The herbage intake and performance of autumn-calving beef cows and their calves when grazing continuously at two sward heights

1990 ◽  
Vol 51 (1) ◽  
pp. 85-92 ◽  
Author(s):  
I. A. Wright ◽  
T. K. Whyte ◽  
K. Osoro

ABSTRACTThirty-nine Hereford × Friesian autumn-calving cows (mean calving date 17 September) and their Charolais-cross calves were used in a 2 × 2 × 2 factorial experiment to assess the effects of feeding level in winter and sward height in summer on intake and performance. Mean estimated metabolizable energy intakes during winter (30 October to 6 May) were 63 (L) or 92 (H) MJ/day. Two sward heights, 4·8 (SI) or 7·6 (Tl) cm, were imposed from turn-out to weaning on 3 July, and a further two sward heights, 4·7 (S2) or 8·0 (T2) cm, from weaning to housing on 1 October. At turn-out the H cows were 17 kg heavier (P > 0·05) than the L cows and their calves were 30 kg heavier (P < 0·01). Cow herbage intakes were significantly higher on the Tl and T2 treatments compared with the SI and S2 treatments as were live-weight changes: 0·94 v. –0·01 kg/day (P < 0·001) for Tl and SI treatments and 0·96 v. –0·18 kg/day (P < 0·001) for T2 and S2 treatments respectively. Calves on the Tl treatment had higher live-weight gains than those on the SI treatment (1·40 v. 0·63 kg/day; P < 0·001). After weaning the SI cows had significantly higher herbage organic matter intakes than the Tl cows (P < 0·05) and had significantly higher live-weight gains (0·51 v. 0·28 kg/day; P < 0·05). Calving difficulty and calf birth weight were not affected by any of the treatments. The results demonstrate that both previous and current level of nutrition have an effect on cow performance. When cows are turned out to pasture at body condition scores of 2·25 to 2·5, the sward heights recommended for spring-calving cows are equally appropriate for autumn-calving cows.

1987 ◽  
Vol 44 (3) ◽  
pp. 363-370 ◽  
Author(s):  
I. A. Wright ◽  
A. J. F. Russel

ABSTRACTGroups of 12 spring-calving cows and their calves were allocated to each of three continuous grazing treatments: cows and calves grazed a 4- to 5-cm sward (LI), cows grazed a 4- to 5-cm sward and their calves grazed an 8- to 10-cm sward (Lh) and cows and calves grazed an 8- to 10-cm sward (Hh). In each case cows and calves grazed separately. Sward height had a large effect on both cow and calf performance and intake. The short swards reduced cow herbage intake proportionately by 0·2 compared with that of the taller sward. Cow live-weight gains were −0·60, −0·59 and 0·42 (s.e.d. 0·103) kg/day on treatments LI, Lh and Hh respectively while calf live-weight gains were 0·80, 0·95 and 1·14 (s.e.d. 0·040) kg/day. Calf milk intakes were 7·05, 5·78 and 9·34 (s.e.d. 0·508) kg/day respectively while daily herbage intakes were 17·2, 22·0 and 19·8 (s.e.d. 1·35) g organic matter per kg live weight for treatments LI, Lh and Hh. There was a negative association between calf herbage and milk organic matter intakes in the treatments where the calves had access to a more generous sward height (treatments Lh and Hh), the regression coefficient being −0·89 (s.e. 0·381), indicating the calves' ability to increase herbage intake in response to a reduction in milk intake. On the LI treatment there was no significant relationship between milk and herbage intakes. The ability of grazing suckled calves to compensate for a reduction in milk intake is thus dependent on sward conditions, and may also depend on herbage digestibility. The increase in herbage intake cannot however compensate fully for a restriction in milk supply.


Author(s):  
I.A. Wright ◽  
T.K. Whyte ◽  
K. Osoro

It has been demonstrated previously that sward height has a large effect on herbage intake and performance of spring calving cows and their calves (Wright and Russel, 1986) with maximum cow and calf live-weight gain occurring when sward height is maintained at 8 to 10 cm. No comparable information is available for autumn calving cows, and the aims of the present experiment were to examine the effect of sward height on cow and calf performance, in the pre- and post-weaning periods in cows that were turned out to pasture in late lactation at two levels of body condition.The experiment was a 2 x 2 x 2 factorial, with two levels of winter feeding, two sward heights from turn-out to weaning, and two sward heights from weaning to housing. During the summer grazing periods there were two replicates. Thirty-nine Hereford x Friesian cows (mean calving date 17 Sept, 1986) with Charolais-cross calves were used. The experiment started on 30 October 1986 when the cows and calves were housed in two groups. One group (L) was fed silage alone and the other group (H) was fed silage plus barley. Estimated daily metabolisable energy intakes were 63 MJ (L) and 92 MJ (H). Calves were fed 1 kg barley/day plus hay ad 1ibitum. The cows were mated to Charolais bulls for 8 weeks from 15 November 1986.


1979 ◽  
Vol 92 (2) ◽  
pp. 443-447 ◽  
Author(s):  
Y. L. P. Le Du ◽  
R. D. Baker

SummaryThe effect of the amount of milk consumed upon the herbage intake and performance of calves at pasture, following a standard rearing period, was investigated using 50 Hereford × Friesian calves purchased at 10–12 days ofage. All calves were offered 6 kg reconstituted milk substitute for a 58 day period indoors and for a subsequent 31 days at pasture. Ten calves were then allocated to each of five milk treatments (0, 2, 4, 6, 10 kg/day) and grazed for a further 63 days. The calves were offered a daily herbage allowance of 60 g dry matter/kg live weight.Daily weight gain was increased by 59 g for each additional kilogramme of reconstituted milk consumed, and herbage intake per unit live weight decreased by 1–24 g/g milk organic matter consumed, equivalent to a reduction in metabolizable energy intake of 9 kJ. Clear effects of both age and diet upon the consumption of herbage were demonstrated. An explanation of the mechanisms governing intake of herbage in milk–fed calves is offered.


1998 ◽  
Vol 78 (2) ◽  
pp. 211-218 ◽  
Author(s):  
S. A. Marshall ◽  
C. P. Campbell ◽  
J. G. Buchanan-Smith

Intake and performance of 40 spring-calving cows with calves was investigated under a rotational grazing management system across three consecutive summers. A 19.2 ha pasture was divided into sixteen 1.2 ha fields with each field being further subdivided into eight 0.15 ha paddocks. Five cows with calves belonging to one of two breed groups (large vs. medium framed) and two body conditions (high vs. low) were randomly assigned to graze each of eight field pairs from May to October of each year. Paddocks not grazed by cow-calf pairs were grazed by yearling heifers or mechanically harvested as hay or silage. Grazing was managed by setting target sward heights for exit of each paddock at 8 to 10 cm and allowing a minimum of 25 to 30 d for regrowth. Paddocks were topclipped and fertilized with 34 kg ha−1 of nitrogen (N) immediately following the second grazing of each paddock. Sward surface height data were collected from 40 measurements taken immediately pre- and post-grazing in each paddock as well as during the regrowth period. Herbage biomass and quality was determined in year 1 by handclipping 10 quadrats (1.22 m × 0.15 m) from each paddock pre- and post-grazing and by clipping 7 similar quadrats from alternate paddocks in each of the other 2 yr. Average pre-grazing sward heights were 24.8, 30.3 and 28.1 cm, in years 1, 2 and 3, respectively. Herbage biomass available for grazing averaged 7.59, 10.62 and 11.04 tonnes DM ha−1 for years 1, 2 and 3, respectively. A positive linear (r = 00.93 P < 0.0001) relationship was established between sward height (cm) and herbage biomass (kg DM ha−1) across all 3 yr. Intake of dry matter (DM), crude protein (CP) and metabolizable energy (ME) was higher for both large- and medium-framed cow-calf pairs in year 3 than in the other 2 yr. Both large- and medium-framed cows lost (P < 0.05) body condition in years 1 and 2, but gained in year 3. Cows from the low body condition group gained (P < 0.05) more than those from the high group in years 2 and 3. Medium-framed calves gained more (P < 0.05) in year 3 than in years 1 and 2. Body condition of cows grazing a multi-species grass-legume pasture can be maintained if not improved provided seasonal variations in quality and quantity are minimized. Key words: Beef cows, pasture, grass-legume, intake


1986 ◽  
Vol 43 (2) ◽  
pp. 211-223 ◽  
Author(s):  
I. A. Wright ◽  
A. J. F. Russel ◽  
E. A. Hunter

ABSTRACTTwo experiments were conducted with weaned, suckled calves to investigate the effect of feeding level during the post-weaning winter on their subsequent performance when continuously grazed on pasture maintained at two sward heights. Low, medium and high levels of winter feeding resulted in winter live-weight gains of 0·31, 0·58 and 0·79 (s.e. 0·027) kg/day (P < 0·001) during the 152-day winter in experiment 1 and 0·44, 0·69 and 0·84 (s.e. 0·029) kg/day (P < 0·001) for 189 days in experiment 2. During summer (93 days in experiment 1 and 87 days in experiment 2) there was a significant effect of winter food level on performance when live-weight gains were 1·10, 1·02, 0·87 and 1·35, 1·23 and 1·19 (s.e. 0·060) kg/day for the low, medium and high winter food levels on the short and tall swards respectively in experiment 1 (P < 0·01) and 0·86, 0·66, 0·51 and 1·26, 1·18 and 0·91 (s.e. 0090) kg/day in experiment 2 (P < 0·001). The cattle showing compensatory growth had higher herbage intakes and it is postulated that this occurred because of a negative association between body fat and herbage intake. Sward height had a large positive effect on herbage intake and live-weight gain and it is concluded that for maximum intake on ryegrass swards, herbage height should be at least 8 cm. Lower levels of winter live-weight gain delayed the time to slaughter, but allowed cattle to achieve heavier carcass weights at a fixed level of fatness.It is concluded that there is no single optimum winter food level for weaned, suckled calves but that the choice will depend upon several factors, including availability of winter and summer food resources, the length of the winter feeding period, the desired date of slaughter and type of carcass to be produced.


1970 ◽  
Vol 12 (1) ◽  
pp. 23-36 ◽  
Author(s):  
T. T. Treacher

SUMMARY1. Scottish Half-bred ewes carrying twin foetuses were fed individually to make live-weight gains in the last six weeks of pregnancy of (1) 20%, (2) 10% and (3) 0% of their live weight in week 14 of pregnancy. In lactation the ewes were fed ad libitum. The lambs were removed 12 to 16 hr after parturition and the ewes were machine-milked twice daily for the first six weeks of lactation.2. Total birth weights per ewe of twin lambs from the treatments were (1) 10·10 kg, (2) 9·44 kg and (3) 8·18 kg and differed significantly.3. The level and pattern of voluntary intake in lactation did not differ significantly between the treatments. Total dry-matter intakes in the six weeks of lactation were (1) 121·9 kg (2) 105·9 kg and (3) 109·5 kg.4. The pregnancy treatments affected the level of milk production and the shape of lactation curves. The total yields in the first six weeks of lactation were (1) 58·8 kg, (2) 43·5 kg and (3) 26·9 kg. Higher contents of fat and protein and the lower content of lactose in the milk from treatment-3 ewes on days 1 and 3 of lactation indicated a slower onset of lactation in these ewes. Between days 7 and 35 of lactation the contents of fat and SNF were lowest on treatment 3 but the differences were not significant.5. The live-weight changes in lactation, which were in inverse order to the gains in late pregnancy, were (1) 3·4 kg, (2) 5·5 kg and (3) 9·5 kg.


1994 ◽  
Vol 58 (2) ◽  
pp. 231-235 ◽  
Author(s):  
A. M. Sibbald ◽  
W. G. Kerr

AbstractTo examine the effects of body condition and previous nutrition on the herbage intake of ewes grazing swards of different heights in autumn, 96 Scottish Blackface X Border Leicester ewes with a wide range of body condition (score 1·75 to 3·50), were initially housed and given 50 g dry matter (DM) per kg metabolic live weight (M)0·75 per day (treatment L) or 95 g DM per kg M0·75 per day (treatment H) of a pelleted dried grass diet (11·6 MJ metabolizable energy per kg DM) for 6 weeks after weaning in July. The H ewes gained more live weight (9·0 v. 2·7 kg) and body condition score (0·39 v. 0·17) than the L ewes. Half the animals from each treatment were then allocated to each of two ryegrass pastures with a sward height of 5 cm (LS) or 10 cm (HS) for a further 6-week grazing period. During the grazing period there was no significant effect of indoor feeding level on herbage intake, but the L ewes gained more live weight (6·4 v. 5·0 kg) than the H ewes. On the HS, compared with the LS sward, mean herbage intakes were higher (70·0 v. 60·5 g DM per kg M0·75) as were gains in live weight and condition score (7·9 v. 3·4 kg; 0·18 v. 0·0). There were no interactions between the effects of sward height and previous feeding level on herbage intake. Ewes in low body condition (< 2·5) at the start of the grazing period ingested the same amount of herbage on both swards (70·3 g DM per kg M0·75) whereas ewes in high body condition (> 2·5) ingested more (67·0 v. 51·6 g DM per kg M0·75) on the HS compared with the LS sward. The responses of ewes in low and high body condition to different sward heights are discussed in relation to appetite drive and aspects of grazing behaviour.


1986 ◽  
Vol 107 (2) ◽  
pp. 357-365 ◽  
Author(s):  
D. L. Coppock ◽  
D. M. Swift ◽  
J. E. Ellis ◽  
K. Galvin

SummaryEnergy budgets and estimates of forage intake requirements were developed for adult camels, cattle, sheep, and goats managed by nomads in the arid Turkana District of north-western Kenya. The estimates were developed by combining our field data on livestock activity patterns, diet quality, weight changes and milk yields with literature based estimates of the associated costs and efficiencies. On an annual basis, the average animal walked 17 km/day and had a total metabolizable energy (ME) allocation of 47% for basal metabolism, 16% for travel, 14% for other activities, and 23% for production. Season and species influenced patterns of energy demand and allocation. Average daily ME requirements ranged from 8·7 MJ (sheep) to 76·7 MJ (camels). ME demand for all species peaked during wet (April-May) or early-to mid-dry periods (June-October), and decreased considerably in the late-dry season (November-March). In the wet season the average sheep or goat allocated 45% of its ME budget to production of milk and gain, followed by cattle (36%) and camels (25%). All species were more similar in ME allocation for production during the late-dry season (7–13%; all to lactation), yet patterns of weight loss during this time indicated that camels experienced the lowest degree of negative energy balance. On an annual basis, camel budgets were the most deviant, as they allocated relatively more ME to activity and relatively less to basal metabolism or weight gain. Estimates of forage dry-matter intakes (per unit live weight per day) ranged from 3·8% (cattle, camels) to 4·6% (sheep, goats) throughout the year, and intakes declined for most species by an average of 50% from the wet to late-dry intervals. This approach has revealed ecological differences among livestock species that help explain the utility of multi-species holdings in this system.


1995 ◽  
Vol 1995 ◽  
pp. 156-156
Author(s):  
R. Pulido ◽  
J.D. Leaver

The increase of milk yield potential of dairy cows raises a number of questions relating to their management at pasture where the intake potential might be limiting. The interaction of initial milk yield (IMY), sward availability (SH) and level of concentrate supplementation (CI) is largely unknown.Two experiments of 42 and 24 days in spring and midsummer were carried out with 45 and 27 Holstein Friesian cows respectively. In spring, five IMY groups (range 16.9 to 35.5 kg/day) and in midsummer three IMY groups (range 22.2 to 31.8 kg/day) were used. In both periods, three compressed sward height(3 to 5, 5 to 7 and 7 to 9 cm) and three CI (0, 3 and 6 kg/day, with 160 g CP/kg DM, 12.8 MJ ME/kg DM) were used. The grazing area consisted of 7.9 ha of perennial ryegrass which was set stocked. The herbage intake (HDMI) was estimated indirectly from individual cow performance. Grazing time (GT) was recorded for each cow on 24 hour observations. Multiple regression analyses were carried out relating the dependent variables herbage intake, grazing behaviour and milk production to the independent variables (IMY, SH, CI).


1996 ◽  
Vol 1996 ◽  
pp. 49-49
Author(s):  
I.A. Wright ◽  
T.J. Maxwell ◽  
A.J.F. Russel ◽  
A.R. Sibbald

Herbage intake by beef cows is highly correlated with sward height and therefore intake can be managed in a predictable manner by controlling sward height. For beef cows this requires adjustment of the grazing area and conservation of herbage which is not grazed, with the silage aftermath subsequently grazed later in the summer. Year-to-year variation in herbage growth rate will result in variation in the amounts of silage produced. Most grazing experiments do not consider this year-to-year variation, but it constitutes one of the major features which has to be accommodated in the operational management of beef cow systems which are based on pastoral resources.During three consecutive summers, 40 spring-calving Hereford x Friesian beef cows and their Charolais-cross calves grazed perennial ryegrass-dominated swards receiving 200 kg N/ha at one of two annual stocking rates (2.0 or 2.5 cows/ha) at one of two sward heights (4 to 5 (short) or 7 to 8 cm (tall)) in a 2x2 factorial experiment, replicated twice.


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