Effects of the composition of irrigated perennial pasture on the milk production of dairy cows and their responses to supplementation with cereal grain-based concentrates

2008 ◽  
Vol 48 (7) ◽  
pp. 866
Author(s):  
C. R. Stockdale

The objective of the research described here was to compare the milk production from paspalum (Paspalum dilatatum Poir.)-dominant swards with milk production from perennial ryegrass (Lolium perenne L.)–white clover (Trifolium repens L.)-dominant swards. Eight experiments were conducted over a 2-year period, during which half the cows grazed pastures that had been established for more than 15 years (old pasture) and were dominated by paspalum in summer, while the remaining cows grazed pastures sown within the previous 2–3 years (new pasture), which were dominated by temperate species. Groups of four to five lactating Friesian cows grazed either old or new pasture and were either unsupplemented or were offered ~5 kg DM/cow.day of a high energy supplement (75% barley and 25% wheat). The hypothesis was that milk production would be greater from cows grazing new pastures than old pastures (at common pasture allowances), but that marginal milk responses when cereal grain-based supplements were fed would be greater when cows grazed old pastures; this was only partially supported. Milk yields were generally greater when cows grazed new pastures, but in six out of eight experiments, the advantage was only ~1 kg milk (100 g fat plus protein)/cow or less. In these six experiments, the difference in metabolisable energy density between the pastures was 0.7 MJ/kg DM or less. When concentrates were fed to supplement grazed pasture, there were seasonal variations, but similar marginal responses in milk production were recorded on both pastures throughout the study.

1996 ◽  
Vol 36 (7) ◽  
pp. 763 ◽  
Author(s):  
M Reeves ◽  
WJ Fulkerson ◽  
RC Kellaway

Three studies were conducted to examine the production response of Friesian cows grazing well-managed lukuyu (Pennisetum clandestinum) pasture to supplementation with a cereal grain concentrate, with and without the inclusion of formaldehyde-treated protein meal. Mean (¦ s.e.) levels of nutrients in the pasture (g/kg DM) on offer were: 205 ¦ 3 crude protein; 683 ¦ 7 in vitro organic matter digestibility; 239 ¦ 2 acid detergent fibre; 615 ¦ 8 neutral detergent fibre and 4.47 ¦ 0.16, 2.51 ¦ 0.06, 31.96 ¦ 0.98, 0.39 ¦ 0.03 and 3.18 ¦ 0.09 of calcium, phosphorus, potassium, sodium and magnesium, respectively. Study 1 was a 3-farmlet study conducted over 45 days (March-April 1993) involving cows 5-6 months into lactation, which compared 3 levels of concentrate feeding at 0 (R0), 3 (R3) or 6 (R6) kg crushed barley/cow.day. Study 2 was an 18-day extension of study 1 with animals in the seventh month of lactation. The concentrate fed was 72% barley and 24% formaldehyde-treated sunflower meal. Pasture intake of individual cows was determined using an alkane technique. Mean milk yields (L/cow. day) in study 1 were 14.2, 18.3 and 18.0, and in study 2 were 12.5, 18.5 and 17.4 for treatments R0, R3 and R6, respectively. Milk fat (3.77 v. 3.26%), but not milk protein, content of the Ro cows was significantly higher than R6 cows in study 1 only. In study 2, the apparent whole-diet digestibility remained constant as concentrate level rose, indicating a negative effect of concentrate fed on forage digestibility in the absence of buffers. Study 3 was a 3 x 4 factorial design plus a 'control' group (0.5 kg barley/cow.day used as a carrier for minerals) to examine the milk production response to 3 levels of concentrate feeding (3, 6 and 9 kg/cow.day) with 4 levels of formaldehyde-treated canola meal (FTCM; 0, 20, 40 and 60% of concentrate). Rations were iso-energetic within levels of concentrates fed. The control group had significantly lower milk production (17.2 L/cow.day), as well as milk protein (2.90%), plasma urea (PU) (5.90 mmol/L) and P-hydroxybutyrate (G-OHB) (0.525 mmo1L) than other treatment groups. The mean milk production response of 0.6 L milk/kg concentrate fed in study 3 at the 3 kg/day level of feeding was lower than observed in studies 1 and 2 (1.4 and 2.0 L/kg concentrate, respectively). The level of metabolisable energy in the concentrate in study 3 had a significant influence on milk production, milk fat and milk protein levels. Plasma glucose and G-OHB levels significantly increased with the incorporation of FTCM into the concentrate. Nonesterified fatty acid levels dropped significantly below levels of other treatments at the lowest level of inclusion of FTCM. PU levels generally increased in response to increasing metabolisable energy and inclusion of FTCM in the concentrate, with an interaction between them. Milk urea (MU) levels (mmol/L) showed a significant linear (P<0.001; r2 = 0.44) relationship to PU levels (mmol/L) as follows: MU = 0.167 + 0.272PU.


1988 ◽  
Vol 28 (4) ◽  
pp. 447 ◽  
Author(s):  
C Grainger

The reduction in milk production following a decrease in feeding level was compared with the increase in milk following an increase in feeding level of cows. Forty cows in their 5th month of lactation were allocated to 2 groups and offered either ad libitum pasture or restricted in their grazing so that, after 32 days, the difference in daily milk yield between the groups averaged 3 L/cow. Cows in each group were then offered cut pasture in stalls for 4 weeks to obtain mean daily intakes of either 14.4 or 10.2 kg DM/ cow The reduction in yield of milk energy (0.133 MJ/MJ metabolisable energy intake) following the decrease of intake from 14.4 to 10.2 kg DM/cow.day was similar to the increase in yield of milk energy (0.140 MJ/MJ metabolisable energy intake) following an increase in intake from 10.2 to 14.4 kg DM/cow.day. We conclude that, for cows in mid-lactation, the decrease in milk production following a decrease in feeding level is similar to the increase in milk production following an increase in feeding level. This implies that increases in milk production due to increased feeding can be predicted from experiments which measured reductions in milk production.


1975 ◽  
Vol 85 (2) ◽  
pp. 315-323 ◽  
Author(s):  
J. N. Peart ◽  
R. A. Edwards ◽  
Elizabeth Donaldson

SUMMARYThe milk production of 14 Finnish Landrace × Blackface ewes suckling either single, twin or triplet lambs was recorded while they were wholly maintained on a high-quality grazed pasture. Intravenous administration of oxytocin followed by hand milking was used to estimate milk production within 4 days of parturition and then at weekly intervals during a 12-week lactation period. At each milking the milk from each ewe was retained for analysis. Herbage samples for analysis were cut by hand shears at weekly intervals at a height simulating the harvesting by the sheep. In vitro analysis showed a decline in the digestible organic matter in the herbage from approximately 75% in the early stages, to around 67% at the end of lactation. The percentage crude protein in the dry matter of the herbage was variable but tended to increase towards the end of the lactation period. The estimated mean total milk production values were 125, 176 and 193 kg for single-, twin- and triplet-suckled groups of ewes, respectively. Almost all of the difference in total yield between the groups of multiplesuckled ewes occurred in the first 4 weeks of lactation. Analysis of variance showed no significant differences between suckling groups in the concentration of any of the milk constituents. Regression analysis showed significant evidence for differences between the linear and quadratic components of the regressions on stage of lactation for the suckling groups only in respect of daily milk yield, energy and protein production. The concentration of constituents other than lactose was higher in colostral milk but the differences were statistically significant only in respect of energy, total solids and fat. The lactose content of ordinary milk was significantly higher than that of colostral milk. The mean daily live-weight gains of the single- and twin-suckled lambs were significantly greater than that of the triplet-suckled group.


1962 ◽  
Vol 59 (1) ◽  
pp. 95-103 ◽  
Author(s):  
J. F. D. Greenhalgh ◽  
K. V. Runcie

1. A group of four Ayrshire and four Friesian cows was strip grazed on a cocksfoot-dominant sward while a second, similar group was zero grazed on herbage cut from the same field. The experiment consisted of five 10-day periods, two in the spring and three in the summer.2. The intakes of all cows were calculated from values for faeces output, estimated by using chromic oxide, and for herbage digestibility, estimated from faeces nitrogen. The regressions used for predicting digestibility were determined with the zero-grazed cows, digestibility coefficients being calculated from measured intake and estimated faeces output values.3. Over the whole experiment there was no difference between treatments in milk yield, herbage digestibility or intake. The solids-not-fat content of the milk of strip-grazed cows was significantly higher than for zero-grazed cows.4. In both spring and summer the increasing maturity of the herbage caused declines from one period to the next in herbage digestibility and intake, and there were declines also in milk yield and solids-not-fat content. The declines were greater for the zero-grazed cows, apparently because they, unlike the strip-grazed animals, were unable to select the more digestible and palatable components of mature herbage. The effects of selective grazing on digestibility, however, were evidently small, for the difference in between the treatment groups was never greater than one unit.5. The estimated energy intakes of both treatment groups corresponded quite well with their theoretical requirements of energy for maintenance, milk production and live-weight gain, and there was no evidence of the energy cost of free grazing being appreciably greater than that of zero grazing.


1985 ◽  
Vol 40 (3) ◽  
pp. 379-388 ◽  
Author(s):  
C. Grainger ◽  
A. W. F. Davey ◽  
C. W. Holmes

ABSTRACTThe performance of 38 Friesian cows with either high or low breeding indexes was measured during the whole lactation and in short-term experiments where the cows were individually given cut pasture in stalls, or grazed on pasture.Cows with high breeding indexes produced more milk fat than did cows with low breeding indexes in the short-term experiments, and during the whole lactation. There was close agreement between the expected differences (predicted from breeding indexes) and the measured differences in milk fat yield. When fresh cut pasture was given ad libitum in stalls the intake per cow was the same between genotypes. However, when intake was expressed per unit of metabolic weight, the mean pasture drymatter intake of the high breeding index cows was 1·05 of that of the low breeding index cows, but the difference was significant in only one of the four indoor feeding experiments.The difference between genotypes in size was not regarded as significant because the differences in mean live weight at calving (high breeding index – low breeding index) of the animals purchased in the 1st and 2nd years were –28 and 9 kg respectively. During the whole lactation, low breeding index cows gained significantly more live weight and lost significantly less body condition than did the high breeding index cows. No significant differences in live-weight and body-condition changes could be detected during the shorter periods (4 to 5 weeks) of the indoor feeding and grazing experiments.It can be calculated that the higher milk production of the high breeding index cows could be explained partly because they eat more (per unit metabolic live weight) and more importantly because they divert a higher proportion of the food they eat to milk production and a lower proportion to live-weight gain than do the low breeding index cows.


2012 ◽  
Vol 52 (12) ◽  
pp. 1117 ◽  
Author(s):  
P. J. Moate ◽  
S. R. O. Williams ◽  
C. Grainger ◽  
M. C. Hannah ◽  
D. Mapleson ◽  
...  

A 3-year experiment compared the effects of wild-type ryegrass endophyte and two novel endophytes on milk production in dairy cattle. On three 9.9-ha farmlets in West Gippsland, Victoria, pasture swards were established that were dominant in perennial ryegrass (Lolium perenne) infected with either wild-type, AR1 or AR37 endophytes. Each farmlet was stocked with 25 spring-calving Holstein–Friesian cows, which rotationally grazed nine paddocks within their farmlet during three lactations over 3 years. The three endophytes are known to produce different alkaloids, with wild-type producing ergot alkaloids, lolitrems and peramine, AR1 producing peramine and AR37 producing epoxy-janthitrems. These alkaloids were present in fresh pasture as well as hay and silage made from that pasture. Grazed pasture comprised 53% of estimated annual DM intake. The proportion was least from December to March when the daily ration of 2 kg DM/cow.day cereal grain was increased to 6 kg/day and forage supplements were fed consisting of purchased lucerne (Medicago sativa) hay and pasture silage grown on the farmlets. There were no differences in pasture accumulation rates or nutritive characteristics of ryegrass pastures on the three farmlets and no differences in the production of milk, fat or protein by cows grazing pasture infected with the three endophytes. Ryegrass staggers was only observed in four cows consuming the wild-type-infected ryegrass in the first year when the highest concentrations of lolitrem B were recorded in pasture. Soil samples showed lower numbers of root aphids (Aploneura lentisci), mealybugs (Pseudococcidae) and pasture tunnel moths (Philobota spp.) beneath ryegrass infected with the AR37 endophyte compared with the other two endophytes. Numbers of redheaded (Adoryphorus couloni) and blackheaded (Aphodius tasmaniae) cockchafers did not differ between treatments. Under dairy management and supplementary feeding regimes common to south-eastern Australia, the novel endophytes AR1 and AR37 had no effect on the milk production compared with the wild-type endophyte, and did not cause ryegrass staggers.


1993 ◽  
Vol 33 (2) ◽  
pp. 141
Author(s):  
SC Valentine ◽  
BD Bartsch ◽  
PD Carroll ◽  
IJ Chirnside

Milk production and composition were measured in 54 Holstein-Friesian dairy cattle fed 8.4 kg DM crushed barley grain daily and either supplemented or not with granulated magnesium oxide (MgO). The supplement was offered for 2 sequential test periods of28 days. During the first test period, cows were offered conserved pasture, conserved cereal crops, and grazed pasture. During the second test period they were only grazed on pasture. In the first period MgO had no effect (b0.05) on milk production or composition. During the second period, more (P<0.05) milkfat was produced by cows offered the MgO supplement than by unsupplemented cows (0.73 v. 0.69 kg/day). During this period the breakeven net milkfat price was calculated as $A1.23/kg.


2004 ◽  
Vol 44 (1) ◽  
pp. 1 ◽  
Author(s):  
C. R. Stockdale

An experiment was undertaken to establish the influence of body condition at calving on milk production and composition using diets typical of those currently used in Victoria. Seventy-two cows were fed differently from April 2001 to achieve target body condition scores (BCS) by 1 month before calving of about 4�(3.5–4.5), 5 (4.5–5.5) or 6 (5.5–6.5) units on an 8-point scale. The actual mean BCS at calving for the 3 treatments were 3.8, 5.2 and 5.7 units (P<0.05). After calving, cows grazed at pasture allowances of about 35 kg DM/cow.day and received 1 of 2 levels of supplementation (1 or 6 kg DM of pelleted concentrates per day) for about the first 10�weeks of lactation. The low BCS cows lost less body condition (0.35 v. 1.27 units; P<0.05) for a shorter period (4.8 v. 7.9 weeks; P<0.05) than did the medium and high BCS cows. The low BCS cows also ate more pasture than the other 2 BCS groups, but only when expressed as a percentage of liveweight (2.91 v. 2.73%; P<0.05). Improvements in BCS at calving resulted in higher milk fat percentages in early lactation (3.31% for low BCS cows v. 3.60% for the 2 higher BCS groups; P<0.05), while milk protein and lactose were not affected (P>0.05). At the lower level of feeding in early lactation, milk production increased (P<0.05) linearly as BCS at calving increased, by 1.0 kg milk per unit of body condition per day. However, when energy intake was increased by feeding 6 kg of concentrates, milk production increased as body condition increased (P<0.05) from the low to medium BCS, but there was no significant benefit beyond the medium BCS. Therefore, the hypothesis, that providing that cows are fed well with grazed pasture supplemented with high-energy concentrates in early lactation, BCS at calving will have no effect on subsequent milk production, was at least partially disproved, and it may be that it is never possible for cows at pasture to be sufficiently well fed.


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.


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