This study explore effect of feeding breeding pigeons pellets with different ring die compression ratio (RDCR) on their reproductive performance, and growth performance, meat quality and intestinal health of squab pigeons. A total of 150 pairs of White King breeding pigeons were randomly assigned to five groups and were fed pellets with a RDCR of 1:6, 1:6.5, 1:7, 1:7.5 or 1:8, respectively, for 46 days. Hardness and durability of pellets, as well as feed intake of breeding pigeons during 1 to 46 days increased linearly with RDCR ( P <0.05). RDCR linearly and/or quadratically increased ( P <0.05) glucose level, as well as alanine aminotransferase and aspartate aminotransferase activities, and linearly reduced ( P <0.05) creatinine level in serum of squabs. RDCR decreased pH (quadratic, P <0.05), drip loss (quadratic, P <0.05), and L* 48h (linear and quadratic, P <0.05) in pectorales. RDCR linearly and quadratically increased jejunal villus height, jejunal ZO1 and ileal ZO2 mRNA expression ( P <0.05). RDCR linearly increased a* 48h and b* 48h in pectorales, as well as ileal villus height and villus height to crypt depth ratio ( P <0.05), while linearly decreased ileal crypt depth ( P <0.05). Ileal total superoxide dismutase activity was enhanced quadratically by RDCR ( P <0.05). Overall, under the present experimental conditions, increasing the RDCR improved pellet quality, meat quality, intestinal morphology, redox status, and barrier function in squabs.
Cheng et al. (Sun,) studied this question.