TY - JOUR
T1 - No effect of short-term exposure to high-fibre diets on the gastrointestinal morphology of layer hens (Gallus gallus domesticus)
T2 - Body reserves are used to manage energy deficits in favour of phenotypic plasticity
AU - Courtney Jones, S. K.
AU - Cowieson, A. J.
AU - Williamson, S. A.
AU - Munn, A. J.
PY - 2013/10/1
Y1 - 2013/10/1
N2 - Using layer hens, Gallus gallus domesticus, we compared the digestive capabilities of birds on a low-fibre diet (LF, 8.49% neutral detergent fibre; NDF), with those fed a high-fibre diet balanced for energy and protein to match the LF diet (high fibre balanced, HFB; NDF=15.61%) and those fed a high fibre unbalanced (HFU) diet (NDF=16.68%). The HFU diet had the lowest apparent dry matter (DM) metabolisability at 58.14±6.46%, followed by HFB, 65.87±3.50 and the LF diet, 70.49±7.07%. Despite significant differences between apparent DM metabolisabilities of LF and HFU diets, no morphometric changes in the gastrointestinal tract (GIT) of layer hens were observed (including crop, gizzard, proventriculus, liver, large intestine, paired caeca and small intestine). Conversely, body mass losses were recorded for animals on HFU diet, while those on the LF and HFB diets actually gained body mass over the 14-day trials. We suggest that the body mass losses seen in the animals fed HFU diets were attributed to losses in adipose tissue, but this was not quantified. Assuming body mass losses were mainly in adipose tissue, we propose that adipose may act to buffer environmental challenges like shortfalls in nutrient acquisition when dietary energy requirements are not met. Compared with smaller birds (e.g. quail), the larger body size of the layer hens may offer them a greater safety margin in terms of body energy reserves before changes in the GIT might be needed to redress energy deficits associated with hard-to-digest, high-fibre diets.
AB - Using layer hens, Gallus gallus domesticus, we compared the digestive capabilities of birds on a low-fibre diet (LF, 8.49% neutral detergent fibre; NDF), with those fed a high-fibre diet balanced for energy and protein to match the LF diet (high fibre balanced, HFB; NDF=15.61%) and those fed a high fibre unbalanced (HFU) diet (NDF=16.68%). The HFU diet had the lowest apparent dry matter (DM) metabolisability at 58.14±6.46%, followed by HFB, 65.87±3.50 and the LF diet, 70.49±7.07%. Despite significant differences between apparent DM metabolisabilities of LF and HFU diets, no morphometric changes in the gastrointestinal tract (GIT) of layer hens were observed (including crop, gizzard, proventriculus, liver, large intestine, paired caeca and small intestine). Conversely, body mass losses were recorded for animals on HFU diet, while those on the LF and HFB diets actually gained body mass over the 14-day trials. We suggest that the body mass losses seen in the animals fed HFU diets were attributed to losses in adipose tissue, but this was not quantified. Assuming body mass losses were mainly in adipose tissue, we propose that adipose may act to buffer environmental challenges like shortfalls in nutrient acquisition when dietary energy requirements are not met. Compared with smaller birds (e.g. quail), the larger body size of the layer hens may offer them a greater safety margin in terms of body energy reserves before changes in the GIT might be needed to redress energy deficits associated with hard-to-digest, high-fibre diets.
KW - Adipose tissue
KW - Apparent metabolisability
KW - Dietary fibre content
KW - Gallus gallus domesticus
KW - Gastrointestinal tract
KW - Layer hens
KW - Neutral detergent fibre
KW - Nutrition dilution
KW - Phenotypic plasticity
UR - http://www.scopus.com/inward/record.url?scp=84884729131&partnerID=8YFLogxK
U2 - 10.1111/j.1439-0396.2012.01332.x
DO - 10.1111/j.1439-0396.2012.01332.x
M3 - Article
C2 - 22882770
AN - SCOPUS:84884729131
SN - 0931-2439
VL - 97
SP - 868
EP - 877
JO - Journal of Animal Physiology and Animal Nutrition
JF - Journal of Animal Physiology and Animal Nutrition
IS - 5
ER -