1652 Rumen protozoal community structures are not altered in lactating dairy cows offered alternative forage crops during short-term grazing experiments

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 805-805
Author(s):  
L. M. Cersosimo ◽  
R. Tacoma ◽  
S. Greenwood ◽  
K. Juntwait ◽  
A. F. Brito ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Community Structures ◽  
Short Term ◽  
Forage Crops ◽  
Lactating Dairy Cows

0620 Performance and rumimal metabolism are not changed in lactating dairy cows offered spring available annual forage crops during a short-term grazing experiment

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 294-295
Author(s):  
K. A. Juntwait ◽  
A. F. Brito ◽  
K. S. O'Connor ◽  
R. G. Smith ◽  
K. M. Aragona ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Short Term ◽  
Forage Crops ◽  
Grazing Experiment ◽  
Lactating Dairy Cows

0621 Performance and ruminal metabolism in lactating dairy cows offered summer available annual forage crops during a short-term grazing experiment

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 295-296
Author(s):  
K. A. Juntwait ◽  
A. F. Brito ◽  
K. S. O'Connor ◽  
R. G. Smith ◽  
K. M. Aragona ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Short Term ◽  
Forage Crops ◽  
Grazing Experiment ◽  
Lactating Dairy Cows

Relationship between milk storage characteristics and the short-term response of dairy cows to thrice-daily milking

1994 ◽  
Vol 58 (2) ◽  
pp. 181-187 ◽  
Author(s):  
R. J. Dewhurst ◽  
C. H. Knight
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Short Term ◽  
Additional Time ◽  
Lactating Dairy Cows ◽  
Total Milk ◽  
Milk Storage ◽  
The Relationship ◽  
Storage Characteristics ◽  
Term Response

AbstractTwenty lactating dairy cows were used to investigate the relationship between the site of milk storage in the udder and the short-term response to thrice-daily milking. Cisternal and alveolar milk volumes were measured 8 h after an ordinary morning milking by catheter drainage and machine milking with oxytocin respectively. The response to thrice-daily milking was assessed using a half-udder technique and the relative milk yields quotient (RMYQ). Over the first 7 days, both halves were milked twice daily (8/16 h intervals) and milk yields over the final 4 days of this period were higher for left fore/right hind (LF/RH) (12·4 (s.e. 0·85) kg/day) than for RF/LH (10·5 (s.e. 0·63) kg/day) which was milked after LF/RH throughout the experiment. Over the following week, LF/RH quarters were milked an additional time (8/8/8 h intervals) and yields over the final 4 days were increased (15•7 (s.e. 0·95) kg/day) compared with control quarters (9·8 (s.e. 0·73) kg/day). In a final 4-day period, animals were milked twice daily and half udder yields were 13·1 (s.e. 0·89) kg/day and 10•6 (s.e. 0·77) kg/day respectively. Differences between yields from the two halves of the udders were highly significant in all 3 weeks of the experiment (P < 0·001). Cistern milk yield as a proportion of total milk yield at 8 h (cistern proportion) averaged 0·170 (s.e. = 0·0275; range 0·020 to 0·334) and tended to be greater for multiparous (0·215, s.e. 0·0279) than for primiparous animals (0·118, s.e. 0·0437; P = 0·076). During the periods of twice-daily milking, the proportion of milk yielded from LF/RH quarters was not significantly related to cistern proportion (P = 0·70 and 0·43 for weeks 1 and 3 respectively). However the response to thrice-daily milking, assessed as RMYQ, was significantly related to cistern proportion both when changing up to, and down from, thrice-daily milking (P < 0·01). Animals with low cistern proportions showed larger responses to thrice-daily milking. There was a significant relationship (P < 0·05) between the responses on changing up to, and down from, thrice-daily milking. Primiparous animals tended to exhibit smaller declines on returning to twice-daily milking than multiparous animals with equivalent responses to thrice-daily milking.

Repeatability of enteric methane determinations from cattle using either the SF6 tracer technique or the GreenFeed system

2016 ◽  
Vol 56 (3) ◽  
pp. 238 ◽  
Author(s):  
M. Arbre ◽  
Y. Rochette ◽  
J. Guyader ◽  
C. Lascoux ◽  
L. M. Gómez ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Tracer Technique ◽  
Short Term ◽  
Experimental Conditions ◽  
Ch4 Emissions ◽  
Lactating Dairy Cows ◽  
Significant Difference ◽  
Enteric Methane ◽  
Expired Gas ◽  
Measurement Period

The SF6 tracer technique (SF6) and GreenFeed system (GF) are two methods for measuring enteric methane (CH4) emissions from cattle. Both methods estimate individual daily CH4 emissions from expired gas samples collected either continuously over 24 h in a canister (SF6) or several times a day during short-term periods (3–8 min) when cattle visit an automated head chamber (GF). The objective of this work was to study repeatability (R) of each method according to duration of measurement period as an indicator of their precision. The R of CH4 measurements was evaluated in two different trials using cows. For Experiment 1, the SF6 technique was used for 20 days in six non-lactating dairy cows fed a hay-based diet; for Experiment 2, the GF system was used for 91 days in seven lactating dairy cows fed a maize silage-based diet. The CH4 data were grouped by periods of 1–10 days (SF6) and 1–45 days (GF). The CH4 emissions averaged 23.6 ± 3.9 g/kg dry matter intake (DMI) for the SF6 and 17.4 ± 3.3 g/kg DMI for the GF on the measurement period. To achieve an R value of 0.70 for CH4 emissions (g/kg DMI), 3-day periods were necessary for SF6 and 17-day periods for GF. The R did not increase after 4-day periods for SF6 (R = 0.73), but increased for GF until 45-day periods (R = 0.90). In our experimental conditions and R = 0.70, the total number of cows necessary to detect a significant difference in CH4 emissions (g/kg DMI) between two treatments (e.g. diet) was similar for SF6 and GF.

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