@article{mahmoud_edens_2012, title={Breeder age affects small intestine development of broiler chicks with immediate or delayed access to feed}, volume={53}, ISSN={["1466-1799"]}, DOI={10.1080/00071668.2011.652596}, abstractNote={1. The relationship between breeder age and chick gastrointestinal tract development to 21 days of age, as influenced by immediate or delayed access to feed, was examined in three consecutive trials. 2. Ross 708 chicks, derived from breeder flocks at 31 (young), 40 (middle) and 63 (old) weeks of age were placed randomly into either a control group with immediate access to feed and water, or a 48 h feed delayed (FD) group with free access to water. 3. FD negatively affected body weight (BW) of chicks derived from young and old flocks through the first and second weeks of age, respectively. Chicks from the older flock absorbed more yolk in the first 48 h with no FD effect. When feed was made available, chicks from the FD group showed a large increase in small intestine weight relative to BW, surpassing (P < 0·05) the control groups across all breeder flock ages. 4. Morphological measurements in all intestinal sections had higher values in chicks derived from the middle age breeder flock. FD to newly hatched chicks from the young breeder flock shortened villi (P < 0·01), decreased crypt depth and villus surface area (P < 0·001) in the duodenum through the first week post hatch. 5. Crypt depths were maximised between 7 and 14 d post-hatch in chicks from young and old breeder flocks, but crypt depths in chicks from the middle aged flocks continued to deepen. 6. The increased crypt depth may augment the number of enterocytes available for villus growth, and facilitate longer villi and greater villus surface area, in chicks from the middle age flocks. Intestinal morphological variation was associated with breeder flock age, which accounted for differential growth in chicks derived from young, middle, and old aged breeder flocks.}, number={1}, journal={BRITISH POULTRY SCIENCE}, author={Mahmoud, K. Z. and Edens, F. W.}, year={2012}, pages={32–41} }
 @article{mahmoud_edens_eisen_havenstein_2004, title={Ascorbic acid decreases heat shock protein 70 and plasma corticosterone response in broilers (Gallus gallus domesticus) subjected to cyclic heat stress}, volume={137}, ISSN={["1096-4959"]}, DOI={10.1016/j.cbpc.2003.09.013}, abstractNote={It is known that ascorbic acid (AA) supplementation can ameliorate the chicken's responses to heat stress. The influence of AA on heart heat shock protein 70 (hsp70) and plasma corticosterone (CS) was evaluated in young male broiler chickens fed either no AA (N-AA) or 500 mg AA /kg (AA) and exposed to cyclic high temperatures (21 to 30 to 21 degrees C) over a 3.5 h period on three consecutive days. Dietary AA supplementation elevated plasma AA and maintained it at high levels after heating, but in N-AA birds, only heat elevated plasma AA. In N-AA fed chickens, plasma CS was elevated and was further increased by heat stress as compared with AA-fed birds. Heart hsp70 expression was greater in N-AA-fed chickens compared to AA-fed chickens, and heat stress further elevated hsp70 in both N-AA- and AA-fed birds. The hsp70 increase after heat was two-fold greater in N-AA- vs. AA-fed birds. Plasma CS and heart hsp70 were positively correlated, plasma AA and heart hsp70 were negatively correlated, and plasma CS and AA were negatively correlated. It was concluded that chickens experience a less severe stress response after exposure to high temperatures when they are provided dietary AA.}, number={1}, journal={COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY}, author={Mahmoud, KZ and Edens, FW and Eisen, EJ and Havenstein, GB}, year={2004}, month={Jan}, pages={35–42} }
 @article{mahmoud_edens_eisen_havenstein_2004, title={The effect of dietary phosphorus on heat shock protein mRNAs during acute heat stress in male broiler chickens (Gallus gallus)}, volume={137}, ISSN={["1878-1659"]}, DOI={10.1016/j.cca.2003.10.013}, abstractNote={A 2 x 2 factorially arranged completely randomized experimental design was used to study the relationship between inorganic phosphorus (Pi) and heat shock protein (HSP) mRNA expression in different organs of commercial broiler cockerels during acute heat stress (HS). Brain, heart, liver and spleen were assayed for hsp70, hsp90alpha and hsp90beta mRNA. At 1 day of age, chickens were assigned randomly to two dietary Pi treatment groups (Pi-: 0.16%; Pi+: 0.5%). At 3 weeks of age, half of the chickens in each Pi group were subjected to HS (Ta=41 degrees C, 60 min) while the other half was maintained in a thermoneutral environment (CN, Ta=25 degrees C). The results showed inter-organ variation in the expression of HSP mRNAs. Brain expressed the most HSP mRNAs while spleen expressed the least. When broilers were subjected to HS, the expression of HSP mRNAs was influenced positively by the consumption of the Pi+ diet. However, analysis of variance revealed that Ta influenced HSP transcription more than phosphorus availability. Thermal stress caused induction of hsp90alpha and hsp90beta in heart, liver and spleen, but hsp90alpha and hsp9beta mRNA levels were stable in brain. Transcription of hsp70 increased (P< or =0.05) in all organs from chickens in HS groups when compared to chickens in CN groups. Although Pi+ did not show any significant increases in the expression of hsp mRNAs, there were consistently larger HSP mRNA values in liver and spleen tissues. The high expression of hsp90alpha and hsp90beta in brain of chicks in both CN and HS conditions could be due to the involvement of hsp90 in steroid hormone receptors or the high metabolic activity of neurons in the central nervous system.}, number={1}, journal={COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY}, author={Mahmoud, KZ and Edens, FW and Eisen, EJ and Havenstein, GB}, year={2004}, month={Jan}, pages={11–18} }