Tibia Ash Content Research Articles

Duck gait: Relationship to hip angle, bone ash, bone density, and morphology

The rapid growth meat birds, including ducks, undergo requires skeletal integrity; however, fast growth may not be conducive to adequate bone structure. A relationship likely exists between skeletal changes and duck mobility. Reduced mobility in meat ducks may have impacts on welfare and production. This study examined the relationships among gait score, bone parameters, and hip angle. Commercial Pekin ducks, ages 14 d (n = 100), 21 d (n = 100), and 32 d (n = 100) were weighed and gait scored with a 3-point gait score system by an observer as they walked over a Tekscan gait analysis system. Gait was scored as GS0, GS1, or GS2 with a score of GS0 defined as good walking ability and a score of GS2 as poorest walking ability. Ducks were humanely euthanized, full body scanned using quantitative computed tomography (QCT), and the right femur and tibia were extracted. Leg bones were cleaned, measured, fat extracted, and ashed. QCT scans were rendered to create computerized 3D models where pelvic hip angles and bone density were measured. Statistical analysis was conducted using PROC MIXED with age and gait score in the model. Body weight increased with age, but within an age, body weight decreased as walking ability became worse (P < 0.01). As expected, linear increases in tibia and femur bone width and length were observed as the ducks aged (P < 0.01). Right and left hip angle increased with duck age (P < 0.01). Additionally, ducks with a GS2 had wider hip angles opposed to ducks with a GS0 (P < 0.01). Bone density increased linearly with both age and gait score (P < 0.05). Femur ash content was lowest in 32-day-old ducks and ducks with GS1 and GS2 (P < 0.0001). Tibia ash content increased with age, but decreased as gait score increased (P < 0.001). The observation that right hip angle changed with gait scores merits further investigation into the relationship between duck mobility and skeletal changes during growth.

계란 난황 레시틴 추출 부산물이 사료 내 Ca 함량을 조절한 산란계의 생산성과 Ca 흡수에 미치는 영향

A 3-weeks feeding trial with 288 laying hens were conducted to determine the efficacy of lecithin-free egg yolk at different levels of dietary Ca on performance and Ca absorption. Laying hens were divided into 6 groups according to calcium level and testing agent; 0% calcium feed (A), 0.2% calcium feed (B), 0.4% calcium feed (C, normal feed), 0.6% calcium feed (D), 0.4% calcium feed + 0.2% egg byproduct (C+ 0.2), 0.4% calcium feed + 0.4% egg byproduct (C+0.4). The final body weight gain of C+0.2 and C+0.4 groups were higher by 1.5% and 7.4% respectively than group C. Tibia ash contents did not show significantly difference, but calcium contents increase (p<0.05) in C+0.2 and C+0.4 groups. Parallel undecalcified tibia joint sections were stained for calcium absorption by the von Kossa’s stain. This result show that lecithin free egg byproduct supplementation to normal calcium feed improved growth performance and calcium utilization in laying hens.

Interactive effect of vitamin D and strontium on performance and bone composition in broiler chickens

Vitamin D and strontium have a close physiological interrelationship in respect to mineral homeostasis and skeletal integrity which is not well defined. To elucidate this relationship a total of 960-day-old male broiler chickens were fed for 40 days one of eight diets comprising of two levels of vitamin D3 (5000 or 10,000IU/kg) and four levels of strontium (0, 400, 800 or 1200mg/kg). Bodyweight gain, feed intake, bone composition and ileal nutrient digestibilities were analysed.All treatments improved BWG in excess of breed Ross 308 expectations and there was no statistical difference in overall performance between treatments. In the starter period, higher vitamin D3 interacted with the highest level of strontium supplementation to reduce BWG (P<0.05) and increase FCR (P<0.05). There was no change in percentage tibia ash content between treatments. Increasing concentrations of dietary strontium resulted in a reduced Ca content (P<0.01) and an increase in strontium (P<0.0001), Mg (P<0.01) and K content (P<0.05) of bone. The ileal digestibility of sodium was reduced in birds fed higher vitamin D3 with the highest level of strontium supplementation (P<0.05).There was no improvement in BWG or FCR by day 40 with higher levels of vitamin D3 and various levels of supplemental strontium however performance was negatively affected in the starter phase. Strontium supplementation in the presence of additional vitamin D3 altered tibia bone composition and reduced Na ileal digestibility. The ratio of 30:1 for calcium to sodium in bone was maintained across all treatments as did the total percentage content of calcium, sodium, strontium, potassium and magnesium at 43%. The higher level of vitamin D3 (10,000IU/kg) with no added strontium (0mg/kg) produced the heaviest BWG per bird by day 40 (3157g) however it was not statistically significant. The higher level of vitamin D3 significantly increased mortality. The feeding of lower doses of strontium and vitamin D3, particularly in the starter phase, requires further investigation.

Performance of Japanese quail on organically complexed minerals by replacing inorganic sources

Day-old quails (459) were divided into 9 groups and each group was assigned with one dietary treatment, viz. T0 (control), T1 (100% organic Zn, Cu and Mn), T2 (100% organic Mn), T3 (50% organic Mn), T4 (100% organic Cu), T5 (50% organic Cu), T6 (100% organic Zn), T7 (50% organic Zn) and T8 (50% organic Zn, Cu and Mn). Weekly body weight and feed consumption were recorded. At 42 day, the serum biochemical indices and carcass characteristics were determined. Also the tibia bone parameters and weight of the immune organs were studied at 42 day of age. At 0 day, 7th day, 14th day and 21st day, the body weight of experimental quail of all the groups did not differ significantly. At 6th weeks, the body weights of T8 attained highest body weight with no significant difference with the body weight of T1, T3, T4 and T7. At 6th week, T8 recoded better FCR with no significant difference from T1, T4, T5 and T7. The serum glucose, serum cholesterol, serum triglyceride, albumin, globulin, albumin and globulin ratio, calcium, phosphorus, SGOT, SGPT, ALP levels of all the treatments of the experimental quails did not differ significantly but the serum protein, urea and haemoglobin of the quails of treatment groups differed significantly. The carcass characteristics of the experimental quail did not differ significantly (P&gt;0.05). The tibia wt (g), tibia length (mm), tibia Ca (%) and tibia P (%) of all the treatments of experimental quails did not differ significantly but the tibia ash content was significantly higher in organic mineral supplemented groups. The weight of lymphoid organs (spleen, bursa and thymus) of experimental quail at sixth week of age of all treatments did not differ significantly. It may be concluded that 50% replacement of inorganic Zn, Cu and Mn with their corresponding organic sources showed better performance in quail.

Increasing levels of phytase in diets formulated with reduced available phosphorus content supplied to male and female broilers

The reduction of the available phosphorus (avP) content in the broiler diet must be followed by the supplementation of adequate phytase. One experiment was conducted with broilers from 15 to 28 days of age to determine the level of necessary phytase when the mashed diet is formulated with 0.213% of avP to enable the results of performance, tibia ash content, and calcium (Ca) utilization similar to those determined for birds fed with diet formulated to meet their nutritional requirements. Thus, 120 broilers were distributed in (4+1) x2 factorial arrangement corresponding to four deficient diets in avP (0.213%) supplemented with phytase (0; 750; 1,500 or 2,250FTU kg-1) plus one positive control diet without phytase (0.426% of avP), supplied to male and female broilers. Males showed better performance and higher totalP retention. Decrease in the avP content of the diet without phytase use worsened the performance, tibia ash content, and Ca retention; however, these parameters were improved gradually with the increase of the phytase level in the diet. Regardless of sex, using 2,250FTU kg-1, it is possible to reduce the avP to 0.213% without impairing performance, tibia ash content, and Ca retention; in addition to reducing the totalP excretion in 56.75% and improving its utilization in 38.58%.

Redução de fósforo em dietas para frangos com base em valores de equivalência da fitase

O objetivo deste trabalho foi avaliar o uso de valores de equivalência da fitase como base para redução de fósforo disponível (P-disp) em dietas para frangos. Foram avaliados dez planos nutricionais com seis repetições de 15 aves cada uma. Avaliaram-se: desempenho, teor de cinzas na tíbia e custo da ração. De 1 a 7 e de 36 a 42 dias de idade, as aves receberam dieta basal; de 8 a 21 dias, dieta sem fitase contendo 3,9 g kg-1 de P-disp e quatro dietas com fitase contendo de 1,1 a 2,5 g kg-1 de P-disp; e de 22 a 35 dias, dieta sem fitase contendo 3,4 g kg-1 de P-disp mais dieta com fitase contendo 1,6 g kg-1 de P-disp. O melhor plano nutricional foi composto pelas dietas: 4,7 g kg-1 de P-disp sem fitase (1 a 7 dias); 2,0 g kg-1 de P-disp suplementada com fitase (8 a 21 dias); 3,4 g kg-1 de P-disp em ração sem fitase (22 a 35 dias); e 3,0 g kg-1 de P-disp em ração sem fitase (36 a 42 dias). A redução do P-disp ocorre no período de 8 a 21 dias de idade e corresponde a 2,0 g kg-1 de ração suplementada com fitase.

Influence of conditioning temperature on the postpellet recovery and efficacy of 2 microbial phytases for broiler chicks

SUMMARY The effect of conditioning temperature on phytase efficacy for growth performance and bone mineralization was evaluated using 432 male Ross broilers. Birds were fed a wheat-soy-based diet that was formulated to be adequate in all nutrients with the exception of available P. Diets were conditioned at 75, 80, 85, or 90°C and fed with (1,000 phytase units/kg) or without 1 of 2 microbial phytases in a 3 × 4 factorial design. Phytase A was found to have greater thermostability than phytase B (78.3 vs. 57.5%) as an average across all conditioning temperatures. Phytase increased (P < 0.05) BW gain from d 0 to 21 and birds fed diets containing phytase A were significantly heavier than birds offered diets with phytase B. Increasing conditioning temperature decreased (P < 0.01) BW gain. Supplementing diets with phytase improved (P < 0.05) FE and birds fed diets containing phytase A were more efficient (P < 0.05) than broilers fed diets containing phytase B. Tibia ash concentrations were improved (P < 0.05) by approximately 10% with phytase A and B compared with birds fed diets without phytase. Birds fed phytase A diets had higher (P < 0.05) bone ash concentrations than birds that received the diet containing phytase B. In conclusion, the inclusion of an intrinsically thermostable exogenous phytase before pelleting would be of benefit to bird performance and bone mineralization in broilers.

Growth responses, excreta quality, nutrient digestibility, bone development and meat yield traits of broiler chickens fed vegetable or animal protein diets

This study was carried out to compare the performance of broilers fed diets containing only vegetable protein (VP) with birds that received an animal protein (AP) in their diets. Cobb 500 day-old male broiler chicks (n = 256) were randomly divided into four experimental groups. The two AP diets contained fish meal and soybean (SBF) and fish meal with canola (CMF); while the two VP diets contained predominantly soybean (SBM) or canola (CAN) meals. All diets were isoenergetic and isonitrogenous, and were pelleted, but amino acid levels were formulated on a total and not digestible basis. Feed intake up to 21 days was highest on the AP diets, and the lowest in the SBM treatment. Birds in the AP diet groups were significantly heavier at 21 days and 35 days than those on the VP diets. Up to 35 days, birds on AP diets had superior feed conversion ratio, while the CAN treatment was the poorest. Excreta moisture level was significantly higher in birds fed the VP diets than those on AP diets. Excreta pH and ammonia concentration were similar between treatments. Protein digestibility was higher in the AP than in the VP diets. Birds raised on VP diets had a significantly lower abdominal fat content than birds on the AP diets. Other meat characteristics measured in this experiment did not differ significantly. Bone development, in terms of breaking strength and latency-to-sit time, was significantly better on the AP diets than that of birds on the VP diets. The birds on the CMF diet had the longest tibia bone, while birds on SBM diet, the shortest. Total tibia ash content on the CMF diet was significantly increased, along with its iron and copper concentration, which were also significantly higher in birds on the same diet than the others. The responses of birds generally indicated that the AP diets were superior to the VP diets.Keywords: Growth, digestibility, fish meal, bone growth, meat quality, soybean meal, canola meal

The effects of sodium gluconate and microbial phytase on performance and mineral utilisation in broiler chicks

An experiment was conducted to investigate the effects of sodium gluconate and microbial phytase (MP) (Natuphos 1000G) supplementation of diets on performance, mineral retention and bone mineralisation in male broiler chicks from a day old to 21 days of age. The experiment was carried out using a completely randomised design with a 3 by 2 factorial arrangement (0, 2 and 4% sodium gluconate and 0 and 750 U MP/kg diet). Diets were formulated with deficient contents of available phosphorus (aP) (2.4 g/kg). Ten replicate cages of four chicks per replicate cage were fed experimental diets. MP supplementation of diets with deficient contents of aP significantly improved weight gain (P &lt; 0.05) and feed efficiency (P &lt; 0.01). The performance results were similar in birds fed the diets without sodium gluconate and the diets with 2% sodium gluconate. However, the dietary inclusion of sodium gluconate at 4% depressed (P &lt; 0.05) the growth of broiler chickens compared with the diet without sodium gluconate. Compared with the diets supplemented with 2% sodium gluconate, the diets supplemented with 4% sodium gluconate decreased (P &lt; 0.05) weight gain and increased (P &lt; 0.05) feed efficiency. MP supplementation increased (P &lt; 0.01) Ca, P, Mg, Zn retention, and tibia ash, Ca and P contents in tibia ash. Diets with sodium gluconate increased (P &lt; 0.05) P and Zn retention. Diets containing sodium gluconate without phytase increased (P &lt; 0.05) Mg retention and P content in tibia ash. The diet with 2% sodium gluconate without phytase also increased (P &lt; 0.05) Ca retention. The dietary inclusion of sodium gluconate at 2% improved (P &lt; 0.05) tibia ash and Ca content in tibia ash. Sodium gluconate and MP had significant interactions in Ca and Mg retention (P &lt; 0.01), and P content (P &lt; 0.05) in tibia ash. In conclusion, the results indicated that phytase and sodium gluconate supplementation of corn–soybean meal low AP diets increased Ca, P, Mg and Zn mineral retention and bone mineralisation in chicks. The addition of MP improved the performance. However, the supplementation of diets with 4% sodium gluconate depressed the performance.

Phosphorus utilization in finishing broiler chickens: Effects of dietary calcium and microbial phytase

A decrease in dietary P, especially in finishing broilers (21 to 38 d old), is a crucial issue in poultry production from an environmental and economic point of view. Nevertheless, P must be considered together with other dietary components such as Ca and microbial phytase. Different corn and soybean meal-based diets varying in Ca [low (LCa) 0.37, medium (MCa) 0.57, and high (HCa) 0.77%], and nonphytate P [nPP; low (LnPP) 0.18 and high (HnPP) 0.32%] content were tested with and without microbial phytase [0 or 500 phytase units (FTU)/kg]. Feed intake, BW gain, bone mineralization, and mineral retention were examined in 144 Ross PM3 broilers (22 to 38 d old) reared in individual cages. Growth performance was not significantly affected by the treatments. Nevertheless, a numerical decrease of ADG and ADFI was observed in HCa-LnPP and LCa-HnPP associated with an increase of feed conversion ratio. Decreased dietary Ca reduced tibia ash content (Ca, linear: P < 0.001; quadratic: P = 0.034) and tibia ash weight for the highest level of nPP (Ca × nPP; P = 0.035). In parallel, increasing dietary Ca reduced the flow of retained P (P = 0.022) but also tibia ash weight in LnPP diets (Ca × nPP; P = 0.035). The responses of the animals in terms of tibia ash content and P retention were improved by the addition of microbial phytase especially for the lowest P diets (nPP × phytase, P = 0.021 and P = 0.009; respectively). Phytase increased dry tibia weight, bone breaking strength, and tibia diameter in broilers fed the highest Ca diets (Ca × phytase; P < 0.05). We conclude that is possible to decrease P levels in finishing broilers, if the Ca content is appropriate. Nevertheless, decreasing the dietary P and Ca cannot allow a maximization of bone mineralization, but the optimal threshold remains to be determined.

Evaluation of an enzyme complex containing nonstarch polysaccharide enzymes and phytase on the performance of broilers fed a sorghum and soybean meal diet

SUMMARY The objective of this study was to evaluate the effect of a multiple-enzyme complex (Rovabio Max) containing carbohydrases and phytase on the performance of 0- to 46-d-old broilers fed a sorghum- and soybean meal (SBM)-based diet. A total of 2,200 broilers were fed sorghum-SBM diets with or without the complex and were compared with a positive control (PC) diet [treatment (T) 1]. Two negative controls (NC) were used: (NC1) in treatments T2 and T3, the AMEn was reduced by 85 kcal/kg, CP was reduced by 1.5%, amino acids were reduced by 1.5%, available P was reduced by 0.153%, and Ca was reduced by 0.12% as compared with the PC diet; (NC2) for treatments T4 and T5, the AMEn was 120 kcal/kg lower, CP was 1.5% lower, amino acids were 1.5% lower, available P was 0.153% lower, and Ca was 0.12% lower than with the PC diet. Both reformulations were then fed with (T3 and T5) and without (T2 and T4) addition of the multiple-enzyme complex. The multiple-enzyme complex treatments (T3 and T5) resulted in broilers with significantly higher final BW when compared with the treatments not containing the complex (T1, T2, and T4). Moreover, the mortality-adjusted FCR (adjusted FCR) was significantly better in T1, T3, and T5 compared with T2 and T4. Birds fed the PC (T1) had significantly lower feed intake than those in all other treatments. There was no effect on mortality (%) among treatments. Tibia ash was statistically lower in T4 than for all other treatments. On the basis of these results, typical commercial sorghum-SBM broiler diets reformulated at −85 kcal/kg of AMEn, −1.5% CP, −1.5% amino acids, −0.153% of available P, and −0.12% of Ca had a negative effect on broiler performance and tibia ash content compared with the performance of broilers fed the PC diet. The use of the multiple-enzyme complex reestablished broiler performance equivalent to that of the PC.

Diets with reduced levels of nutrients supplemented with phytase and amino acids for broilers

One performance experiment and another metabolism experiment were conducted simultaneously with broilers from 22 to 35 days of age, evaluating five diets in six replicates. The control diet, without phytase, contained 19% of crude protein (CP); 0.412% of available phosphorus (aP) and 0.824% of calcium (Ca). The other diets were supplemented with phytase and were formulated with 0.262% of aP and 0.524% of Ca, with the CP level ranging from 19 to 16%. In the performance assay, 750 birds were used, in which were evaluated the performance, the tibia ash content and yields of carcass, cuts, and abdominal fat at 35 days of age. The metabolism assay was conducted with 90 birds, evaluating the apparent metabolizable energy corrected by the nitrogen balance; the metabolizability coefficient of dry matter (MCDM) of the diets, and also the balance and retention of nitrogen (N) and phosphorus (P). Diets did not affect performance, tibia ash content and yields of carcass, breast and thigh + drumstick. However, birds fed diet containing 16% of CP showed greater abdominal fat. Diets containing 19% of CP had the smaller energetic value and MCDM. The retention of N and P was higher in birds fed diets formulated with reduced CP content and phytase. Therefore, when the broiler feed is supplemented with phytase and amino acids it is possible to reduce the CP, aP and Ca for up to 16; 0.262 and 0.524%, respectively.

Effects of Supplemental Dietary Phytase on Performance and Blood Biochemical Parameter of Broiler Chicks

An experiment was conducted to study the effects of phytase enzyme on performance, blood biochemical parameter and tibia ash content of broiler chicks. Two hundred eighty Ross broiler chicks were located randomly to seven experimental diets at four replicates (cages) and fed from 5 to 28 days of age. A positive control diet (0.422% non-Phytate Phosphorus, nPP) and a negative control diet (0.316% nPP) were used, and five more diets were manufactured by supplementing the negative control diet with 300, 600, 1,200, 2,400, and 24,000 FTU/kg of exogenous phytase (Phyzyme XP). The addition of exogenous phytase above 600 FTU/kg and 1200 FTU/kg improved (P<0.05) feed conversion ratio and body weight gain of the birds fed the negative control diet, respectively. Decreasing nPP content in the diet reduced tibia ash (P<0.001) content and phytase supplementation increased it (P<0.001) as logarithmic liner equation. Phosphorus concentration of serum chicks fed negative control diet was reduced and phytase supplementation above 600 FTU/kg increased it. However, negative control diet increased alkaline phosphatase activity of serum and addition of phytase above 2400 FTU/kg reduced its activity to level of positive control diet (P<0.01). Albumin concentration of serum chicks was increased by addition of phytase above 600 FTU/kg diet. The lowest calcium content and highest total protein concentration of serum chicks were seen at treatment of 600 FTU/kg phytase. These results demonstrated that addition of 600 FTU/kg phytase to low-available phosphorus diets (75% of NRC recommended) improved performance of broiler chicks due to improve utilization of phytate phosphorus of corn-soy bean meal diets.

Effect of citric acid and microbial phytase enzyme on ileal digestibility of some nutrients in broiler chicks fed corn-soybean meal diets

A total of 270 Ross 308 male broilers were used in a randomized complete block design for a period of five weeks. The experiment included nine treatments, three replicates with 10 birds in each replicate of 3×3 factorial design. Two main factors of citric acid (CA) (0, 3 and 6%) and a microbial phytase (MP) (0, 500 and 1000 IU/kg) were used. The results indicated that diets containing 3% CA caused significant increase in P content in tibia ash, ileal digestibility of crude protein, apparent metabolizable energy, total phosphorus and body weight (P<0.01). Addition of 6% CA to diets compared with diets without acid and the diets having 3% CA, significantly decreased (P<0.01) body weight, average daily gain, average daily feed intake, Ca content in tibia ash, ileal digestibility of crude protein, apparent metabolizable energy and total phosphorus. Also, 6% CA diet caused significant increase in measured GI-tract organs (P<0.05). The different levels of MP significantly increased ileal digestibility of nutrients, tibia ash, Ca and Mg contents in tibia ash (P<0.01), but had no significant effect on measured GI-tract organs. The diets having 1000 unit of MP caused a significant improvement on performance factors (P<0.05) and P content in tibia ash (P<0.01). These results demonstrated that addition of MP and 3% CA to the diet caused improvement in ileal nutrients digestibility, growth performance and increased minerals retention of broiler chickens.

Efficacy of Phytase Preparations to Improve P Availability in Young Turkeys

Phytate phosphorus of plant ingredients is not substantially available to poultry because of the lack of endogenous phytase enzymes in their gastrointestinal tract. There are substantial differences among broilers, turkeys, and ducks in terms of plant P utilization. We studied whether the availability of P is different for two Phytase enzymes in turkeys. Finase and a New Phytase product developed recently were tested in 3 to 5 week old turkeys. The efficacy of Finase and the New Phytase were determined on the basis of P balance and tibia data. A low P maize soybean meal based diet was supplemented at 0, 250 and 500 FTU/kg levels of Finase and 0, 250, 500 and 750 FTU/kg of the New Phytase. Excretions were collected in a balance trial and tibia parameters were obtained after the turkeys had received their respective diets for 17 days. Utilization of P from the basal diet was 35.5% which significantly improved by Finase to a maximum of 47.3% and by the New Phytase to a maximum of 48.7% at the highest level of supplementation. The utilization of Ca did not improve. Tibia ash concentration improved by Finase and the New Phytase supplementation. It is concluded that the Finase and the New Phytase efficiently improve the utilization of P in turkeys and may help protect the environment by causing a reduction in excretion P.

Effects of Balancing Rice Bran Based Diets for Up to Four Amino Acids on Growth Performance of Broilers

Objective of this study was to determine whether the adverse effects associated with high dietary rice bran (RB) inclusion levels in broiler diets could be corrected by balancing diets for higher number of amino acids (AA). The experiment followed a completely randomize design in 2x4 factorial arrange-ment. Eight experimental diets were formulated using linear model based computer software (CUFATotal Feed). Treatment factors were two dietary RB levels (20 and 40%) and four levels of AA considerations in ration formulation (1. lysine and methionine, 2. 1 + isoleucine, 3. 2 + valine, 4. 3 + threonine). When rations were balanced for lysine and methionine, many of the other AAs were in ex-cess. No practical ration could be formulated to meet the threoine requirement. Twenty-two-day old broiler chicks (n=144) were allocated into 48 pens and fed one of the eight experimental diets ad libitum from 23-43 days. Balancing the diets for higher number of AAs had no significant effect on any of the growth performance parameters. Live weight on day 43, weight gain from day 23-43 and feed intake and the tibia ash contents of the broiler fed 40% dietary RB were significantly lower than those of 20% RB fed counterparts. However, feed conversion ratios were not significantly different between the birds fed two dietary RB levels. Interaction between RB levels and the number of AAs considered in ration formulation was not significantly different with respect to any of the growth parameters measured. It was concluded that balancing rations for up to four amino acids; lysine, methionine, isoleucine and va-line did not mitigate the adverse effects of 40% dietary RB in broiler growth performance. Key words: Amino acids; Broiler performance; Rice bran DOI: 10.4038/tare.v12i2.2790 Tropical Agricultural Research & Extension 12(2): 2009 pp.57-61

Growth performance and nutrient utilization of broiler chickens fed diets supplemented with phytase alone or in combination with citric acid and multicarbohydrase

An experiment was conducted to determine the effect of supplementing a corn-soybean meal-based diet with phytase alone or in combination with citric acid (CA) or multicarbohydrase, a preparation containing nonstarch polysaccharide-degrading enzymes, or both, on growth performance, nutrient utilization, and bone mineralization. A total of 360 one-day-old broiler chicks were assigned to 6 dietary treatments, consisting of 12 pens of 5 birds each, and were fed experimental diets from 1 to 21 d of age. The diets included a positive control (0.46% nonphytate P; 1.1% Ca) and a negative control (NC; 0.26% nonphytate P; 0.89% Ca) without or with phytase (600 U/kg) alone, phytase plus CA (5 g/kg), phytase plus multicarbohydrase (Superzyme OM; 0.6 g/kg), or phytase (Ronozyme P-CT) plus CA and multicarbohydrase. Birds fed the positive control diet had higher (P<0.05) BW gain (764 vs. 594 g/21 d) and tibia ash content (50.0 vs. 38.3%) than those fed the NC diet. Phytase improved (P<0.05) BW gain (632 g/21 d), which increased further (P<0.05) to 673 g/21 d for the phytase plus multicarbohydrase diet. In contrast to phytase alone, phytase plus multicarbohydrase supplementation improved (P<0.05) feed conversion ratio of the NC diet from 1.37 to 1.32. Tibia ash content for the NC diet increased (P<0.05) from 38.3 to 42.4% due to phytase addition. Phytase improved (P<0.05) ileal digestibility of P from 29.5 to 43%, and the addition of CA or multicarbohydrase, or both, to a phytase-supplemented diet further increased (P<0.05) P digestibility to 51.5, 53.4, and 54.3%, respectively. Phytase addition improved (P<0.05) diet AMEn content from 2,959 to 3,068 kcal/kg, which tended (P<0.06) to increase further with CA (3,150 kcal/kg) or multicarbohydrase (3,142 kcal/kg) addition. No beneficial interactions were detected between CA and multicarbohydrase for all response criteria measured. Results show that addition of multicarbohydrase to the phytase-supplemented broiler diets improved nutrient utilization and growth performance.

Effect of dietary citric acid, flavomycin and their combination on the performance, tibia ash and immune status of broiler

The goal of this research was to investigate the effect of citric acid (CA), the antibiotic growth promoter flavomycin (FL) and their combination on the growth performance, tibia ash and immune status of broilers. One hundred and sixty straight run day-old broiler chicks (Hubbard Classic) were randomly distributed into four dietary groups, with four replicate cages having 10 birds in each. Standard corn-soybean-based basal starter diet was given to control birds. Diets for other groups were further fortified by 0.5% CA, 0.001% FL and their combination (0.5% CA plus 0.001% FL). On day 35, CA and its combination (CA + FL) group had 17 and 12% increase in live weight compared with control, respectively (P &lt; 0.05). Total live weight on day 35 was 1141, 1337, 1169, and 1275 g bird-1 in different groups, respectively (P &lt; 0.05). Cumulative feed intake was higher (P &lt; 0.05) in CA and its combination (CA + FL) compared with the control and FL groups on day 28. Supplementation with CA improved (P &gt; 0.05) feed conversion ratio [FCR; feed intake (kg):weight gain (kg)] compared with FL and its combination (CA + FL). Carcass yield was increased (P &gt; 0.05) due to the addition of CA and its combination (CA + FL). Tibia ash content in the CA group (59.0) was higher (P &lt; 0.05) than in the control (53.6%), FL (53.1%) and their combination (57.1%). The lymphocyte cells associated with immunity in the lymphoid organs (caecal tonsil, bursa Fabricius and ileum) were more densely populated, suggesting an increased level of innate immunity in the CA group. Overall mortality was low (1.25%), and there were no treatment-related effects on mortality. Citric acid reduced the pH of formulated feeds, but mild reduction was found in the pH of the faeces. Dietary supplementation of 0.5% CA increase weight gain, feed intake, tibia ash deposition and non-specific immunity (P &lt; 0.05) as well as feed efficiency and carcass yield (P &gt; 0.05) of broilers. Citric acid has potential as a growth promoter to replace the antibiotic growth promoter FL.Key words: Citric acid, flavomycin, growth performance, immunity, tibia ash, broiler

Meta-analysis of phosphorus utilisation by broilers receiving corn-soyabean meal diets: influence of dietary calcium and microbial phytase

Pollution relative to phosphorus excretion in poultry manure as well as the soaring prices of phosphate, a non-renewable resource, remain of major importance. Thus, a good understanding of bird response regarding dietary phosphorus (P) is a prerequisite to optimise the utilisation of this essential element in broiler diets. A database built from 15 experiments with 203 treatments was used to predict the response of 21-day-old broilers to dietary non-phytate P (NPP), taking into account the main factors of variation, calcium (Ca) and microbial phytase derived from Aspergillus niger, in terms of average daily feed intake (ADFI), average daily gain (ADG), gain to feed (G:F) and tibia ash concentration. All criteria evolve linearly (P < 0.001) and quadratically (P < 0.001) with dietary NPP concentration. Dietary Ca affected the intercept and linear component for ADG (P < 0.01), G:F (P < 0.05) and tibia ash concentration (P < 0.001), whereas for ADFI, it affected only the intercept (P < 0.01). Microbial phytase addition impacted on the intercept, the linear and the quadratic coefficient for ADFI (P < 0.01), ADG (P < 0.001) and G:F (P < 0.05), and on the intercept and the linear component (P < 0.001) for tibia ash concentration. An evaluation of these models was then performed on a database built from 28 experiments and 255 treatments that were not used to perform the models. Results showed that ADFI, ADG and Tibia ash concentration were predicted fairly well (slope and intercept did not deviate from 0 to 1, respectively), whereas this was not the case for G:F. The increase in dietary Ca concentration aggravated P deficiency for all criteria while phytase addition had a positive effect. The more P deficiency was marked, the more the bird response to ADFI, ADG, G:F and tibia ash concentration was exacerbated. It must also be considered that even if the decrease in dietary Ca may improve P utilisation, it could in turn become limiting for bone mineralisation. In conclusion, this meta-analysis provides ways to reduce dietary P in broiler diets without impairing performance, taking into account dietary Ca and microbial phytase.

Evaluation of equivalency values of microbial phytase to inorganic phosphorus in 22- to 42-day-old broilers

SUMMARY This experiment was conducted to evaluate the equivalency values of microbial phytase to inorganic phosphorus (Pi) in 22- to 42-d-old broilers fed a corn-soybean meal diet. Ten dietary treatments were designed in which diet 1 was the basal diet [calcium 0.90%, total phosphorus 0.35%, nonphytate phosphorus (NPP) 0.13%] and diet 4 was control (calcium 0.90%, total phosphorus 0.57%, NPP 0.35%). Diets 2 and 3 included 0.20 and 0.27% of NPP, and diets 5 to 10 contained graded levels of microbial phytase (125, 250, 500, 1,000, 2,000, and 4,000 U/kg of diet). Body weight gain, feed intake, phosphorus retained, plasma Pi concentration, tibia ash content, and tibia-breaking strength increased, but plasma calcium concentration decreased with increasing dietary NPP content (from 0.13 to 0.35%) or phytase activity. Microbial phytase caused an increase, whereas dietary NPP caused a decrease in phytate phosphorus (PP) retention. When 4,000 U of phytase was added to the basal diet with 0.13% NPP, 95% PP was released based on tibia ash content, and broiler BW gain and feed intake were equal to those of broilers fed the control diet (NPP 0.35%). Microbial phytase at 125, 250, 500, 1,000, 2,000, and 4,000 U/kg of diet was determined to be equivalent to the addition of 0.035 to 0.208% of Pi from dicalcium phosphate in 22- to 42-d-old broilers. These data suggest that high levels of microbial phytase could release almost all dietary PP and replace all supplemental Pi in growing-finishing broilers.