نویسنده: drghlmkriactivemngr

Application

Environmental and economic concerns regarding phosphorus (P) in broiler production pledge a reduction in dietary P provision. However, to maintain growth performance and bone mineralisation, optimisation of P utilisation appears crucial.

Introduction

In broilers, P is involved in many essential functions, representing a Ney element in the maintenance of growth performance and bone mineralisation (Le ́ tourneau-Montminy et al., 2010). Thus, it must be of major concern that current economic and environmental pressures leading to an unavoidable decrease in dietary P supply represent a threat to animal productivity. Then it is necessary to find P sources with high levels of bioavailability. The aim of the present study was to determine the bioavailability of P from six commercial sources of dicalcium phosphate (DCP2: 17.75% P; DCP3: 17% P; DCP4: 17% P; DCP5: 18.5% P; DCP6: 17% P; DCP7: 18.06% P) relative to standard source (P1=Phosphoric acid 85%, contains 26.87% P), for broiler chicNs.

Material and methods

A total of 440 1-d-old Ross-308 female broiler chicNens were randomly allotted to 1 of 4 replicate cages (5 chicNs/cage) for each of 22 treatments in a completely randomized design involving seven P sources and 3 levels of added P (0.15, 0.30, or 0.45%) plus a control diet containing 0.15% available P. Feed and water were available ad libitum for an experimental phase of 42-d. Data were analysed using the GLM procedure of SAS. Duncan’s multiple range test was used to determine differences among treatment means at P<0.05. Relative bioavailability values of P were estimated using P1 as the standard source by slope ratio comparison from multiple linear regressions (Little et al., 1997).

Results

Body weight gain (BW), average daily feed intaNe, FCR, carcass and breast fractional weight, alNaline phosphatase (ALP), tibia characteristics (length (L), ash content, bone strength (BS)) were different significantly, between P levels and sources at 42d. Based on slope ratios from the linear regression of BW, FCR, ALP, BS, L and ash%, on added levels of available P, the bioavailability of P in source no. 2, 3 and 7 were the same, relative to phosphoric acid.

Conclusion

Phosphorous originated from sources no. 2, 3, 5 and 7 were 20% and 40% more available to broilers than sources no. 4 and 6, respectively, in enhancing tibia length (Figure 1).

چاپ مقاله در انتشارات کمبریج

Application

An evident concept is that choline bioavailability is <100% in corn-soybean meal diets, but choline is essential for prevention of fatty liver and perosis in poultry.

Introduction

It has long been Nnown that chicNens fed corn-soybean meal diets containing choline in excess of the NRC (1994) requirement, still need supplemental choline to achieve maximum growth (Marvel et al. 1943). The aim of the present study was to evaluate three commercial sources of choline (product of Belgium (CHO1), China (CHO2) and Germany (CHO3) for broiler chicNen.

Material and methods

Two hundred female broiler chicNens (Ross 308) reared in a 42 days trial. Ten dietary treatments included three dietary added levels of choline (400, 800 and 1200 mg/Ng) to the basal diet (contained 862 mg choline/Ng). Birds received experimental feed ad libitum. Treatments replicated 4 times each included five chicNens in a completely randomized design. Performance (body weight gain and feed conversion ratio), carcass characteristics (breast, thighs, liver and abdominal fat fractional weight), liver fat content, different fatty acids (palmitic acid, oleic acid, linoleic acid, palmitoleic acid : stearic acid) in liver fat content and also bone physical properties were compared statistically. Data were analysed using the GLM procedure of SAS. Duncan’s multiple range test was used to determine differences among treatment means at P<0.05. Relative bioavailability values of choline were estimated using CHO2 as the standard source by slope ratio comparison from multiple linear regressions (Little et al., 1997).

Results

Performance, carcass and bone characteristics had no significant difference between sources of commercial choline. Relative bioavailability of mentioned sources of choline did not show significant difference (Table 1).

Table 1

Relative bioavailability values (RBV) of choline sources (CHO1 and CHO3) in comparison with reference source (CHO2) based on slope ratios from linear regressions of feed conversion ratio, liver fat content, palmitoleic acid:stearic acid and bone strength on added levels of choline to basal diet at 42 days of age Dependent variable Choline

Conclusion

It is not necessity to add excess sources of choline to corn-soybean meal diets with low levels of metabolizable energy (ME) and crude protein (CP), because of same performance (P>0.05) of birds which received different levels of choline. The re-evaluation of choline requirement of broiler chicNens offered corn-soybean meal diets with high levels of ME and CP is recommended to achieve optimum performance.

چاپ مقاله در انتشارات کمبریج

Abstract

This study aimed to evaluate the relative bioavailability value (RBV) of different manganese mono oxide (MnO) sources and manganese sulfate (MnSO4) in broiler diets as well as their effect on tibial characteristics, and serum inorganic phosphorous (P), calcium (Ca) and Mn concentrations. The experiment was carried out based on a completely randomized design (CRD) with 660 broiler chicks (Ross 308) assigned to 12 dietary treatments with 6 replicates of 10 birds each.

The experimental diets consisted of one basal diet (as control), and 10 treatment groups which were supplemented with 400 or 800 mg/kg of feed of 1-5 MnO sources with 35%, 25%, 45-55%, 30%, and 40% purities, respectively; MnSO4 was also used (800 mg/kg of feed) in a treatment group as a reference standard with 100% bioavailability. The mean RBV of MnO sources (27.27 to 181.82%) showed a significant difference (P<0.05). The results also showed sera Ca and Mn concentrations, and retention of Mn in diet and tibia bone were significantly affected by different Mn sources used (P<0.05).
Although no differences were observed for sera P, Ca, and Mn concentrations, regardless of the level of supplementation (P<0.05). The results of this study demonstrated that the purity of Mn supplement sources has a relationship with RBV of Mn, Mn absorption, and its retention in broiler bone and ileum.

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