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1.
Between 1967 and 1975, 416 beef animals were grazed rotationally on an indigenous pasture (11.65 ha) containing Festuca rubra, Holcus lanatus, Poa trivialis and Agrostis spp. and dicotyledonous plants, but little Lolium perenne or Trifolium repens. Part of the land received fertilizer nitrogen at rates varying between 120 and 200 kg h?1 each year and part did not; some of the land was grazed only and some was cut and then grazed. The winter gains of the animals (approx. 45 kg) were more variable and less than the summer gains (approx. 155 kg). Summer gain was inversely correlated with winter gain. An increase in initial weight of animals purchased from 1973 onwards did not increase either winter or summer gain. Friesians gained more than Hereford-cross animals during the winter, but there was no difference in summer gain. During 9 years the average animal weight per grazed ha in April was increased from 1260 to 2122 kg. The mean total gain on 1165 ha of grass was 6486 kg per annum in the first 3 years and 7266 kg per annum in the last 3 years. The average annual production was 590 kg live-weight gain and 1.01 t hay or 2.33 t silage per ha. The output of fertilized grass in 1975 was calculated as 842 Livestock Unit Grazing Days (LUGD) per ha and that from unfertilized grass as 360 LUGD per ha. The overall output of utilized metabolizable energy in 1975 was 59–7 GJ h?1, with 69.3 GJ h?1 from fertilized grass and 29.8 GJ h?1 from unfertilized grass. 相似文献
2.
E. D. WILLIAMS 《Grass and Forage Science》1986,41(2):179-182
Assessments were made of the clover yield and clover content between early June and late July 1984 of white clover in a permanent pasture which had been slot-seeded in spring 1982.
Past reserves of phosphate or application of propyzamide alone only slightly increased clover dry matter yield but together they increased it from 13 to 785 kg dry matter ha-1 and gave 31% clover in the total herbage yield. Applications of P2 O5 during the experiment, alone or together with past reserves of phosphate, Iased clover yield from 13 to 242 kg dry matter ha-1 and the proportion of clover from 1 to 10%. However, highest yields (1282 kg) and clover content (37%) were attained when P2 O5 and propyzamide were applied to treatments with past reserves of phosphate.
These results confirmed the trends evident during the second year and also indicated a potential role for grass-suppressants in increasing management options during the early years after slot-seeding. 相似文献
Past reserves of phosphate or application of propyzamide alone only slightly increased clover dry matter yield but together they increased it from 13 to 785 kg dry matter ha
These results confirmed the trends evident during the second year and also indicated a potential role for grass-suppressants in increasing management options during the early years after slot-seeding. 相似文献
3.
An estimate of the level of pest damage on enclosed upland permanent pasture in England and Wales was made by reducing invertebrate populations with insecticides at thirteen well-distributed sites and measuring the effect on herbage growth over a 3-year period. Potential pests were fewer in number than on lowland pastures and there was a wide range in herbage yield between sites. Insecticide treatment significantly increased annual yields at only three of the sites, and significantly decreased yield at two of the sites. Insect damage to grassland appears to be much less important in upland than in lowland areas: this may be due to the relative scarcity of frit-fly in these areas, but this could change if its preferred host, ryegrass, were encouraged by intensification of sward management in the uplands. At all but one of the sites insecticide treatment led to considerable soil compaction, probably as a consequence of suppressing earthworm populations. 相似文献
4.
Herbage potassium levels were measured in 1986 in a permanent pasture under continuous grazing with cattle and receiving 200 kg N ha−1 . In April, before grazing started, K concentration in the herbage was relatively uniform across the pasture, with a value of 1·9 ± 0·038% K in the herbage dry matter. In July, a significantly lower concentration of herbage K was found in the grazed areas of the pasture (1·8 ± 0·10%) compared with the level (2·4 ± 0·088%) found in the rejected areas of the sward. The difference between the grazed and rejected areas was similar in September, with 1·6 ± 0·087% and 2·2 ± 0·172% K, respectively, in the herbage dry matter. This result suggests that herbage growth in the grazed areas might have been limited by K supply and highlights the need for more information on the K requirements of grazed grassland. 相似文献
5.
Potential pasture production in the uplands of Wales 总被引:1,自引:0,他引:1
Only a very limited number of species, including red fescue (Festuca rubra) , perennial ryegrass ( Lolium perenne) , timothy (Phleum protense) and white clover (Trifolium repens) are considered as suitable for wet hill land. Detailed comparison of red fescue, perennial ryegrass and timothy on contrasting acid brown earth and stagnogley soils from 1966 to 1969 at Pant-y-dŵr Hill Centre (305 m OD) highlighted the advantages of red fescue in annual DM production and its more even distribution over a longer growing season but also indicated drawbacks of slow initial establishment and lower feed quality. In vitro DOMD of red fescue averaged 645 g kg−1 over the year compared with 690 g kg−1 for perennial ryegrass and timothy. Assessment of a narrow range of species under surface seeding conditions on a stagnogley soil from 1971 to 1975 confirmed the value of red fescue in DM production and persistence. The results are discussed in relation to the characteristics required in herbage species for hill land improvement. 相似文献
6.
This study investigated the long‐term effects on sward composition and animal performance of applying different fertilizer regimes to upland permanent pasture. The experiment, which was carried out in 2008, was based on a set of replicated (n = 3) plots that had been established in 1990. The effects of applying (i) N, P, K and lime, (ii) P and K plus lime and (iii) lime only were compared with a treatment that received no nutrient applications. Using a put‐and‐take stocking system, the plots were grazed to a target sward surface height of 4 cm by ewes and lambs from April to early August and by ewes only from August to mid‐October. The long‐term reduction in nutrient inputs had led to decreases in the percentages of both sown and unsown grass species within the sward (P < 0·05), and an increase in the percentage of mosses and litter (P < 0·05), with a corresponding reduction in nutritional value. Although there were no statistically significant treatment‐related differences in lamb growth rates, lower fertilizer inputs were associated with a marked decline in stock carrying capacity and associated overall productivity during both the pre‐ and post‐weaning periods (P < 0·001). The findings highlight the challenges faced when attempting to reconcile production and environmental objectives in upland systems. 相似文献
7.
The indirect estimation of the digestibility in cattle of herbage from Belgian permanent pasture 总被引:1,自引:0,他引:1
Relationships between herbage organic matter digestibility measured in vivo , and faecal nitrogen concentration were determined. Measurements of in vivo digestibility were made on twenty-nine herbages, cut from mixed improved permanent pastures with Lolium perenne as the predominant grass and offered ad libitum to cattle. The faecal nitrogen index predicted the herbage digestibility with good accuracy, and the equations obtained should have application for such determinations on Belgian pastures. 相似文献
8.
R. W. J. Steen 《Grass and Forage Science》2002,57(4):401-404
Abstract The effects of turning beef cattle out to pasture earlier in the spring than is conventional in Northern Ireland on performance until slaughter in late summer were examined. Thirty‐eight steers, which were initially 525 kg live weight (LW), were divided into blocks of two according to breed type, previous plane of nutrition and LW and were allocated to two treatments at random within each block. Steers on Treatment 1 were turned out to pasture on 14 March and grazed a permanent perennial ryegrass‐based pasture with a mean sward surface height of 8·4 (s.e. ± 0·36) cm until Treatment 2 steers were turned out on 2 May. Thereafter, all steers grazed as a single group until slaughter at the same estimated carcass fat content, which occurred between June and September. Between the two turnout dates, steers on Treatment 2 were given grass silage ad libitum. For the early and late turnout treatments, respectively, LW gains between the two turnout dates were 1·5 and 0·7 kg d?1, carcass gains from 14 March until slaughter (mean 143 d) were 0·69 and 0·53 (s.e. ± 0·022) kg d?1, and carcass weights were 370 and 347 (s.e. ± 2·7) kg. It is concluded that, under the conditions of this experiment, turning beef cattle out to pasture in early spring may offer economic benefits in beef production in situations in which this is practicable. 相似文献
9.
Results are given on the effect of sodium (Na) fertilizer applied as NaNO3 in five application sat 0 (Nil), 32 (Low) or 64 (High) kg Na ha -1yr-1 and the residual effect of sodium chloride(NaCl) fertilizer applied in the previous year on the growth rate and the chemical composition of herbage cut at fortnightly intervals over the grazing season. Na fertilizer at Low and High rates increased herbage Na contents by 20 and 40% respectively. Magnesium (Mg) content in herbage was increased at Low Na fertilizer application rate but there was no difference between the Nil and the High Na treatments. Calcium (Ca) content was increased in proportion to Na fertilizer level. Potassium (K) content of Nil Na herbage exceeded that of Low and High, but there was no effect of treatment on total harvested K yields. The contents of phosphorus (P), sulphur (S), true protein (TP) and modified acid detergent fibre (MADF) in herbage were not affected, but the dry matter digestibility (DMD) was increased with increasing Na fertilizer level. Applying Na fertilizer at the Low and High levels gave similar increases in water-soluble carbohydrates (WSC) and ash contents and decreased crude protein (CP) and non-protein nitrogen (NPN) contents. Net herbage accumulation(fresh and dry weight) was increased by 15 and 26% at the Low and High Na fertilizer application rates respectively. NaCl fertilizer residues from the previous year increased herbage Na, DM, DMD and WSC contents, reduced K contents and did not affect Ca, P, S, CP, TP and NPN contents. Residues from Na fertilizer decreased MADF and ash contents at the Low and High Na application rates. The main and residual effects of Na fertilizer were generally maximal in early season and diminished as the season progressed, with many of the effects eliminated by late season. Proportionally 0·70 of Na applied was recovered in the first two grazing seasons after application. The effects of Na fertilizer on mineral ratios are also described, together with the implications for animal health. 相似文献
10.
Lamina wettability, assessed using water droplet contact-angle and surface water-retention measurements on excised leaves, was examined in Lolium perenne cv. Melle, cv. Condesa and an indigenous population from an old pasture, Holcus lanatus, Poa trivialis and Agrostis stolonifera. The species fell into two significantly distinct categories, those with unwettable laminae, namely H. lanatus and A. stolonifera , and those with highly wettable laminae, P. trivialis and the three L. perenne populations. There was no significant difference between the L. perenne populations, which had the most wettable laminae overall. The possible implication of these differences in lamina wettability on animal production is discussed. 相似文献
11.
The effects of high-concentrate diets and pasture on the concentration of conjugated linoleic acid in beef muscle and subcutaneous fat 总被引:2,自引:0,他引:2
Abstract In view of the evidence indicating several potential benefits of high intakes of conjugated linoleic acid (CLA) on human health, an experiment was conducted to examine the effects of the diet of beef cattle on the total CLA concentration in muscle and subcutaneous fat. High‐concentrate [steers consumed 515 g concentrates and 485 g grass silage kg?1 dry matter (DM) for 8 weeks followed by 887 g concentrates and 113 g grass silage kg?1 DM for 14 weeks until slaughter] and high‐forage (steers consumed 803 g grass silage and 197 g concentrates kg?1 for 8 weeks followed by grass silage only for 10 weeks and then grazed perennial ryegrass‐based pasture for 23 weeks until slaughter) treatments were imposed on 48 steers, which were crosses of continental beef breeds (initially 414 kg live weight) The concentrates were based on barley, extracted soyabean meal, molassed sugarbeet pulp and maize meal. The silages were of medium to low digestibility and contained 117–137 g crude protein kg?1 DM and 83–158 g ammonia‐N kg?1 total N. The pasture was of high quality and contained 168 g crude protein, 234 g acid‐detergent fibre and 222 g water‐soluble carbohydrate kg?1 DM. Samples of muscle were taken post slaughter from the m. semimembranosus, m. gluteobiceps, m. longissimus and m. deltoideous muscles, and subcutaneous fat was taken from over the m. longissimus. Concentrations of total CLA in the tissues were for the high‐concentrate and high‐forage treatments, respectively (mg 100 g?1 fresh tissue), m. gluteobiceps 18 and 47 (s.e. 3·5); m. semimembranosus 9 and 20 (s.e. 1·6); m. longissimus 15 and 35 (s.e. 3·2), m. deltoideous 20 and 59 (s.e. 4·3); subcutaneous fat 584 and 1975 (s.e. 138·7). It is concluded that muscle and subcutaneous fat tissue from grass‐fed cattle contained three times as much CLA as those from concentrate‐fed cattle, and that the consumption of beef from grass‐fed cattle should be effective in increasing the intake of CLA by humans. 相似文献
12.
J. R. M. Pezzopane P. M. Santos S. R. M. Evangelista C. Bosi A. C. R. Cavalcante G. M. Bettiol C. A. de Miranda Gomide G. Q. Pellegrino 《Grass and Forage Science》2017,72(1):104-117
Projected change in forage production under a range of climate scenarios is important for the evaluation of the impacts of global climate change on pasture‐based livestock production systems in Brazil. We evaluated the effects of regional climate trends on Panicum maximum cv. Tanzânia production, predicted by an agro‐meteorological model considering the sum of degree days and corrected by a water availability index. Data from Brazilian weather stations (1963–2009) were considered as the current climate (baseline), and future scenarios, based on contrasting scenarios in terms of increased temperature and atmospheric CO2 concentrations (high and low increases), were determined for 2013–2040 (2025 scenario) and for 2043–2070 (2055 scenario). Predicted baseline scenarios indicated that there are regional and seasonal variations in P. maximum production related to variation in temperature and water availability during the year. Production was lower in the Northeast region and higher in the rainforest area. Total annual production under future climate scenarios was predicted to increase by up to 20% for most of the Brazilian area, mainly due to temperature increase, according to each climate model and scenario evaluated. The highest increase in forage production is expected to be in the South, Southeast and Central‐west areas of Brazil. In these regions, future climate scenarios will not lead to changes in the seasonal production, with larger increases in productivity during the summer. Climate risk is expected to decrease, as the probability of occurrence of low forage productions will be lower. Due to the predicted increase in temperature and decrease in rainfall in the Northeast area, P. maximum production is expected to decrease, mainly when considering scenarios based on the PRECIS model for the 2055 scenario. 相似文献
13.
CHRISTINE J. STANDELL 《Grass and Forage Science》1990,45(3):249-255
The benefits of reducing competition from the surrounding grass sward against slot-seeded clover were measured in terms of white clover dry matter production following applications of two grass-suppressing herbicides, propyzamide and carbetamide.
Clover was slot-seeded in early June 1983 and herbicides were applied in September and October 1983. The later application was more damaging to the surrounding sward. Generally, the September spraying was more effective in encouraging white clover, especially from July of the following year. Only by September 1984 did the October applications result in higher clover yields than the September applications.
Propyzamide had the greater stimulatory effect on white clover production but it also damaged the grass more than carbetamide. Increasing the dose of each herbicide increased grass damage. However, with treatments applied in September, the loss was more than compensated for by an increase in clover and in total dry matter production at the end of the year.
The results suggest that either of these herbicides, but especially propyzamide, can be used to increase both total dry matter production from the sward and the contribution from slot-seeded white clover. 相似文献
Clover was slot-seeded in early June 1983 and herbicides were applied in September and October 1983. The later application was more damaging to the surrounding sward. Generally, the September spraying was more effective in encouraging white clover, especially from July of the following year. Only by September 1984 did the October applications result in higher clover yields than the September applications.
Propyzamide had the greater stimulatory effect on white clover production but it also damaged the grass more than carbetamide. Increasing the dose of each herbicide increased grass damage. However, with treatments applied in September, the loss was more than compensated for by an increase in clover and in total dry matter production at the end of the year.
The results suggest that either of these herbicides, but especially propyzamide, can be used to increase both total dry matter production from the sward and the contribution from slot-seeded white clover. 相似文献
14.
E. D. WILLIAMS 《Grass and Forage Science》1984,39(2):201-204
The establishment and growth of white clover (cv. Grasslands Huia) was investigated in two experiments with seeds sown in slots cut in old permanent pasture in early May 1982. In the first experiment, fully protected from pests and diseases, either 50 (low), 100 (medium) or 200 (high) seeds were sown evenly per metre length of slot; 100 seeds were also sown in a clumped pattern unevenly. In the second experiment, the effects of various combinations of molluscicide, insecticide and fungicide were investigated.
Nine weeks after sowing there were 27, 37, 34 and 62 seedlings m−1 on the low, medium even, medium uneven and high seed-rate treatments, representing percentage establishments of 54, 37, 34 and 31 respectively. By September, however, there were no significant differences between the dry weights m−l of any of the treatments. In the second experiment, damage by slugs occurred early in treatments without molluscicide and caused a mean reduction of 70% in seedling establishment. As a result significantly smaller dry weights m−1 of clover were recorded in September in these than in other treatments. Failure to protect against insects resulted in smaller seedlings.
The results indicated that variations in seed rate within the range investigated were not critical but that failure to protect against pests decreased percentage establishment and subsequent growth. 相似文献
Nine weeks after sowing there were 27, 37, 34 and 62 seedlings m
The results indicated that variations in seed rate within the range investigated were not critical but that failure to protect against pests decreased percentage establishment and subsequent growth. 相似文献
15.
Jacqueline dos Santos Oliveira Luis Depablos Bruno Grossi Costa Homem Igor Machado Ferreira Robert Michael Boddey Adenilson José Paiva Márcio André Stefanelli Lara Daniel Rume Casagrande 《Grass and Forage Science》2023,78(3):416-424
To define the best grazing management strategy, it is important to assess animals' responses to variations in the structure and composition of tropical forages. This 2-year study evaluated animal response to Marandu palisadegrass (Urochloa brizantha)-calopo (Calopogonium mucunoides) mixed pastures managed under rotational grazing. Treatments consisted of three defoliation frequencies defined by rest periods interrupted at 90% (90LI), 95% (95LI) and 100% (100LI) of photosynthetically active radiation interception (LI). The stubble post-grazing height target was 15 cm. Statistical difference was declared at p < .10. The 100LI had lowest crude protein (CP) and in vitro dry matter digestibility (IVDDM) for the Marandu palisadegrass (p = <.001 both) and calopo (p = .003 and p = .067, respectively). Also, the OM digestibility decreased 7.0% in the 100LI condition than 90LI and 95LI treatment (p = .005). There was no difference in forage, grass, and legume intakes between the treatments (p > .10). The 100LI treatment decreased CP intake from grass in 33.3% (p = <.001) compared to other treatments. Greatest production of microbial N (p = .093) occurred with the 90LI treatment. The CP/digestible organic matter (DOM) ratio, urinary N excretion and retained N were lowest in the 100LI treatment (p = <.001, p = .007 and p = .014, respectively). The recommendation for grazing between 90 and 95% of LI is recommended because of greater CP intake and N utilization for the animals and improved the nutritive value of Marandu palisadegrass and calopo mixed pastures. 相似文献
16.
White clover (cv. Grasslands Huia) was slot-seeded in April 1982 into plots of permanent pasture of differing botanical composition and reserves of soil phosphate. In one investigation the short-term effects of placing different amounts of phosphate (P2O5) in different positions in relation to the slot were investigated. In another, emphasis was given to effects of a grass-suppressing herbicide, propyzamide, on herbage growth and clover contributon during the second year. Fewer seedlings established on plots with a high initial P status and abundant in Holcus lanatus and Alopecurus pratensis than on plots deficient in P2O5 and dominated by Agrostis capillaris and Festuca rubra. P2O5decreased numbers of establishing clover seedlings when applied in the slots but not when placed beneath them. Growth was increased most when placement was beneath the slot. Application of P2O5to plots previously supplied with it resulted in 7.2 g total above ground and 1.7 g stolon dry weight (m row)?1compared to 1.3 and 0.1 g respectively in plots with low reserves and DO applied P2O5. Propyzamide greatly increased the yield and the contribution of clover in the presence of high initial P status and applied P2O5. Without propyzamide, clover made only a small contribution until July, averaging 7% for the whole season with little benefit from residual P. Clover growth in late summer was increased from 41 to 292 kg DM ha?1 where P2O5 was applied to P-deficient plots sprayed with propyzamide in the previous autumn. The large increases in clover contribution following propyzamide application were accompanied by small decreases in total seasonal yield of grass. The proportions of H. lanatus and. F. rubra. were decreased and of A. capillaris, increased. Spread of clover from the slots was slow during the first year but was encouraged by both P2O5 and propyzamide during the second year. Factors requiring further investigation are discussed. 相似文献
17.
The effects of delayed emergence of white clover (cv. Grasslands Huia) seedlings, following slot-seeding during spring and early summer 1983, were simulated by sowing seeds at intervals into slots cut in turves of permanent grassland in soil-filled tanks or in the field. The resulting spread and growth of the species were assessed during the following 15–18 months. The effects of propyzamide, a grass-suppressing herbicide (at 0·2 kg ha-1 ), were also investigated in the field.
A delay of 10 or 18 days in the sowing of seeds in turves in the tanks reduced clover dry weight yield from 23 to 11 during 1983 and from 118 to 96 g (0·12 m)-2 during 1984. Spread of stolons from the slots was also greatly delayed and effects persisted for at least a year. Increased clover growth on the earliest sown treatment more than compensated for a slightly smaller yield of grass.
In the field, yields of clover from late summer 1983 until spring 1984 closely reflected the order of emergence. Afterwards, differences were less clear-cut but the cumulative yield of clover until August 1984 of the earliest-sown treatment was twice that of a treatment sown 20 d later. Effects of delayed sowing in summer 1983 were more pronounced on stolons than on foliage growth when measured in September 1984, with significant reductions in many stolon attributes even with 8 d delay in sowing. Application of propyzamide in autumn 1983 increased clover yield during 1984 from 1·7 to 3·0 and total herbage yield from 7·1 to 8·6 t ha-1 .
The results demonstrated some of the benefits of rapid seedling emergence and of the use of a grass-suppressing herbicide, but did not indicate any interaction between the two factors. 相似文献
A delay of 10 or 18 days in the sowing of seeds in turves in the tanks reduced clover dry weight yield from 23 to 11 during 1983 and from 118 to 96 g (0·12 m)
In the field, yields of clover from late summer 1983 until spring 1984 closely reflected the order of emergence. Afterwards, differences were less clear-cut but the cumulative yield of clover until August 1984 of the earliest-sown treatment was twice that of a treatment sown 20 d later. Effects of delayed sowing in summer 1983 were more pronounced on stolons than on foliage growth when measured in September 1984, with significant reductions in many stolon attributes even with 8 d delay in sowing. Application of propyzamide in autumn 1983 increased clover yield during 1984 from 1·7 to 3·0 and total herbage yield from 7·1 to 8·6 t ha
The results demonstrated some of the benefits of rapid seedling emergence and of the use of a grass-suppressing herbicide, but did not indicate any interaction between the two factors. 相似文献
18.
Fiorella Cazzuli Carolina Bremm Martín Jaurena Dennis Poppi Martín Durante Marcelo Adolfo Benvenutti Jean Victor Savian Thais Devincenzi Pablo Rovira Ximena Lagomarsino Andrés Hirigoyen Fernando A. Lattanzi 《Grass and Forage Science》2023,78(2):306-316
It is unclear to what extent and on which variables does supplementing beef cattle on native grasslands affect sward structure, specifically on the dynamics of its grazing horizons. Three hypotheses were tested: (i) during a grazing down process under similar forage allowance, supplemented animals take longer to finish each grazing stratum, than their unsupplemented counterparts, (ii) in both cases, the upper stratum will be heavily depleted before the subsequent strata are grazed, (iii) some species and/or forage fractions are consumed faster than others, regardless of the animals being supplemented (corn dried distillers grains with solubles, DDGS, at 0.7% of their body weight, BW, on a dry matter, DM, basis) or not. Three blocks of stockpiled native grasslands were used and split into two treatments plots (n = 6), on which either supplemented (S) or control (C) heifers of 10.6 ± 0.6 months of age and an initial BW of 143 ± 9 kg, were used. A 2.5 × 0.5 m observation grid was installed on the sward, generating 384 observation points on each plot. On these observation plots, sward height (SH) and visually assessed green forage mass percentage (%G) were registered every other day for 12 consecutive days. No differences were found between the horizontal grazing dynamics between supplemented and control animals in terms of how they switched from the upper grazing horizon to the successive ones. In both cases, when the upper grazing horizon was heavily depleted, the subsequent horizon was being depleted by its half. Differences of preference for C3 species over C4 was observed for both treatments, but this effect was more meaningful for control animals. Grazing time never fully compensated for the decline in intake rate during depletion throughout the grazing horizons. Pasture intake declined when the animals transition from grazing the top grazing horizons to the lower horizons, irrespective of the level of supplementation. Managing the sward structure in terms of sward height will be beneficial to maximizing individual animal performance, for both C and S animals. Native grasslands paddocks with a greater C3 gasses predominance will always be preferred to C4 dominated paddocks, regardless of an eventual supplementation practice. 相似文献
19.
Fifty-four lactaling dairy cows were grazed for 24 weeks on pasture receiving 0 (Nil), 32 (Low) or 64 (High) kg Na ha-1 yr-1 and with (+) or without (-) 100g NaHCO3 buffer included in a maize gluten concentrate supplement. Cattle grazed the Na-fertilized pasture to a lower height, particularly in the High treatment. Cows grazing pasture with Na fertilizer produced more milk, and milk fat concentration increased in direct proportion to amount of Na fertilizer applied and with NaHCO3 . This increase was greatest in early season. Milk protein concentration was not affected by Na fertilizer application or NaHCO3 buffer addition. Milk lactose concentration was increased by Na fertilizer application but not by NaHCO3 supplementation. Cows in the Na-applied treatments gained more live weight but there was no effect of treatment on condition score change. Grazing time and drinking frequency increased linearly with increasing pasture Na. Ruminating time and biting rate were similar at the Low and High treatments and greater than the Nil treatment. NaHCO3 , supplementation increased drinking frequency and decreased the rate of concentrate intake. Cow reproductive performance was not significantly affected by Na fertilizer application. During the residual period, cows that had previously grazed the Na-fertilized pasture had reduced milk fat and protein contents. 相似文献
20.
A comparison of conventional and automatic milking system pasture utilization and pre‐ and post‐grazing pasture mass 下载免费PDF全文
C. E. F. Clark S. R. Farina S. C. Garcia M. R. Islam K. L. Kerrisk W. J. Fulkerson 《Grass and Forage Science》2016,71(1):153-159
Automatic milking systems (AMS) present an opportunity for dairy farmers to not only improve their lifestyle and conditions of work, but also save on labour costs and/or increase the time available to focus on overall farm management. However, the viability of AMS will rely on achieving high levels of pasture utilization. Well‐established pasture management principles are implemented on many conventional milking system (CMS) farms and high levels of pasture utilization are achieved; however, the ability to follow these same principles on AMS is unknown. This study compared levels of pasture utilization and pre‐ and post‐grazing pasture mass between AMS and CMS farms at the same site when managed by the same pasture management principles. From 1 March 2007 to 29 February 2008, pre‐ and post‐grazing compressed height, milk yield and milk composition data were collected for two CMS farms and one AMS farm at the Elizabeth Macarthur Agricultural Institute, Camden, Australia. Despite differences in pre‐ and post‐ grazing pasture mass between milking systems, pre‐grazing mass was predominantly maintained within the bounds of 2200 and 2500 kg DM ha?1 and post‐grazing mass between 1400 and 1500 kg DM ha?1 (5–6 cm height). Similar levels of pasture utilization (mean 13 500 kg DM ha?1 year?1) were recorded between AMS and CMS farms. These findings highlight the ability to follow established grazing management principles and achieve high levels of pasture utilization on pasture‐based AMS farms. 相似文献