An assessment of whether energy was the first factor limiting production of dairy cows grazing kikuyu grass pasture

1979 ◽  
Vol 19 (100) ◽  
pp. 530 ◽  
Author(s):  
KW Moir ◽  
HG Dougherty ◽  
PJ Goodwin ◽  
FJ Humphreys ◽  
PR Martin
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
Body Weight Loss ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Limiting Factor ◽  
Dietary Energy ◽  
Predominant Species ◽  
Kikuyu Grass ◽  
Whole Plants

Whole plants of kikuyu grass were taken at intervals over a 9-month period from four commercial dairy farms on which this grass was the predominant species. The plants were separated into leaf and stem fractions and their metabolizable energy (ME) concentrations were estimated from their cell-wall contents. The overall mean ME in the dry matter of leaf and stem on each farm was of the order of 11 and 9 MJ kg DM-1, respectively. From considerations of appetite limits depending upon whether energy was derived mainly from leaf or stem, and taking into account ME supplied from supplementary feeds, and ME requirements for milk production, it was concluded that the production of the herd with the highest mean production cow-1 (4140 kg lactation-1) was limited by dietary energy concentration, although the genetic capacity of the cows to produce milk at the expense of body weight loss overcame this limitation to some extent. On the other farms with low to intermediate levels of productivity, the amount of food on offer was the first limiting factor.

Effects of abomasal fat infusion on dry matter intake, milk production and splanchnic metabolism in dairy cows at two stages of lactation

1997 ◽  
Vol 1997 ◽  
pp. 21-21
Author(s):  
J.A. Benson ◽  
C.K. Reynolds ◽  
D.J. Humphries ◽  
D.E. Beever ◽  
S.M. Rutter
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Dry Matter ◽  
Energy Concentration ◽  
Dietary Energy ◽  
Negative Effects ◽  
Stage Of Lactation ◽  
Fat Infusion ◽  
Fat Supplements ◽  
Two Stages

Fat is often fed to dairy cows as a means of increasing dietary energy concentration; however feeding fat often reduces feed intake. For many fat supplements this can be due to negative effects on rumen digestion, however feeding rumen inert fat and post ruminal infusions of fat can also depress intake although the mechanism by which this happens is not clear. The effect of fat on intake may also be influenced by stage of lactation as in early lactation fatty acid levels in the blood can be elevated. The aim of the present study was to investigate the effects of fat infusion into the abomasum on dry matter (DM) intake, milk production and metabolism of splanchnic tissues (portal drained viscera (PDV) and liver) in early and mid lactation cows.

The effect of dietary energy concentration on protein utilization during late pregnancy in ewes

1975 ◽  
Vol 85 (1) ◽  
pp. 175-184 ◽  
Author(s):  
J. A. Guada ◽  
J. J. Robinson ◽  
C. Fraser
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Nitrogen Retention ◽  
Late Pregnancy ◽  
Nitrogen Utilization ◽  
Metabolizable Energy ◽  
Late Gestation ◽  
Energy Concentration ◽  
Dietary Energy ◽  
Unit Increase

SUMMARYFrom 62 days of gestation to parturition, 20 Finnish Landrace x Dorset Horn ewes were each offered one of four diets with roughage to concentrate ratios of 20:80; 40:60; 60:40 and 80:20, at daily metabolizable energy and digestible crude protein intakes of 490 kJ and 3·55 g/kg W0·75respectively. Plasma concentration of free fatty acids, glucose and urea were determined weekly, and nitrogen balance and digestibility trials were carried out at 70–80 and 130–140 days of gestation.On all treatments the concentration of plasma free fatty acids increased during pregnancy from approximately 200–600 μ-equiv./l and the concentration of glucose and urea decreased by approximately 25%.Digestibility coefficients for dry matter and organic matter increased from 58 to 68% and from 60 to 70% respectively as the proportion of concentrates in the diet increased and were not affected by stage of gestation. The apparent digestibility of nitrogen was not affected by the energy concentration of the diet.Between mid and late gestation there was a mean increase in daily nitrogen retention of 2·5 g and an improvement in the efficiency of nitrogen utilization of 19 percentage units.Nitrogen retention and the efficiency with which the apparently digested nitrogen intake was retained increased as the dietary energy concentration was increased. The mean daily increases in nitrogen retention were 0·0135 and 0·0039 g for each percentage unit increase in the concentrate portion of the diet at mid and late gestation respectively. The corresponding values for the improvement in the efficiency of nitrogen utilization were 0·13 and 0·10%.

Prediction of the true metabolizable energy concentration in forages for ruminants

1986 ◽  
Vol 43 (2) ◽  
pp. 183-194 ◽  
Author(s):  
R. J. Dewhurst ◽  
A. J. F. Webster ◽  
F. W. Wainman ◽  
P. J. S. Dewey
Keyword(s):  
Lactic Acid ◽  
Crude Protein ◽  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Solid Phase ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Outflow Rate ◽  
Better Than ◽  
Chemical Description

ABSTRACTA model has been developed to predict the true metabolizable energy (ME,) concentration in forages given to ruminants.The chemical description of forages is based on the concentrations of ash, crude protein, ether extract, sugars and α-glycans, β-glycans and lignin, volatile fatty acids and lactic acid. The model assumes complete fermentation of sugars, α-glycans and lactic acid. The extent of fermentation of β-glycans and crude protein is determined in part by rumen solid-phase outflow rate, which can itself be predicted from dry-matter intake.The model was tested using 121 graminaceous forages whose chemical composition and concentration of metabolizable energy had been measured in the Feedingstuffs Evaluation Unit at the Rowett Research Institute. The agreement between observed and predicted ME, for all classes of forage was nearly always as good as, or better than, the best prediction from single attributes of food chemistry which could only be determined retrospectively and were not consistent even within classes of forage. The model predicts a decline in ME, with increasing rumen solid-phase outflow rate which is determined mainly by the extent of fermentation of β-glycans.

The production and composition of milk from dairy cows fed hay and supplemented with either brewers' grains or rolled barley grain

1982 ◽  
Vol 22 (116) ◽  
pp. 155 ◽  
Author(s):  
SC Valentine ◽  
RB Wickes
Keyword(s):  
Dairy Cows ◽  
Milk Fat ◽  
Dry Matter ◽  
Barley Grain ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Price Ratio ◽  
Nutritive Values ◽  
Friesian Cows

Four groups of seven Friesian cows were offered 70% of their calculated metabolizable energy requirements as pasture hay and either 2.4, 4.8 or 7.2 kg/d of dry matter (DM) as wet brewers' grains or 3.9 kg DM/d as rolled barley. A further group of cows received no supplement. The quantities of brewers' grains offered were calculated from in vitro digestible DM content to provide lo%, 20% and 30%, respectively, of metabolizable energy requirements and the rolled barley 30% of metabolizable energy requirements. The cows consumed a mean of 2.2,4.3 and 6.1 kg DM/d, respectively, as brewers' grains and 3.9 kg DM/d as rolled barley. The daily yields of milk (litres), protein (kg) and solids not fat (kg), respectively, were greater (P < 0.05) for the cows offered brewers' grains at 4.8 kg DM/d (1 5.6,0.49, 1.36) and 7.2 kg DM/d (16.4, 0.54, 1.45) than for the cows offered rolled barley (13.3, 0.45, 1.21). Daily yields of milk fat from the cows offered either 4.8 or 7.2 kg DM/d of brewers' grains or rolled barley did not differ significantly. There were no significant differences between treatments in liveweight change. It was concluded that wet brewers' grains and rolled barley offered as supplements to dairy cows fed hay have similar nutritive values for milk production. It was calculated that for milk fat production the break even landed price ratio of brewers' grains to barley is 1:1.26.

The effects of milking cows three times daily

1982 ◽  
Vol 34 (2) ◽  
pp. 197-201 ◽  
Author(s):  
D. A. Poole
Keyword(s):  
Food Intake ◽  
Milk Yield ◽  
Dry Matter ◽  
Milk Quality ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Total Food ◽  
The Mean ◽  
Carry Over ◽  
Daily Milk

ABSTRACTThe experiment assessed the effects on performance from calving to the 20th week of lactation of milking cows three times daily (3 × ) compared to milking twice daily (2 × ). After 20 weeks all cows were milked 2 ×. Each treatment consisted of 18 cows and 11 heifers. The mid-calving date was 21 September 1979.Complete diets of the same composition were offered separately to each group in quantities equivalent to 1040 g/kg of their previous intake. The diet for the first 18 weeks of lactation was estimated to have an energy concentration within the range 11·0 to 11·3 MJ metabolizable energy per kg dry matter. After 18 weeks, the diet was reformulated to reduce the energy concentration to 10·3 MJ per kg dry matter. Total food intakes for the 20 weeks of treatment were 2352 kg dry matter (3 ×) and 2241 kg dry matter (2 ×). From 8 April 1980 the cows were turned out to grass to complete their lactations.During the 20 weeks the mean daily milk yields of heifers were 19·3kg (3×) and 171kg (2×) (P<005). Cow yields were 28·4 (3×) and 23·9 kg (2×) (P< 0·001) during the same period. After 3× daily milking ceased, there were some positive carry-over effects on milk yield and food intake.Lactation yields from heifers were 4881 (3 ×) and 4498 kg (2×), whilst for cows the equivalent yields were 6485 (3 ×) and 5694 kg (2 ×) (P<0·01). There were no significant differences in milk quality. At 20 weeks after calving the cows milked 3 × daily had gained less weight, but by 44 weeks from calving the weight gains were similar at 42 (3 ×) and 45 kg (2 ×).

The effect of body condition of dairy cows at calving on their food intake and performance when given complete diets

1982 ◽  
Vol 35 (1) ◽  
pp. 113-119 ◽  
Author(s):  
P. C. Garnsworthy ◽  
J. H. Topps
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
High Energy ◽  
Metabolizable Energy ◽  
Energy Output ◽  
Positive Energy ◽  
Total Period ◽  
Condition Score ◽  
And Performance ◽  
Soya Bean Meal

ABSTRACTIn two trials, three groups of eight dairy cows were fed for 2 months before calving to achieve condition scores at calving of 1·5 to 2 (low), 2·5 to 3 (medium) and 3·5 to 4 (high). For 16 weeks after calving, all cows were given a complete diet composed of silage, malt distillers' grains, barley, swedes and soya bean meal (metabolizable energy 12·25 and 12·35 MJ/kg dry matter in trials 1 and 2 respectively).In both trials, significant differences were found between groups in dry-matter intake after calving. Cows that had higher condition scores at calving ate less and reached maximum intake of dry matter later than cows with lower condition scores (high, medium and low condition-score cattle attained maximum intakes in 14·5, 12·7 and 9·3 weeks in trial 1, and in 141, 9·6 and 7·9 weeks in trial 2). In trial 1, no difference was found in milk yield but, in trial 2, cows that had lower condition scores at calving produced slightly more milk. In both trials, cows that had higher condition scores at calving lost more body weight and condition, over a longer period, and started to regain the losses later than cows with lower condition scores. The biological efficiencies of milk production (energy output/energy input) from 8 weeks before calving until 16 weeks after calving were 0·302, 0·299 and 0·295 in trial 1, and 0·312, 0·290 and 0·306 in trial 2, for the low, medium and high groups respectively.It was concluded that cows with lower condition scores at calving produced more milk directly from food rather than via body fat, were in positive energy balance earlier in lactation and over the total period were biologically more efficient than cows with higher condition scores. There appears to be no benefit from feeding cows to achieve a condition score greater than 1·5 to 2 at calving if high-energy complete diets are offered in early lactation.

Production characteristics of high-yielding dairy cows

1983 ◽  
Vol 36 (3) ◽  
pp. 321-334 ◽  
Author(s):  
D. R. Neilson ◽  
C. T. Whittemore ◽  
M. Lewis ◽  
J. C. Alliston ◽  
D. J. Roberts ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Energy Intake ◽  
Milk Yield ◽  
Body Condition ◽  
Dry Matter ◽  
Management Strategies ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Dry Matter Intake ◽  
Gross Efficiency

ABSTRACTUnderstanding the relationships between food intake, milk output and body condition in high-yielding dairy cows is crucial in determining suitable management strategies. During two winter feeding periods 38 and 37 cows were individually fed, to appetite, complete diets which on average contained 11·7 MJ metabolizable energy per kg dry matter and comprised grass silage, concentrate meal and brewers' grains (draff). The groups' mean 305-day yield was 7 240 kg (s.d. 1 281) with 42 g (s.d. 4·3) fat per kg. Regression analysis was carried out to describe dry-matter intake both for 26 weeks post calving and for four successive 6-week periods from calving. The final equations, which had a residual s.d. of 0·07 to 0·10 of the observed intake, included milk yield, cow size and a measure of body-condition change. The cows were divided into three groups (high, medium and low) on two criteria: (1) mean milk yield (MJ/day) during the first 26 weeks of lactation and (2) post-calving backfat index determined ultrasonically. Differences were found between milk-yield groups from gross efficiency (milk yield (MJ)/energy intake (MJ metabolizable energy)) (P < 0·001), mean metabolizable energy intake (MJ/day) (P < 0·01), dry-matter intake as a proportion of live weight (P < 0·05), and post calving live weight (kg) (P < 0·05). Differences were found between backfat-index groups for maximum backfat loss and loss to day 42 (P < 0·001); also for mean live weight during the 26 weeks and post calving live weight (P < 0·001), dry-matter intake as a proportion of live weight (P < 0·05) and lactation number (P < 0·05). Interactions were found between the milk yield groups and backfat groups for milk yield (P < 0·01) and gross efficiency (P < 0·05) with the fattest group containing the highest and lowest yields and efficiencies.

The effect of dietary metabolizable energy concentration upon the pre- and post-weaning performance of growing rabbits

1983 ◽  
Vol 36 (2) ◽  
pp. 229-236 ◽  
Author(s):  
Catherine Butcher ◽  
M. J. Bryant ◽  
E. Owen ◽  
I. Leach ◽  
D. H. Machin
Keyword(s):  
Weight Gain ◽  
Milk Yield ◽  
Dry Matter ◽  
Post Partum ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Adaptation Period ◽  
Live Weight Gain ◽  
Weight Gains

ABSTRACTTwenty-five Californian does were mated and given pelleted diets of either 8(LE) or 10(HE) MJ/kg dry matter (ruminant metabolizable energy values) throughout gestation and lactation. Litter sizes were adjusted to six offspring per doe. Milk yield was estimated from the weight differences of the litters before and after suckling, when the opportunity for nursing was confined to once daily. The young rabbits were allowed access to either the LE or HE diets from 18 days of age. Weaning took place at 32 days of age when four rabbits from each doe grouP × pre-weaning diet were slaughtered. Diet had no effect on litter size or birth weight, but does on the LE diet had lower live weights post partum (P < 0·05). Dry-matter consumption by the does on the LE diet was greater than for the HE diet (P < 0·05) both during gestation and lactation, but calculated metabolizable energy intakes were lower during lactation. There were no statistically significant differences between treatments for milk yield or live-weight gain to weaning and dry-matter intakes of the young at weaning, but daily live-weight gain from fostering to 18 days of age was greater for litters of does fed the HE rather than the LE diet (P < 0·05). There were no statistically significant differences between diets for carcass traits at weaning.After weaning, 32 rabbits were given either the LE or HE diet until 2 kg live weight when they were slaughtered. A post-weaning × pre-weaning diet interaction (P < 0·05) occurred for live weights of the rabbits at the start of the post-weaning trial (i.e. after a 10-day adaptation period) with LE: LE rabbits being lighter than other rabbits as a results of poor live-weight gains during the adaptation period. Live-weight gains to slaughter were greater for the pre-weaning LE diet (P < 0·05) and the post-weaning HE diet (P < 0·01), although dry-matter intakes of the HE diet were less (P < 0·05). Rabbits on the LE diet had greater empty gut weights (P < 0·05) and lighter livers (P < 0·05) at slaughter.

Effect of work applied at different stages of lactation on milk production, reproduction and live-weight change of F1 crossbred dairy cows used for draught

1999 ◽  
Vol 69 (3) ◽  
pp. 473-480 ◽  
Author(s):  
E. Zerbini ◽  
Alemu Gebre Wold
Keyword(s):  
Dairy Cows ◽  
Weight Change ◽  
Dry Matter ◽  
Post Partum ◽  
Live Weight ◽  
Principal Component ◽  
Experimental Period ◽  
Metabolizable Energy ◽  
Early Lactation ◽  
Natural Pasture

AbstractThis study examined whether work applied at different stages of lactation had any effect on reproduction of cows under two feeding regimes. Twenty-four F1 crossbred dairy cows (12 Friesian × Boran and 12 Simmental × Boran) were allocated one of two diets (H + 3: natural pasture hay + 3 kg concentrate per day; and H + 5: natural pasture hay + 5 kg concentrate per day) and one of three work treatments — starting 45 days (D45), 90 days (D90) and 135 days (D135) post partum — using a principal component analysis score based on milk yield, live weight, calving interval and parity. Cows pulled sledges for 50 days (pull = 108 N per 100 kg live weight). Over the experimental period of 315 days, cows on diet H + 5 travelled a similar distance and produced amounts of fat-corrected milk (FCM) similar to those of cows on diet H + 3. Total intake of dry matter per kg live weight 0·75 was higher for cows on diet H + 5 than for cows on diet H + 3 and was similar across work times. Hay dry-matter intake was greater for the H + 3 group than for the H + 5 group at 180 days post partum and thereafter. Cows on diet H + 5 lost less weight in early lactation and gained more in mid and late lactation than cows on diet H + 3. During the work period, live-weight change was similar across diets but it was different between work treatments D45 and D135. The interval from calving to conception decreased by 63 and 101 days when start of work was delayed from D45 to D90 and from D45 to D 135, respectively. Output/input ratios of metabolizable energy equivalents were 0·35 for H + 3 and 0·37 for H + 5 diet, and 0·34, 0·37 and 0·40 for work times D45, D90 and D135, respectively. These results indicate that work started in early lactation significantly increased days to conception and decreased overall productivity of lactating working cows. Farmers must weigh the relative importance and cost of delayed ploughing against those of delayed oestrus or against the cost of borrowing draught power.

Evaluation of pasture for beef cattle from measurements of cell wall in separated leaf and stem fractions

1983 ◽  
Vol 100 (3) ◽  
pp. 513-518 ◽  
Author(s):  
K. W. Moir ◽  
J. P. Ebersohn
Keyword(s):  
Cell Wall ◽  
Dry Matter ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Dietary Energy ◽  
High Cell ◽  
Grazing Cattle ◽  
Weight Gains ◽  
Tropical Grass

SUMMARYThree pastures, pangola–clover, setaria, and tropical grass–legume, were grazed for a 9-month period by 12 steers of initial live weight of 199 kg on each. For the first 5 months live-weight gains were, respectively, 1·2, 0·76 and 0·43 kg per day, mostly higher than could be expected for estimated dietary energy concentrations of 10·1, 8·9 and 8·7 MJ of metabolizable energy (ME) per kg of dry matter. The high live-weight gains were not explained satisfactorily by dry-matter intakes as measured from faeces voided and dietary digestible dry matter, but were possible if published values for the requirements of ME for growth and fattening were too high. Cell wall, in vitro digested cell wall and nitrogen in separated leaf and stem fractions were useful indices for evaluating pasture for grazing cattle, but they did not predict live-weight gain.

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