Carrie L. Walk

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An experiment was conducted to determine the influence of 2 levels of dietary Ca from limestone and 3 levels of phytase on broiler performance, bone ash, gastrointestinal pH, and apparent ileal digestibility (AID) of Ca, P, and amino acids. Cobb 500 broilers (n = 576) were allowed access to one of 6 corn-soy diets from 0 to 16 d. Experimental diets(More)
An experiment was conducted to evaluate the influence of a novel microbial phytase on performance, tibia ash, and the content of phytate, phytate esters, and inositol in the gizzard of young broilers. Male Cobb 500 broilers (n = 1,680) were fed 1 of 7 experimental diets: positive control (PC) formulated to meet or exceed nutrient recommendations; PC plus(More)
An experiment was conducted to evaluate the influence of a novel microbial phytase on broiler performance from d 0 to 42 and tibia ash at d 21. Male Cobb 500 broilers (n = 2,016) were fed 1 of 7 experimental diets: positive control (PC) formulated to meet or exceed nutrient recommendations; PC plus dicalcium phosphate (PC+DCP) formulated to provide Ca and P(More)
An experiment was conducted to evaluate the influence of a highly soluble Ca (HSC) source on performance, bone ash and mineralization, and apparent ileal digestibility of Ca, P, N, and energy in Ross 708 broiler chickens. Dietary Ca was supplied by the HSC source and monocalcium phosphate to provide 4 levels of Ca (0.45, 0.60, 0.75, or 0.90%). Available P(More)
An experiment was conducted to test the hypothesis that values for apparent total tract digestibility (ATTD) of Ca in pigs are influenced by endogenous Ca lost from the gastrointestinal tract. The objective was to determine the endogenous loss of Ca, the ATTD of Ca, and the true total tract digestibility (TTTD) of Ca in canola meal without and with(More)
An experiment was conducted to test the hypothesis that the standardised digestibility of Ca in calcium carbonate and Lithothamnium calcareum Ca is not different regardless of the level of dietary Ca, and that phytic acid affects the digestibility of Ca in these two ingredients to the same degree. The objectives were to determine where in the intestinal(More)
An experiment was conducted to determine the quantitative relationships between standardized total tract digestible P (STTD P) and total Ca intakes with their retention and excretion by growing pigs fed corn-soybean meal diets. Forty-eight crossbred barrows (BW = 22.7 ± 2.9 kg) were allotted to 1 of 8 diets, housed individually in pens for 3 wk, and then(More)
An experiment was conducted to evaluate the effects of dietary enzymes on performance, tibia ash, and intestinal goblet cells of broilers administered a live coccidia oocyst vaccine (Coccivac B, Schering Plough, Kenilworth, NJ). Cobb 500 straight-run broilers were obtained and one-half of the chicks were sprayed with the live coccidia oocyst vaccine. Chicks(More)
Crossbred pigs (n=288; average age=21±3 d and BW=7.1±0.2 kg) were used in a 42-d trial to determine the influence of a microbial phytase and various doses of ZnO on growth performance and serum minerals. Pigs (6 castrated males or females/pen) were randomly allotted to treatments in a 2×3 factorial arrangement with 2 dietary levels of a microbial phytase (0(More)
The objective of this study was to evaluate the effects of dietary Ca, P, and phytase on performance, intestinal morphology, bone ash, and Ca and P digestibility during a necrotic enteritis (NE) outbreak. The 35-d trial was designed as a 2 × 2 × 2 factorial, which included 2 Ca levels (0.6 and 0.9%), 2 P levels (0.3 and 0.45%), and 2 levels of phytase [0(More)