Effect of grain supplementation and the provision of chemical or physical fibre on marginal milk production responses of cows grazing perennial ryegrass pastures

2001 ◽  
Vol 41 (4) ◽  
pp. 465 ◽  
Author(s):  
W. J. Wales ◽  
Y. J. Williams ◽  
P. T. Doyle
Keyword(s):  
Milk Production ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Milk Fat ◽  
Crude Protein ◽  
Ground Level ◽  
Large Degree ◽  
Herbage Intake ◽  
Cereal Grain

An experiment was undertaken to establish the marginal milk production response from cereal grain supplementation by dairy cows grazing irrigated perennial pastures in spring and whether the addition of a hay supplement would improve that response. Cows were offered perennial ryegrass (Lolium perenne L.)–white clover (Trifolium repensL.) pasture at allowances (measured to ground level) of 20 or 40 kg dry matter (DM)/cow.day. Additional cows offered the low allowance were also offered supplements of pasture hay as a cube or pellet (2.5 kg DM/day), cereal grain as a pellet (5.0 kg DM/day) or cereal grain plus pasture hay (7.5 kg DM/day) as a pellet (1.75:1 DM basis) or cube (1.97:1 DM basis). The 7 treatments were replicated 3 times, and 63 cows were used (3 cows/treatment). The in vitro DM digestibility, crude protein and neutral detergent fibre (NDF) concentration of the barley and perennial pasture hay were 863 and 563 g/kg DM, 131 and 92 g/kg DM, and 182 and 666 g/kg DM, respectively. Cows from all treatments consumed herbage with an in vitro DM digestibility of 833 g/kg DM, crude protein content of 214 g/kg DM and NDF concentration of 457 g/kg DM compared with the pregrazed herbage on offer of 771, 174 and 527 g/kg DM, respectively. The mean pregrazing herbage mass of 4.13 t DM/ha consisted of perennial ryegrass (507 g/kg DM), white clover (188 g/kg DM), weeds (194 g/kg DM) and dead material (111 g/kg DM). Without supplements, cows consumed 11.2 kg DM/day at the low pasture allowance and 15.6 kg DM/day at the high allowance. Herbage intake did not decline to a large degree when barley was included in the diet, where a substitution rate of 0.2 kg reduction in pasture DM/kg DM cereal grain supplement was measured. The NDF concentration of the diet consumed was lowest (P< 0.05) for the grain pellet treatment (370 g NDF/kg DM) and highest (P&lt;0.05) for the fibre pellet (493 g NDF/kg DM) and the fibre cube (507 g NDF/kg DM) treatments. Fat-corrected milk yield increased (P<0.05)) from 20.1 to 24.5 kg/cow.day when cows consumed 4.5 kg DM cereal grain/day with a marginal milk response of 1.0 kg 4% fat-corrected milk/kg DM concentrate supplement. Supplementation with grain or hay had no significant effect (P>0.05) on milk fat, protein or lactose concentrations. The cows offered the high allowance spent more (P<0.05) time grazing than those offered the low allowance, but there were no significant differences in rumination time. Cows spent more time ruminating when consuming the grain &plus; fibre cube compared with the other supplement treatments, which were lower (P<0.05) and similar. Cows offered pasture at the low allowance ruminated the least. The rumen pH was not different between treatments and averaged 5.9. The ratio of acetate plus butyrate: propionate was not different between treatments and averaged 4.3. This study has shown that feeding cereal grain to cows grazing pastures high in perennial ryegrass resulted in acceptable marginal milk responses of 1 kg milk/kg DM of cereal grain in spring because of sufficient NDF in the diet. As there was adequate NDF in the diet, further supplements with pasture hay as cubes or pellets had no effect on marginal milk responses .

Effects of feeding additional pasture hay in autumn to dairy cows grazing irrigated perennial ryegrass-white clover pasture and supplemented with barley grain

2000 ◽  
Vol 40 (1) ◽  
pp. 1 ◽  
Author(s):  
W. J. Wales ◽  
D. W. Dellow ◽  
P. T. Doyle ◽  
A. R. Egan
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Milk Fat ◽  
Crude Protein ◽  
Barley Grain ◽  
Fibre Content ◽  
Neutral Detergent Fibre ◽  
Herbage Intake ◽  
Clover Pasture

Two experiments were undertaken to investigate responses by dairy cows grazing irrigated perennial pastures in autumn to supplementation with barley grain and pasture hay. Cows in late lactation were offered limited amounts of perennial ryegrass–white clover pasture at 26 kg DM/cow. day. Supplements were offered as nil or 6.0 kg DM/cow.day plus perennial pasture hay at 0, 0.5, 1.2, 2.0 or 3.0 kg DM/cow. day in a replicated experiment with 6 treatments using 36 cows (3 cows/treatment replication). The second experiment, which was conducted concurrently with experiment 1, measured aspects of rumen function and blood parameters in 3 groups of 3 rumen fistulated lactating cows grazing at the same herbage allowance and supplemented with barley (6.0 kg DM/cow. day) and 0, 1.0 or 3.0 kg DM of pasture hay daily. The in vitro DM digestibility and crude protein and neutral detergent fibre content of the barley and perennial pasture hay was 863 and 640 g/kg DM, 134 and 87 g/kg DM and 192 and 615 g/kg DM, respectively. In experiment 1, the cows from all treatments consumed herbage (mean s.d.) with an in vitro DM digestibility of 811 21.8 g/kg DM, crude protein content of 233 26.0 g/kg DM and neutral detergent fibre content of 404 39.4 g/kg DM compared with the pregrazed herbage on offer of 710, 152 and 526 g/kg DM, respectively. The mean pregrazing herbage mass of 3.75 t DM/ha in experiment 1 consisted of perennial ryegrass (580 g/kg DM), white clover (100 g/kg DM), weeds (110 g/kg DM) and dead material (210 g/kg DM). Without supplements, cows consumed 10.0 kg DM/day of this pasture with a neutral detergent fibre intake of 4.43 kg/day. The herbage grazed in experiment 2 was similar. Herbage intake did not decline to a large degree when barley was included in the diet indicating a very low substitution rate under the prevailing conditions where herbage allowance was only 26 kg DM/cow. day. Inclusion of hay progressively decreased (P<0.05) herbage intake, with substitution averaging 1.2 kg DM of herbage/kg DM of hay. Total DM intakes (15.5 kg DM/cow. day) were similar for the barley and the barley plus hay treatments up to 2.0 kg DM hay/cow. day; total DM intake was higher (P<0.05) for the 3.0 kg hay treatment. Milk production increased (P<0.05) with grain and hay supplementation, the marginal response being 0.8–1.0 kg milk/kg DM supplement, however, there was no significant difference between the 5 supplemented treatments. Supplementation with hay had no significant effect (P>0.05) on milk fat or milk protein contents which averaged 44.6 and 35.2 g/kg milk, respectively. The ratio of acetate + butyrate:propionate was 4.1:1 when cows consumed 6.0 kg barley, which was around the critical ratio of 4:1 for milk fat of 40 g/kg. Increasing the amount of hay in the diet did not alter this ratio. Because of the high levels of substitution of hay for pasture, changes in neutral detergent fibre intake were small between supplemented treatments. The rumen pH, ammonia-N concentration and volatile fatty acid concentration were relatively stable during the day because of a relatively slow rate of eating (1.5 kg DM/h) and long rumination time (about 6.8 h/day). Ruminal pH was rarely below 6.0, even when barley was given alone, suggesting that fibre digestion was not compromised. Additional fibre as supplemental hay to cows in late lactation grazing irrigated pasture did not improve milk production when the neutral detergent fibre content of the diet was above an average of 336 g/kg DM. Use of hay as a means of providing additional fibre could reduce herbage utilisation.

Effect of grain and straw supplementation on marginal milk-production responses and rumen fermentation of cows grazing highly digestible subterranean clover pasture

2003 ◽  
Vol 43 (5) ◽  
pp. 467 ◽  
Author(s):  
W. J. Wales ◽  
P. T. Doyle
Keyword(s):  
Milk Production ◽  
Milk Fat ◽  
Protein Concentration ◽  
Milk Protein ◽  
Subterranean Clover ◽  
Ground Level ◽  
Ruminal Fluid ◽  
Cereal Grain ◽  
Production Response

The marginal milk-production response to cereal grain supplementation of dairy cows grazing irrigated subterranean clover (Trifolium subterraneum L.) pasture in spring was investigated. We also determined whether the addition of a perennial ryegrass (Lolium perenne L.) straw supplement would improve that response. There were 8�replicated treatments in a factorial design with 2 amounts of cereal grain pellet [0 and 5.0 kg dry matter (DM)/cow.day] and 4 amounts of straw (0, 0.5, 1.0 and 2.0 kg DM/cow.day), 48 cows in total. Cows in all treatments grazed subterranean clover at an allowance (measured to ground level) of 19 kg DM/day. The barley and wheat pellet and straw had a neutral detergent fibre (NDF) concentration of 164 g/kg DM and 704 g/kg DM, respectively. Cows from all treatments consumed pasture with an in vitro DM digestibility of 743�g/kg DM and NDF concentration of 313 g/kg DM, compared with the pregrazed pasture on offer of 707 and 360, respectively. Pasture DM intake was not affected (P>0.05) by supplementation with either grain or straw, and averaged 12.7�kg�DM/cow.day. Cows supplemented with grain achieved a marginal milk-production response of 1.0�kg�fat-corrected milk (FCM)/kg DM grain. However, with increasing amounts of straw, responses of 0.0, 0.9 and 0.5 kg FCM/kg DM grain were observed. Fat-corrected milk yields were not different (P>0.05) between straw treatments and averaged 25.8 kg FCM/cow.day. Grain feeding significantly (P<0.05) reduced milk fat concentration and increased (P<0.05) milk protein concentration, although offering increasing amounts of straw had no significant (P>0.05) effect on either milk fat or milk protein concentration. Average ruminal fluid pH was significantly (P<0.05) lower when cows consumed cereal grain pellets than with those treatments without cereal grain (5.82 v. 6.09). There were no differences (P>0.05) in ruminal fluid pH among cows that consumed different amounts of straw. When cows were managed to limit intake of subterranean clover by restricting pasture allowance, supplementation with cereal grain resulted in acceptable marginal milk-production responses of 1.0 kg FCM/kg DM cereal grain. Under these circumstances, providing additional NDF as straw did not improve the milk-production response to cereal grain, with NDF ranging from 290 to 337 g/kg DM when 0–1.7 kg DM straw was consumed.

Dry matter intake and nutrient selection by lactating cows grazing irrigated pastures at different pasture allowances in summer and autumn

1998 ◽  
Vol 38 (5) ◽  
pp. 451 ◽  
Author(s):  
W. J. Wales ◽  
P. T. Doyle ◽  
D. W. Dellow
Keyword(s):  
Milk Production ◽  
Perennial Ryegrass ◽  
Crude Protein ◽  
Dry Matter ◽  
Fibre Content ◽  
Lactating Cows ◽  
Dry Matter Digestibility ◽  
Herbage Intake ◽  
Selection For

Summary. Three experiments investigating the effects of herbage allowance on the consumption of nutrients by lactating cows were conducted on irrigated perennial pastures in northern Victoria during summer and autumn. Experiment 1 was conducted in mid lactation (autumn–early winter) with perennial ryegrass [54% of dry matter (DM)]–white clover (22% of DM) pasture offered at allowances of 15, 20, 30 and 40 kg DM/cow.day. Herbage intake increased (P<0.001) from 8.0 to 14.6 kg DM/cow.day as allowance increased and this was associated with a decrease (P<0.001) in utilisation from 54 to 37%. The cows consistently selected a diet 11% higher in in vitro dry matter digestibility than that in the pasture on offer, but selection for crude protein increased (P<0.001) from 21 to 41% above that in herbage on offer as herbage allowance increased. Neutral detergent fibre content of the diet selected was lower (P<0.001) than that in herbage on offer. Along with these changes, milk production increased (P<0.001) from 9.0 to 15.5 kg/day as herbage allowance increased at a marginal response of 0.99 kg milk/kg extra DM consumed. Experiments 2 and 3 were conducted in mid lactation (summer) on pasture containing 28% paspalum, 26% weeds, 17% perennial ryegrass or 36% paspalum, 19% weeds and 24% ryegrass respectively. Pasture allowances were between 20 and 70 kg DM/cow.day. Herbage intake increased (P<0.001) from about 8 to 17 kg DM/cow.day as allowance increased in both experiments and was accompanied by a decrease (P<0.001) in utilisation from about 40 to less than 25%. In experiment 2, the cows consistently selected a diet with a similar in vitro dry matter digestibility to that of the herbage pregrazing, regardless of allowance, but selection for crude protein increased (P<0.05) from 25 to 45% above that in herbage on offer, as allowance increased. In experiment 3, the diet selected was 13% greater (P<0.001) in in vitro dry matter digestibility and 42% greater (P<0.001) in crude protein than the herbage on offer. Neutral detergent fibre content of the diet selected was lower (P<0.001) than that in herbage on offer in experiment 3, while the difference was small in experiment 2. Along with these changes, milk production increased (P<0.001) (in experiment 2, 12.3–15.0 kg/cow.day; experiment 3, 10.0–15.8 kg/cow.day) as herbage allowance increased, but the marginal responses were lower (0.28 kg milk/kg extra DM consumed in experiment 2, 0.64 kg milk/kg extra DM consumed in experiment 3) than observed in experiment 1 reflecting the differences in pasture quality.

Dry matter intake, nutrient selection and milk production of dairy cows grazing rainfed perennial pastures at different herbage allowances in spring

1999 ◽  
Vol 39 (8) ◽  
pp. 923 ◽  
Author(s):  
P. J. Moate ◽  
D. E. Dalley ◽  
J. R. Roche ◽  
C. Grainger
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Crude Protein ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Neutral Detergent Fibre ◽  
Dry Matter Digestibility ◽  
Herbage Intake ◽  
Selection Differentials

Summary. The effect of herbage allowance (20, 30, 40, 50, 60 and 70 kg DM/cow. day) on the consumption of nutrients from herbage and milk production by cows in early lactation, was examined. The experiment was conducted on rainfed perennial ryegrass pastures in September and October 1997 in south-eastern Victoria, Australia. The herbage on offer comprised 64% perennial ryegrass, 21% other grasses, 1% white clover, 5% weeds and 9% dead material on a dry matter (DM) basis. The average pregrazing herbage height was 13 cm, at an estimated pregrazing herbage mass of 3.6 t DM/ha. The herbage on offer was of high quality containing 11.6 MJ metabolisable energy/kg DM, 202 g crude protein/kg DM and 525 g neutral detergent fibre/kg DM. Concentrations of calcium, magnesium, sodium, potassium, phosphorus, sulfur and chloride were 4.4, 2.2, 4.4, 31.2, 3.5, 2.7 and 11.4 g/kg DM, respectively. As daily herbage allowance per cow increased, dry matter intake increased curvilinearly (P<0.01) from 11.2 to 18.7 kg DM/cow. day. This was associated with a decrease in utilisation of herbage from 54 to 26% and an increase in milk production from 25.9 to 29.1 kg/cow. day. The cows on all treatments grazed for less than 8.7 h/day. The increase in intake was achieved by an increase in the rate of herbage intake from 1.5 to 2.2 kg DM/h for herbage allowances of 20 and 70 kg/cow.day, respectively. Irrespective of herbage allowance, cows selected a diet that was approximately 10% higher in in vitro dry matter digestibility and 30% higher in crude protein than that in the herbage on offer. The neutral detergent fibre content of the herbage selected was lower (P<0.05) than that on offer. The herbage consumed contained more (P<0.05) magnesium, potassium and sulfur, the same amount of calcium and phosphorus and less (P<0.05) sodium and chloride than the herbage on offer. For rainfed perennial pastures in spring, herbage allowance is an important factor in determining voluntary feed intake and production of dairy cows. To achieve 30 L from herbage, without supplementation, high herbage allowances are required. The increase in herbage intake, with increasing herbage allowance, resulted from an increase in rate of dry matter intake and not an increase in grazing time. No relationship was evident between herbage allowance and the selection differentials for in vitro dry matter digestibility, crude protein and neutral detergent fibre. Selection differentials for rainfed perennial pastures in spring are similar to those reported for irrigated perennial pastures in northern Victoria in spring and autumn. When determining nutrient requirements it is important to consider the interaction between herbage intake and nutrient concentration in the herbage.

Effects of season and time since defoliation on the nutritive characteristics of three irrigated perennial pasture species in northern Victoria 1. Energy, protein and fibre

1999 ◽  
Vol 39 (5) ◽  
pp. 555 ◽  
Author(s):  
C. R. Stockdale
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Crude Protein ◽  
Energy Content ◽  
Energy Concentration ◽  
Neutral Detergent Fibre ◽  
Plant Parts ◽  
Metabolisable Energy ◽  
Grazing Dairy Cows

The study reported here compared the nutritive characteristics of the 3 most common irrigated perennial pasture species grown in northern Victoria as they regrew after defoliation at various times during the year. In addition, the relative influence of changes to the proportions of morphological components and the nutritive characteristics of the individual components on the quality of whole plants was examined. The nutritive characteristics of white clover (Trifolium repens cv. Haifa), ryegrass (Lolium perenne cv. Ellet) and paspalum (Paspalum dilatatum) were examined at weekly intervals on 4 occasions during spring–autumn, 1993–94. On each occasion, pastures were defoliated with a drum mower and allowed to regrow for up to 9 weeks; defoliation dates were 24 September, 26 November, 28 January and 25 March. The variation in estimated metabolisable energy [obtained from in vitro dry matter (DM) digestibility], crude protein and detergent fibre concentrations within species was significantly (P<0.01) less than between clover and the grasses. White clover was consistently high in metabolisable energy (9.3–11.2 MJ/kg DM) and crude protein (17.7–27.7% DM), and low in neutral detergent fibre (27.8–39.8% DM) in all periods. At the other extreme, paspalum had a metabolisable energy content that peaked at 9.3 MJ/kg DM, and fell as low as 7.4 MJ/kg DM. Paspalum also had low protein (7.5–14.7% DM) and very high neutral detergent fibre (61.9–69.9% DM) concentrations. Ryegrass varied greatly in metabolisable energy concentration between the 4 periods, being high in autumn (average of 10.2 MJ/kg DM) and low in summer–autumn (average of 8.4 MJ/kg DM). Metabolisable energy apart, there were few differences in the crude protein and detergent fibre contents of ryegrass and paspalum. Perennial ryegrass is generally considered a superior feed to paspalum, but the data indicate this is not always the case under irrigation in northern Victoria. The nutritive characteristics of the plant fractions (leaf, stem, dead, inflorescence) were analysed separately to give an indication of the limits to selection by grazing cows. Differences in metabolisable energy between leaf and stem in both white clover and perennial ryegrass suggested that grazing dairy cows could consume a pasture diet which is likely to be slightly higher in energy than that in the herbage on offer. With paspalum, this is unlikely to be the case because differences in energy content between plant parts were small. However, with all species, cows should be able to consume herbage that is significantly higher in protein, and lower in detergent fibre, than that on offer because of differences in their concentrations in leaf and stem. The nutritive characteristics of morphological components of each species remained relatively constant throughout the study. Therefore, it would seem that it is the proportions of these fractions in the plant, together with severity of grazing, that will largely determine the degree of selection that can occur.

Degradabilities of dry matter and crude protein from perennial herbage and supplements used in dairy production systems in Victoria

1999 ◽  
Vol 39 (6) ◽  
pp. 645 ◽  
Author(s):  
W. J. Wales ◽  
P. T. Doyle ◽  
D. W. Dellow
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Cottonseed Meal ◽  
Crude Protein ◽  
Dry Matter ◽  
Production Systems ◽  
Dry Matter Digestibility ◽  
Cereal Grain ◽  
Outflow Rate

Summary The nylon bag technique was used to estimate the degradability of the dry matter (DM) and crude protein (CP) of herbage samples and supplementary feeds from recent grazing experiments with dairy cows conducted in Victoria. The cumulative disappearance data for CP were used to calculate the effective rumen degradability of CP (ERDP, g/kg DM) for these feeds at rumen outflow rates of 0.02, 0.05 or 0.08/h. Crude protein was more extensively degraded than DM in all herbage samples collected before grazing, or in those samples taken to represent the herbage consumed by grazing cows. The ERDP of spring pastures (excluding the dead material and postgrazed samples) was generally in the range 103–197 g/kg DM, at an outflow rate of 0.02/h and in the range 74–142 g/kg DM, at an outflow rate of 0.08/h. For summer pastures, the ERDP was generally in the range 80–128 g/kg DM, at an outflow rate of 0.02/h and in the range 58–108 g/kg DM, at an outflow rate of 0.08/h. For autumn pastures, ERDP ranged from 108 to 170 g/kg DM, at an outflow rate of 0.02/h and from 84 to 140 g/kg DM, at an outflow rate of 0.08/h. There were only 2 herbage samples collected during the winter, which had ERDP of 237 and 249 g/kg DM, at an outflow rate of 0.02/h and 213 and 222 g/kg DM, at an outflow rate of 0.08/h. Values for ERDP tended to be higher for these winter samples compared with spring samples. In contrast, autumn samples tended to have lower ERDP than spring samples. It is shown that metabolisable protein is unlikely to limit milk production of cows consuming 17 kg herbage DM/cow. day and producing up to 30 L milk/day, when milk production is determined from metabolisable energy supply. The excesses in metabolisable protein ranged from 0.48 to 1.21 kg/cow. day from a subset of spring herbage samples cut to represent that selected by cows and from 0.14 to 0.23 kg/cow. day from summer herbage samples. The degradability characteristics of the herbage samples were similar to some estimates for temperate herbages in the United Kingdom and from limited data from Australia and should form a useful basis on which to assess whether additional metabolisable protein is required as supplements for dairy cows grazing pastures in Victoria. There was a positive (P<0.01) relationship between CP content and ERDP (R2 = 0.93), across herbage samples indicating it could be possible to estimate ERDP for herbage samples that have been assessed for CP content. There was also a significant (P<0.01) positive relationship between the effective degradability of DM of herbage and ERDP (R2 = 0.77). The relationships between in vitro dry matter digestibility or neutral detergent fibre and ERDP were also significant (P<0.01), but accounted for even less of the variability. The ERDP in cereal grain-based supplements ranged from 87 to 111 g/kg DM, at a outflow rate from the rumen of 0.02/h, compared with 70–92 g/kg DM, at an outflow rate of 0.08/h. The compounded supplements containing varying levels of cereal grain, lupins and cottonseed meal, had effective degradabilities of CP that generally declined as the content of lupins decreased and the content of cottonseed meal increased. However, ERDP increased to 152 g/kg DM because of the increasing CP content with increasing cottonseed meal. These results are compared with previously published estimates of effective degradability of CP for supplementary feeds.

scholarly journals Effects of pasture species and irrigation on milk production over four summers in the Waikato

2001 ◽  
pp. 215-221
Author(s):  
E.R. Thom ◽  
V.T. Burggraaf ◽  
C.D. Waugh ◽  
D.A. Clark
Keyword(s):  
Milk Production ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Tall Fescue ◽  
Red Clover ◽  
Milk Composition ◽  
In Vitro Digestibility ◽  
Botanical Composition ◽  
Jersey Cows

Milk production by Jersey cows grazing a common allowance of irrigated or non-irrigated pastures over four summers (1997-2000) is described. The pastures were: (1) high-endophyte perennial ryegrass-white clover (2) tall fescue, phalaris, cocksfoot, white clover, red clover (3) same as (2) plus paspalum (4) endophyte-free ryegrass, timothy, white clover, red clover and (5) existing high-endophyte ryegrass-white clover. Irrigation improved milksolids yield by 5% over 4 years, with inconsistent effects on milk composition, no effects on pasture in vitro digestibility and nitrogen content, and usually no effect on pasture botanical composition. In 1997, cows on (1) produced the lowest milksolid (MS) yields. Cows grazing ryegrass-white clover (1 and 5) produced less than those on tall fescue-based pastures (2 and 3) (0.74 vs 0.86 kg MS/cow/day) in 1998, and the yields of cows on ryegrass/timothy-based pastures (4) were best (0.96 kg MS/cow/day). The same trends in milksolids yield occurred in 1999, except for cows on (1) which were similar to (4). Cows on existing pasture often produced the lowest milksolid yields. Trends in milksolids production over the 4 years reflected trends in total clover (red + white) contents. Keywords: cocksfoot, dairy cows, grazing, pasture quality, perennial ryegrass, persistence, phalaris, red clover, tall fescue, timothy, triple mix, volunteer ryegrass, white clover

Protein supplementation of cows grazing limited amounts of paspalum (Paspalum dilatatum Poir.)-dominant irrigated pasture in mid-lactation

2000 ◽  
Vol 40 (7) ◽  
pp. 923 ◽  
Author(s):  
W. J. Wales ◽  
D. W. Dellow ◽  
P. T. Doyle
Keyword(s):  
Milk Production ◽  
Cottonseed Meal ◽  
Milk Fat ◽  
Rumen Fluid ◽  
Protein Supplementation ◽  
Canola Meal ◽  
Paspalum Dilatatum ◽  
Protein Supplements ◽  
Cereal Grain

Two experiments were undertaken in summer to investigate production responses by dairy cows offered paspalum (Paspalum dilatatum Poir.)-dominant irrigated pasture to the inclusion of protein supplements with different rumen degradable protein characteristics in cereal grain-based concentrates. In experiment 1, cows in mid lactation were offered limited amounts of herbage, at an allowance of 28 kg DM/cow. day together with 8.0 kg DM/cow. day of a pelleted supplement containing: (i) mainly barley and wheat; (ii) barley, wheat and canola meal; or (iii) barley, wheat and cottonseed meal for 35 days. The 3 supplements were formulated to have similar in vitro DM digestibilities. In experiment 2 aspects of rumen function were measured in 9 rumen fistulated lactating cows, individually fed indoors on paspalum-dominant herbage harvested daily with a finger bar mower. Cows were offered the same amount of supplements for 28 days. Pasture intakes were similar to those of the grazing cows in experiment 1. In experiment 1, there were no effects (P>0.05) of dietary treatment on herbage intake (10.2 kg DM/cow. day) or selection of nutrients from herbage. The concentration of crude protein in the total diet consumed was lower (P<0.05) for the barley + wheat treatment (137 g/kg DM), compared with the barley + wheat + canola meal and barley + wheat + cottonseed meal treatments, which were 179 and 183 g/kg DM, respectively. In vitro DM digestibility of the feed consumed by cows was similar across the treatments, and all diets contained greater than 400 g neutral detergent fibre/kg DM, indicating there were no limitations due to dietary fibre. There were no significant effects (P>0.05) of dietary treatments on milk production (21.8 kg/cow. day), milk fat concentration (34.1 g/kg) or milk protein concentration (29.8 g/kg). Urea-N was higher (P<0.01) in the milk of cows fed the barley + wheat + canola meal and the barley + wheat + cottonseed meal treatments compared with the barley + wheat treatment. In experiment 2, rumen fluid pH was higher in cows consuming barley + wheat pellets than in cows consuming barley + wheat + canola meal on most sampling occasions. Rumen ammonia-N concentration was lowest in the barley + wheat treatment and highest in the barley + wheat + canola meal treatment. When cows grazing paspalum-dominant irrigated pasture were supplemented with 8 kg DM of a cereal-based supplement, metabolisable protein was calculated to be present in sufficient quantities to support at least 22 kg milk/cow. day and, hence, was not limiting milk production. It is concluded that protein supplements offered to cows in mid-lactation, grazing irrigated pastures in summer, are unlikely to give a milk production response beyond that achieved with cereal grain.

Effects of wild-type, AR1 and AR37 endophyte-infected perennial ryegrass on dairy production in Victoria, Australia

2012 ◽  
Vol 52 (12) ◽  
pp. 1117 ◽  
Author(s):  
P. J. Moate ◽  
S. R. O. Williams ◽  
C. Grainger ◽  
M. C. Hannah ◽  
D. Mapleson ◽  
...  
Keyword(s):  
Milk Production ◽  
Perennial Ryegrass ◽  
Milk Fat ◽  
Ergot Alkaloids ◽  
First Year ◽  
Wild Type ◽  
Grazed Pasture ◽  
Cereal Grain ◽  
Eastern Australia ◽  
Feeding Regimes

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.

Feeding an energy supplement with white clover silage improves rumen fermentation, metabolisable protein utilisation, and milk production in dairy cows

2006 ◽  
Vol 57 (4) ◽  
pp. 367 ◽  
Author(s):  
D. C. Cohen ◽  
C. R. Stockdale ◽  
P. T. Doyle
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
White Clover ◽  
Milk Fat ◽  
Crude Protein ◽  
Theoretical Calculations ◽  
High Energy ◽  
Nitrogen Excretion ◽  
Energy Supplement ◽  
Frequent Feeding

Six rumen-fistulated Holstein-Friesian cows were used in a Latin square design to test the hypothesis that more frequent feeding of a high energy supplement to cows consuming high-protein white clover silage would improve microbial protein production, resulting in greater N retention and higher milk yields. The white clover silage (10.7 MJ metabolisable energy (ME)/kg DM) was fed to cows either alone (WCS) or with 4.5 kg DM of rolled barley grain (12.1 MJ ME/kg DM). The grain was offered either 24 times (WCS/24B) or twice daily (WCS/2B, at 0800 and 1700 hours). Cows offered the supplements, regardless of feeding frequency, had higher (P < 0.05) organic matter (17.3 v. 16.0 kg/day) and estimated ME (208 v. 189 MJ/day) intakes than cows offered white clover silage alone. Mean daily ruminal fluid pH (P < 0.05) and ammonia-N concentrations (P < 0.05) were lower in the supplemented treatments, with total VFA concentrations being highest (P < 0.05) in the WCS/2B treatment. Nitrogen intake and output in the faeces were similar for all 3 treatments. However, nitrogen excretion was lower (P < 0.05) in urine (174 v. 218 g/day) and higher (P < 0.05) in milk (115 v. 93 g/day) of cows offered the supplements. The crude protein consumed by cows on all 3 diets was estimated to be well in excess of cow requirements. The supplements reduced the calculated net losses of ammonia-N from the rumen from 25% of total crude protein intake for WCS to 14% in the 2 supplement treatments, and increased the metabolisable protein supply available for milk production. Increases in metabolisable protein were estimated to be due to a higher microbial crude protein contribution in the supplemented treatments compared with the WCS treatment. Grain supplements increased (P < 0.05) milk yield (22.4 v.19.6 kg/day) and although there were no significant differences in milk fat and protein concentrations between treatments, the latter tended to increase with grain supplementation. Milk yield was higher in the WCS/24B treatment than in the WCS/2B treatment, but neither the calculated nor the measured rumen variables were sufficiently different to explain this effect of frequency of feeding the grain. One possible explanation for the difference was the marked fluctuations in key rumen variables throughout the day in the WCS/2B compared with the WCS/24B treatment. Such fluctuations in the rumen environment are not accounted for in theoretical calculations since associative effects are not considered. The benefits of a higher milk production as a result of more frequent feeding of the supplement to cows should be considered in context of the additional effort or costs associated with more frequent feeding.

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