The relative sensitivity of tibia bone mineral content (BMC) and density (BMD), percentage ash (ash), and shear force as indicators for dietary Ca and P was compared in 3-wk-old broiler chicks. One hundred eight 7-d-old chicks were grouped by weight into 6 blocks of 3 cages each with 6 birds per cage. Three corn-soybean meal-based diets were randomly assigned to cages within each block. The diets were low P, medium P, and adequate P and were formulated to contain 4.0, 5.1, and 7.8 g of total P/kg feed, respectively; and 5.1, 6.7, and 10.0 g of Ca/kg feed, respectively. The chicks were fed the experimental diets for 14 d. On d 22, chicks were killed, and tibiae were removed from 3 birds/cage. Weight gain, feed intake, feed efficiency, BMC, BMD, shear force, and ash were determined. The BMC and BMD were determined using dual energy x-ray absorptiometry. Correlations among the various bone status variables and dietary Ca and P were determined. Growth performance criteria and ash increased linearly, and BMC and BMD increased linearly and quadratically as dietary concentrations of Ca and P increased. The correlation coefficient between dietary Ca and BMC, BMD, shear force, or ash was 0.89, 0.91, 0.50, or 0.89, respectively; and between dietary P and BMC, BMD, shear force, or ash was 0.88, 0.91, 0.48, or 0.89, respectively. The correlation coefficient between ash and BMC, BMD, or shear force was 0.92, 0.93, or 0.67, respectively. The correlation coefficients for linear regression between shear force and BMC or BMD was 0.56. The regression model for predicting percentage ash using BMD was as follows: percentage ash = 24 + (240 x BMD) with an r2 of 86%. It is concluded that in broiler chicks, tibia ash, BMC, and BMD may be more sensitive than shear force as indicators of dietary Ca and P concentrations and that BMD as measured by dual energy x-ray absorptiometry may be used to predict percentage of tibia ash.

Two trials were conducted to evaluate the efficacy of a new microbial phytase (Phyzyme XP) for broiler chicks. Trial 1 used 192 8-d-old male broilers in a 14-d trial to assess growth and nutrient utilization. Dietary treatments (221.9 g/kg CP) included a positive control [5.0 g/kg nonphytate P (NPP)], negative control (1.2 g/kg NPP), and negative control plus 500 or 1,000 phytase units/kg of diet. Phytase addition increased weight gain, feed intake, feed efficiency, and tibia and toe ash (linear, P < 0.01) with tibia ash also responding quadratically (P < 0.05). Apparent ileal digestibility of P (linear and quadratic, P < 0.05), tryptophan, and valine (linear, P < 0.05) also increased. Linear and quadratic responses were observed for retention of DM, nitrogen, P, and several amino acids (P < 0.05) with added phytase. Trial 2 utilized 576 1-d-old male broilers over a 42-d period to evaluate growth performance. Diets were formulated for starter (222.7 g/kg CP) and grower (201.5 g/kg CP) phases and included a positive control (starter and grower, 5.0 and 3.8 g/kg NPP, respectively); negative control (starter and grower, 2.4 and 1.8 g/kg NPP, respectively); negative control plus 500, 750, or 1,000 phytase units/kg; and negative control plus 500 phytase units/kg of Natuphos phytase. Phytase increased weight gain and feed intake (starter, grower, overall) as well as feed efficiency during the starter period (linear, P < 0.05). Feed intake was also improved during the grower period and overall (quadratic, P < 0.05). Tibia and toe ash of birds fed for the first 21 d increased (linear, P < 0.05) with tibia ash also increasing quadratically (P < 0.05). Overall, tibia and toe ash were improved due to phytase addition (linear and quadratic, P < 0.05). In conclusion, this microbial phytase, derived from Escherichia coli and expressed in Schizosaccaromyces pombe, elicited improved growth performance, bone mineralization, and P utilization in broiler chicks.

An evolved Escherichia coli-derived phytase was evaluated for its efficacy in improving growth performance and nutrient utilization of broiler chicks. One hundred forty-four 7-d-old male broiler chicks were grouped by weight into 6 blocks of 6 cages with 4 birds per cage. Six corn-soybean meal-based mash diets were randomly assigned to cages within each block. The 6 diets were adequate P (7.7 g of P/kg of diet), low P (3.9 g of P/kg of diet), low P diet plus 0.75 or 1.5 g of inorganic P from monosodium phosphate, and low P diet plus the evolved Escherichia coli phytase at 500 or 1,000 units/kg of diet. The chicks were fed the experimental diets from 8 to 22 d of age. The evolved Escherichia coli phytase improved weight gain (P < 0.05), feed intake (P < 0.01), percentage tibia ash (P < 0.01), and retention of P (P < 0.001), Ca (P < 0.01), N (P < 0.05), and a number of amino acids (P < 0.05). The evolved Escherichia coli phytase was, therefore, efficacious in improving broiler growth performance, bone characteristics, and retention of P, Ca, N, and a number of amino acids.

This study examined correlations of historical changes in diet and physical inactivity with the rise of noncommunicable diseases (NCDs) in Kenya. Historical data on diet, wage jobs by industry, urbanization, gross domestic product (GDP), and morbidity due to NCDs were extracted from Kenya Statistical Abstracts, Food and Agriculture Organization (FAOSTAT), and the World Bank online database. These data were plotted and correlations between these factors and the incidence of different NCDs over time were evaluated. There was a rapid rise in the incidence of circulatory disease starting in 2001, and of hypertension and diabetes starting in 2008. The rise of these NCDs, especially hypertension and diabetes, was accompanied over the same period by a rise in per capita GDP and physical inactivity (as measured by increased urbanization and declining proportion of agricultural and forestry wage jobs); a rise in per capita supply of rice, wheat and its products, and cooking oils; and a decline in the per capita supply of maize and sugar. In conclusion, the positive correlations between indicators of dietary consumption and physical inactivity and rates of hypertension, circulatory disease, and diabetes suggest that the rapid rise of NCDs in Kenya may be, in part, due to changes in these modifiable factors.

The efficacy of three Escherichia coli-derived phytase preparations on the performance and nutrient utilization of broiler chicks was evaluated. Two hundred sixteen 7-d-old male broiler chicks were grouped by weight into 6 blocks of 6 cages with 6 birds per cage. Six corn-soybean meal-based diets were randomly assigned to cages within each block. The 6 diets were adequate P, very low P, and low P and contained (g of P/kg of diet) 7.7, 4.0, and 5.1, respectively; and low-P diet plus phytase preparation A, B, or C at 1,000 units/kg of feed. All 3 phytase preparations were produced in different yeast production systems with slightly different glycosylation patterns. Preparation A was produced in Pichia pastoris, B in Schizosaccharomyces pombe, and C in Saccharomyces cerevisiae. The chicks were fed the experimental diets from 8 to 22 d of age. Excreta samples were collected between 17 and 21 d of age. At the end of the study, blood was collected, chicks were killed, and tibiae were removed from 3 birds per cage. Weight gain, feed intake, and feed efficiency among the 3 phytase preparations did not differ, although only phytase A diet outperformed (P < 0.05) the low-P diet in terms of weight gain and feed efficiency. All 3 phytase diets outperformed (P < 0.05) the low-P diet in bone mineral content, density, strength, percentage ash, P retention, and serum P levels. Phytase B diet outperformed the adequate-P diet in bone strength. All 3 preparations increased (P < 0.05) Ca retention with phytase B or C showing a better retention of Ca than phytase A. All 3 phytase preparations showed similar P use as indicated by BW gain and tibia bone characteristics.

The influence of the form of phytic acid on the regulation of mucin and endogenous losses of amino acids, nitrogen and energy in chickens was investigated. Forty-eight 10-week-old male broilers were grouped by weight into eight blocks of six cages with one bird per cage. Birds received by intubation six dextrose-based combinations of phytic acid and phytase arranged in a 3 £ 2 factorial consisting of phytic acid form (no phytic acid, 1·0 g free phytic acid or 1·3 g magnesium -potassium phytate) and phytase (0 or 1000 units). Each bird received the assigned combination added to 25 g dextrose at each of the two feedings on the first day of experimentation. All excreta were collected continuously for 54 h following feeding and frozen until analysed. Frozen excreta were thawed, pooled for each bird, lyophilised, ground, and analysed for DM, energy, nitrogen, amino acids, mucin, and sialic and uric acids. Chickens fed either magnesium-potassium phytate or free phytic acid showed increased (P,0·05) loss of crude mucin and sialic acid. The amount of crude mucin lost was significantly greater (P, 0·05) with magnesiumpotassium phytate than with free phytic acid treatment. Both phytic acid treatments also increased (P, 0·05) endogenous loss of threonine, proline and serine. In conclusion, the form of phytic acid fed to chickens affects the extent of mucin and endogenous amino acid losses from the gastrointestinal tract.

O. 2005. Phytase activity along the digestive tract of the broiler chick: A comparative study of an Escherichia coli-derived and Peniophora lycii phytase. Can. J. Anim. Sci. 85: 61-68. Residual activity of an Escherichia coli-derived phytase and a commercially available Peniophora lycii phytase along the digestive tract of broiler chicks was compared in order to evaluate their relative resistance to hydrolysis in the digestive tract. Seventy-two 7-d-old male broiler chicks were grouped by weight into six blocks of three cages with four birds per cage. Three corn-soybean meal-based diets were randomly assigned to cages within each block. The three diets were a low P diet containing 3.9 g P kg -1 diet; and low P diet plus either E. coli-derived phytase or the P. lycii phytase at 1000 units kg -1 of feed. The chicks were fed experimental diets from 8 to 22 d of age. At the end of the study, chicks were killed and the contents of the crop, proventriculus and gizzard, jejunum and ileum were collected, freeze-dried, ground and analyzed for phytase activity. Escherichia coli-derived phytase had more residual activity at the proventriculus and gizzard, jejunum and ileum when compared with the P. lycii phytase (P < 0.0001). The E. coli-derived phytase may be more resistant to hydrolysis in the digestive tract when compared with the P. lycii phytase.

1. The role of cholecalciferol and phosphorus in the regulation of intestinal mucosa phytase was investigated in broiler chicks. 2. A total of 144 7-d-old male broiler chicks were grouped by weight into 6 blocks of 4 cages with 6 broiler chicks per cage. Four maize-soybean meal-based mash diets were randomly assigned to cages within each block. The 4 diets consisted of cholecalciferol at 0 or 75 microg/kg and total phosphorus at 3.6 or 7.0 g/kg in a 2 x 2 factorial arrangement. The birds were given the experimental diets for 12 d under conditions which excluded ultraviolet light. 3. Broiler chicks fed on diets with the higher concentration of cholecalciferol had higher Vmax and Km of the mucosa phytase, weight gain, feed intake, feed efficiency and percentage tibia ash, higher ileal digestibility of dry matter, energy, phosphorus (P) and calcium (Ca), and increased retention of dry matter, nitrogen, P, Ca and energy. 4. Broiler chicks receiving diets with the higher P concentration showed lower Vmax and Km of the intestinal mucosa phytase but greater weight gain, feed intake, feed efficiency and percentage tibia ash, higher ileal digestibility of dry matter, energy, P and nitrogen, and increased retention of dry matter, energy, nitrogen and Ca. 5. In conclusion, both dietary P and cholecalciferol influenced the activity of intestinal mucosa phytase.