Effects of broiler breeder management on pullet body weight and carcass uniformity.

An experiment was conducted to study the effect of broiler breeder feeding management practices on pullet performance, BW uniformity, and carcass traits during rearing (to 22 wk of age). At 3 wk of age, 1,200 Ross 308 breeder pullets were assigned to one of 5 treatments: 1) control: standard mash diet, fed daily; 2) high fiber: mash diet containing 25% lower nutrient density, fed daily; 3) scatter: standard diet in pellet form scattered on litter, fed daily; 4) skip-a-day: standard mash diet, fed on alternate days; or 5) grading: standard mash diet, fed daily (birds sorted into low, average, and high BW groups every 4 wk). Birds on the high fiber treatment consumed more feed (P<0.0001) and had the highest feed conversion ratio (FCR; P<0.004) but the lowest ME to gain and CP to gain ratios (P≤0.002). Skip-a-day treatment pullets consumed more ME and CP than birds in any other treatment (P<0.001). Grading yielded the highest BW uniformity at 22 wk of age (CV=6.2%), while control and high fiber treatment groups were least uniform (CV>15%; P<0.0001). Skip-a-day feed restriction produced birds with the significantly lowest breast muscle and highest liver weight compared to all other treatments (P<0.05). Variation in shank length, chest width, and breast muscle was lowest in the grading treatment, whereas the CV for fat pad and liver was lowest in the skip-a-day treatment. In this trial, broiler breeder target BW profiles were achieved using combinations of quantitative and qualitative feed restriction, or preemptive management practices. Qualitative diet dilution and skip-a-day management did little to increase flock uniformity relative to the control during the most intense period of feed restriction (7 to 19 wk). Scatter feeding increased flock uniformity to a small degree, whereas grading yielded the highest increase in BW and carcass trait uniformity.

Modeling ovarian follicle growth in commercial and heritage Single Comb White Leghorn hens.

Approximately 84% of the energy in chicken eggs resides in the yolk. A robust model of ovarian follicle development is therefore valuable for estimating energy requirements of laying hens. The current experiment was designed to model the growth of ovarian follicles in 32-wk-old modern commercial line (CL) and unselected heritage line (HL) Single Comb White Leghorn hens. The volume of yolk deposited daily during the rapid growth phase (RGP) was estimated using a double dye technique. For 21 d, 8 CL and 8 HL hens were fed capsules (no. 1) containing Sudan IV (red) and Sudan Black dyes on alternate days. An additional 8 control CL hens were fed empty capsules. Eggs were collected, and the daily volume of yolk deposited was estimated. Significant differences are reported where P < 0.05. Dye had no significant effect on BW, ME intake, or egg weight. Maintenance ME requirements were 192 and 177 kcal/kg(0.67) for CL and HL hens, respectively. Duration of the RGP was shorter (7.35 d) in the CL hens compared with the HL hens (7.95 d). A nonlinear Lomolino model described follicular weight, which varied between strains over d 2 to 9 of follicle development; at each day during development, follicle weights were higher where RGP were shorter. The volume of yolk deposited for the 8 d preceding oviposition in CL was 0.17, 0.28, 0.43, 0.99, 1.84, 2.47, 2.82, 2.86, and 2.51 cm(3); and in HL was 0.17, 0.33, 0.72, 1.40, 2.15, 2.46, 2.48, 2.32, and 1.93 cm(3). The HL had a higher rate of yolk deposition 7 to 5 d before oviposition, and CL had a higher rate of yolk deposition 3 to 1 d before oviposition with no significant difference between lines on d 4 before oviposition. Although growth patterns differed, there were no differences among lines in final follicle weights (14.1 g) or retained energy (42.4 kcal).

Effect of bird cage space and dietary metabolizable energy level on production parameters in laying hens.

A study was conducted to assess the effects of varying cage spaces on a commercial laying hen strain fed differing levels of dietary metabolizable energy (ME) for 15 wk. Four cage space allowances (342, 413, 516, and 690 cm2/hen) were combined with 3 levels of dietary ME (2,800, 2,850, and 2,900 kcal of ME/kg) in a 4 x 3 factorial arrangement. Each treatment was assigned to 6 replicate cages for a total of 72 cages in randomized complete block design. Feed intake and metabolizable energy intake were significantly (P < 0.01) greater for hens housed at 690 cm2/hen compared with those housed at 413 and 342 cm2/hen, but not those housed at 516 cm2/hen, across all dietary ME levels. Egg production and egg mass were significantly (P < 0.001) improved for hens housed at 690 cm2/ hen in contrast to other cage spaces and across all energy levels. There were no interaction effects of ME levels on laying hen performance at varying cage space except for body weight change. Hens housed at 516 cm2/ hen and fed 2,800 kcal of ME/kg exhibited the greatest weight change, which was significantly (P < 0.05) greater than those fed other levels of ME at the same cage space. Hens housed at 690 cm2/hen had significantly (P < 0.05) greater ME efficiency of egg production than hens housed at other cage spaces. Hens fed the diet with 2,900 kcal of ME/kg had significantly (P < 0.001) greater ME digestibility compared with those fed 2,800 or 2,580 kcal of ME/ kg with differences of 107 and 118 kcal of ME/kg, respectively. There were no significant effects of ME levels observed except ME digestibility, and no significant effects of cage space allowance on egg weight, hen weight, bone ash, or maintenance energy intake. It is evident that decreasing the number of birds per cage and increasing cage space allowance per hen had an overall positive effect on performance.

Effect of supplementation of two different sources of phytase on egg production parameters in laying hens and nutrient digestiblity.

Hens were fed corn-soybean meal diets containing 0.35, 0.25, 0.15, or 0.10% nonphytate phosphorus (NPP) (40 to 60 wk). Phytases A and B were added at 0.25, 0.15, and 0.10% at 250 to 300 units of phytase (FTU)/kg feed in a 3 x 3 factorial; 0.35% was a control diet. Treatments were replicated with eight cages per treatment (five hens per cage) in a randomized complete block design. Phytase supplementation had a significant effect on several production parameters: feed intake, feed conversion, and egg mass. Results showed nonsignificant effects (P < 0.06) on feed intake when hens were supplemented with phytase A or B and consumed more feed compared to the basal diet at 0.10% NPP. The feed conversion of birds fed 0.10% NPP without phytase was the least efficient compared to the other nine treatments (P < 0.05). Egg mass was significantly greater for hens supplemented with phytases A and B than for hens fed the basal diet at low (0.10%) NPP (P < 0.05). There were no significant differences in egg production, egg weight, specific gravity, Haugh units, wet shell, or dry yolk percentages. Dry shell percentage was higher among basal diets at 0.15 and 0.25% NPP in contrast to phytase, whereas albumen and dry yolk percentages were significantly higher for diets with phytase than for the basal diet at 0.10% NPP. Bone ash percentage was uncharacteristically high in hens fed 0.10% NPP without phytase; however, mortality was 22% in this group. Phytase supplementation improved Ca and P digestibilities to varying degrees. Supplementation of phytase in normal, corn-soybean meal diets improved feed intake, feed conversion, and egg mass and elicited a response in shell quality and egg components at the low (0.10%) NPP.

6-L-alanineferrirubin, a ferrichrome-type siderophore from the fungus Aspergillus ochraceous.

The molecular structure of 6-L-alanineferrirubin tetradecahydrate, [Fe(C41H64N9O16)].14H2O, has been determined in order to confirm its chemical structure. The structural results show that the presence of an alanine in place of a serine or a glycine at position 6 in the cyclic hexapeptide has very little effect on the conformation of the 18-membered ring or on the geometry of the octahedral iron coordination.

Formation of Ent-isophleichrome by Cladosporium herbarum Isolated from Sugar Beet.

An isolate of Cladosporium herbarum obtained from leaves of sugar beet produced a phytotoxic red pigment which was identified as ent-isophleichrome (1). Production of the pigment was dependent on composition of the culture medium. The toxicity of ent-isophleichrome to sugar beet was strongly influenced by light. The polyketide biosynthetic origin of ent-isophleichrome in C. herbarum was demonstrated by (13)C acetate labelling/(13)C NMR studies.

Structure and molecular mechanics of ferrirhodin.

C41H64FeN9O17.7 1/2H2O, Mr = 1146.0, orthorhombic, P2(1)2(1)2(1), a = 9.740 (7), b = 16.764 (10), c = 32.632 (17) A, V = 5328 (6) A3, Z = 4, D chi = 1.43 g cm-3, Mo K alpha, lambda = 0.71069 A, mu = 3.26 cm-1, F(000) = 2428, T = 138 (2) K, R = 0.0986 for 3543 observed reflections. Ferrirhodin, a ferrichrome siderophore (iron transport agent) was isolated from low-iron cultures of Aspergillus versicolor and A. nidulans. The compound is isomeric with another microbial siderophore, ferrirubin, but is different in having cis, rather than trans, anhydromevalonic acid as acyl groups. The conformation of the molecular backbone and iron coordination geometry compares well with ferrirubin and other ferrichrome structures. The differences between the acyl groups of ferrirubin and ferrirhodin are explored using molecular-mechanics modeling.

Purification and crystallization of ferric enterobactin receptor protein, FepA, from the outer membranes of Escherichia coli UT5600/pBB2.

The ferric enterobactin receptor protein, FepA, was isolated and purified from the outer membranes of a genetically transformed strain of Escherichia coli (UT5600/pBB2) using anion-exchange chromatography, chromatofocusing and gel filtration. The purified protein was found to crystallize from 25 mM sodium phosphate buffer in the presence of 0.8% beta-D-octylglucoside under a range of conditions. The protein formed mostly small rods and needle-shaped crystals in the hanging drop method.

Siderophores of highly phytopathogenic Alternaria longipes. Structures of hydroxycoprogens.

Alternaria longipes ATCC 26293, a highly phytopathogenic fungus, has been found to produce a large number of siderophores under iron-deficient conditions. Most of the compounds are members of the coprogen family. Structures of three novel siderophores, termed hydroxycoprogens, have been determined by 1H and 13C NMR, FAB mass spectrometry and partial hydrolysis. The compounds are analogs of coprogen, neocoprogen I and isoneocoprogen I, in which one of the terminal trans-anhydromevalonic acid residues is replaced by a trans-4,5 dihydroxy-3-methyl-2-pentenoic acid residue.

Structure of ferrichrome-type siderophores with dissimilar N delta-acyl groups: asperchrome B1, B2, B3, D1, D2 and D3.

Asperchromes are a series of iron-chelating compounds which contain a cyclic hexapeptide backbone as in ferrichrome siderophores and differ from the latter in having heterogenous acyl groups in the ornithine side chains. The molecular structures of the asperchrome B and D series have been determined by 1H- and 13C-NMR spectroscopy; single-crystal X-ray diffraction was used to determine the detailed structural features of asperchrome B1 and asperchrome D1. Asperchrome B1 crystallizes in the triclinic space group P1 with a = 1.3143(5) nm, b = 1.2200(5) nm, c = 0.8949(3) nm, alpha = 105.17(4) degrees, beta = 94.03(3) degrees, gamma = 109.65(3) degrees, V = 1.2843 nm3, Z = 1, rho chi = 1.446 g cm-3. Final R = 0.054 for 4625 reflections measured at 138 K using MoK alpha. Asperchrome D1 crystallizes in the monoclinic space group P2(1) with a = 1.2248(11) nm, b = 1.3795(9) nm, c = 1.3644(6) nm, beta = 93.24(6) degrees, V = 2.3016 nm3, Z = 2, rho chi = 1.418 g cm-3. Final R = 0.110 for 3180 reflections measured at 138 K using MoK alpha radiation. The conformation of the molecular backbone and iron coordination geometry in both asperchrome B1 and D1 compare well with those observed in other known ferrichrome siderophores. The differences in the acyl groups are illustrated and the structural results are correlated with their iron transport properties.

N alpha-dimethylcoprogens. Three novel trihydroxamate siderophores from pathogenic fungi.

Three novel siderophores have been isolated from a highly pathogenic strain of Alternaria longipes (ATCC 26293). The compounds are N alpha-dimethylated analogs of coprogen, neocoprogen I and isoneocoprogen I. Structures of the compounds have been determined by 1H- and 13C-NMR, fast-atom-bombardment (FAB) mass spectroscopy and partial hydrolysis. One of the new compounds, N alpha-dimethylcoprogen, is also produced, as the major siderophore, in another fungus, Fusarium dimerum.

Siderophore mediated iron(III) uptake in Gliocladium virens. 2. Role of ferric mono- and dihydroxamates as iron transport agents.

The Fe(III) transport properties of the monohydroxamates, cis-fusarinine (cF) and trans-fusarinine (tF), and the dihydroxamate, dimerum acid (DA), the major siderophores of the fungus, Gliocladium virens ATCC 24290, have been investigated using labeled ferric siderophores. Fe(cF)3, Fe(tF)3 and Fe2(DA)3 (and also one of the minor trihydroxamates, ferricrocin) transport extracellular 55Fe(III) very efficiently into the fungus. Coprogen, another minor trihydroxamate, behaves as a weak Fe(III)-transporting agent. The respiratory poisons, KCN and NaN3, significantly inhibit uptake activity, indicating that the Fe(III) uptake mediated by Fe(cF)3, Fe(tF)3, and Fe2(DA)3 involves active transport systems in the membrane. A number of fungal species, both producers and nonproducers of cF, tF, and DA, show ability at varying degrees to transport 55Fe(III) bound to these siderophores.

Siderophore mediated iron(III) uptake in Gliocladium virens. 1. Properties of cis-fusarinine, trans-fusarinine, dimerum acid, and their ferric complexes.

Gliocladium virens (ATCC 24290) produces two monohydroxamates (cis- and trans-fusarinine) and a dihydroxamate (dimerum acid) as the major siderophores in the culture filtrate. This fungus also produces minor quantities of three trihydroxamates (the deferri forms of ferricrocin, coprogen B, and coprogen). Structural features of the free ligands and the metal complexed forms of cis-fusarinine (cF), trans-fusarinine (tF), and dimerum acid (DA) have been investigated using electronic (visible), circular dichroism (CD), and NMR spectroscopy. In aqueous solution, in the pH range of 6.5-8.0, all of the ferric complexes of cF (and tF) exist as 3:1 chelates. Fe(cF)3 [or Fe(tF)3] forms both lambda and delta coordination isomers, but the former in a slight excess. DA forms a 3:2 ferric complex in the pH range of 5.0-8.0. Iron coordination in Fe2(DA)3 is predominantly delta. DA ligands in Ga2(DA)3 exist as two different conformers at a ratio of 2:1. In mixed solution cF, tF, and DA form a large number of homogeneous and heterogeneous Fe(III) chelates.

Molecular recognition of siderophores in fungi: role of iron-surrounding N-acyl residues and the peptide backbone during membrane transport in Neurospora crassa.

Recognition of ferric siderophores in Neurospora crassa was found to depend on the number and kind of N-acyl residues that surrounded the iron coordination center. In the coprogen series, uptake decreased in the order of coprogen, neocoprogen I, and neocoprogen II, indicating that gradual replacement of the N-transanhydromevalonyl groups by N-acetyl groups had an adverse effect on uptake. The reverse effect was observed in the ferrichrome series, where uptake decreased in the order of ferrichrysin, asperchrome D1, asperchrome B1, and ferrirubin. Configuration of the anhydromevalonyl group (cis or trans) in ferrichromes was also an important determinant in the recognition process. On the basis of uptake and inhibition studies, it is proposed that in ferrichromes part of the molecule (iron configuration and the N-acyl groups) is responsible for binding, whereas another (cyclic peptide ring) is involved in the subsequent process of transport.

Separation of ferrichromes and other hydroxamate siderophores of fungal origin by reversed-phase chromatography.

Iron(III) chelates of nineteen trihydroxamate siderophores of fungal origin, including ferrichromes, coprogen and triacetylfusarinine C, were separated on a preparative scale with a reversed-phase column using the octadecyl silica gels LRP-1 or LRP-2 as the stationary phase and a water-methanol gradient as the mobile phase. Using this system in combination with silica gel column chromatography, most siderophores can be obtained in pure form. Factors affecting the mobility of these compounds in the reversed-phase system are discussed.

Extracellular siderophores from Aspergillus ochraceous.

A large number of iron-chelating compounds (siderophores) were isolated from supernatants of iron-deficient cultures of a mold isolate, subsequently identified as Aspergillus ochraceous . Siderophores in their iron chelate form were purified to homogeneity by using Bio-Gel P2, silica gel, and C-18 bonded silica gel (reverse-phase) columns. Most of these compounds, as identified by 1H and 13C nuclear magnetic resonance spectroscopy and X-ray crystallography, belong to the ferrichrome family. The organism produces ferrirubin and ferrichrysin as the predominant and the second major compound (62 and 15% of the total siderophores), respectively. Ferrichrysin appears as the first siderophore in the medium on day 2 of growth. Several of the other siderophores are novel and ranged in quantities from 0.2 to 5% of the total. The trivial names asperchrome A, B1, B2, C, D1, D2, and D3 are proposed for these novel compounds, which are all members of the ferrichrome family, and all but the first one contain a common Orn1 - Orn2 - Orn3 - Ser1 -Ser2-Gly cyclic hexapeptide ring with three dissimilar ornithyl delta-N-acyl groups. Another compound which appeared late in the growth period was similar to fusarinine C ( fusigen ). All of these compounds showed growth factor activity to various extents in bioassays with Arthrobacter flavescens Jg-9. None of these compounds showed antibacterial activity against Escherichia coli or Bacillus megaterium.