Corrigendum - Seasonal variation in voluntary feed intake and growth in cashmere bucks fed ad libitum diets of low or high quality

1994 ◽  
Vol 45 (2) ◽  
pp. 355
Author(s):  
SW Walkden-Brown ◽  
BW Norton ◽  
BJ Restall

The effects of season and diet quality on voluntary feed intake and growth were examined in mature cashmere bucks over a 16 month period at Wollongbar (29�S., 153� E.). Three-year-old bucks were individually housed under natural photoperiod and fed ad libitum diets of High (pelleted lucerne, CP 17.6%, ME 8.3 MJ/kg) or Low (pasture hay; CP 6.9%, ME 6.6 mJ/kg) quality, between July 1988 and Oct. 1989 (n = 6/treatment). Bucks on both diets exhibited a seasonal pattern in voluntary feed intake with maximal intakes during spring and summer, and minimal intakes during autumn. The pattern appeared to be circannual with high intakes during spring of both years. Liveweight also varied with season peaking in mid to late summer and reaching a seasonal nadir in late autumn or early winter. Change in liveweight was closely associated with digestible energy intake ( r = 0-87, P < 0.001) resulting in a growth cycle closely resembling that of voluntary feed intake. In both treatments, bucks lost weight throughout autumn, while growth rates were maximal between mid-winter and mid-spring. Diet quality did not alter the magnitude of the autumnal decline in liveweight with bucks losing 7.6% (Low) and 7.8% (High) of liveweight during this period. However, bucks on the high quality diet exhibited significantly elevated growth rates between mid-winter and mid-spring. We conclude that mature cashmere bucks exhibit an annual growth cycle with weight loss during autumn and maximal weight gains between mid-winter and mid-spring; that the growth cycle is driven primarily by changes in voluntary feed intake; and that increasing diet quality does not reduce the autumnal decline in liveweight but significantly increases liveweight gain during the seasonal peak in growth.

1994 ◽  
Vol 45 (2) ◽  
pp. 355
Author(s):  
SW Walkden-Brown ◽  
BW Norton ◽  
BJ Restall

The effects of season and diet quality on voluntary feed intake and growth were examined in mature cashmere bucks over a 16 month period at Wollongbar (29�S., 153� E.). Three-year-old bucks were individually housed under natural photoperiod and fed ad libitum diets of High (pelleted lucerne, CP 17.6%, ME 8.3 MJ/kg) or Low (pasture hay; CP 6.9%, ME 6.6 mJ/kg) quality, between July 1988 and Oct. 1989 (n = 6/treatment). Bucks on both diets exhibited a seasonal pattern in voluntary feed intake with maximal intakes during spring and summer, and minimal intakes during autumn. The pattern appeared to be circannual with high intakes during spring of both years. Liveweight also varied with season peaking in mid to late summer and reaching a seasonal nadir in late autumn or early winter. Change in liveweight was closely associated with digestible energy intake ( r = 0-87, P < 0.001) resulting in a growth cycle closely resembling that of voluntary feed intake. In both treatments, bucks lost weight throughout autumn, while growth rates were maximal between mid-winter and mid-spring. Diet quality did not alter the magnitude of the autumnal decline in liveweight with bucks losing 7.6% (Low) and 7.8% (High) of liveweight during this period. However, bucks on the high quality diet exhibited significantly elevated growth rates between mid-winter and mid-spring. We conclude that mature cashmere bucks exhibit an annual growth cycle with weight loss during autumn and maximal weight gains between mid-winter and mid-spring; that the growth cycle is driven primarily by changes in voluntary feed intake; and that increasing diet quality does not reduce the autumnal decline in liveweight but significantly increases liveweight gain during the seasonal peak in growth.


1998 ◽  
Vol 1998 ◽  
pp. 131-131
Author(s):  
J. J. Hyslop ◽  
A. Bayley ◽  
A. L. Tomlinson ◽  
D. Cuddeford

De-hydrated forages are often fed to equids in the UK in place of more traditional grass hay, particularly where individual animals are known to have a sensitivity to dusty, mouldy hay which may play a part inducing respiratory problems such as chronic obstructive pulmonary disease (COPD). One such alternative forage is short-chop de-hydrated grass. However, there is very little information available on voluntary feed intake (VFI), apparent digestibility and nutrient intake parameters when de-hydrated grass is offered to equids compared with traditional grass hay. This study examines the VFI and apparent digestibility in vivo of a short-chop de-hydrated grass compared with a traditional grass hay and determines their ability to meet the predicted energy and protein needs of mature ponies.Six mature Welsh-cross pony geldings with a mean liveweight (LW) of 281 kg (s.e.d. 0.89) were individually housed and offered ad libitum access to either short-chop de-hydrated grass (DHG) or traditional grass hay (HAY) plus 60 g/h/d minerals. The DHG and HAY were made from the same 2nd cut perennial ryegrass sward cut on the same day.


1967 ◽  
Vol 9 (4) ◽  
pp. 463-470 ◽  
Author(s):  
M. J. Ulyatt ◽  
K. L. Blaxter ◽  
I. McDonald

Three sheep with permanent fistulas of the rumen were each given dried grass and two hays, each in three different amounts, and the apparent digesti-bility of the roughages in the rumen and distal to the rumen was determined. A lignin ratio method was used to measure digestibility.With increase in the amount of the poorest hay given, the proportion digested in the rumen fell and that distal to the rumen increased. With the second hay this effect was also noted but was not statistically significant. The voluntary intakes ofdry matter varied from 1·94 kg/day for the dried grass to 1·28 for the poorest hay. The volumes of distribution of polyethylene glycol in the rumen when feed was offered ad libitum, however, were the same, irrespective of the type of feed, at between 14·1 and 15·2 litres. These observations were confirmed at slaughter. The results support the hypothesis that sheep voluntarily consume roughages of different qualities to achieve constant fill of their rumens, and that little regulation of voluntary intake can be attributed to distension of the hind gut.


1998 ◽  
Vol 130 (3) ◽  
pp. 357-366 ◽  
Author(s):  
R. E. NEWMAN ◽  
S. J. McCONNELL ◽  
R. H. WESTON ◽  
M. REEVES ◽  
C. BERNASCONI ◽  
...  

In two experiments conducted at Badgery's Creek, NSW (Latitude 34°S) the roles of testosterone and the thyroid hormones triiodothyronine (T3) and thyroxine (T4) as possible initiators of the change in voluntary feed intake (VFI) associated with the seasonal reproductive behaviour (rut) in male fallow deer were investigated.In Expt 1, the association between changes in these hormones with the onset of the rut was assessed in deer in which the timing of this event was manipulated by changing the photoperiod, or by melatonin administration. Groups were maintained under either natural photoperiod (n=6; control), a constant long daylength (16 h light[ratio ]8 h dark; n=9; LD group) or a constant long daylength and implanted with melatonin capsules (n=5; LD+M group) for 7 months from December until the following July. Blood samples were obtained weekly and VFI recorded.Feed intake decreased by 94% from the last week of March for 3 weeks in the control group. Changes of a similar magnitude were measured in the LD and LD+M groups but these changes were advanced by 1 and 9 weeks respectively in these groups. In all groups, circulating testosterone concentrations increased markedly at a time corresponding with the decrease in VFI. The concentrations returned to basal levels with the resumption in VFI. A distinct decrease in plasma concentrations of T3 and T4 in all three groups was associated with the decrease in VFI, however, the relationship with T3 was less apparent.In Expt 2, the role of testosterone in the regulation of the decline in VFI was investigated. Fallow bucks were treated with testosterone enanthate every 4 or 5 days for 28 days up to 6 weeks prior to the expected onset of the rut. Plasma testosterone concentrations, which were increased 13-fold, resulted in a decline in VFI which was comparable to that observed in the subsequent rut. Plasma free fatty acid concentrations were correlated negatively with the decline in VFI.Thus, the seasonal increase in circulating testosterone concentrations plays an important role in initiating the fall in VFI associated with the rut. As the rut was still apparent in animals maintained under an extended photoperiod, it is possible that factors other than decreasing daylength act as the cue for the timing of the rut.


Author(s):  
A.L. Lightfoot ◽  
A.W. Armsby ◽  
C.F. Widdows

An experiment was carried out to determine which feeding method maximised feed intake of growing pigs and to record growth rates, feed conversion efficiency and backfat measurements. There is an increasing tendency for dry fed pigs to be fed ad libitum or to appetite in order to increase growth rates and throughput of building.Limited information is available on how the modern genetically improved pig will respond to high levels of feeding and whether ad libitum feeding will encourage higher feed intake than feeding to appetite either wet or dry.


1998 ◽  
Vol 1998 ◽  
pp. 130-130 ◽  
Author(s):  
J. J. Hyslop ◽  
A. L. Tomlinson ◽  
A. Bayley ◽  
D. Cuddeford

Many mature, non-pregnant, non-lactating equids are often kept in circumstances where they are expected to perform only light physical work or activity eg: a childs pony. Consequently their maintenance energy and protein needs can often be met at very restricted feed intake levels. Conversely, when they are housed during the winter months it is believed desirable to manage such animals on unrestricted ad libitum feeding regimes in order to allow the animals to exhibit their natural feed intake pattern and consume forage on a little and often basis throughout the daily feeding period. However, ad libitum access to the diet may lead to such animals becoming excessively fat. These conflicting needs of low energy and protein requirement coupled with the desirability of unrestricted access to the diet could both be met, at least in part, if a low quality forage is available ad libitum. This study examines the voluntary feed intake and apparent digestibility in vivo of a mature threshed grass hay offered ad libitum and determines its ability to meet the predicted energy and protein needs of mature ponies.


Rangifer ◽  
1993 ◽  
Vol 13 (3) ◽  
pp. 91 ◽  
Author(s):  
J. M. Suttie ◽  
R. G. White ◽  
T. R. Manley ◽  
B. H. Breier ◽  
P. D. Gluckman ◽  
...  

Growth in temperate and arctic deer is seasonal, with higher growth rates in spring and summer while growth rates are low or negative in autumn and winter. We have measured IGF1 concentrations in the plasma of reindeer calves exposed to a manipulated photoperiod, indoors, of either 16 hours light followed by 8 hours dark each day (16L:8D) (n = 3) or 8L:16D (n = 3) from about the autumnal to the vernal equinox, to determine whether the seasonal growth spurt normally seen in spring is associated with changes in the circulating level of IGF1. A high quality concentrate diet was available ad libitum. The animals were weighed, and bled every 2 weeks and plasma samples assayed for IGF1 by radioimmunoassay. 6-8 weeks after the start of the study those calves exposed to 16L.-8D showed a significant increase in plasma IGF1 concentration which was maintained until the close of the experiment, 24 weeks after the start. In contrast IGF1 plasma concentrations in those calves exposed to a daylength of 8L:16D did not significantly alter during the study. The elevated IFG1 in the 16L:8D group was associated with rapid weight gain compared with the 8L:16D group. We have shown that the seasonal growth spurt is preceded by an elevation in plasma IFG1 concentration. Further, this elevation in IGF1 is daylength dependent. For comparison IGF1 and growth rate seasonal profiles from temperate and tropical deer are included. This comparison reveals that seasonal increases in IGF1 take place only in animals with a seasonal growth spurt. Thus IGF1 plasma level elevations seem most closely associated with the resumption of rapid growth in spring following the winter.


2002 ◽  
Vol 2002 ◽  
pp. 155-155
Author(s):  
J. J. Hyslop ◽  
B. A. Hedley ◽  
R. Keatinge ◽  
D. G. Chapple

An understanding of the dry matter intake (DMI) capacity of suckler cows is crucial to the provision of adequate nutrition during lactation. However, quantitative data on the likely feed intake patterns of modern continental x dairy suckler cow genotypes is scarce. The objective of the current experiment was to determine voluntary DMI in Simmental x Holstein/Friesian (SIM) and Belgian Blue x Holstein/Friesian (BB) autumn calving suckler cows offered a grass silage based diet ad libitum.


1994 ◽  
Vol 34 (8) ◽  
pp. 1107 ◽  
Author(s):  
TJ Johnson ◽  
SG Gherardi ◽  
S Dhaliwal

Young cashmere bucks (n = 113; offspring of mating of domesticated mainland feral does with commercial mainland, Bernier, and Faure Island bucks) were offered a high protein-high energy pelleted diet of lucerne chaff, lupin seed, and barley grain [crude protein, 202 kg; dry matter (DM) solubility, 75.0%] or a low protein-low energy diet of oaten chaff and oat grain (crude protein, 71 kg; DM solubility, 59.6%) ad libitum in groups (n = 4-8) from 14 January to 17 December 1987. Intakes and liveweight gains were measured for January-April, May-July, and August-December. Total fibre and cashmere production (weight, fibre diameter, yield) were recorded at shearing in June, October, and December. Faure bucks produced 34 and 64% more (P<0.05) cashmere on the high, than the low, quality diet at shearings in June and December, respectively; Bernier bucks produced twice as much (P<0.05) cashmere on the high quality diet at the October shearing. Mainland bucks produced similar amounts of cashmere on both diets at each shearing. The fibre produced on the high quality diet had a lower yield of cashmere and the cashmere had a greater diameter at shearings in June (26.0 v. 41.1% w/w, 16.7 v. 15.8 pm; both P<0.001) and December (22.1 v. 27.0% w/w, P<0.05; 16.9 v. 16.4 pm, P<0.01). The cashmere produced by Faure bucks was, on average, 1.0 pm coarser than that of the mainland and Bernier bucks at each shearing. Liveweights of bucks followed a seasonal pattern and increased at a faster rate in January-April and August-December than in May-July. Liveweight gains adjusted for body sizes were greater (P<0.001) for bucks on the high, than the low, quality diet in January-April (2.85 v. 1.71 g/kg LW0.75.day) and, conversely, lower (P<0.05) in August-December (1.49 v. 1.69 g/kg LW0.75.day) . Liveweight gains of all 3 genotypes adjusted for body sizes were markedly lower (P<0.05) in May-July, irrespective of diet (0.75 and 0.55 g/kg LW0.75.day for the high and low quality diet, respectively), with the exception of Bernier bucks on the high quality diet (1.67 g/kg LW0.75.day). The lower liveweight gains were not associated with decreases in the intakes of the diets. These results indicate that diet quality affects cashmere production and growth of Western Australian cashmere goats.


1968 ◽  
Vol 10 (4) ◽  
pp. 345-357 ◽  
Author(s):  
D. J. A. Cole ◽  
J. E. Duckworth ◽  
W. Holmes ◽  
A. Cuthbertson

1. Over the weight range 23–50 kg live weight, pigs were fed either ad libitum or to a restricted scale. From 59 to 91 kg live weight, eight pairs of barrows and eight pairs of gilts were fed on each of two diets varying in nutrient density. The effects of feed restriction, nutrient density of the diet and sex on voluntary feed intake, performance and carcass characteristics were studied.2. Pigs which had been restricted grew more slowly and contained less fat and more lean at 50 kg live weight.3. When restricted pigs were offered feed ad libitum from 59 to 91 kg live weight they ate more and had higher daily intakes of digestible energy than pigs liberally fed in early life.4. There was evidence of compensatory growth in pigs which had received the restricted diet, but there was no significant difference in feed utilization between restricted and ad libitum pigs. It was concluded that the compensatory growth was largely the result of increased appetite.5. Pigs finally fed on a low energy diet, in comparison with those on a high energy diet, ate more feed but less digestible energy indicating that appetite was physically limited. Efficiency of conversion of digestible energy to live weight was similar on both treatments. A higher proportion of acetic acid was produced in the caecum of pigs fed the low energy diet. Pigs receiving the low energy diet had lower killing-out percentages not entirely caused by differences in the weight of the gut and its contents. The carcasses of pigs on the low energy diet were leaner than those on the high energy diet.6. Barrows consumed more digestible energy per day than gilts, required more feed and digestible energy per unit live-weight gain, had lower killing-out percentages, shorter carcasses, larger backfat measurements and smaller eye-muscle areas as estimated by A × B measurements. Barrow carcasses contained less dissected lean and more fat than gilts' carcasses.7. The results are discussed in relation to other work and it is concluded that voluntary feed intake is influenced by the nutrient density of the diet and the level of energy requirement of the pig, which may be affected by previous nutritional history.


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