The Effect of Different Totals and Ratios of Dietary Calcium and Phosphorus on the Performance and Incidence of Leg Abnormalities of Male and Female Broiler Chickens

Abstract

A factorial experiment involving 1,404 day-old Shaver broiler chicks (702 of each sex) assessed the effects of total calcium (Ca) and available phosphorus (AP) and their ratio (Ca: AP) during the starter (0 to 21 days) and finisher (22 to 42 days) periods on general performance, tibia strength, tibia ash, Ca and P content of tibia ash, tibia dyschondroplasia, twisted legs, and total leg abnormalities. Nine starter and nine finisher diets were used with the percentage Ca and AP ranging from .98 to 1.47 and .39 to .67, respectively, for the starters and from 1.00 to 1.40 and .32 to .51, respectively, for finishers. In general, optimum weight gain, live body weight, feed conversion, tibia strength, tibia dry weight, and tibia ash were obtained when the highest Ca + P was fed, but lower Ca:AP ratios were also effective for some traits. Tibial dyschondroplasia (TD) and total leg abnormalities, however, were highest when these diets were fed. The results indicate that the ratio of Ca:AP in the diet is a determining factor in causing TD in broiler chickens. As the ratio of Ca:AP in the diets widened in response to increased Ca or decreased P, the incidence of TD and total leg abnormalities decreased (P less than .05).

Effect of Dietary Cation-Anion Balance and Calcium Content on General Performance and Incidence of Leg Abnormalities of Broiler Chickens

“…(Edwards and Veltmann 1983;Edwards 1984;Hulan et al 1985Hulan et al , 1986 (Hulan et al 1985(Hulan et al , 1986. The detrimental effect of high Ca on weight gain (Table 5) and feed conversion (Tables 6 and 7) (Tables 3 and 7).…”

“…Prior to formulating the experimental diets, each ofthe constant ingredients (Table l) was analyzed for Ca, P, Na, K and Cl as previously described (Hulan et al 1986 these data are presented elsewhere (Simons et al 1987 For personal use only. (Edwards and Veltmann 1983;Edwards 1984;Hulan et al 1985Hulan et al , 1986 (Hulan et al 1985(Hulan et al , 1986.…”

“…More recently, Hulan et al (1985,1986) observed the same effect for P but not for Ca. Furthermore, Edwards (1984) and Hulan et al (1985Hulan et al ( , 1986 found that the ratio of Ca:P in the diet affects TD in broiler chickens.…”

The effect of non-phytate phosphorus and phytase levels on performance, egg and tibia quality, and pH of the digestive tract in hens fed higher-calcium-content diet

“…The physiological roles of these two macro minerals are intricately linked (Selle et al, 2009). There is a significant interaction between dietary Ca and P, and an improper ratio of Ca to P could depress growth performance in broilers (Hulan et al, 1985;Rao et al, 2003Rao et al, , 2006. This issue is more difficult to address in hens than in chickens because of hens' high calcium needs.…”

Exigências de cálcio para codornas japonesas fêmeas de um a 35 dias de idade

“…Animal Sciences Maringá, v. 31, n. 1, p. 7-12, 2009 prejudicial, agindo de maneira contrária ao esperado, ou seja, reduzindo a deposição. Hulan et al (1985) encontraram resultados que diferem dos obtidos neste experimento para a deposição de cinzas na tíbia, sendo verificado aumento na deposição de cálcio na tíbia das fêmeas com o aumento do nível de cálcio na ração.…”