The Effect of Feeding Calcium- and Phosphorus-Deficient Diets to Broiler Chickens During the Starting and Growing-Finishing Phases on Carcass Quality

Abstract

There is considerable data on the effect of reducing inorganic Ca and P in broiler finisher diets on carcass quality. However, there is limited information on the effect of reducing dietary Ca and P during the different phases of growout. Two experiments were conducted from 0 to 35 d in floor pens. In both experiments, at least 4 replicates per treatment (50 chicks per replicate) were used. Corn-soybean meal and soybean oil-based diets deficient in Ca and P were fed. During the starter phase (ST), from 0 to 18 d, chicks were fed a 23% CP diet containing 0.60% Ca and 0.47% total P (tP). During the grower-finisher phase (GF), from 19 to 35 d, birds were fed a 19% CP diet containing 0.30% Ca and 0.37% tP. A combination of 1,000 phytase units/kg of Natuphos phytase and 5 microg/kg of 1alpha-hydroxycholecalciferol (P + 1alpha) was supplemented to some of the feed during the ST and GF. Diets containing adequate Ca and P were also fed during the ST (0.90% Ca and 0.68% tP) and GF (0.80% Ca and 0.67% tP). The level of tibia ash and the incidence of bone disease were measured at 18 and 35 d. At the end of the experiments, birds were processed and evaluated for muscle hemorrhages and broken bones. In both experiments, broilers fed diets that were not P + 1alpha supplemented demonstrated poor bone mineralization, considerable leg problems, and a high incidence of broken bones after processing. Broilers fed P + 1alpha throughout had more broken clavicles and femurs compared with birds fed the adequate diets. Day-18 tibia ash was significantly correlated to broken tibias and femurs during processing. Day-35 tibia ash was better correlated to bloody breast meat than to broken bones. It is concluded that carcass quality depends on the levels of Ca and P fed and the age of the bird. Tibia ash, traditionally used as an indication of bone strength, was better correlated to the incidence of bloody breasts.

Cumulative effect of phytase and vitamin D supplementation on performance and bone mineralization in broiler

“…In other studies by Ahmad et al (2000) and it was reported that P deficient diets result in decreased bone ash percentage and supplementation of phytase improved the bone ash contents. Driver et al (2006) performed an experiment to evaluate tibial strength with toe and tibia ash by supplementation of different phytase levels in feed. They reported that microbial phytase addition in diets increased toe and tibia ash.…”

Whole hatchery waste meal as alternative protein and calcium sources in broiler diets

“…Values recorded for abdominal fat and internal organs (liver, lungs, heart and gizzard) did not show any particular trend. Carcass quality depends on the level of calcium and phosphorus fed to animals (Driver et al, 2006). There were slight variations in the results obtained for blood parameters (table V) such as WBC, RBC, HGB, HCT, MCH and MCHC.…”

Effects of Broiler Litter Management Practices on Phosphorus, Copper, Zinc, Manganese, and Arsenic Concentrations in Maryland Coastal Plain Soils

“…The slightly higher pH observed in the soil is likely due to incorporation of the broiler litter. Broiler litter contains some residual calcium carbonate (CaCO 3 ) from the diets; CaCO 3 is added to the broiler diets to increase bone density (Driver et al 2006). A common farming practice on most of these farms in the past, before no-till planting was introduced, was deep incorporation of the broiler litter before planting.…”

“…The broiler diet is supplemented with nutrients [e.g., phosphorus (P)] and metals [e.g., copper (Cu), zinc (Zn), manganese (Mn), and arsenic (As)] to stimulate growth, increase feed performance, and to ensure healthy birds (National Research Council 1994;Driver et al 2006). In many cases, feed supplements are added in excess of the animals' needs and are excreted in the manure (National Research Council 1994;Moore 1998).…”