Supplementation of sulfur and folic acid improves performance of broiler chicken fed suboptimal concentrations of dietary methionine.

BACKGROUND: Supplementation of sulfur (S) and folic acid (FA) are known to spare the dietary requirement of methionine (Met) in chicken. An experiment was conducted to determine the effects of feeding graded concentrations of FA (0, 2, 4, 6, 8 mg kg-1 ) and two concentrations of S (0 and 2 g kg-1 ) in 5 × 2 factorial design. Diet without FA and S was considered as negative control (NC). Another diet with the recommended concentration of Met was considered as the positive control (PC). Each diet was offered ad libitum from day 1 to 42 to 10 pens of 20 male chicks each. RESULTS: Broilers fed the NC diet had lower body weight gain (BWG), high feed conversion ratio, lower ready-to-cook yield, higher lipid peroxidation and reduced concentrations of protein and albumin in serum. BWG improved with FA at day 21 and showed a trend of improvement at day 42. Similarly, BWG improved with S supplementation at day 42. The FA and S interaction indicated a significant reduction in lipid peroxidation with S supplementation at the majority of FA levels. Serum protein fractions increased with increased dietary FA content and increased further with S supplementation. CONCLUSION: Based on the results, it is concluded that the combination of FA (4 mg kg-1 ) and S (2 g kg-1 ) improved BWG. Similarly, the feed efficiency with 6 mg FA alone or with S was similar to the PC group. The improvement was probably due to the increase in protein accretion and reduction in lipid peroxidation with FA and S supplementation. © 2022 Society of Chemical Industry.

High doses of phytase on growth performance and apparent ileal amino acid digestibility of broilers fed diets with graded concentrations of digestible lysine.

Two experiments of the same design were conducted to determine the influence of phytase on performance and apparent ileal digestibility (AID) of amino acids in broilers fed graded concentrations of digestible lysine (dgLys). Cobb 400, male broilers were allocated to 1 of 16 diets consisting of 4 basal diets formulated at 80, 88, 96, or 104% of the Cobb 400 dgLys requirements for each feeding phase. Phytase was included in each basal diet at 0, 750, 1,500, or 3,000 phytase units (FTU)/kg. In Exp. 1, 33 birds/pen from hatch to day 42 were fed a 2-phase feeding program with 12 replicate pens/diet. In Exp. 2, there were 25 birds/pen from hatch to day 21 and 8 replicate pens/diet. Data were analyzed as a 4 × 4 factorial and means separated using orthogonal contrasts. In Exp. 1, feed intake (FI) increased (quadratic, P < 0.05) as dgLys increased in the diet. Body weight gain (BWG) increased (quadratic, P < 0.05) as dgLys concentration or phytase dose increased in the diet. As phytase dose increased in the diet, feed conversion ratio (FCR) was improved in a linear or quadratic (P < 0.05) manner depending on the dgLys concentration of the diet (dgLys × phytase, P<0.05). In Exp. 2, FI linearly (P < 0.05) increased as dgLys increased in the diet. Increasing the concentration of dgLys or phytase in the diet increased (quadratic, P < 0.05) BWG and improved (quadratic, P < 0.05) FCR. The AID of most amino acids was influenced by a dgLys × phytase interaction (P < 0.05), except threonine, valine, tryptophan, serine, cysteine, or leucine (linear or quadratic effect of phytase, P < 0.05), where phytase improved the AID in birds fed diets containing 80, 88, or 96% of the dgLys requirement, but not birds fed 104%. The predicted dgLys requirement to maximize performance, carcass, and digestible lysine intake was 97.6 to ≥ 104%. The predicted dose of phytase to maximize BWG or FCR was between 1,990 and 2,308 FTU/kg, regardless of the dgLys concentration in the diet. The predicted dose of phytase to maximize carcass weight was between 1,527 and 2,658 FTU/kg of diet and to maximize breast weight was 0 to ≥ 3,000 FTU/kg diet, depending on the dgLys concentration in the diet. In conclusion, optimal performance in the absence of phytase could be achieved at much lower levels of lysine in the presence of phytase.

Effect of supplementing different concentrations of organic trace minerals on performance, antioxidant activity, and bone mineralization in Vanaraja chickens developed for free range farming.

An experiment was conducted to determine the performance, antioxidation activity, and bone mineral content in Vanaraja chickens fed diet supplemented with organic trace minerals (oTM) at reduced levels. A total of 360 day-old chicks were selected and distributed randomly into 60 battery brooder pens. A maize-soybean meal-based control diet was supplemented with inorganic trace minerals (iTM), i.e., Mn, Zn, Fe, and Cu at 50, 45, 40, and 7.5 mg/kg, respectively, and varying concentration of oTM, i.e., Zn, Mn, Cu, Fe, I, Se, and Cr at 45, 50, 7.5, 40, 2, 0.30, and 0.25 mg/kg (diet II); 33.75, 37.50, 5.63, 30.0, 1.50, 0.23, and 0.19 mg/kg (diet III); 22.5, 25.0, 3.75, 20.0, 1.0, 0.15, and 0.13 mg/kg (diet IV); 18.0, 20.0, 3.0, 16.0, 0.80, 0.12, and 0.10 mg/kg (diet V); and 13.5, 15.0, 2.25, 12.0, 0.60, 0.09, and 0.08 mg/kg (diet VI), respectively. Each diet was allotted randomly to ten replicates and fed ad libitum from 1 to 42 days of age. The body weight at 14, 28, and 42 days was not affected by reducing the supplementation of oTM concentration in the diets. Similarly, feed intake at 14 days of age was not affected but reduced significantly (P < 0.05) in the group fed diet IV (50% oTM) compared to that in the other groups. The higher feed conversion ratio and increased concentration of Ca, P, and trace minerals in tibia were evident in the group fed oTM-supplemented diets compared to the diet containing iTM. Activities of glutathione peroxidase and ferric reducing ability in plasma did not differ in the groups fed on lower concentration of oTM compared to those fed on diet I (control diet). Therefore, it is concluded that the dietary supplementation of trace minerals can be reduced greatly when supplemented as organic form without affecting growth and antioxidant status in Vanaraja chickens.

Effect of supplementing organic selenium on performance, carcass traits, oxidative parameters and immune responses in commercial broiler chickens.

An experiment was conducted to determine the effect of supplementing various concentrations (0, 100, 200, 300, or 400 µg/kg diet) of organic Se on growth performance, carcass traits, oxidative stress, and immune responses in commercial broiler chickens reared in open-sided poultry house under tropical climatic conditions. Each diet was fed ad libitum to eight replicates consisting of six birds in each pen from 1 to 42 d of age. Body weight gain and feed efficiency, and relative weight of liver, abdominal fat and ready to cook yields were not affected (p>0.05) by organic Se supplementation to broiler diets. Lipid peroxidation in plasma decreased, while activities of glutathione peroxidase and glutathione reductase in plasma increased (p<0.01) linearly with Se concentration in diet. The ratios between heterophyls and lymphocytes and relative weight of lymphoid organs (bursa, spleen, and thymus), and antibody production to Newcastle disease vaccination were not affected (p>0.05) by Se supplementation to broiler diets. However, the cell-mediated immunity (lymphocyte proliferation ratio) increased (p<0.01) linearly with dietary Se concentration. The results of the present study indicate that the supplementation of Se did not influence body weight and feed efficiency. However, supplementation of Se increased antioxidant status and lymphocyte proliferation in broiler chickens.

Effect of nutrient density on production performance, egg quality and humoral immune response of brown laying (Dahlem Red) hens in the tropics.

A study was conducted to evaluate the effect of various concentrations of metabolizable energy (ME) with graded incremental levels of crude protein (CP) and essential amino acids (lysine and methionine) on production performance, egg quality and humoral immune response of Dahlem Red laying hens. Four experimental diets based on maize-soybean meal-deoiled rice bran were prepared. Diet 1 was fed as a control diet containing 2,600 kcal ME/kg, 15% CP, 0.75% Lys and 0.36% Met, and in the other three diets (D2, D3 and D4), concentrations of the above nutrients were increased by 2.5%, 5.0% and 7.5%, respectively. The levels of Ca (3.5%) and available P (0.32) were constant in all the diets. Each diet was offered ad libitum from 28 to 40 weeks of age to eight replicates containing six birds in each replicate. The egg production, egg weight and egg mass (in grams of egg per hen per day) were not affected by increasing the nutrient density up to 7.5% (2,795 kcal ME/kg diet) compared to the control group (2,600 ME/kg diet). However, feed consumption and feed efficiency (in grams of egg per gram of feed) were influenced by the variation in the nutrient density of diets. As the nutrient density increased by 5% (2,730 ME/kg diet), birds consumed significantly (P < 0.001) less feed. The birds in the 7.5% higher density group produced significantly (P < 0.05) higher egg mass per unit feed consumption compared to the control diet. Increasing nutrient density up to 7.5% had no effect on relative weight of albumen, yolk or shell. The Haugh unit, yolk colour and shell thickness were also not affected due to variation in the nutrient density. The humoral immune response measured at 34 and 40 weeks was progressively improved by increasing the nutrient density up to 5%. Increasing the nutrient density beyond 5% in the diet had no further influence on the humoral immune response. Based on the results of the present study, it can be concluded that Dahlem Red laying hens required 2,795 kcal/kg ME, 16% CP, 0.8% lysine and 0.4% methionine for eliciting optimum performance and immune response during 28 to 40 weeks of age.