Laura David likes this technical article:
I. INTRODUCTIONCalcium (Ca) is an important nutrient for skeletal development, muscle contraction, nerve impulses, acid-base balance, and a cofactor for blood clotting and endogenous enzymes. Due to the involvement of Ca in numerous functions in the body, accurate supply of dietary Ca is essential for optimal growth, feed efficiency and nutrient utilisation. Oversupply of dietary Ca or an imbalanc ...
This member gave a presentation on February 21, 2024
At the following event:
35th Annual Australian Poultry Science Symposium
Article published the January 16, 2024
I. INTRODUCTIONCalcium (Ca) and phosphorous (P) are two essential minerals for the skeletal growth and other biological functions in poultry. Maintaining an appropriate balance between Ca and P is necessary as these minerals are closely associated in their absorption and post absorptive utilisation. Because of the recent works on the measurement of digestible Ca in feed ingredients, initiative has ...
Article published the September 11, 2023
I. IntroductionPoultry diets are currently formulated based on total calcium (Ca) and available phosphorus, with a ratio of 2:1 being maintained between them. For a number of reasons, there is increasing interest in shifting the formulations based on digestible Ca and digestible P. To enable this move, information is required of the requirements of digestible Ca and digestible P. A recent study at ...
Laura David likes the comment:
Dear Laura David.
I just wanted to emphasize the importance of excretion via kidneys on the difference of measures made at ileum or total excreta collection methods. That this is different for Ca and P, I totally agree with you.
Laura David likes the comment:
I am just curious, would someone please explain to me the logic of SID Ca or P? I understand that SID assays were developed for amino acid "digestibility" in chicks from assays with pigs. In pigs there is considerable fermentation in the handout so ileal canulas avoid that problem. It isn't practical to cannulate the end of the ileum in chicks, so half of the ileum was chosen as a substitute. ...
Participation in Forum on July 25, 2023
Gene Pesti, as evidenced by several research works (Zhand & Adeola, 2017; 2018; Fang et al., 2007 – poultry and pigs) and pointed by Aaron Cowieson, SID Ca/P is more additive in complex mixtures. Some nutrient recommendations have already started using SID P (NRC, 2012) in feed formulations as pointed by Joshua Jendza. Therefore, a concurrent use of SID Ca is necessary because of the int ...
Laura David likes the comment:
Dear Dr. Pesti. It's an interesting question. The rationale seems to me the same we use for energy. When measured at ileal level, we are talking about digestible energy (or total tract for swine). When measured in excreta (total tract collection), we call it metabolizable because part of it has been absorbed, metabolized and excreted via urine (mainly as N). For phosphorus (P), which is excreted i ...
Laura David likes the comment:
Aaron Cowieson - The benefits of using standardized digestibility is exactly as you say, but I was of the impression that using Ileal instead of total tract digestibility was more a matter of convenience. We already collect illegal samples for SID of amino acids, and using those same samples for mineral analysis as well is simply easier than collecting a separate excreta sample. Particularly when ...
Laura David likes the comment:
Gene Pesti the main benefit of SID systems is that they are more additive in complex mixtures. There is a lot of published work showing that considering basal endogenous loss of the focal nutrient makes LCF more precise. AID systems tend to under-estimate the nutrient concentration in the finished feed because basal endogenous loss has been considered multiple times in the estimation of the dige ...