Abstract
We studied the effects of lactation stage and postpartum rate of increase
of concentrate allowance on daily fermentable organic matter (FOM)
intake, rumen papilla surface area, and fractional VFA absorption rate
(kaVFA). The concentrate treatment aimed to create a transient difference
in daily FOM intake. Twelve rumen-cannulated, Holstein-Friesian cows
had free access to either a dry period ration or a basal lactation ration.
Starting at 4 DIM, concentrate allowance increased at a high (1.0 kg
DM/d; HIGH, n = 6) or a low rate (0.25 kg DM/d; LOW, n = 6) up to a
maximum of 10.9 kg DM/d. On sampling days (-50, -30, -10, 3, 9, 16,
30, 44, 60, and 80 DIM), the rumen contents were evacuated and papilla
biopsies taken. Thereafter, kaVFA was measured using the empty washed
rumen technique with 46 L McDougall buffer (pH 6.0, 39°C), containing
120 mM VFA (60% acetic, 25% propionic, and 15% butyric acid) and
a marker (Co-EDTA). From -50 to 3 DIM, FOM intake was 5.7 ± 0.3
kg/d (P = 0.29), papilla surface area decreased from 34.4 to 28.0 ± 2.0
mm2 (P = 0.02) and kaVFA decreased from 0.51 to 0.33 ± 0.03 /h (P <0.01), with no differences between future treatment groups HIGH and
LOW (P = 0.33). From 3 to 80 DIM, FOM intake, papilla surface area,
and kaVFA increased to 15.0 ± 0.3 kg/d, 63.4 ± 2.0 mm2, and 0.75 ± 0.03
/h respectively (all P <0.01). A treatment by DIM interaction occurred
for daily FOM intake (P <0.01), which was greater in group HIGH at
16 DIM (12.3 vs. 10.1 ± 0.3 kg/d, P <0.01), and for papilla surface
area (P = 0.01), which was greater in group HIGH from 16 DIM (46.0
vs. 33.2 ± 2.0 mm2, P <0.01) through to 44 DIM (60.5 vs. 49.7 ± 2.0
mm2, P = 0.01). However, a treatment by DIM interaction did not occur
for kaVFA (P = 0.28), which was similar for group HIGH and LOW at
16 DIM (0.60 vs. 0.56 ± 0.03 /h, P = 0.53) and 44 DIM (0.69 vs. 0.69
± 0.03 /h, P = 0.95). In conclusion, lactation stage but not concentrate
treatment affected kaVFA. This suggests kaVFA increases with, but is
not limited by, papilla surface area during the first weeks of lactation,
which was affected by the rate of increase of concentrate allowance.
| Original language | English |
|---|---|
| Title of host publication | Book of abstracts of 2015 Joint Annual Meeting of ADSA-ASAS |
| Pages | 455 |
| Volume | 98 |
| Publication status | Published - 2015 |
| Event | Joint Annual Meeting 2015 ADSA-ASAS - Orlando Duration: 12 Jul 2015 → 16 Jul 2015 |
Conference
| Conference | Joint Annual Meeting 2015 ADSA-ASAS |
|---|---|
| City | Orlando |
| Period | 12/07/15 → 16/07/15 |