This is a draft schedule. Presentation dates, times and locations may be subject to change.
68
Environmental Impacts from Cattle Consuming Tannin-Containing Hays
Monday, July 10, 2017
Exhibit Hall (Baltimore Convention Center)
Elizabeth K Stewart, Utah State University, Logan, UT
Karen A. Beauchemin, Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada
Jennifer W. MacAdam, Department of Plants, Soils, and Climate, Utah State University, Logan, UT
Juan J Villalba, USU - Utah State University, Logan, UT
The cow-calf phase counts for approximately 80% of the total beef production system greenhouse gas emissions. There is potential for tannin-containing hays to reduce these environmental impacts. Fifteen mature beef brood cows and 9 yearling beef heifers were blocked by weight and randomly assigned to 3 groups of 5 cows or 3 heifers and fed tannin-containing (birdsfoot trefoil-BFT, sainfoin-SAN, small burnet-SML), or non-tannin containing (alfalfa-ALF, cicer milkvetch-CMV, meadow bromegrass-MB) hays in 4 trials. Groups of cows were fed BFT, CMV or MB in Trial 1 and ALF, SAN or SML in Trial 3. Groups of heifers were fed ALF, MB or SAN in Trial 2 and BFT, CMV or SML in Trial 4. Each trial used a completely randomized block design with repeated measures during 5 days following a 14-d adjustment period. Nine cows and 9 heifers were selected for total collection of enteric methane using the SF6 methodology, feces and urine while intake was measured for all animals. Methane emission from cows was lower for SML than ALF (P=0.04) or SAN (P=0.03; Table 1). Additionally, cows and heifers fed tannin-containing hays showed lower urine (UUN) and blood urea nitrogen (BUN) than animals fed non-tannin containing hays (Table 1), suggesting a shift in nitrogen excretion from urine to feces. In conclusion, tannin-containing legumes consumed as hays have the potential to reduce environmental impacts of cattle fed in confinement.
Table 1.
Treatments (Cows)
|
Trial
|
Trial 1
|
Trial 3
|
Items
|
BFT
|
CMV
|
MB
|
SEM
|
P-Value
|
ALF
|
SAN
|
SML
|
SEM
|
P-Value
|
BUN (mg/dL)
|
6.9a
|
16.5b
|
10.0a
|
1.6
|
0.0033
|
18.7a
|
13.4b
|
4.2c
|
1.8
|
0.0003
|
UUN (g/day)
|
81.7ac
|
228.7b
|
82.9c
|
19.9
|
0.0043
|
216.8
|
98.6a
|
24.4b
|
26.6
|
0.0084
|
CH4 (L/day)
|
46.29a
|
44.84a
|
55.12a
|
5.97
|
0.51
|
52.79a
|
51.37a
|
28.72b
|
5.79
|
0.048
|
Intake (g intake/kg BW)
|
15.5a
|
15.19a
|
12.27a
|
1.94
|
0.45
|
15.92ab
|
12.82a
|
18.29b
|
1.44
|
0.062
|
Treatments (Heifers)
|
Trial
|
Trial 2
|
Trial 4
|
Items
|
ALF
|
MB
|
SAN
|
SEM
|
P-Value
|
BFT
|
CMV
|
SML
|
SEM
|
P-Value
|
BUN (mg/dL)
|
27.9a
|
10.9b
|
14.9b
|
16.1
|
0.0007
|
14.8a
|
19.2a
|
4.5b
|
27.7
|
0.023
|
UUN (mg/day)
|
238.7a
|
32.8b
|
44.1b
|
17.5
|
0.0003
|
119.6a
|
183.9b
|
23.8c
|
8.2
|
<.0001
|
CH4 (L/day)
|
54.11a
|
52.58a
|
37.09a
|
7.57
|
0.26
|
37.25a
|
39.08a
|
36.11a
|
5.15
|
0.91
|
Intake (g intake/kg BW)
|
24.42a
|
16.95b
|
19.86ab
|
0.95
|
0.0043
|
23.0a
|
19.78b
|
16.96c
|
0.68
|
0.0021
|
Means in a row with different superscripts differ (p<0.1).