Progesterone clearance rate in lactating dairy cows with two levels of dry matter and metabolisable energy intakes

2002 ◽  
Vol 72 (1-2) ◽  
pp. 11-25 ◽  
Author(s):  
A.R Rabiee ◽  
D Dalley ◽  
J.M Borman ◽  
K.L Macmillan ◽  
F Schwarzenberger
Author(s):  
J.M. Mcgrath ◽  
J.W. Penno ◽  
K.L. Davis ◽  
R. Wrenn

The nutritional value of pasture silage made in New Zealand is often sub-optimal for lactating dairy cows. As farming systems require more pasture silage to be used in an attempt to increase lactation lengths and milksolids production per cow, the quality of this silage becomes more important. In spring 1995, pastures were closed for silage at weekly intervals from 11 September to 17 October, representing six distinct closure dates, to determine the effect that date and length of closure has on pasture quality. In spring 1997 pastures were grazed to different residuals (1.2- 1.4, 1.8-2.0, 2.1-2.4 and 2.5-2.9 t DM/ha) and then closed for silage to determine the effect that post grazing residual has on pasture quality. In both experiments pasture dry matter (DM) yield and chemical and botanical composition was monitored over the 63 day closure. Pasture closed on 11 or 17 September had higher metabolisable energy (ME) (P


Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 104
Author(s):  
Shulin Liang ◽  
Chaoqun Wu ◽  
Wenchao Peng ◽  
Jian-Xin Liu ◽  
Hui-Zeng Sun

The objective of this study was to evaluate the feasibility of using the dry matter intake of first 2 h after feeding (DMI-2h), body weight (BW), and milk yield to estimate daily DMI in mid and late lactating dairy cows with fed ration three times per day. Our dataset included 2840 individual observations from 76 cows enrolled in two studies, of which 2259 observations served as development dataset (DDS) from 54 cows and 581 observations acted as the validation dataset (VDS) from 22 cows. The descriptive statistics of these variables were 26.0 ± 2.77 kg/day (mean ± standard deviation) of DMI, 14.9 ± 3.68 kg/day of DMI-2h, 35.0 ± 5.48 kg/day of milk yield, and 636 ± 82.6 kg/day of BW in DDS and 23.2 ± 4.72 kg/day of DMI, 12.6 ± 4.08 kg/day of DMI-2h, 30.4 ± 5.85 kg/day of milk yield, and 597 ± 63.7 kg/day of BW in VDS, respectively. A multiple regression analysis was conducted using the REG procedure of SAS to develop the forecasting models for DMI. The proposed prediction equation was: DMI (kg/day) = 8.499 + 0.2725 × DMI-2h (kg/day) + 0.2132 × Milk yield (kg/day) + 0.0095 × BW (kg/day) (R2 = 0.46, mean bias = 0 kg/day, RMSPE = 1.26 kg/day). Moreover, when compared with the prediction equation for DMI in Nutrient Requirements of Dairy Cattle (2001) using the independent dataset (VDS), our proposed model shows higher R2 (0.22 vs. 0.07) and smaller mean bias (−0.10 vs. 1.52 kg/day) and RMSPE (1.77 vs. 2.34 kg/day). Overall, we constructed a feasible forecasting model with better precision and accuracy in predicting daily DMI of dairy cows in mid and late lactation when fed ration three times per day.


Author(s):  
J.D. Leaver ◽  
R.C. Campling

Supplementary feeding of grazing dairy cows is often uneconomic, and whilst supplementation with silage (buffer feeding) can be worthwhile, this often leads to a depletion of winter forage stores. In this study, a mixture of brewers grains and treated straw was used as a supplement. Offered as a 1:1 mixture in the dry matter (DM), it is a purchased substitute for grass silage, having a similar cost, and similar metabolisable energy (ME) and crude protein (CP) contents. The high seasonality adjustments to milk price in mid-late season make supplementation potentially worthwhile.Experiments were carried out from April to September in 1988 and 1989, which had moderate and very low rainfall respectively. Each year 20 British Friesian cows which calved December to March (1988 experiment) and February-April (1989) were allocated at random to either treatment B or C. In B, the cows were offered a 1:1 mixture (DM basis) of brewers grains and NaOH treated chopped barley straw for 60 minutes after morning milking. In C, the cows received no supplement. Both groups were fed 1.0 kg/day of concentrates in the milking parlour. Due to the severe drought in 1989, concentrate feeding was increased to 5.0 kg/day for all cows during the last 4 weeks of the experiment. Also, urea-treated whole crop wheat was fed at a level of 2.5 kg DM/day during the last 7 days.


1968 ◽  
Vol 48 (1) ◽  
pp. 41-46 ◽  
Author(s):  
V. S. Logan ◽  
L. J. Fisher ◽  
P. S. Hayden

Vacuum silages made from Pioneer 383 and Pride 5 corn were fed with concentrate and with and without hay to lactating dairy cows. Yields per hectare in terms of dry matter were 8,850 kg for Pioneer 383 and 8,350 kg for Pride 5. Intake of silage dry matter was significantly higher (P < 0.05) for Pride 5 (11.4 kg/day) than for Pioneer 383 (9.8 kg/day), and significantly lower (P < 0.05) for both silages when hay was fed (11.4 kg/day versus 9.7 kg/day). Fat-corrected milk production was significantly higher (P < 0.05) for Pride 5 (17.0 kg/day) than for Pioneer 383 silage (15.8 kg/day), and significantly higher (P < 0.05) when hay was fed, than without hay supplementation (167 kg/day versus 16.0 kg/day). Utilization of silage dry matter in terms of fat-corrected milk production per hectare was 10,486 kg for Pride 5 corn silage and 11,176 kg for Pioneer 383 corn silage.


1991 ◽  
Vol 52 (1) ◽  
pp. 11-19 ◽  
Author(s):  
D. A. Jackson ◽  
C. L. Johnson ◽  
J. M. Forbes

ABSTRACTAn experiment was carried out to investigate the effects of compound composition and silage characteristics on silage intake, feeding behaviour and productive performance of dairy cows during the first 25 weeks of lactation. Over a period of 3 years, 36 lactating British Friesian cows (12 per year), in their third or later lactations, were divided into two groups. The cows in each group received either compound S, in which the principal energy source was cereal starch, or compound F containing a mixture of high quality digestible fibre. Cows given compound F ate 2·2 kg more silage dry matter per day (P < 0·05). The type of compound had no effect on the frequency of silage feeding and the time spent eating was significantly different only over weeks 10 to 25 of lactation (P < 0·05), with cows on compound F spending on average 20 min longer feeding per day. Cows on compound F produced 1·7 kg more milk per day than cows on compound S. Although there were no significant differences in the concentration of milk constituents, compound F was associated with higher yields of milk constituents. Significant differences were found between the years of experiment in the frequency of feeding (P < 0·05) and also in the concentration of milk protein and milk fat. There were no significant differences in the magnitude of live-weight change between treatments or year of experiment.


1970 ◽  
Vol 74 (1) ◽  
pp. 11-21 ◽  
Author(s):  
A. J. Mudd

SUMMARYGroups of lactating dairy cows were fed on grass which had received various amounts of nitrogen and potash fertilizers. In the early part of the season not only was the herbage concentration of calcium and phosphorus lower in grass which had received potash fertilizer but in addition the ‘availability’ of the calcium to cows was depressed. Grass which had received large amounts of nitrogen fertilizer had a comparatively low dry-matter content in the autumn. Cows fed such grass were in negative balance for calcium at this time. As expected high dietary potassium gave rise to high excretion of potassium in the urine which in turn was correlated with high excretion of magnesium. These various factors are likely to affect the incidence of metabolic disease.


1997 ◽  
Vol 1997 ◽  
pp. 4-4
Author(s):  
T. Yan ◽  
F. J. Gordon ◽  
R. E. Agnew ◽  
M. G. Porter ◽  
D. C. Patterson

The metabolisable energy (ME) requirement for maintenance (MEm) can be determined by measuring the fasting metabolism of the non-lactating cow, but this approach cannot encompass any differences in maintenance metabolic rate between lactating and non-lactating animals. The MEm and efficiency of ME use for lactation (k1) can also be estimated by regression of energy outputs against ME intake (MEI). During 1992 to 1995, a total of 221 Holstein/Friesian lactating dairy cows, which were offered grass silage-based diets, were subjected to gaseous exchange measurements in indirect open-circuit respiration calorimeters. The objective of the present study was to use these data to predict the MEm and k1 by a range of regression techniques for lactating dairy cows offered grass silage-based diets.


1969 ◽  
Vol 49 (3) ◽  
pp. 383-388
Author(s):  
A. L. Hoogendoorn ◽  
C. M. Grieve

Chromic oxide (Cr2O3) in paper pellets was used as an indicator for digestibility studies with four Holstein-Friesian cows fed rations composed of different roughage to concentrate ratios. Cows A and B received one pellet, or 3.46 g of Cr2O3, whereas cows C and D received three pellets, or 10.38 g of Cr2O3, daily.Recovery of Cr2O3 in the feces varied from 84 to 103% for animals A and B and from 92 to 95% for animals C and D. The coefficients of apparent digestion of dry matter were lower (P < 0.01) when the Cr2O3 method was used instead of the conventional method. When samples were taken at 0500, 0900, 1300 and 1700 hours, the Cr2O3 method gave average estimates of digestibility for animal pairs A, B and C, D that were 94.2 and 97.5% of those obtained by the conventional method. Standard deviations for both the Cr2O3 and conventional methods were relatively high.Excretion patterns of Cr2O3 were not signicantly correlated with those of crude protein, phosphorus and calcium. The average concentrations of crude protein, phosphorus and calcium in compounded feces samples collected at 0500, 0900, 1300 and 1700 hours were 101.3, 100.6 and 96.7% of those in samples of the total excretions.The daily administration of 10.38 g of Cr2O3 at 0900 hours for eight days, and the collection of fecal grab samples at 0500, 0900, 1300 and 1700 hours daily during the last five days seemed satisfactory for estimating apparent digestibility of dry matter.


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