The effect of winter feeding level on subsequent grazing behaviour and herbage intake of Charolais heifers

1995 ◽  
Vol 61 (2) ◽  
pp. 211-217 ◽  
Author(s):  
R. Ferrer Cazcarra ◽  
M. Petit

AbstractTwo groups of eight Charolais heifers were used to examine the effect of feeding level during the post-weaning winter on the grazing behaviour and herbage intake over three periods during the first 2 months of grazing. The winter diets (L and H) were given to achieve a mean difference of 50 kg between groups at turn-out. The heifers were set-stocked together on a hill pasture where sward height was maintained at 12 cm.The winter live-weight gains were 0·31 and 0·70 (s.e. 0·032) kg/day for L and H heifers respectively, and spring gains 1·94 and 1·66 (s.e. 0·082) kg/day respectively. Intakes increased throughout the spring grazing for both groups. Absolute intakes were lower for L than for H heifers only during the first period (P < 0·05). Intake per kg live weight was higher in L than in H heifers (23·0 v. 21·1 (s.e. 0·54) g organic matter (OM) per kg live weight). Bite weights of H heifers were constant throughout (434, (s.e. 12·9) mg OM), while bite weights ofL heifers only reached those of H heifers in the last period. Bite weight was linearly related to live weight. Bite rates were not different between groups, but L heifers compensated for lower bite weight by grazing longer and they increased their grazing time after turn-out faster than H heifers. Grazing time was mainly responsible for higher relative intakes in L heifers, and thus, partly, for compensatory gain observed.

1995 ◽  
Vol 61 (3) ◽  
pp. 497-506 ◽  
Author(s):  
R. Ferrer Cazcarra ◽  
M. Petit

AbstractMature dry cows, 18-month-old heifers and 7-month-old female calves of the Charolais breed (eight animals of each age) were strip-grazed on moderate (15cm) or tall (52 and 32cm) cocksfoot swards over two 15-day experimental periods. The swards were leafy regrowths of 2 (short) and 8 (tall) weeks of age. Herbage intake was estimated by the alkane method, and grazing behaviour was visually recorded.Bite weight was lower, grazing time and biting rate greater, and organic matter in take of grass (OMIG) higher on shorter swards, the latter being related to a higher in vitro digestibility and nitrogen concentration. Average OMIG per kg live weight (M) was 15·2, 19·1 and 17·0 (s.e.d. 0·49)g in cows, heifers and calves respectively. The average allometric coefficient between OMIG and M was 0·88 (similar between swards), and close to that obtained with hay after the grazing trial.Faecal markers suggested a greater selectivity of calves compared with older cattle. Average bite weights (BW) were 310 (s.e. 40), 467 (s.e. 112) and 718 (s.e. 144)mg OM in calves, heifers and cows respectively. The allometric coefficient between BW and M was higher in short swards than in tall ones. Biting rates increased and grazing times tended to decrease with age of cattle.


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.


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.


1995 ◽  
Vol 61 (3) ◽  
pp. 511-518 ◽  
Author(s):  
R. Ferrer Cazcarra ◽  
M. Petit ◽  
P. D'hour

AbstractMature non-lactating cows, 18-month-old heifersand7-month-oldfemale calves of the Charolais breed (eight animals of each age) were strip-grazedon short (S, sward surface height: 7·5 cm), medium (M,10·2 cm) and tall (T, 21·1 cm) cocksfoot (Dactylis glomerata) swards at a daily herbage allowance of 40 g dry matter per kg live weight over three 15-day experimental periods. The swards were leafy regrowths of 1 (S), 2 (M)and 3·5 (T)weeks of age. Herbage intake was estimated by the n-alkane method, and grazing behaviour was recorded visually.Intakes per kg live weight of calves and heifers were higher than those of cows on all swards(P < 0·01). Calves tended to maintain intake, whereas cows and heifers reduced their intake as sward height decreased. Bite weight decreased linearly with sward height, this decrease being greater for larger animals (P < 0·001). As sward height decreased, the scaling factor of bite weight to live weight decreased. Biting rates increased as sward height decreased (P < 0·001) and were lower in calves than in older cattle (P < 0·001). Calves had lower intake rates per kg live weight than cows in T swards, and the reverse was true in S swards (P < 0·001). Younger cattle always grazed longer than cows, but differences were reduced as sward height decreased (P < 0·01). Cows and heifers wereunable to increase their grazing time sufficiently to compensate for lower intake rates in S and M swards, resulting in reduced herbage intakes. Faecal markers and grazing behaviour suggested a greater selectivity by calves compared with older cattle.


1977 ◽  
Vol 24 (3) ◽  
pp. 343-353 ◽  
Author(s):  
G. W. Arnold ◽  
H. A. Birrell

SUMMARYHerbage intake and grazing times were measured in four experiments in which adult sheep grazed short and long pastures. The digestible organic matter (DOM) intake of adult wooled Merino and Corriedale wethers was higher, both absolutely and per kg live weight, when they were lower in live weight due to prior under-nutrition. The relative differences were similar on both abundant and scant pasture and were proportional to the relative differences in live weight. The higher intakes were achieved by differences in the time spent grazing and in the rate of intake per hour of grazing. DOM intake of shorn sheep was increased by up to 44% per kg live weight within 5 weeks of shearing in two experiments when the mean temperature was 8°C but no increase in DOM intake was observed in four other experiments when the mean temperature was 11°C. Shorn sheep achieved higher intakes on both abundant and scant pastures by increasing intake per hour of grazing.


1992 ◽  
Vol 54 (2) ◽  
pp. 243-248 ◽  
Author(s):  
R. G. Gunn ◽  
J. A. Milne ◽  
A. J. Senior ◽  
A. M. Sibbald

AbstractThe effects on reproductive performance offeeding supplements to ewes grazing predominantly perennial ryegrass swards before and during mating which started in mid November were examined with approximately 200 Scottish Blackface ewes in each of three experiments. In two experiments, ewes were offered no supplement (C), 600 g barley (S(B)) or 500 g barley + 100 g white-fish meal (S(B + FM)) per head per day from 3 weeks before until 3 weeks after the start of the mating period. Ewes in experiment 1 were grazed on different areas and in experiment 2 were rotated around these areas on a 12-day cycle. Initial herbage allowance in both experiments was 40 to 50 kg organic matter per ewe and stocking rates ranged from 10 to 14 ewes per ha. Ewes in experiment 3 were rotated around the same areas on a 10-day cycle at a stocking rate of 18 ewes per ha and offered either no supplement (C) or 600 g barley (S(B)) per head per day when live weight started to decrease or sward height declined to 3·5 cm, whichever occurred first. Both of these occurred shortly after the start of mating. Sward height fell from mid October and throughout November and was between 3 and 4 cm at the start of mating in all experiments.There were no differences in response to the (S(B)) and (S(B + FM)) treatments in live weight, body condition or reproductive performance in experiments 1 and 2 and the effects of supplementation were examined with these treatments pooled.Supplementation had very little effect on live weight, resulting in higher values only in experiment 1 but did produce higher body condition in all experiments. This occurred by the start of mating in experiment 1 but not until mid December in experiment 3 and early January in experiment 2.A significant increase in the number of lambs born per ewe lambing was obtained from supplementation when the data from experiments 1 and 2 were combined (P < 0·05). There was no response in reproductive performance to supplementation in experiment 3. It was concluded that supplementation in the pre-mating period can improve reproductive performance when sward height declines from 6 to 3·5 cm but that supplementation in the post-mating period may not, even when the sward height is below 3·5 cm.


1991 ◽  
Vol 53 (2) ◽  
pp. 257-260 ◽  
Author(s):  
R. G. Gunn ◽  
J. M. Doney ◽  
W. F. Smith ◽  
A. D. M. Smith ◽  
D. A. Sim ◽  
...  

The effects on herbage intake of changes of herbage mass associated with different stocking rates were studied in Greyface (Border Leicester × Scottish Blackface) ewes in the autumn. Intake was measured in 5-day periods in late September (PI), late October (P2) and late November (P3) on two established, perennial ryegrass/white clover swards (SI and S2). Both swards had previously been variably stocked to produce areas with a range in herbage masses, some of which were grazed continuously (G) at stocking rates declining from 18 to 6 ewes per ha.Intake was also measured in P2 and P3 on other areas of the swards which were ungrazed for 6 weeks in September and October (C) and then stocked at 18 ewes per ha. Intakes of dry matter, organic matter and digestible organic matter were 16 g, 10 g and 7·5 g/kg live weight, respectively. Organic matter digestibility was 075 in PI and P2 but declined in P3.Differences in herbage intake and digestibility arose largely because of differences between the swards in herbage mass, sward height and sward density. Ewes in condition scores > 3·00 in early September had lower intakes at all times than did thinner ewes. Changes in sward management associated with different strategies of use had little long-term effect on herbage intake. Keywords: digestibility, herbage, sheep, stocking rate.


1986 ◽  
Vol 107 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Lindsey Caird ◽  
W. Holmes

SUMMARYInformation on the total organic matter intake, concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY), herbage organic matter digestibility (HOMD), herbage mass, sward height (SHT) or herbage allowance (HAL) measured individually for 357 cows at one of three sites was assembled. Observed intake was compared with intakes predicted by existing intake equations and new prediction equations based on regression models or regression and least-squares constants were developed. Major factors affecting intake were MY, LW, WL, C and HAL or SHT. Although HOMD was correlated with intake, better predictions were obtained when HOMD was omitted. There were differences between sites possibly associated with differences in measurement techniques.The predictive value of some existing equations and new equations were tested against independent sets of data. A simple equation (A) based on MY and LW (Ministry of Agriculture, Fisheries and Food, 1975) gave satisfactory average predictions but the mean square prediction error (MSPE) was high. The equations of Vadiveloo & Holmes (1979) adjusted for bias gave a relatively low MSPE. The preferred new equations for grazing cattle included MY, LW, WL, C and HAL or SHT, and their MSPE were similar to or lower than for indoor equations.The discussion indicates that a simple equation (A) would give adequate predictions for farm planning. The more detailed equations illustrate the inter-relations of animal with sward conditions and concentrate allowances. Predicted intakes may deviate from actual intakes because of short-term changes in body reserves.


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