groups. The results demonstrated that the crude protein, total amino acids, alkaline protease, trichloroacetic acid–soluble nitrogen (TCA-SN), TCA-SN/total nitrogen, total peptides, DH, and free-hydroxyproline levels in the M6 group were greater than those in any other group (p &lt; 0.05). Furthermore, the weight gain in the M6 group was superior to that of the FM and MSM groups in 0–21 and 0–35-day-old broilers (p &lt; 0.05). In conclusion, B. subtilis M6 likely efficiently decomposes MSM to improve the protein properties and nutritional value of the product after fermentation. Supplementation with 5% FMSMP may promote weight gain in broilers.