Photoperiodic entrainment of seasonal changes in appetite and growth in pony colts

1998 ◽  
Vol 1998 ◽  
pp. 133-133
Author(s):  
Z. Fuller ◽  
J.E. Cox ◽  
C. McG. Argo
Keyword(s):  
Food Intake ◽  
Seasonal Changes ◽  
Environmental Pressures ◽  
Ambient Temperatures ◽  
Forage Availability ◽  
Photoperiodic Regime ◽  
Gross Energy ◽  
Ad Libitum ◽  
Pelleted Diet ◽  
Voluntary Food Intake

During winter, voluntary food intake (VFI) and growth decreased in light horse weanlings given ad libitum access to a forage/concentrate diet (Cymbaluk et al, 1989). These changes were attributed to decreased ambient temperatures. However, photoperiodically entrained seasonal changes in VFI and growth are documented in other Northern ungulates (Moen, 1978) and may comprise an adaptation to changes in forage availability. Throughout their evolution, horses experienced similar environmental pressures and may demonstrate similar photoperiodic adaptations. This study characterised changes in VFI and growth in pony colts maintained under an artificial photoperiodic regime.Seven, 2 year-old pony colts of Welsh Mountain type (182.4 ± 5.4 kg), were obtained from pasture (53°N). Animals were individually housed in loose-boxes, within a light-proof building. Measured quantities of a complete pelleted diet (gross energy = 16.7 MJ.kgDM-1), calculated to exceed appetite by at least 1 kg, were offered daily.

Photoperiodic entrainment of seasonal changes in appetite and growth in pony colts

1998 ◽  
Vol 1998 ◽  
pp. 133-133
Author(s):  
Z. Fuller ◽  
J.E. Cox ◽  
C. McG. Argo
Keyword(s):  
Food Intake ◽  
Seasonal Changes ◽  
Environmental Pressures ◽  
Ambient Temperatures ◽  
Forage Availability ◽  
Photoperiodic Regime ◽  
Gross Energy ◽  
Ad Libitum ◽  
Pelleted Diet ◽  
Voluntary Food Intake

During winter, voluntary food intake (VFI) and growth decreased in light horse weanlings given ad libitum access to a forage/concentrate diet (Cymbaluk et al, 1989). These changes were attributed to decreased ambient temperatures. However, photoperiodically entrained seasonal changes in VFI and growth are documented in other Northern ungulates (Moen, 1978) and may comprise an adaptation to changes in forage availability. Throughout their evolution, horses experienced similar environmental pressures and may demonstrate similar photoperiodic adaptations. This study characterised changes in VFI and growth in pony colts maintained under an artificial photoperiodic regime.Seven, 2 year-old pony colts of Welsh Mountain type (182.4 ± 5.4 kg), were obtained from pasture (53°N). Animals were individually housed in loose-boxes, within a light-proof building. Measured quantities of a complete pelleted diet (gross energy = 16.7 MJ.kgDM-1), calculated to exceed appetite by at least 1 kg, were offered daily.

Photoperiodic entrainment of seasonal changes in the appetite, feeding behaviour, growth rate and pelage of pony colts

2001 ◽  
Vol 72 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Z. Fuller ◽  
J. E. Cox ◽  
C.McG. Argo
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Feeding Behaviour ◽  
Average Daily Gain ◽  
Day Length ◽  
Individual Values ◽  
Weight Density ◽  
Photoperiodic Regime ◽  
Pelleted Diet ◽  
Voluntary Food Intake

AbstractRelationships among photoperiod and changes in voluntary food intake, feeding behaviour, growth and pelage were determined in seven, 2-year-old pony colts (182·4 (s.e. 5·4) kg). Individually housed colts were provided with ad libitum access to a complete pelleted diet (gross energy = 16·7 MJ/kg dry matter). Voluntary food intake (VFI, kg/ day) was calculated daily and body weights were recorded weekly throughout the 36-week study. Feeding behaviour was evaluated at approximately 4-week intervals by continuous observation (24 h), and the hair weight density (HWD, mg/cm2) of shoulder pelage was determined fortnightly. Day length was artificially manipulated to mimic the prevailing mid-summer photoperiod (16 h light: 8 h dark, 16L: 8D). After 1 week of the study (and the preceding fortnight), day length was abruptly decreased and thereafter animals were exposed to alternating 14-week periods of short (SD, 8L: 16D) and long days (LD, 16L: 8D). The mean daily VFI of individual ponies was calculated weekly and normalized for digestible energy (DE) content and metabolic body weight (DEI, MJ/kg M0·75). The average daily gain (ADG, kg/day) in body weight of each individual was calculated weekly. The apparent digestibility of dietary energy (digestibility) was determined over 72 h (no. = 6) on two occasions (days 92 to 95 and 190 to 193) during the study. Digestibility was similar in both periods (0·48, s.e. 0·01). DEI, ADG and HWD changed in a cyclic manner throughout the study. The period of the appetite cycle (24·4 (s.e. 1·3) weeks) did not differ from that of the 28-week photoperiodic regime. DEI decreased from a maximum of 1·4 (s.e. 0·03) MJ/kg M0.75 per day (day 21), to a nadir of 0·75 (s.e. 0·02) MJ/kg M0.75 per day (day 154, P < 0·001) and had increased (P < 0·001) to attain a second zenith (0·93 (s.e. 0·01) MJ/kg M0.75 per day) before the end of the study. Ponies ate discrete meals of similar duration, but meal frequency was associated with changes in VFI (r = 0·77) as was proportion of time spent feeding (r = 0·79). Changes in ADG reflected those of DEI. Body weight was stable for 4 weeks at the nadir of the appetite cycle. Maximal HWD was coincident with the nadir of the appetite and growth cycles. Regression of individual values for DEI on ADG described a linear relationship (R2 = 0·80) which could be used to predict the energy requirements of growing ponies maintained under similar conditions:DEI total (MJ/kg M0·75 per day) = 0·654ADG (kg/day) + 0·789 (1).The duration of the photoperiod, appetite, growth and pelage cycles were similar, suggesting a causal relationship. Physiological responses to photoperiodic change were not immediate and exhibited a delay of 5 to 8 weeks.

Effect of diurnally fluctuating high ambient temperatures on performance and feeding behaviour of multiparous lactating sows

2000 ◽  
Vol 71 (3) ◽  
pp. 571-575 ◽  
Author(s):  
N. Quiniou ◽  
D. Renaudeau ◽  
S. Dubois ◽  
J. Noblet
Keyword(s):  
Food Intake ◽  
Milk Production ◽  
Feeding Behaviour ◽  
Post Partum ◽  
Lactation Performance ◽  
Large White ◽  
Ambient Temperatures ◽  
Total Food Intake ◽  
Daily Food ◽  
Ad Libitum

AbstractForty-two multiparous Large White sows were used to investigate the effect of diurnally fluctuating temperature (T) on lactation performance and feeding behaviour. The animals were allocated to one of the four thermic treatments: constant T at 25°C (25C) and 29°C (29C) or equal-mean diurnal cyclic T varying from 21 to 29°C (25V) and from 25 to 33°C (29V). Photoperiod was fixed to 14 h of light. The sows were given food ad libitum between the 7th and the 19th day post partům. Lactation performance was measured for all sows whereas the feeding behaviour was recorded only on 28 sows. The ad libitum food intake was comparable at 25C and 25V (6•31 kg/day) as were milk production and body reserves mobilization. In contrast, food intake at 29V was higher than at 29C (4•53 v. 3•48 kg/day) with no difference in milk production between the two treatments. The increased daily food intake at 29V resulted from higher intakes over the coolest periods of the day and especially during the dark period. Neither meal size nor daily number of meals were significantly affected by T. Feeding behaviour was mainly diurnal but with differences between treatments: 0•90 of total food intake at 29C v. 0•78 at the other three T It appears that the effects of diurnally fluctuating T on lactation performance of sows depend on the mean level of T

Growth and herbage consumption of grazing Merino and Border Leicester lambs reared by their mothers or fostered by ewes of the other breed

1972 ◽  
Vol 14 (3) ◽  
pp. 317-322 ◽  
Author(s):  
J. P. Langlands
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Milk Production ◽  
Live Weight ◽  
The Other ◽  
Weight Gains ◽  
Ad Libitum ◽  
Voluntary Food Intake

SUMMARYEight Border Leicester castrated male lambs (wethers) were fostered on to 8 Merino ewes (MB) at birth, and 10 Merino wethers were fostered on to Border Leicester ewes (BM). Two additional groups of 10 wethers consisted of Border Leicester lambs (BB) and Merino lambs (MM) reared by their natural mothers. The lambs and ewes grazed together and growth rate, and milk and herbage consumption of the lambs were recorded.Live-weight gains to weaning at 74 days were 275, 245, 204 and 184 g/day for groups BB, MB, BM and MM respectively. Lambs reared by Border Leicester ewes received more milk and consumed less grass than lambs of similar genotype reared by Merinos, but BM lambs consumed less milk than BB lambs. Merino lambs also consumed less grass than Border Leicester lambs.It was concluded that Merinos grew more slowly than Border Leicester lambs primarily because of their lower voluntary food intake. The lower milk production of Merino ewes was considered to be of secondary significance since if herbage is available ad libitum, lambs with high voluntary intakes will compensate for the lack of milk by consuming more forage.

A comparison of the seasonal hormone changes and patterns of growth, voluntary food intake and reproduction in juvenile and adult red deer (Cervus elaphus) and Père David's deer (Elaphurus davidianus) hinds

1989 ◽  
Vol 122 (3) ◽  
pp. 733-745 ◽  
Author(s):  
A. S. I. Loudon ◽  
J. A. Milne ◽  
J. D. Curlewis ◽  
A. S. McNeilly
Keyword(s):  
Food Intake ◽  
Breeding Season ◽  
Seasonal Changes ◽  
Red Deer ◽  
Species Differences ◽  
Energy Utilization ◽  
Significant Advance ◽  
Plasma Prolactin ◽  
Père David’S Deer ◽  
Voluntary Food Intake

ABSTRACT Non-domesticated seasonally breeding ungulates exhibit marked seasonal changes in metabolic rate, voluntary food intake (VFI), pelage growth and moult and hormone secretion. It is not known whether these seasonal rhythms are regulated by the same central processes which control the onset and termination of the breeding season. Here we compare two closely related deer species which have significantly different mating and calving seasons. Seasonal changes in VFI, liveweight, coat growth, plasma prolactin and tri-iodothyronine (T3), and the timing of the breeding season were examined over a 15-month period in six adult post-pubertal red and Père David's deer from January to April the following year. The timing of the seasonal changes in prolactin, T3, VFI and coat growth were all significantly advanced by 56, 23, 60 and 54 days respectively in the Père David's deer. The times of onset and termination of the breeding season of Père David's deer were also significantly advanced by 90 days, but in both species, the breeding season was of similar duration (160 ± 5 (s.e.m.) days). Changes in liveweight of adult red deer could be explained by changes in VFI rather than efficiency of utilization. This was not the case in Père David's deer and may indicate seasonal changes in the efficiency of energy utilization. In order to establish whether these species differences develop with age, we undertook a second study in which seasonal changes in VFI, growth, plasma prolactin concentrations and the timing of the onset of the breeding season were recorded for ten red deer and six Père David's deer from 6 to 18 months of age. Both species exhibited a similar decline in VFI in the first autumn of life. Subsequently, the Père David's deer exhibited an advance in the timing of the seasonal peak in VFI and prolactin (21 and 66 days respectively); puberty occurred 3 months earlier than in red deer. The earlier breeding season of the Père David's deer was associated with a significant advance in a range of seasonal endocrine and physiological parameters. These species differences may develop with age. Our data indicate that seasonal patterns of metabolism and growth may be closely linked to those mechanisms which also regulate the onset and termination of the breeding season. Journal of Endocrinology (1989) 122, 733–745

Inter-age correlations of body weight, weight gain and food intake within and between breeds of cattle

1985 ◽  
Vol 40 (1) ◽  
pp. 23-32 ◽  
Author(s):  
R. B. Thiessen
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
Daily Intake ◽  
Average Daily Intake ◽  
Daily Food ◽  
Ad Libitum ◽  
Pelleted Diet ◽  
Very High ◽  
High Range

ABSTRACTIn a multibreed experiment, 292 heifers from 25 British cattle breeds were fed a standard pelleted diet ad libitum from 12 to 72 weeks of age. Inter-age correlations involving body weight, weight gain, average daily food intake and cumulated food intake were measured across traits at the same age and within and across traits at ages separated by an interval of 12, 24, 36 and 48 weeks. Within-breed correlations were phenotypic but between-breed correlations were genetic.The between-breed inter-age correlations involving body weight, cumulated intake and average daily intake were all very high (range 104 to 0·94) and declined only gradually as the intervening age interval increased from 12 to 48 weeks. Inter-age correlations involving weight gain were lower but usually above 0·7. The within-breed correlations by contrast were invariably lower and declined much more rapidly as the age interval increased. Although the between-breed and within-breed correlations differed in magnitude there was a similarity in their overall pattern.For breed samples, body weight at young ages provided very accurate rankings at later ages for body weight, cumulated intake and average daily intake. Body weight was almost as reliable as food intake itself for predicting cumulated intake.For individuals within breeds predicted rankings at later ages were not very accurate for body weight or cumulated intake and they became worse as the age interval increased. Neither weight gain nor average daily intake could be predicted with any reliability.Inter-age correlations while dependant on age interval did not depend on age itself in the case of body weight and cumulated intake, although they were age-dependant for weight gain and to a lesser extent for average daily intake. Reciprocal correlations between body weight and cumulated intake were very symmetrical whereas those involving weight gain and daily intake were asymmetrical.

Interrelationships between physical and metabolic control of voluntary food intake in fattening, pregnant and lactating mature sheep: a model

1977 ◽  
Vol 24 (1) ◽  
pp. 91-101 ◽  
Author(s):  
J. M. Forbes
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Abdominal Fat ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Final Body Weight ◽  
Pregnancy And Lactation ◽  
Endocrine Factors ◽  
Ad Libitum ◽  
Voluntary Food Intake

SUMMARYA model has been developed in which the voluntary food intake of sheep is related directly to metabolizable energy requirements unless physical or endocrine limitations intervene.Although no ‘set point’ for body weight or body fat is incorporated in the model, mature sheep offered food ad libitum are predicted to reach eventually a plateau of body weight due to progressive depression of gut capacity by the increasing volume of abdominal fat. The final body weight is proportional to the digestibility of the diet. During pregnancy and lactation metabolic, physical and endocrine factors interact in such a way as to give predicted patterns of feed intake similar to those observed in practice with several qualities of diet.

Sex and season are major determinants of voluntary food intake in sheep

2001 ◽  
Vol 13 (8) ◽  
pp. 577 ◽  
Author(s):  
Iain J. Clarke
Keyword(s):  
Food Intake ◽  
Recent Work ◽  
Seasonal Changes ◽  
Seasonal Pattern ◽  
Late Summer ◽  
Reduce Food Intake ◽  
Orexigenic Peptide ◽  
The Brain ◽  
Female Sheep ◽  
Voluntary Food Intake

Seasonal changes in voluntary food intake (VFI) are seen in various species, including sheep. This paper reviews recent work in this area, especially in relation to alterations in the expression of appetite-regulating peptides in the brain of the sheep. Work in the hamster is also reviewed because this is another species in which VFI is regulated by photoperiod. In normally grazing sheep, appetite is maximal in the late summer/early autumn and minimal in spring. This appears to be owing to increased expression of the orexigenic peptide, neuropeptide Y. Similar results are obtained in sheep that are subjected to controlled photoperiod. The same does not appear to be true for hamsters. Further work in sheep has shown that there is a seasonal pattern of responsiveness to leptin that is more pronounced in females than in males. In particular, the effect of leptin to reduce food intake is maximal in female sheep in the spring; reasons for the sex difference are discussed.

The effects of food intake during lactation and post weaning on the reproductive performance and hormone and metabolite concentrations of primiparous sows

1996 ◽  
Vol 63 (2) ◽  
pp. 297-306 ◽  
Author(s):  
C. M. Carroll ◽  
P. B. Lynch ◽  
M. P. Boland ◽  
L. J. Spicer ◽  
F. H. Austin ◽  
...  
Keyword(s):  
Food Intake ◽  
Reproductive Performance ◽  
Ovarian Function ◽  
Serum Insulin ◽  
Post Partum ◽  
Corpora Lutea ◽  
Serum Growth Hormone ◽  
Ad Libitum ◽  
Group D ◽  
Voluntary Food Intake

AbstractThe objective of this study was to investigate the effect of low food intake on post-weaning fertility and hormone concentrations in primiparous sows. One hundred and forty primiparous sows (Landrace × Large White) were randomly assigned to one of four treatment groups: (A) restricted to 3 kg food per day during lactation and 2 kg food per day post weaning (no. = 36); (B) restricted to 3 kg food per day during lactation and ad libitum feeding post weaning (no. = 33); (C) ad libitum feeding throughout with a mean voluntary food intake of 3·7 kg/day during lactation (no. = 36); and (D) ad libitum feeding throughout with a mean voluntary food intake of 4·9 kg/ day during lactation (no. = 35). Litters were standardized at eight to 10 pigs at 2 days post partum and were weaned at 27·2 (s.e. 0·5) days post partum. After weaning, sows were observed twice daily for signs of oestrus and were mated on the day(s) of standing oestrus. Six sows from each group were fitted with indwelling jugular cannulae 2 days before weaning. Blood samples were collected 1 day before weaning (W−l), 1 day after weaning (W+l) and 4 days after weaning (W+4), and these sows were slaughtered on W+4. Ovaries were recovered, follicles and corpora lutea were counted, and folUcular fluid collected. Sows given food at a restricted level (groups A and B) lost more backfat during lactation than sows given food ad libitum (groups C and D) (P < 0·01). Piglet weaning weights, weaning to conception intervals and the proportion of sows ovulating by W+4 were not significantly different among groups. In sows that did not ovulate, numbers of large follicles were not significantly different among groups but the low food intake (groups A, B and C) sows had more medium-sized follicles than high food intake (group D) sows (P < 0·01). FolUcular fluid concentrations of oestradiol, progesterone and insulin-like growth factor-1 (IGF-1) did not differ among groups (P > 0·05). Plasma non-esterified fatty acids concentrations were greater in groups C and D than in groups A and B on W−l, W+l and W+4. Serum insulin and plasma glucose concentrations were lower in groups C and D than in groups A and B on W−l and W+l, but were similar among groups on W+4. Serum growth hormone concentrations were lower in group D than group A and B on W−l and W+l but not W+4. Concentrations of IGF-1 in serum were greater in groups C and D than groups A and B on W−l and W+l but not W+4. It is concluded that low food intakes during lactation and post weaning affected body condition, serum hormones and metabolites and ovarian function of primiparous sows without dramatically affecting ovarian hormones or reproductive performance.

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