The Influence of Steam Pelleting on the Utilization of Phosphorus by the Laying Hen

Abstract

S UMMERS et al. (1967) reported that commercial steam pelleting resulted in enhanced utilization of dietary phosphorus from plant origin when fed to young growing chickens. Considering the relatively high level of phytin or organic phosphorus present in most poultry diets and the fact that a large percentage of poultry feed is being steam pelleted the economic importance of such a finding is readily apparent. For the laying hen phosphorus from plant origin is usually considered to be around 50% available. However, from a review of the work of Singsen et al. (1962), Temperton and Cassidy (1964), Waldroup et al. (1965Waldroup et al. ( , 1967 and Nelson (1967) it is apparent that there are a number of factors influencing the availability of plant phosphorus and that there is lack of agreement as to how much can be utilized by poultry.The present work was undertaken to study the influence of steam pelleting on the utilization of phytin phosphorus by the laying hen. At the same time an attempt was made to gain information on the value of phytin or plant phosphorus in meeting the laying hens requirement for egg production purposes. MATERIALS AND METHODSIn experiment 1 White Leghorn strain cross pullets that had been reared on regular starting and growing diets were used. These birds were placed in 8 inch laying cages at 18 weeks of age. After the pullets were in production for approximately 6 weeks (29 weeks of age) they were weighed and production to-date assessed. The pullets were allocated into groups of 6 and housed in individual cages. They were arranged so that body weight and egg production were distributed evenly throughout the experiment. Five such groups were then placed on each of the experimental treatments with the 6 birds in each replicate having a common feed trough. The basal diet used is shown in Table 1 (diet 1). This diet served as a control and contained 0.25% of calculated available phosphorus. Gillis et al. (1953) reported that phytin phosphorus was approximately 50% available to the laying hen and on the basis of this report most nutritionists have used a value of 50% of the total phosphorus present in plant sources as being available to the laying hen. Throughout the manuscript, unless otherwise stated, available phosphorus refers to 50% of the phosphorus present in plant material and 100% of that present in calcium phosphate. Further treatments consisted of the addition of 0.16 and 0.32% of phosphorus from a commercial calcium phosphate 1 supplement to the basal diet. Alterations were made in the levels of limestone and kaolin in order to keep all diets equal in calcium. All diets were fed in the form of mash, however, for one series of diets the bran portion was steam pelleted and reground before being mixed with the other ingredients. The duration of the experiment was 10, 28 day periods. Feed consumption was recorded at the end of

Dietary Phosphorus Needs of Laying Hens

“…The results also demonstrated that a ration containing no IP, 0.10% AP and 0.30% TP was not satisfactory for laying hens. For the most part, the data agree with the findings of Pepper et al (1959) and Pepper et al (1969) and Hunt and Chancey (1970) in the low levels of P can fulfill die hen's requirement. Pepper et al (1959) and Pepper et al (1969) also reported that the P requirement of hens could be fulfilled by rations in which all P was of plant origin.…”

“…The National Research Council (1971) recommended a dietary P level of 0.6% and indicated that a portion of this P should be in organic form. Vohra et al (1974) reviewed the literature and suggested that 0.4% P in laying hen rations was adequate but gave no indication as to sources of the P. Since Pepper et al (1959) reported that rations containing 0.38% P, all of plant origin with 0.11% as non-phytin P, were adequate for laying hens, several papers have been published indicating that the hen's P requirement is less than that recommended by the National Research Council (1971) (Pepper et al 1969;Hunt and Chancey, 1970;and Summers et al, 1976). However, Waldroup et al (1967), Garlich et al (1975) and Garlich and Parkhurst (1976) found that levels of 0.34 to 0.44% P were not satisfactory for maintaining high rates of egg production and health of the hens.…”

The Effect of Dietary Levels of Calcium and Phosphorus on Performance and Retention of These Nutrients by Laying Hens

“…There are also many reports indicating that dietary phosphorus levels below those normally used in commercial rations can be fed to laying hens without detrimental effects on performance (Pepper et al, 1969;Damron et al, 1974;Summers et al, 1976;Scott etal, 1976;Edwards and Suso, 1981;Mikaelian and Sell, 1981). Furthermore, a number of investigators have reported that low levels of phosphorus improved shell quality (Hunt and Chancey, 1970;Scott et al, 1976;Garlich, 1979).…”