Feed Conversion Research Articles

Evaluation of protease plus a precision-biotic on body weight gain and feed conversion ratio in broilers from 0 to 42 days of age

This study aims to evaluate the effects of a protease combination with a precision biotic on body weight gain (BWG) and feed conversion ratio (FCR) of broilers from day 0 to 42. 1,400 Cobb 500 male chicks were reared on seven different diets, including an unrestricted positive control (PC–Diet 1) and a negative control (NC–Diet 2) with slightly reduced crude protein, apparent metabolizable energy (AME), and digestible amino acids. Five additional treatment diets were formulated using the negative control and varying concentrations of a protease (Diets 3-4; 33ppm and 50ppm, respectively) and in combination with a precision biotic (Diets 5-7; 33ppm + 700ppm; 50ppm + 500ppm; and 50ppm + 700ppm, respectively). The PC treatment showed significantly different feed intake and FCR compared to all other treatments in all production phases (P < 0.05). There are no significant differences in non-PC treatments in all production phases for BWG and FCR (starter p=0.230 and 0.300; grower p=0.443 and 0.237; finisher p=0.450 and 0.896; overall p=0.111 and 0.497, respectively), nor is there any in terms of mortality (p=0.800). These findings may provide valuable information to producers to optimize flock performance efficiently and cost-effectively.

Effects of dietary metabolizable energy and crude protein levels on laying performance, egg quality and fecal microbiota of Taihe Silky Fowl during the peak laying period.

The experiment aimed to study the effect of dietary metabolizable energy (ME) and crude protein (CP) on laying performance, egg quality, serum routine biochemical and lipid metabolism indicators, the apparent digestibility of nutrients, and fecal microbiota of Taihe Silky Fowl (TSF) during the peak laying period. A total of 540 26-week-old TSF female fowls were randomly allocated to 9 groups with 5 replicates per group and 12 fowls per replicate. The fowls were fed with a 3 × 3 factorial arrangement of treatments diets (ME:10.88,11.30, or 11.72 MJ/kg; CP: 15, 16, or 17%). With the increasing CP level, the egg weight (EW) (P=0.023), egg production (EP) (p=0.047), and egg mass (EM) (p=0.022) enhanced, while the feed conversion rate (FCR) (p=0.023) decreased. As the ME levels grew, the average daily feed intake (ADFI) (p<0.001) and FCR (p=0.045) decreased. With enhanced ME, the triglycerides (TG) (p=0.037), total cholesterol (TCHO) (p=0.041), and high-density lipoprotein cholesterol (HDL-C) (p=0.028) increased, whereas the low-density serum lipoprotein cholesterol (LDL-C) (p=0.039) decreased. The apparent digestibility of crude protein increased as the ME level increased (p= 0.029) and as the CP level decreased (p=0.027). At the same time, the apparent digestibility of gross energy increased as the ME level increased (p=0.018). Different levels of ME or CP changed the composition of fecal microbiota, 17% CP increased the abundance of Bifidobacterium. It is suggested that 10.88 MJ/kg dietary ME and 17% CP level are suitable for the nutritional requirements of TSF during the peak laying period.

The impact of myostatin variants on growth traits in South African Bonsmara beef cattle

Double muscling occurs when the myostatin (MSTN) gene is deactivated due to a series of mutations, leading to uncontrolled muscle growth and excessive muscle fiber accumulation, as the gene can no longer effectively regulate muscle development. This study aimed to assess the impact of MSTN variants and their combinations on growth traits, namely direct birth weight (BWDIR), direct weaning weight (WWDIR), average daily gain (ADG) and feed conversion ratio (FCR) in the South African (SA) Bonsmara. Genomically enhanced estimated breeding value (GEBVs) for traits of interest, and MTSN genotypes for SA Bonsmara animals were available for the study. Thirteen MSTN variants (Nt821, Q204X, F94L, E226X, E291X, C313Y, Nt419, S105C, D182N, Nt414, Nt324, Nt267, and Nt748) were routinely genotyped using the IDBv3 SNP array. Genotypic frequencies of MSTN variants ranged from 1.18% for Q204X to 35.02% for Nt748. No association was observed between the Nt267 variant and any growth traits, while both Nt748 and Nt414 variants affected WWDIR, ADG and FCR (p < 0.05). The results of the effect of multiple variants on growth traits indicated that there was an additive effect when more than one MSTN variant was present in an individual. This study is the first study to report the impact of MSTN variants on traits of economic importance in the SA Bonsmara breed.

Evaluation of black soldier fly larvae oil (Hermatia illucens L.) calcium salt as an alternative fat source for laying quail diets.

This study aims to determine the effect of adding saponified black soldier fly larvae oil calcium salt (BSFLO-SCa) to quail feed as an alternative source of fat on laying performance, blood lipid profile, egg quality, and gene expression in lipid metabolism. A total of 120 female Japanese quails (Coturnix japonica) aged 24 weeks were divided into 3 treatments, each with 8 replications, and each replication consisted of 5 quails in a completely randomized design. The applied treatments were the inclusion of basal feed as a control (T0) and basal feed supplemented with 1% BSFLO-SCa (T1) and 2% BSFLO-SCa (T2). The study indicated that the supplementation starting from 1% of BSFLO-SCa significantly decrease (p<0.05) in feed conversion ratio (FCR), blood lipid profile (total cholesterol, LDL-cholesterol). Gene expression on fat synthesis of fatty acid synthase (FAS) and cholesterol synthesis of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) downregulated (p<0.05). In addition, the other parameters did not affect by supplementation of 1% BSFLO-SCa. The inclusion at 2% of BSFLO-SCa significantly increased (p<0.05) protein content of yolk and albumen, egg weight, egg shape index, and gene expression on fat oxidation of carnitine palmitoyltransferase-1 (CPT-1). Egg yolk cholesterol, egg albumen ash, haugh unit (HU), and gene expression on fat synthesis of acetyl-CoA carboxylase (ACC) were significantly reduced (p<0.05). Addition of 2% BSFLO-SCa in the feed improves performance, egg quality, and reduces cholesterol in the blood and eggs of quail. This improvement is accompanied by a reduction in the expression of key genes involved in lipid metabolism. BSFLO-SCa oil has the potential to be an alternative oil source in quail feed.

The efficacy of prebiotic supplementation in mitigating heat stress and improving the survival of antibiotic-free broilers’ production in hot climates

BackgroundBangladesh is a hot tropical country, and various antibiotics have been included in broiler feed for many years to manage, prevent, and treat illnesses and improve production performance, like many other developing countries. This study mainly evaluates the efficacy of prebiotic supplementation in mitigating heat stress and improving the survival of antibiotic-free broiler production in hot climates.Materials and methodsA cocktail of banana peel, papaya peel, and watermelon rind was used as a prebiotic. A total of 350 one-day-old chicks (Ross-308) were allotted into five treatment groups each with 7 replicates: T1 (prebiotics, 15 ml/L), T2 (commercial probiotics Lactolase P, 1 g/L), T3 (synbiotics, 7.5 ml/L prebiotics + 0.5 g/L probiotics), T4 (freshwater), and T5 (antibiotics, 1 g/L). Besides other treatments, the aqueous extracts of banana peels, papaya peels, and watermelon rinds were prepared as prebiotics, and these were provided to the experimental birds through drinking water from 5 to 32 days of age.ResultsThe findings revealed nonsignificant (P > 0.05) variations in water intake, feed intake, feed conversion ratio (FCR), dressing weight, dressing percentage, heart and gizzard weights, and thigh meat yield. Significant (p < 0.05) differences were observed in body weight, body weight gain, and breast meat yield. It was observed that birds consumed five times more water than feed when the environmental temperature was above 38 °C. Significant (p < 0.05) differences in the survival rates of birds were observed among treatment groups. The highest rate of survival was obtained in T1 (100%), followed by T2 (93.3%), and T3 (90%), and the lowest percentage was recorded in T4 (66.6%) and T5 (73.3%).ConclusionPrepared prebiotics could mitigate heat stress, promote growth rate under hot climates, and be used as substitutes for antibiotics to safely produce broilers in hot climates.

Effect of coated calcium feeding on growth performance, carcass traits, immunity, blood biochemistry and tibial bone morphometry in commercial broiler chicken.

The bone abnormalities pose great concern in heavy, rapidly growing broilers, resulting in significant economic loss, and health issues in birds. To address these problems and prevent unnecessary mineral excretion into environment, it is crucial to optimise the inclusion level of dietary calcium in broiler's diet. The calcium utilisation by the bird is also affected by its source, particle size, bioavailability etc. Hence this study aimed to study the effect of partially replacing conventional dietary calcium source with coated calcium on growth performance, immune response, carcass traits, blood calcium and phosphorus, and mineral retention in broilers. About 416 broiler chicks were randomly distributed into four treatments, each with eight replicates of 13 birds and fed with iso-calcium, isocaloric, and isonitrogenous diet for 42 days. The T0 (control) was a basal diet while the T1, T2, and T3, were treatment diets in which conventional calcium source (limestone) was partially replaced with coated calcium by 10, 20, and 30% respectively. The birds of T3 group showed higher (P < 0.05) body weight gain, better feed conversion ratio and higher carcass yields compared to T0, T1, and T2 diet fed birds. Further the treatment groups exhibited higher (P < 0.05) cell-mediated and humoral immune responses and immune organ weights compared to control. The tibial bone weight, length and average diameter was highest (P < 0.05) in T3. Moreover, the T3 diet fed group also showed higher (P < 0.05) calcium and phosphorus content in serum and bone and lowest content of these minerals in the excreta followed by T2, T1 and control. These findings suggest that a 30% conventional calcium source with coated calcium may be used as a high-grade mineral source for broiler chicken feed.

Growth performance and ruminal fermentation characteristics of Thai-native beef cattle fed cassava pulp fermented with Lactobacillus casei TH14 and additives.

Raw cassava pulp is a low-nutritional agro-industry residue with a high moist content that is susceptible to rot. Biodegradation of cassava pulp by adding Lactobacillus spp. plus stimulants could boost bio-acidity to preserve cassava pulp as ruminant feed. This investigation assessed the effect of ensiled cassava pulp without or with Lactobacillus casei TH14 (LTH14), urea, and molasses on the intake, digestibility, rumen fermentation, and growth performance of native Thai beef cattle. Eight Thai-native beef bulls (170.3 ± 20.2kg of initial body weight) were randomly assigned to two treatment groups in a completely randomized design: cassava pulp ensiled without additives (CPFNO; n = 4) and cassava pulp ensiled with the combination of LTH14 (2.5g per ton of fresh material), urea (4% DM), and molasses (4% DM) (CPFWA; n = 4). The intake of the concentrate diet and ensiled cassava pulp did not differ (p > 0.05) between the CPFNO and CPFWA groups, including final body weight, average daily gain (ADG), and feed conversion ratio (p > 0.05). However, CPFWA affected higher rice straw intake compared to the CPFNO group (p < 0.05). The intake and digestibility of crude protein (CP) were greater for the CPFWA group at 43.86% and 30.87%, respectively, compared to the CPFNO group (p < 0.05). Ruminal ammonia-nitrogen (NH3-N)and blood urea-nitrogen (BUN) were increased when animals were fed with CPFWA (p < 0.05). The average total volatile fatty acids (VFA) concentration of CPFWA was greater than that of CPFNO by 27.49% (p < 0.05). In conclusion, CPFWA supplementation can enhance rice straw intake, CP intake and digestion, total ruminal VFA concentration, and BUN levels, without adversely affecting growth performance.

Effects of Edible Grass (Rumex patientia L. × Rumex tianschanicus A. LOS) Leaf Powder on Growth Performance, Antioxidant Properties, Cecal Short-Chain Fatty Acids, and Microbial Community Levels in Broilers

The hybrid plant edible grass (Rumex patientia L. × Rumex tianschanicus A. LOS), a member of the Rumex genus, presents a novel food source with a protein content of approximately 30–40%. By incorporating non-traditional feed sources, such as edible grass leaf powder (EGLP), into broiler production, costs could be reduced. The experimental subjects of this study were Arbor Acres (AA) broilers. A total of 300 newly hatched broilers were randomly divided into to five groups, with each group consisting of six cages, housing 10 birds per cage. The control group was fed a basal diet composed of maize and soybean meal. In the experimental groups, varying percentages (3%, 6%, 9%, and 12%) of EGLP were substituted for the corn–soybean meal in the basal diet. In the diet, for days 1–21, the corn content was reduced from 1.90% to 8.20%, and the soybean meal content was lowered from 1.50% to 6.00%. Similarly, in the diet, for days 22–42, the corn content was decreased from 1.17% to 7.00%, while the soybean meal content was reduced by 1.50% to 6.00%. The experiment lasted 42 days and was divided into two phases: the brooding phase (days 1 to 21) and the finishing phase (days 22 to 42). The results show that substituting 3% and 6% EGLP for corn and soybean meal significantly increased the average daily gain (ADG) during the brooding period compared to the control group (p &lt; 0.01). Additionally, the group with a 3% substitution rate exhibited a significant increase in the average daily feed intake (ADFI) during the brooding phase (p &lt; 0.01). Throughout the 42-day experiment, substituting 3% and 6% of EGLP for maize and soybean meal did not significantly affect the overall growth performance of broilers (p &gt; 0.05). However, a 6% supplementation notably reduced the feed conversion ratio (FCR) (p &lt; 0.01). Both the 3% (EG3) EGLP and 6% (EG6) EGLP replacement meals significantly enhanced the antioxidant capacity of broiler chickens, as indicated by the increased levels of the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) (p &lt; 0.01). Additionally, broilers supplemented with 3–12% showed a marked increase in cecal short-chain fatty acids (SCFAs) compared to the control group (p &lt; 0.01). The 3% EGLP replacement diet also significantly boosted the prevalence of Lactobacillus in the cecum (p &lt; 0.01). Furthermore, after EGLP supplementation, there was a higher abundance of SCFA-metabolizing bacteria, particularly Alistipes and Christensenellaceae_R-7, compared to pre-treatment (p &lt; 0.05). The prevalence of Clostridium was significantly greater in the groups receiving 9% and 12% EGLP (p &lt; 0.05), while Butyrivibrio levels were notably higher after supplementation with 12% EGLP (p &lt; 0.05).

Productivity and economic performance of Nellore young bulls fed diets with increasing fiber content.

Adequate neutral detergent insoluble fiber (NDF) content in the total diet can improve intake efficiency, prevent rumen disorders, and enhance the health and performance of feedlot-finished beef cattle. We hypothesized that an increase in dietary fiber levels would decrease the productive performance but increase the economic performance of young bulls in confinement. Thus, it was aimed to evaluate the effect of increasing fiber levels on feed intake, wastage, and productive and economic performance of Nellore young bulls finished in confinement. We used 20 Nellore cattle, non-castrated males, 30 months old, and average body weight (BW) of 416.35 ± 2.2kg distributed in a completely randomized design, kept in individual stalls. Animals were divided into four treatments consisting of four levels of neutral detergent insoluble fiber (NDF) (25%, 30%, 35%, and 40% NDF) in total DM. Nutrient intake, feed conversion, feed waste, body weight (BW) at slaughter, total weight gain (TWG), average daily gain (ADG), hot carcass weight (HCW), and carcass yield (CR) were evaluated. In addition, economic parameters (revenue, food expenses, and gross margin) were calculated and compared. The dry matter (DMI), organic matter (OMI), crude protein (CPI), and ether extract (EEI) intakes showed quadratic behavior. The DMI maximum estimated was 28.5% NDF in the diet. The NDF and ADF intakes showed a positive linear effect and the starch intake had a negative linear effect. There was a significant positive linear effect (P < 0.05) for the variables total mixed ration (TMR) offered and daily and total RTM intake. Minimum RTM wastage was estimated with a diet containing 30% NDF. The maximum points for BW at slaughter, HCW, and ADG were 29.9%; 29.6%, and 25% NDF, respectively. The costs of concentrate and silage showed a positive linear behavior, as did the ADG costs and the carcass equivalent cost (P < 0.05). The maximum point of the revenue estimate (US$/animal) was 29.9% of NDF, 26.1% of NDF for the total expenditure on food (US$/animal), and 32.5% of NDF for the gross margin (U$/animal). In conclusion, the animals fed a 30% NDF diet showed the best performance and economics, in addition to less food waste. We recommend 25 to 32.5% of NDF in the diet to obtain maximum productive and economic performance when finishing Nellore young bulls in confinement.

The effect of experimental diets incorporating fermented soybean meal on growth metrics and utilization of nutrients in broiler chickens

The aim of this study was to explore the impact of fermented soybean meal (FSBM) on the nutritional quality of feed, growth performance indicators, and nutrient utilization in broiler chickens, aiming to overcome the challenges associated with locally produced soybean meal stemming from anti-nutrients and variations in nutritional quality. The study methodology included assessing growth performance metrics through two-way ANOVA statistical analysis and evaluating nutrient utilization in broiler chickens. Results indicated that broiler chickens fed with FSBM exhibited superior performance, displaying the highest average weekly weight gain (452 grams), optimal feed conversion ratio (1.39), extended intestinal length (225 cm), increased intestinal weight (297.5 grams), and heightened activity of digestive enzymes compared to other treatment groups throughout the feeding trials. The results of this study suggest that FSBM’s better digestibility helps broiler chickens grow faster. This makes it a possible replacement for animal protein sources like fish meal in poultry feed production, which is good for both local poultry feed producers and consumers.

Oregano essential oil and Bacillus subtilis role in enhancing broiler’s growth, stress indicators, intestinal integrity, and gene expression under high stocking density

This study investigates the role of dietary Bacillus subtilis and oregano essential oil in mitigating the effects of high stocking density on growth performance, carcass traits, physiological stress indicators, gene expression, and intestinal integrity in broiler chickens. A total of, 1250 one-day-old Ross 308 male broiler chicks were randomly allocated to five experimental groups, where each group had five replicates of 50 chicks. Group 1 (control, LSD): 15 chicks/m2 fed a basal diet without feed additive, group 2 (HSD): 20 chicks/m2 fed a basal diet without feed additive, group 3 (BHSD): 20 chicks/m2 fed a basal diet supplemented with B. subtilis (500 mg/kg diet), group 4 (OHSD): 20 chicks/m2 fed a basal diet supplemented with oregano essential oil (300 mg/kg diet), group 5 (CHSD): 20 chicks/m2 fed a basal diet supplemented with oregano essential oil and B. subtilis. At 35 days of age, there was a noticeable improvement in the growth performance of broilers fed CHSD under high stocking density through the increase in body weight gain, dressing percentage, and crude protein digestibility with a decrease in feed conversion rate compared to other groups. Adding CHSD enhanced the state of oxidation and immunity through increasing superoxide dismutase, glutathione peroxidase, and the relative weight of bursa of Fabricius, while decreasing malondialdehyde, in addition to increasing plasma triiodothyronine levels. The microbial structure and morphometric parameters improved in the group that received the CHSD compared to the other groups, where villus height and Lactobacillus population increased, whereas Escherichia coli and Clostridium perfringens population decreased. Glucose transporter 2 (GLUT2), fatty acid transporter 1 (FABP1), and amino acid transferase 1 (CAT1) gene expression levels significantly increased when feeding on oregano essential oil with B. subtilis. In conclusion, combining oregano essential oil and B. subtilis supplements mitigated the effects of high stocking density by enhancing growth performance, antioxidative status, and intestinal integrity, in addition to modifying the genetic expression of genes related to nutrient absorption.

Effect of different levels of turmeric (Curcuma longa) on productivity in broiler chickens

This research was conducted to evaluate the effect of different levels of turmeric powder on the performance, blood parameters, immunity, intestinal morphology, carcass characteristics, cecum microbial flora, fatty acid profile and sensory evaluation of breast meat of broiler chickens. A completely randomized design was used including four levels of turmeric powder (250, 500, 750 and 1000 mg/kg diet) and a control treatment (without turmeric), in 5 replications. The growth performance was measured periodically and at the end of the 42-day period, three chickens from each experimental unit were killed for carcass examination. In order to check blood parameters at the end of the course, blood samples were taken from three chickens from each experimental unit. To check the immunity of broiler chickens, the weight percentage of immune glands was also evaluated. To measure the morphology of the cecum, one chicken from each experimental unit was killed to check the desired traits. The results of the experiment showed that different levels of turmeric had a significant effect on performance, carcass characteristics, blood parameters, immunity, intestinal morphology, cecal microbial flora, fatty acid profile, and the sensory evaluation of breast meat (P&lt;0.05). The results of the experiment showed body weight, feed intake and feed conversion ratio (FCR) at the end of the period were significant in the treatments that received turmeric powder (P&lt;0.05). Survival percentage, produced body weight per square meter, and final profit was also significant (P&lt;0.05). Relative weight of abdominal fat, villus height and villus height/ crypt depth of the small intestine were significant in the treatments receiving turmeric powder (P&lt;0.05). By adding turmeric powder to the diet of broiler chickens, the microbial population of the cecum also became significant (P&lt;0.05). The concentration levels of uric acid, total cholesterol, glucose, HDL, albumin and liver enzymes alkaline phosphatase and ALT were significant in the birdsreceiving turmeric powder (P&lt;0.05). Turmeric powder in the diet of broilers also had a significant effect on chondroitinic acid, linoleic acid and total polyathenoids (P&lt;0.05). Turmeric powder was significant on the lactobacilli microbial population (P&lt;0.05). The results of this experiment showed that fat content, juicyness, crispyness, chewability, elasticity, mouthfeel and general acceptance were significantly improved (P&lt;0.05). In this research, the treatment receiving 500 mg of turmeric powder per kg had the greatest effect on the measured characteristics of broiler chickens. It can be concluded that the addition of the powder of these medicinal and aromatic plants to the diet of broiler chickens has beneficial effects on the carcass characteristics and meat quality. Keywords: fatty acid, blood plasma, abdominal cavity, triglyceride, feed conversion ratio, Curcuma longa

The effect of high levels of Glycyrrhiza glabra powder on performance, carcass characteristics, blood parameters, immunity, intestinal microbial flora, intestinal morphology and breast muscle fatty acid profile in broilers

In order to investigate the effect of licorice medicinal plant on performance, carcass characteristics, fatty acid profile of breast muscle, intestinal microbial flora, blood constitutes and immunity of broiler chickens, an experiment using a completely randomized design with 3 treatments, 4 replications, 10 chicks per repetition and a total of 120 pieces of one-day-old male broiler chickens of commercial strain Ross 308 were performed for 42 days. Experimental treatments included three different levels of licorice (0, 300 and 400 mg/kg feed). Data was analyzed using SAS statistical software and averages were compared at the 5% probability level with Duncan's multiple range test. The results showed that although variation in feed consumption, weight gain and feed conversion ratio was not significant in any of the rearing periods (P≥0.05), the highest feed consumption, weight gain and the best feed conversion ratio was observed in the final period of chickens were fed with Diet containing 400mg/kg licorice. Also, according to the data, the best European index was related to this treatment. In addition, the use of two levels of licorice had no significant effect on carcass characteristics or intestinal microbial flora; however, the highest increase in body weight and the lowest number of Lactobacillus acidophilus bacteria were observed at the higher level of licorice. However, these high levels did not lead to a decrease in abdominal fat. According to the results obtained, different levels of licorice led to a significant reduction of harmful fats such as cholesterol, triglycerides, VLDL and LDL (P&lt;0.05). Furthermore, although the level of HDL was not significant (P≥ 0.05), its highest amount was seen at high levels of licorice. In addition, the lowest amount of total protein, albumin and globulin was observed at the level of 400 mg/kg of licorice. According to these results, although the amount of glucose was lowest its level was not significant (P≥0.05), Also, the use of this same level of licorice had no significant effect on the function of the humoral immune system in response to antigen injection (SRBC Antibody against sheep red blood cell) or antibody titer against Newcastle virus and influenza (P≥0.05). Nevertheless, according to the data, the highest antibody titer against Newcastle virus and SRBC antigen was associated with this treatment. These results also showed that high levels of licorice led to an increase in the number of Bifidobacterium. Villi width and crypt depth decreased at the high dose of licorice, but the ratio of villi length to crypt depth increased. In addition, the use of different levels of licorice could not reduce the ratio of saturated to unsaturated fatty acids compared to the control group. Therefore, based on the results of this research, it is recommended to use the level of 400 mg/kg of licorice to supplement the diet of broilers of Ross 308 strain.

Effects of Dietary Protein Levels, Net Energy Levels, and Essential Amino Acid-to-True Protein Ratios on Broiler Performance

Supplementing essential amino acids (EAAs) without considering non-EAA (NEAA) and energy contents in reduced-crude protein (CP) diets may alter EAA-to-true protein (E:T) and energy-to-protein ratios, potentially compromising growth. This study aimed to evaluate the effects of CP, E:T, and net energy (NE) on broiler performance. The treatments were as follows: T1—reduced CP (16%, RP), low NE (9.9 MJ/kg, LNE), low E:T (0.56, LE:T); T2—RP, LNE, high E:T (0.60, HE:T), with imbalanced EAA (excess Met and deficient Thr); T3—RP, high NE (10.4 MJ/kg, HNE), LE:T; T4—RP, HNE, HE:T; T5—normal CP (18%, NP), LNE, LE:T; T6—NP, LNE, HE:T; T7—NP, HNE, LE:T; and T8—NP, HNE, HE:T. The study employed as-hatched Cobb 500 broilers in two experiments. Exp.1 studied the broiler performance from d19 to 35, with eight replicates per treatment and 16 birds per replicate (n = 1024). Birds were randomly assigned to different treatments, and at the end of their lives, all were dissected to determine their sex and account for any gender-related effects. Exp.2 measured NE values in respiration chambers from d25 to 28, with six replicates per treatment, and two birds (a male and a female) per replicate (n = 96). The bird gender was determined through high-resolution melting curve analysis of feather DNA. The measured NE values were used to calculate NE intake (NEi) in Exp.1. The results showed that T4 improved (p &lt; 0.001) weight gain (WG), feed conversion ratio (FCR), and NEi relative to T1, T2, and T3, and protein efficiency (WG/CP intake) relative to all treatments. The live performance (feed intake, WG, FCR) and NEi of birds fed T4 reached a level equal to those of birds fed NP diets (T5 to T8). These results suggest that a dietary E:T ratio of 0.60 is necessary to maximize nutrient utilization and to restore growth rate in broilers fed RP diets.

Lysophospholipid Supplementation in Broiler Breeders’ Diet Benefits Offspring’s Productive Performance, Blood Parameters, and Hepatic β-Oxidation Genes

The present study aimed to investigate whether supplementation of modified lysophospholipids (LPLs) in the diet of broiler breeders can benefit their offspring. A total of 264 49-week-old breeders (Ross 308) were allocated and fed based on a 2 × 2 factorial arrangement with two levels of dietary energy (normal energy = 2800 kcal/kg and low energy = 2760 kcal/kg) and two LPL levels (0 and 0.5 g/kg) for periods of 8 and 12 weeks. The offspring were assessed for growth performance, serum parameters, hepatic antioxidative capability, and expression of genes involved in liver β-oxidation at 7 days old. The LPL inclusion improved (p &lt; 0.01) average body weight (ABW), average daily gain (ADG), and feed conversion ratio (FCR). The offspring of 61-week-old breeders fed with LPL exhibited reduced serum triglyceride levels (p &lt; 0.01) but an increase in hepatic glutathione peroxidase (p &lt; 0.05). The LPL increased (p &lt; 0.001) the mRNA expression of the PGC-1α gene in the liver. Supplementing LPL in low-energy diets resulted in higher FABP1 gene expression (p &lt; 0.05) in the intestine. In conclusion, LPL supplementation in the breeders’ diet improved offspring performance by enhancing fatty acid absorption, hepatic indices, and the expression of genes involved in liver β-oxidation.

Growth performance, carcass characteristics, fatty acid composition, blood parameters, and gut morphology of Italian quails fed diets containing chia seed (Salvia hispanica L.)

The main objective of the study was to determine the growth, hematological parameters, and gut-associated attributes in Italian quails fed chia seed (Salvia hispanica L.) (CS). Two hundred mixed-sex, 1-day-old Italian quails were randomly distributed into four treatment groups (n=50 birds/group) kept in five replicate pens with 10 birds per pen from day 1 to 35, under a completely randomized design. The control group received a basal diet with no CS, whereas the other groups were fed diets containing 1%, 2%, and 3% CS. Results revealed that for the 0-5 weeks study period, the live weigh, and the feed conversion ratio (FCR) were significantly (P = 0.05) improved with supplementation of 3% CS. However significant (P &lt; 0.05) difference was noticed within groups for slaughter live weight, hot carcass, cold carcass, dressing percentage, heart and liver weight, and pH of carcass at the time of slaughter and after 24 hours. Similarly, breast meat dry matter, ash percentage, cooking loss, and water holding capacity were also not influenced (P &lt; 0.05) by supplementation of CS. Regarding gut associated attributes, the ileal villus height (VH) of the control diet is higher compared with those fed CS means supplementation of CS resulted in reduced (P &lt; 0.05) VH, whereas crypt depth (CD) was reduced (P = 0.001) quadratically. The total protein and cholesterol profile significantly (P = 0.001) improved, and the lipids profile decreased significantly (P = 0.001) with the supplementation of CS. The CS-fed groups had substantially greater values of myristoleic acid, linoleic acid, docosahexaenoic acid, PUFA, USFA, PUFA/SFA, UFA/SFA, and omega 6 (n6), whereas lower values of palmitoleic acid, stearic acid, eicosanoic acid, erucic acid, SFA in breast meat of quails compared to the control group. In conclusion, the supplementation of 3% CS resulted in better growth performance, improved blood parameters, and enhanced nutritional profile of quail breast meat for human consumption.

Effects of dietary fermented mealworm larvae and stocking density on performance, blood stress indicator and intestine parameters of broilers

The present study was conducted to evaluate the effects of the supplementation of defatted mealworm larvae meal fermented with probiotics as a new antibacterial feed additive to the diet of broilers reared under normal- (NSD) and high- (HSD) stocking density on growth performance, blood and slaughtering parameters, microorganism content and morphology of ileum and short-chain fatty acids content of ceca. A total of four hundred and fifty one-d-old Ross 308 male broiler chicks were randomly distributed into six groups of similar mean weight, each containing five replicates. Experimental treatments consisted of a 2 x 3 factorial arrangement with two levels of stocking density (12 birds/m2 as NSD and 18 birds/m2 as HSD) and three different mash diets: CONT- a corn-soybean meal-based diet containing no fermented defatted mealworm larvae meal (FDM) (0%); FDMLP- the diet obtained by supplementing DM fermented with Lactobacillus plantarum to the CONT diet (0.4%); FDMLB- the diet obtained by supplementing DM fermented with Lactobacillus brevis to the CONT diet (0.4%). HSD significantly decreased the growth performance except feed conversion ratio (FCR), carcass yields (CYs), Lactobacillus spp. content and villus height (VH) and villus surface area (VSA) of ileum and short-chain fatty acids (SCFAs) concentrations of ceca, but, increased the blood heterophil/lymphocyte (H/L) ratio and Escherichia coli content and crypt depth (CD) of ileum of broilers compared to NSD. The FDMLP and FDMLB diets significantly improved the FCR and increased final body weight (BW), BW gain, Lactobacillus spp. content and VH and VSA of ileum and SCFAs concentrations of ceca, however, reduced the blood H/L ratio and Escherichia coli content and CD of ileum of broilers when compared to the CONT diet. In conclusion, FDMLP and FDMLB can be utilized as new antibacterial feed additives in broiler diets regardless of stocking density.

Effect of the application of sage (Salvia officinalis L) as a phytogenic additive in rabbit feed

The purpose of the experiment was to determine the effect of the addition of dried ground whole leaves of the herb Salvia officinalis L in the feed for fattening rabbits, on the productive parameters, some blood indicators and carcass characteristics. The inclusion of ground dry leaves of the herb sage in feed for fattening rabbits has a positive effect on productive performance. In the experimental group were improved average daily gain by 29,2% (P&lt;0,05), feed conversion ratio by 19% (P&lt;0,05) for the entire experimental period and average daily feed consumption by 3,8% (P&lt;0,05) during the first week of the experiment compared to the control.The tested additive did not reliably affect the parameters of the slaughter analysis, the chemical analysis of the meat and blood parameters.

Nutrient density and the collaborative impact of exogenous enzyme blend on the performance of broiler chicken.

This study evaluates the collaborative effect of exogenous enzyme blend and dietary nutrient density on the performance of broiler chicken. A total of 600 Ross 308 broiler chickens with same average initial body weight were randomly assigned to 5 treatments. Each treatment contained 8 replicates, and 15 birds per replicate. The diets included a control (CON) starter/finisher (S/F) diet with metabolizable energy (ME) 3,100/3,200 in Kcal/kg and crude protein (CP) content 22.0.0/20.00 in % as (S/F 3,100/3,200 Kcal/kg + CP, 22.00/20.00 %). S/F with ME 3,060/3,150 Kcal/kg + CP 21.50/19.50 % with and without the exogenous enzyme blend as (S/F 3,060/3,150 Kcal/kg + 21.50/19.50 % with, and without the exogenous enzyme blend), and lastly, S/F with ME 3,010/3,100 Kcal/kg + CP 21.50/19.50 % with, and without the exogenous enzyme blend as (S/F 3,010/3,100 Kcal/kg + 21.50/19.50 % with, and without the exogenous enzyme blend). The impact of the treatments was tested on growth performance, nutrient digestibility, blood metabolites, intestinal microflora, and morphology of broiler chicken. The inclusion of exogenous enzyme blend in the nutrient-deficient diet S/F 3,060/3,150 + 21.50/19.50 increased (p<0.05) broilers body weight, feed conversion ratio, nutrient digestibility of crude protein, gross energy, phosphorus, and blood phosphorus, with tendency (p<0.10) of higher dry matter. The treatment also showed lower (p<0.05) total anaerobic bacteria, coliform, and higher (p<0.05) villus height (VH) in the jejunum, with tendencies (p<0.10) of higher lactobacillus in the ileum and caecum, and higher tendency (p<0.10) of VH in duodenum and ileum. We concluded that the improved performance could be attributed to the potency of S/F 3,060/3,150 + 21.50/19.50 supplemented with 0.05% of the multienzyme to reduce the level of potential pathogenic bacteria with an increased level of positive bacteria, which in turn creates an enabling intestinal villi structure in broiler chicken.

Effects of Formaldehyde-Treated Feed on Rumen Metabolism and Blood Biochemistry in Lambs: A Review

This review evaluates the impact of formaldehyde treatment on feed for lambs, focusing on its effects on rumen metabolism and blood biochemical indicators. Formaldehyde is commonly used as a feed additive to improve nutritional efficiency and preserve feed quality. This review synthesizes data from various studies to assess how formaldehyde-treated feed influences rumen fermentation parameters, including volatile fatty acid (VFA) production, rumen pH, and microbial activity. Additionally, the review examines the effects of formaldehyde treatment on key blood biochemical markers such as glucose, urea nitrogen, and liver enzymes. Studies indicate that formaldehyde treatment can enhance the stability and digestibility of feed, potentially improving nutrient utilization and overall animal performance. The preservation of protein and reduction in feed spoilage are highlighted as significant benefits, contributing to more consistent rumen function and metabolic efficiency. However, the impact on rumen microbial populations and VFA profiles shows mixed results, with some studies reporting improved microbial efficiency and others noting minimal changes. The review also discusses potential adverse effects, including alterations in blood biochemical parameters. While formaldehyde treatment generally maintains or improves key indicators like blood glucose and protein levels, excessive use may lead to concerns such as elevated urea nitrogen levels and potential liver enzyme disruptions, the review concludes that formaldehyde-treated feed can be a valuable tool in optimizing feed efficiency and lamb health, provided it is used judiciously. Future research is recommended to further elucidate the long-term effects on rumen microbiota and metabolic processes, ensuring balanced benefits without compromising animal welfare.