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 2 Final body weight, ruminal pH, concentrations of ruminal volatile fatty acid (VFA) in ruminal fluid and level of IGF-1 in blood of hay-fed (CON) and high-grain-fed sheep (G7–28)

Item	Treatment				SEM	Contrast, P
Item	CON	G7	G14	G28	SEM	Treatment	Linear	Quadratic	Cubic
Final body weight, kg	25.73^b	26.24^ab	28.40^ab	29.23^a	0.51	0.024	0.003	0.845	0.47
Rumen parameters
Ruminal pH	6.81^a	5.99^b	5.94^b	5.84^b	0.09	< 0.001	< 0.001	< 0.001	0.106
Acetate, mmol/L	66.26	69.33	70.36	74.53	1.74	0.436	0.117	0.877	0.744
Propionate, mmol/L	18.45	19.33	19.88	23.85	1.08	0.315	0.095	0.474	0.695
Isobutyrate, mmol/L	0.61	0.81	0.68	0.78	0.04	0.363	0.343	0.563	0.165
Butyrate, mmol/L	5.74^b	16.03^a	20.17^a	18.78^a	1.41	< 0.001	< 0.001	< 0.001	0.906
Isovalerate, mmol/L	0.53	0.87	0.64	0.87	0.07	0.198	0.185	0.664	0.096
Valerate, mmol/L	0.67^b	1.36^a	1.29^a	1.32^a	0.09	0.008	0.008	0.029	0.188
Total VFA, mnol/L	92.26^b	107.73^ab	113.02^a	120.13^a	3.24	0.006	0.001	0.402	0.588
Blood parameter
IGF-1 in plasma, ng/mL	195.88^b	255.74^ab	329.70^a	293.35^a	15.15	0.004	0.002	0.043	0.221

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
SEM standard error of mean
^{a, b}Means within a row with different superscripts differ (P < 0.05)

ISSN: 2049-1891