Pathogen-induced anorexia: a herbivore strategy or an unavoidable consequence of infection?

2014 ◽  
Vol 54 (9) ◽  
pp. 1190 ◽  
Author(s):  
Ilias Kyriazakis
Keyword(s):  
Immune Response ◽  
Food Intake ◽  
Feeding Behaviour ◽  
Infected Animal ◽  
Energy Content ◽  
Poor Quality ◽  
Low Energy ◽  
High Quality ◽  
Model Predictions ◽  
Voluntary Food Intake

A reduction in voluntary food intake is a common feature of infection with pathogens and is frequently referred to as pathogen-induced anorexia. Anorexia has been previously viewed either as an unavoidable consequence of infection or as an animal strategy that enables them to cope with the consequences of infection. Both approaches lead to certain expectations as far as the characteristics of anorexia are concerned. By linking anorexia to host immune response one should be able to make predictions about when and for how long anorexia would occur. By appreciating what an infected animal is trying to achieve through its feeding behaviour, one would be able to make predictions about the extent of anorexia on different quality foods. The thesis of the paper is that these approaches should no longer be viewed as mutually exclusive, but, by combining them, one should be able to make pathogen-induced anorexia more predictable. This is done in the development of a model that aims to predict the food intake of grazing sheep exposed to an abomasal parasite. The predictions of the model are consistent with the features and consequences of parasite-induced anorexia of sheep given access to moderate and high quality foods. However, there is a degree of uncertainty about the validity of predictions made by the model on anorexia seen on poor quality foods of low energy content. This is not a deficiency of the model developed but can be attributed to the lack of appropriate experiments against which model predictions can be tested.

The effect of restricted access to food on the voluntary food intake of pigs

1978 ◽  
Vol 90 (1) ◽  
pp. 77-82
Author(s):  
D. Wyllie ◽  
J. B. Owen
Keyword(s):  
Food Intake ◽  
Food Access ◽  
Energy Content ◽  
Low Energy ◽  
Strong Reaction ◽  
Time Period ◽  
Obese Rats ◽  
Access To Food ◽  
Low Energy Diet ◽  
Voluntary Food Intake

SUMMARYTwo experiments were carried out to examine the effects of restricted food access on the voluntary food intake of pigs given diets of varying energy content or palatability. Where pigs were offered access to food for a restricted time period each day, the voluntary food intake was reduced in relation to the length of access allowed. Compensation was slow, particularly where a low-energy diet was fed. Younger pigs (35–45 kg) compensated faster than heavier pigs (100–110 kg). The responses of the heavier pigs appeared to be similar to those reported for genetically obese rats in their strong reaction to diets of different energy content or palatability.

Short-term feeding behaviour of dairy cows relative to food composition and stage of lactation

1998 ◽  
Vol 1998 ◽  
pp. 25-25
Author(s):  
B.L. Nielsen ◽  
N.C. Friggens ◽  
I. Kyriazakis ◽  
B.J. Tolkamp ◽  
G.C. Emmans
Keyword(s):  
Food Intake ◽  
Dairy Cows ◽  
Feeding Behaviour ◽  
Food Composition ◽  
Short Term ◽  
Physiological Mechanisms ◽  
Stage Of Lactation ◽  
Behavioural Characteristics ◽  
Major Factors ◽  
Voluntary Food Intake

Short-term feeding behaviour (STFB) has been used to elucidate the physiological mechanisms which control eating. It has been proposed as a means by which to predict voluntary food intake, and could be used to quantify behavioural characteristics of the cow. The first step in assessing the usefulness of STFB for these purposes is to identify the major factors which influence STFB. The aim of the study reported here was to evaluate, in dairy cows, the differences in STFB resulting from two different foods, the effect of stage of lactation on STFB, and the effect on STFB of changing from one food to another.

scholarly journals On the quality of Svalbard reindeer pasture in the summer and autumn

Rangifer ◽  
1984 ◽  
Vol 4 (1) ◽  
pp. 16 ◽  
Author(s):  
Hans Staaland
Keyword(s):  
Fatty Acids ◽  
Food Intake ◽  
Energy Content ◽  
Late Summer ◽  
Ether Extract ◽  
High Quality ◽  
Svalbard Reindeer ◽  
Protein Fiber ◽  
Pasture Plants

<p>Late summer and autumn reindeer pasture plants from Adventdalen, Svalbard were analyzed for contents of fatty acids, energy content, protein, fibre, ether extract as well as content of macro minerals. Food intake of grazing reindeer in Adventdalen was estimated from fecal production. Large intake of high quality food seems to account for the growth and fattening of Svalbard reindeer during summer.</p><p>Om kvaliteten p&aring; reinbeite av reinbeite p&aring; Svalbard sommer og h&oslash;st.</p><p>Abstract in Norwegian / Sammendrag: Innholdet av fettsyrer, energi, protein, fiber, eterekstrakt og makromineraler ble analysert i reinbeiteplanter fra Adventdalen p&aring; Svalbard. Plantene ble samlet p&aring; ettersommeren. Forinntaket hos beitende rein i Adventdalen ble estimert ut fra fecesproduksjonen. Et stort inntak av for med h&oslash;y kvalitet synes &aring; kunne forklare vekst og fettlagring hos Svalbard-reinen om sommeren.</p><p>Huippuvuorten poronlaidunten laadusta kesalla ja syksylla.</p><p>Abstract in Finnish / Yhteenveto: Rasvahappojen, energian, fiiberin, eetteriuutteen ja makromineraalien sisaltoa analysoitiin poronlaidunkasveissa Huippuvuorten Adventtilaaksosta. Kasvit kerattiin loppukesalla. Adventtilaaksossa laiduntavien porojen rehun kulunki arvioitiin lannan maarasta. Korkealaatuisen rehun suuri kulutus nayttaa vovan selittaa Huippuvuorten porojen kasvun ja rasvakerrostuman kesalla.</p>

scholarly journals In silicoexploration of the mechanisms that underlie parasite-induced anorexia in sheep

2011 ◽  
Vol 106 (7) ◽  
pp. 1023-1039 ◽  
Author(s):  
Yan C. S. M. Laurenson ◽  
Stephen C. Bishop ◽  
Ilias Kyriazakis
Keyword(s):  
Experimental Data ◽  
Food Intake ◽  
Protein Content ◽  
Energy Content ◽  
Direct Reduction ◽  
Food Composition ◽  
Low Energy ◽  
Published Data ◽  
Teladorsagia Circumcincta ◽  
Consequent Reduction

A model was used to investigate two mechanisms describing reductions in food intake (anorexia) observed during gastrointestinal parasitism in lambs, and to explore relationships between anorexia and food composition. The mechanisms were either a reduction in intrinsic growth rate, leading to a consequent reduction in food intake (mechanism 1; M1), or a direct reduction in food intake (mechanism 2; M2). For both mechanisms, lambs growing from 2 to 6 months of age were modelled, with one of three levels of trickle challenge withTeladorsagia circumcincta. Scenarios were simulated for feeds varying in either protein or energy content, or both. Major differences were found between the predictions resulting from M1 and M2 on low-energy foods that constrained the intake of uninfected lambs through bulk. With M1, food intake was governed by the first operating constraint, whereas with M2 an additivity of constraints was observed. On the other foods, the duration of anorexia increased with increasing energy content of feed for M1, whilst the duration of anorexia decreased with increasing protein content of feed for M2.For foods that did not have an impact upon lambs' gastrointestinal tract capacity, published data were consistent with predictions of M2. Due to an absence of experimental data, no conclusions could be drawn for relationships between anorexia and food composition in the presence of other limiting constraints, such as bulk for low-energy foods. In conclusion, available experimental data and model predictions were consistent with anorexia having an impact directly on food intake, and with impacts of anorexia increasing with decreasing protein content.

Influence of high ambient temperatures on food intake and feeding behaviour of multiparous lactating sows

2000 ◽  
Vol 70 (3) ◽  
pp. 471-479 ◽  
Author(s):  
N. Quiniou ◽  
D. Renaudeau ◽  
S. Dubois ◽  
J. Noblet
Keyword(s):  
Food Intake ◽  
Ambient Temperature ◽  
Dietary Protein ◽  
Feeding Behaviour ◽  
Meal Size ◽  
Lactation Period ◽  
Large White ◽  
Significant Difference ◽  
Ad Libitum ◽  
Voluntary Food Intake

AbstractForty multiparous Large White sows were used to investigate the effects of five ambient temperature levels (18, 22, 25, 27, and 29°C) and two dietary protein contents on their feeding behaviour during lactation. At each temperature treatment, ambient temperature was kept constant over the 21-day lactation period. Dietary protein content was either 140 or 170 g/kg with essential amino acids levels calculated to he non-limiting. Photoperiod was fixed to 14 h of artificial light. The animals were given food ad libitum between the 7th and the 19th day of lactation. Feeding behaviour was not influenced by diet composition. Over the 13 days under ad libitum feeding conditions, voluntary food intake decreased from 7·80 to 3·50 kg/day between 18 and 29°C, which was achieved through a decreased daily number of meals at the highest temperature (6·8 to 4·5 at 18 and 29°C, respectively). No significant difference among temperatures was observed on meal size, even if the highest (1372 g) and the lowest (883 g) values were obtained at 18 and 29°C, respectively. Rate of food intake was not influenced by temperature and averaged 133 g/min; consequently, decreased voluntary food intake under heat exposure resulted in reduced ingestion time (61 and 29 min/day at 18 and 29°C, respectively). Hourly food intake peaked at the beginning and the end of the light period. It resulted in a mainly diurnal partition of food intake. This partition was significantly affected by temperature as proportionately 0·87 and 0·91 of total food intake occurred during the day at 27 and 29°C, respectively, v. 0·81 on average between 18 and 25°C. Number of meals was lower during the night (1·1 v. 5·2 during the day on average); it decreased with increased temperature both during the day and the night. Meal size was lower during the night (938 v. 1080 g during the day on average). The ratio between water and food intake was significantly higher at 29°C (8·1 v. 4·2 l/kg on average between 18 and 27°C). Standing activity averaged 124 min/day with no significant difference between temperatures.

The prediction of the voluntary food intake of pigs on poor quality foods

1998 ◽  
Vol 66 (3) ◽  
pp. 713-723 ◽  
Author(s):  
L. N. Tsaras ◽  
I. Kyriazakis ◽  
G. C. Emmans
Keyword(s):  
Food Intake ◽  
Prior Experience ◽  
Live Weight ◽  
Poor Quality ◽  
Crude Fibre ◽  
Acid Detergent Fibre ◽  
Ad Libitum ◽  
Dry Food ◽  
Highly Correlated ◽  
Voluntary Food Intake

AbstractAn experiment was carried out to investigate the proposal that the voluntary food intake of pigs, when given foods based on bulky materials, can be accurately predicted from the water-holding capacity (WHC, g water per g dry food) values of the foods. A basal food (B), with 12·9 MJ digestible energy and 249 g crude protein per kg dry matter, was diluted to two extents by either sugar-beet pulp (S), grass meal (G) or soya hulls (H). The contents of the bulky materials in the total diets were either 320 g/kg (foods BS, BG and BH) or 800 g/kg (foods S, G and H). Each of these six foods was givenad libitumto six pigs in period I, which lasted for 21 days, with a further four given B. In period II, which lasted for 14 days and followed period I immediately, the pigs were also given their food ad libitum. Only the 36 pigs from the six ‘bulky“treatments (i.e. on treatments other than B) continued in a change-over design. Two pigs from each of the six ‘bulky’ treatments were allocated to the three foods of the same level of dilution (e.g. the six pigs from BS were changed to BS, BG and BH). Of the ‘bulk’ characteristics measured (crude fibre, acid-detergent fibre, neutral-detergent fibre, apparent digestibility of the organic matter, density and WHC) only WHC accounted sufficiently for the effects of the foods on the voluntary food intake of the pigs. The two methods of centrifugation and filtration that were used for the WHC determination were very highly correlated (r = 0·978), with food B having the lowest value, 3·86 g water per g dry food, and food S having the highest value, 8·48 g water per g dry food, when measured by centrifugation. In both periods the rate of intake was calculated as g/kg live weight per day, scaled intake (SFI). Live-weight gain and food conversion efficiency both decreased significantly (P< 0·001) as B was diluted with S, G and H. For the six ‘bulky’ feeding treatments SFI in the last 14 days of period I was proportional to the reciprocal of the WHC of the foods: SFI (g/kg per day) = 235 (s.e. 6·3). No effects of previous feeding treatment on site were observed in period II as a whole; however, intake initially increased when the food had lower WHC than the one previously offered and decreased when it had higher WHC. It was concluded that: (a) the WHC of a food is a sufficient descriptor of its ‘bulk’ and that it accounts for the effects on the voluntary food intake of pigs; (b) the detailed methods used for measuring WHC need to be standardized; (c) pigs can adapt more rapidly to bulky foods when they have had prior experience of such foods; (d) the length of time needed to observe an intake, which will be characteristic of the bulky food on offer, depends on the prior experience of the pig.

Relationships among reproductive status, nutritional status, and food characteristics in a natural population of Peromyscus maniculatus

1991 ◽  
Vol 69 (3) ◽  
pp. 555-559 ◽  
Author(s):  
John S. Millar ◽  
Xuhua Xia ◽  
Michael B. Norrie
Keyword(s):  
Food Intake ◽  
Nutritional Status ◽  
Alimentary Tract ◽  
Peromyscus Maniculatus ◽  
Natural Populations ◽  
Poor Quality ◽  
Low Energy ◽  
Reproductive Status ◽  
Energy Reserves ◽  
Lactating Females

We compared digestibility of consumed food, dimensions of the alimentary tract, body fat and body size in relation to sex and reproductive status of overwintered adult Peromyscus maniculatus to assess the applicability of these measures of food intake and nutritional status to natural populations. Nonbreeding females were smaller than other sex and reproductive categories, but they had the largest alimentary tracts and energy reserves for their size. Lactating females were large, but they had low energy reserves and only averaged-sized alimentary tracts. Nonbreeding males ate relatively poor quality foods, had the smallest alimentary tracts for their size, and had low energy reserves. Most of these patterns were interpretable based on the known biology of this population. We conclude that these measures can provide insights into intraspecific variation in food intake and nutritional status in natural populations of Peromyscus.

scholarly journals Nutrition al manipulation of feeding behaviour of birds

2021 ◽  
Vol 38 (2) ◽  
pp. 46-56
Author(s):  
E. J. Ubah ◽  
F. O. Abeke ◽  
I. I. Madziga
Keyword(s):  
Feed Intake ◽  
Feeding Behaviour ◽  
Laying Hens ◽  
Energy Content ◽  
Eating Behaviour ◽  
Low Energy ◽  
Free Access ◽  
Passage Rate ◽  
Eating Time ◽  
Rate Experiment

 A research to manipulate the feeding behaviour of laying hens from nutritional perspective was conducted with 504 ISA Brown. Seventeen (17) week old ISA brown with weights ranging between 1590 and 1812 g were allocated to six dietary treatments. There were seven replicates per treatment with 12 birds each making a total of 42 pens in all. Experimental diets differed in the levels of energy, levels insoluble Non Starch Polysaccharide (NSP) and the particle sizes of the NSP. Birds had free access to water and feed during which feeding observations with video cameras were made to observe and record the feeding behaviour of birds at 17, 21, 25, 29, 33 and 35 weeks of age. A computer software programme called Observer 5.0 was used to analyze the observations by one person for 30 minutes per cage. In order to gain more insight in the feeding behaviour of laying hens, 60 laying hens were used for a passage rate experiment using titanium dioxide as an inert marker: Five birds were used for each dietary treatment, and replicated twice. At t=0, three titanium capsules were offered to each bird. After five different time points (30, 90, 180, 270 and 360 minutes), these birds were sacrificed and dissected. The gut (titanium) contents from different segments of the GIT (crop, gizzard, ileum, colon and caeca) of each bird were analysed using spectrophotometer at an absorbance of 408 nm. Results from the study indicate that the feeding behaviour of laying hen can be manipulated nutritionally. Bulky diets (10.6 MJ/kg) significantly (P<0.05) increased the eating time of laying hens by 15% compared with normal energy content (11.8 MJ/kg) and this led to consumption of more feed (average 2355g) than those of normal energy diets (2175g). Similarly, the separate effect of NSP, NSP coarseness and interaction between low energy; NSP and NSP coarseness influenced the eating behaviour. Feeding layers with low density diet containing a combination of low energy high NSP coarse NSP increased the amount of time birds spent feeding by 32% and consequently increased the feed intake by 11% (average feed intake of 135g ) above normal energy low NSP mixture diet (average feed intake of 120g). The passage rate experiment showed that Low energy High non starch polysaccharide coarse (LeHnspcoarse) diet reduces the gut transit time, thus birds quickly feel hungrier after a period of satiety, possibly resulting in a short inter-meal interval. Conclusively, the interaction between low energy, high NSP and NSP coarseness influence birds' feeding behaviour necessitating increase in eating time and faster passage rate via the GIT  

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.

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