Effect of altering dietary mineral balance on growth, leg abnormalities, and blood base excess in broiler chicks.
Broiler cockerels were used in four trials of 3-wk duration to investigate the effects of altering dietary cation:anion ratios on chick growth, leg abnormalities, bone, and blood parameters. Dietary cation content was changed using Ca and Mg, whereas the anions P, Cl, and S were included at various levels, giving several total cation:anion ratios with several levels of ions. Narrowing the cation:anion ratios increased 3-wk body weights and the incidence of both dyschondroplasia and varus deformation. Further increases in dietary anion concentration generally caused a slight depression of body weights. Supplementation of Ca or Mg to diets containing high levels of anion relative to cation decreased the incidence of leg problems and lowered 3-wk body weights. Blood pH was not significantly affected by dietary mineral alterations, although pH tended to decrease as anion content was increased. Addition of P significantly reduced blood HCO3 and base excess (meq/L). Base excess was negatively correlated (P less than .05) with the incidence of TD and 3-wk body weights. Two strain-crosses of broiler cockerels, fed diets which had previously increased the incidence of leg abnormalities, exhibited no significant differences in the incidence of varus deformation or dyschondroplasia. The strain-cross of chicks having the lowest base excess had higher incidences of both leg disorders, although body weights were identical.
Halley
J T
JT
Department of Animal Sciences, University of Arkansas, Fayetteville 72701.
Nelson
T S
TS
Kirby
L K
LK
Johnson
Z B
ZB
D000136:Acid-Base Equilibrium; D000818:Animals; D000838:Anions / Q000378:metabolism; D001835:Body Weight; D002412:Cations / Q000378:metabolism; D002645:Chickens / Q000254:growth & development*; D004032:Diet; D006614:Hindlimb / Q000002:abnormalities*; D006863:Hydrogen-Ion Concentration; D008297:Male; D008903:Minerals / Q000378:metabolism*
D000838:Anions; D002412:Cations; D008903:Minerals