Morphological adaptation of sheep’s rumen epithelium to high-grain diet entails alteration in the expression of genes involved in cell cycle regulation, cell proliferation and apoptosis

Table 1 Ingredient and chemical composition of the diet (DM basis)

Item	Diet
Item	Hay	High-grain diet
Ingredient composition, % DM
Oat hay	63.40	26.00
Alfalfa hay	33.00	14.00
Corn meal	0	34.20
Wheat meal	0	18.00
Soybean meal	0	4.20
CaCO₃	1.00	1.00
NaCl	0.40	0.40
CaHPO₄	1.20	1.20
Mineral and vitamin supplement^a	1.00	1.00
Nutrient composition^b
DE, MJ/kg DM	8.88	11.73
CP, % DM	11.18	11.92
Crude fat, % DM	2.09	2.49
Crude fiber, % DM	28.41	12.90
NDF,% DM	44.45	24.54
ADF, % DM	19.52	10.15
Crude ash, % DM	8.34	4.53
Starch, % DM	3.25	32.34

^aContained 16% calcium carbonate; 102 g/kg of Zn; 47 g/kg of Mn; 26 g/kg of Cu; 1,140 mg/kg of I; 500 mg/kg of Se; 340 mg/kg of Co; 17,167,380 IU/kg of vitamin A; 858,370 IU/kg of vitamin D; and 23,605 IU/kg of vitamin E
^bValues were analyzed based on the Feed Database in China [60]
Sheep assigned to CON (n = 5), G7 (n = 5), G14 (n = 5) and G28 (n = 5) received a high-grain diet for 0, 7, 14 and 28 d, respectively