Responses to supplements by weaned lambs grazing mature pasture or eating hay in yards

Freer, M.; Dove, H.; Axelsen, A; Donnelly, J. R.; McKinney, GT

doi:10.1071/ea9850289

Cited by 9 publications

(11 citation statements)

References 13 publications

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“…The increase of up to 58% in the intake of pasture with moderate levels of supplementation is considerably greater than that previously reported for sheep grazing mature pasture (Allden, 1981;Foot, McIntyre & Heazlewood, 1983;Freer et al 1985). Although the N content of the pasture was the most likely limitation that would have been satisfied by the supplement, the mean level in the diet selected, 1-2% on a D.M.…”

Section: Interaction Between the Intakes Of Supplement And Roughagementioning

confidence: 80%

“…The pasture plots and yards were drawn from those used in previous experiments (Freer et al 1985). The pasture consisted mainly of silver grass (Vulpia spp.)…”

Section: Plotsmentioning

confidence: 99%

“…During each period, diet samples were collected via an oesophageal fistula from two additional sheep on each plot. Procedures for collection and preparation and for nitrogen and in vitro digestibility were described by Freer et al (1985). Neutral detergent fibre was estimated by the method of Goering & Van Soest (1970).…”

Section: Estimates Of Food Intake By Individtial Animalsmentioning

confidence: 99%

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Responses to supplements by weaned lambs when grazing mature pasture or eating hay cut from the same pasture

et al. 1988

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Weaned cross-bred lambs either grazed mature pasture or were confined to yards where they were offered material cut from ungrazed areas of the same pasture. A 1:2 mixture (on an air-dry basis) of sunflower meal and oat grain was offered for 81 days at 0, 200, 400 or 600 g/head or ad libitum. Individual estimates of intake of pasture and supplement by grazing sheep at four levels of supplementation were made on four adjacent plots.Weight gain increased from -30 to 178 g/day in the grazing animals as supplement intake increased up to 1030 g D.M./day and from -25 to 142 g/day in the yarded animals as supplement intake increased to 1076 g D.M./day. Growth of greasy wool increased from 4-5 to 11-7 g/day for grazing animals and from 4-5 to 10-2 g/day for those kept in yards.At levels of supplement intake below 400 g D.M./day, the intake of grazed pasture increased by up to 58% compared with unsupplemented animals. However, when the intake of supplement was increased to about 650 g D.M./day, pasture intake fell, with an estimated substitution rate of 1 -1 g D.M. pasture per g D.M. supplement. At all levels of supplementation, the intake of hay by the yarded lambs was less than half the intake of herbage in the field. However, at levels of supplement intake between 300 and 500 g D.M./ day, the substitution rate was similar to that measured in the grazing animals, suggesting that this is an attribute of roughage quality, rather than differential eating behaviour between grazing and yarded animals.The wastage, w (g D.M./day), of supplement was linearly related to the amount offered, s (g D.M./day), by the equation w = 0263s -38-8; R 2 = 089 Variability in supplement intake between individual grazing lambs was not affected by the level of supplementation but the coefficient of variation of supplement intake was considerably greater than that of the intake of unsupplemented pasture. Variability in the intake of pasture increased with the level of supplementation but variability in the total intake of food was similar at each level of supplement, indicating some degree of individual compensation in the intake of the two components. INTRODUCTIONgrazing animals than in the intake of those in yards. However, the results did not indicate whether the In an examination of the possible role of supple-higher level of substitution resulted from the poorer ments for weaned lambs over the summer, Freer et quality of the roughage available to the grazing al. (1985) found that when a mixture of sunflower lambs or from a possible inhibition of their grazing meal and oat grain was offered to lambs eating hay activity due to supplementation. in yards, their weight continued to increase at the The experiments reported here attempted to same rate up to high levels (1 kg/day) of supple-resolve this question by comparing the responses to mentation. However, when the same mixture was supplementation of weaned lambs that were grazing offered to lambs grazing mature pasture, the rate of mature pasture with those of lambs that received response was...

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Section: Interaction Between the Intakes Of Supplement And Roughagementioning

confidence: 80%

“…The pasture plots and yards were drawn from those used in previous experiments (Freer et al 1985). The pasture consisted mainly of silver grass (Vulpia spp.)…”

Section: Plotsmentioning

confidence: 99%

Section: Estimates Of Food Intake By Individtial Animalsmentioning

confidence: 99%

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Responses to supplements by weaned lambs when grazing mature pasture or eating hay cut from the same pasture

et al. 1988

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“…Substitution rates usually increase as the nutritive value and leaf content of forage improves and the ability of grazing sheep to select a better-quality diet than pen-fed sheep may have led to a greater substitution rate of lupins for forage under the grazing conditions than under the pen conditions. Similarly, Freer et al (1988) concluded that the higher substitution rate exhibited by grazing than by yarded lambs at moderate to high levels of supplementation (Freer et al 1985) was a result of the higher quality of the roughage consumed by grazing animals rather than differences in eating behaviour between grazing and yarded animals. However, the plateau in growth rate response in the present experiment at the relatively low level of 72.5 g/wether.day was unexpected, given that the growth rate response to lupins access in the pen experiments did not appear to have plateaued at 127 and 155 g/wether.day (Experiments 1 and 2, respectively).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of a remote drafting system for regulating sheep access to supplement

Bowen¹,

Pepper²,

McPhie³

et al. 2009

Anim. Prod. Sci.

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Abstract. Remote drafting technology now available for sheep makes possible targeted supplementation of individuals within a grazing flock. This system was evaluated by using 68 Merino wethers grazing dry-season, native Mitchell grass pasture (predominantly Astrebla spp.) as a group and receiving access to lupin grain through a remote drafter 0, 1, 2, 4 or 7 days/week for 8 weeks. The sole paddock watering point was separately fenced and access was via a one-way flow gate. Sheep exited the watering point through a remote drafter operated by solar power and were drafted by radio frequency identification (RFID) tag, according to treatment, either back into the paddock or into a common supplement yard where lupins were provided ad libitum in a self-feeder. Sheep were drafted into the supplement yard on only their first time through the drafter during the prescribed 24-h period and exited the supplement yard via one-way flow gates in their own time. The remote drafter operated with a high accuracy, with only 2.1% incorrect drafts recorded during the experimental period out of a total of 7027 sheep passes through the remote drafter. The actual number of accesses to supplement for each treatment group, in order, were generally less than that intended, i.e. 0.02, 0.69, 1.98, 3.35 and 6.04 days/week. Deviations from the intended number of accesses to supplement were mainly due to sheep not coming through to water on their allocated day of treatment access, although some instances were due to incorrect drafts. There was a non-linear response in growth rate to increased frequency of access to lupins with the growth rate response plateauing at~3 actual accesses per week, corresponding to a growth rate of 72.5 g/head.day. This experiment has demonstrated the application of the remote drafting supplementation system for the first time under grazing conditions and with the drafter operated completely from solar power. The experiment demonstrates a growth response to increasing frequency of access to supplement and provides a starting point with which to begin to develop feeding strategies to achieve sheep weight-change targets.

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“…reduction in forage intake due to supplementation; Moore et al, 1999), thus bypassing any positive effect on intake due to digestive complementation between foods (e.g. Freer et al, 1985). Since substitution and complementation (i.e.…”

Section: Discussionmentioning

confidence: 99%

Devaluation of low-quality food during early experience by sheep

Catanese

Freidin

Cuello

et al. 2011

Animal

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A ruminant's early experience with low-quality food (LQF) is expected to increase its acceptance and preference in adulthood. Contrarily, we found that experienced sheep (ES) exposed to mature oat hay early in life ate less of this LQF than inexperienced sheep (IS). A possibility is that ES might have devaluated the LQF through continuous comparisons against high-quality food (HQF) supplements (sunflower meal and ground corn) that were simultaneously available during early experience. In this study, we tested the devaluation hypothesis with a successive negative contrast (SNC) procedure. In a consummatory SNC procedure, 'shift' subjects are unexpectedly changed from HQF to LQF, and their consumption is then compared against the consumption of 'unshift' subjects that receive LQF all throughout the SNC procedure. The magnitude of the difference in consumption between preshift and postshift is regarded as a measure of the degree to which both foods (HQF and LQF) are perceived to differ hedonically. When sheep from our previous study were 300 days old, both ES and IS were randomly assigned to either shift (ES-S and IS-S) or unshift conditions (ES-U and IS-U; n 5 6 in each group). Groups ES-S and IS-S were fed HQF (alfalfa hay) during the preshift phase, and then suddenly changed to LQF (oat hay) in the postshift phase. Groups ES-U and IS-U (controls) were fed only LQF throughout the SNC procedure. Subjects in ES-S showed a significantly lower intake of LQF than those in ES-U in the first postshift session (i.e. they showed an SNC effect), which was not observed in IS. These results agree with ES subjects having devalued LQF during early experience. We discuss the possibility that high levels of nutrient supplementation can result in devaluation of LQF (i.e. decrease in preference and acceptance), whereas restricted levels of supplementation may promote a positive experience with LQF.Keywords: early experience, food valuation, low-quality food, sheep, successive negative contrast ImplicationsEarly experience with specific foods can improve their acceptance and preference later in life. However, our past and present results with sheep suggest that mere exposure to foods in early life may not be sufficient to attain that outcome. Behaviour towards a food source and learning about its consequences depend not only on the food's intrinsic properties but also on the alimentary context in which it is presented. Current results can be interpreted as showing that the use of high levels of nutrient supplementation can cause a negative experience with LQF (i.e. a decrease in the preference and acceptance), whereas restricted levels of supplementation (a more typical scenario) may promote the opposite result (i.e. enhanced experience with LQF). IntroductionEarly food experience has the potential to increase food acceptance (voluntary intake of a given food) and preference (choices among food alternatives) in ruminants (Provenza and Balph, 1987;Distel and Provenza, 1991;Distel et al., 1994). Moreover, preference for low-quality f...

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Responses to supplements by weaned lambs grazing mature pasture or eating hay in yards

Cited by 9 publications

References 13 publications

Responses to supplements by weaned lambs when grazing mature pasture or eating hay cut from the same pasture

Responses to supplements by weaned lambs when grazing mature pasture or eating hay cut from the same pasture

Evaluation of a remote drafting system for regulating sheep access to supplement

Devaluation of low-quality food during early experience by sheep

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