Impact of high-energy diets on the rumen environment and digital cushion in confined cattle

Tavares, Nicolas C.; Barbosa, Antônio A.; Bermudes, Rogério F.; Rechsteiner, Sandra M.E.F.; Cruz, Luis A.X.; Bruhn, Fabio Raphael P.; Silva, Paula M.; Martins, Charles F.

doi:10.1590/1678-5150-PVB-6230

ABSTRACT:

This study aimed to identify gross and microscopic changes, caused by high-energy diets, in the rumen environment and hoof of confined beef cattle. The study sample comprised 40 confined heifers (Bos taurus) with no disease history divided into four experimental groups using different diets: Group 1 (D1, control), 48:52 forage:concentrate ratio; Group 2 (D2), 30:70 forage:concentrate ratio; Group 3 (D3), 30:70 forage:concentrate ratio + sucrose; Group 4 (D4), 100% concentrate. All animals underwent clinical examination, assessment of ruminal fluid pH and lameness, and sample collection after slaughter for histopathology of the hoof laminae and digital cushion and ruminal tissue. All dependent variables of the study were compared using the SPSS 20.0 statistical software. The variables that did not show normality (HR, RM, ST, and CRT) were compared with application of the Kruskal-Wallis test followed by the Dunnet’s multiple comparison test. All other variables were submitted to analysis of variance (ANOVA) followed by Tukey’s test. The different diets had an impact on the rumen environment (p<0.05) of the heifers assessed, with momentary general depression in the first 12 h after sucrose induction (D3), as well as mild clinical signs in D4. The animals in D3 and D4 presented lower motility (p<0.05) and ruminal pH (p<0.01) than those in D1. Of the 40 heifers, 27.5% (n=11) showed gross lesions in the epithelium of ruminal pillars, whereas 22.5% (n=9) of those in D3 and D4 presented these lesions. Sole corium thickness varied between heifers in D3 compared with those in D1 and D2 (p<0.05). Therefore, high-energy diets, as used in this study, alter some clinical parameters and the rumen environment, causing lesions in the rumen mucosa, and of lesser intensity, in the hoof corium and laminae, suggestive of laminitis.

INDEX TERMS:
High-energy diets; rumen environment; digital cushion; confined cattle; acidosis; hoof; histology; laminitis; confinement

[1] *Corresponding author: martinscf68@yahoo.com.br

Feed	Treatment (forage:concentrate ratio)
Feed	D1 (48:52)	D2 (30:70)	D3 (30:70)	D4 (0:100)
Corn silage (kg/MS)	3.750	2.240	2.240	0.00
Concentrate (kg/MS)	4.050	5.440	5.440	7.425
Dry matter (kg)	7.800	7.680	7.680	7.425

Components	Diet (forage:concentrate ratio)
Components	D1 (48:52)	D2 and D3 (30:70)	D4 (0:100)
DM	100	100	100
OM	1.20	0.75	1.75
NDF	43.25	37.73	28.54
ADF	22.35	19.42	14.54
CP	8.90	9.84	11.32
EE	4.71	4.96	5.37
TDN	71.07	74.90	81.29

Diet	Diarrhea
Diet	Presence	Absence
D1	20.0 (2)^a	80.0 (8)^a
D2	50.0 (5)^ab	50.0 (5)^ab
D3	100.0 (10)^c	0.0 (0)^c
D4	70.0 (7)^b	30.0 (3)^b
Total % (n)	60.0 (24)	40.0 (16)

Variable	D1	D2	D3	D4
T (°C)*	39.8 (0.11)^a	39.6 (0.08)^a	39.9 (0.10)^a	39.8 (0.11)^a
RR (mov/min)*	49.8 (5.96)^a	50.8 (4.49)^a	60.0 (5.01)^a	65.5 (4.18)^a
HR (beat/min)**	106.5 (27.00)^a	100.0 (20.00)^a	110.0 (11.25)^a	105.0 (16.00)^a
CRT (s)**	2.0 (0.25)^a	2.0 (1.00)^a	2.0 (0.00)^a	2.0 (0.25)^a
ST**	0.0 (0.00)^a	0.0 (0.00)^a	0.0 (0.25)^a	0.0 (0.00)^a
RM (mov/min)**	3.0 (0.25)^a	3.0 (1.00)^ab	2.0 (0.00)^b	2.0 (0.25)^b
pH*	6.4 (0.17)^c	5.4 (0.17)^b	4.5 (0.09)^a	5.1 (0.05)^b

Diet	Changes of epidermal cells
	MLFD		LLFD		MLHD		LLHD
	No	Yes	No	Yes	No	Yes	No	Yes
D1% (n)	70 (7)^a	30 (3)^a	80 (8)^a	20 (2)^a	40 (4)^a	60 (6)^a	40 (4)^a	60 (6)^a
D2% (n)	20 (2)^a	80 (8)^a	60 (6)^a	40 (4)^a	40 (4)^a	60 (6)^a	20 (2)^a	80 (8)^a
D3% (n)	20 (2)^a	80 (8)^a	50 (5)^a	50 (5)^a	20 (2)^a	80 (8)^a	20 (2)^a	80 (8)^a
D4% (n)	20 (2)^a	80 (8)^a	50 (5)^a	50 (5)^a	20 (2)^a	80 (8)^a	10 (1)^a	90 (9)^a
Total	32.5 (13)	67.5 (27)	60.0 (24)	40.0 (16)	30.0 (12)	70.0 (28)	22.5 (9)	77.5 (31)

Brasil

Brasil

Impact of high-energy diets on the rumen environment and digital cushion in confined cattle

O impacto de dietas de alto valor energético sobre o ambiente ruminal e o tecido digital em bovinos confinados

ABSTRACT:

Diet	Laminar tapering and stretching
	MLFD		LLFD		MLHD		LLHD
	No	Yes	No	Yes	No	Yes	No	Yes
D1% (n)	90 (9)^a	10 (1)^a	90 (9)^a	10 (1)^a	90 (9)^a	10 (1)^a	70 (7)^a	30 (3)^a
D2% (n)	70 (7)^ab	30 (3)^ab	90 (9)^a	10 (1)^a	60 (6)^ab	40 (4)^ab	50 (5)^a	50 (5)^a
D3% (n)	30 (3)^b	70 (7)^b	70 (7)^a	30 (3)^a	50 (5)^ab	50 (5)^ab	30 (3)^a	70 (7)^a
D4% (n)	40 (4)^b	60 (6)^b	50 (5)^a	50 (5)^a	30 (3)^b	70 (7)^b	40 (4)^a	60 (6)^a
Total	57.5 (23)	42.5 (17)	75.0 (30)	25.0 (10)	57.5 (23)	42.5 (17)	47.5 (19)	52.5 (21)

Digit CT	D1	D2	D3	D4
MRFD	0.35 (0.02)^a	0.33 (0.02)^a	0.31 (0.03)^a	0.34 (0.03)^a
LRFD	0.39 (0.02)^a	0.37 (0.02)^a	0.32 (0.03)^a	0.33 (0.04)^a
MLFD	0.39 (0.03)^b	0.33 (0.02)^ab	0.28 (0.02)^a	0.33 (0.03)^ab
LLFD	0.38 (0.03)^a	0.39 (0.02)^a	0.22 (0.02)^a	0.34 (0.02)^a
MRHD	0.29 (0.03)^a	0.31 (0.27)^a	0.25 (0.02)^a	0.29 (0.03)^a
LRHD	0.32 (0.02)^ab	0.35 (0.03)^b	0.26 (0.02)^a	0.29 (0.02)^ab
MLHD	0.29 (0.02)^a	0.32 (0.02)^a	0.24 (0.01)^a	0.28 (0.02)^a
LLHD	0.36 (0.02)^b	0.30 (0.02)^ab	0.26 (0.02)^a	0.32 (0.03)^ab