Do endogenous seasonal cycles of food intake influence foraging behaviour and intake by grazing sheep?

AbstractVoluntary food intake (VFI) of chopped timothy hay and metabolic rate were each measured in each month of the year in six non-breeding ewes of each of three breeds. Metabolic rate was measured using indirect calorimetry over a range of food intakes and adjusted for intake to an estimated maintenance metabolic rate (MMR). The breeds compared were the Dorset Horn (DT), Scottish Blackface (BF) and Shetland (SH), the first being less seasonal in reproductive and other characteristics than the other two which are hill or northern latitude breeds. There was significant overall variation between months in VFI which was higher in the summer (July to September) than in the winter (December to February) months (P < 0·001). There was a significant breed × month interaction (P < 0·01), the seasonal effect being most strongly observed in the BF and SH ewes, whose VFI in summer was proportionately 0-1 greater than the year-round mean but was 0-1 lower in the winter. The DT ewes showed much less seasonal variation in VFI. There was no overall difference in VFI between breeeds (DT: 43-7; BF: 49-5; SH: 48-1 g dry matter per M075 live weight per day, P > 0·1). Although MMR varied significantly between months (P < 0·001), there was no systematic variation between summer and winter. There was no significant breed × month interaction, but the MMR differed significantly (P < 0·001) between breeds giving a high overall MMR in BF (DT: 322-7; BF: 356-6; SH: 324-5 kf/kg M0·75 per day). No significant correlation existed (P > 0·05) between the monthly mean MMR and VFI in any of the breeds. The causal relationship between seasonal cycles of basal metabolic rate and VFI is questioned.

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Seasonal variation in voluntary food intake and post-weaning growth in lambs: a comparison of genotypes

Animal Science ◽

10.1017/s0003356100012782 ◽

1991 ◽

Vol 52 (2) ◽

pp. 279-285 ◽

Cited By ~ 9

Author(s):

G. R. Iason ◽

A. R. Mantecon

Keyword(s):

Seasonal Variation ◽

Food Intake ◽

Live Weight ◽

Normal Rate ◽

Seasonal Cycles ◽

Negative Deviation ◽

Individual Analysis ◽

Growth Regime ◽

Rate Of Increase ◽

Voluntary Food Intake

ABSTRACTVoluntary food intake (VFI) was measured daily and live weight (LW) was measured weekly in a total of 39 growing lambs of six genotypes given a similar complete chopped-straw based diet in experiments in 1983, 1985, 1987 and 1988. The six genotypes and the years of study were: Scottish Blackface (BF), 1983 and 1988; Suffolk × (Border Leicester × BF) (BL × BF), Suffolk × (East Friesland × Cheviot) (EF × NCC), Suffolk × (East Friesland × BF) (EF × BF), 1985; Welsh mountain (WM) and Beulah (BH), 1985. Measurements were made on lambs penned individually within 6 weeks of weaning at 5 to 6 months of age through to slaughter in the following spring. During this period there was an increase in LW and VFI associated with growth. Regression lines were fitted to LW and weekly means of daily VFI against week for each individual. Analysis of deviations about these lines showed a decline in VFI in BF lambs around December and to a lesser e×tent in BL × BF from December to January. The decline in VFI in BF was observed in two different years. A negative deviation from the normal rate of increase in LW was also apparent although it was much less marked and present in EF × NCC lambs as well as BF and BF × NCC. Any such variability of seasonal cycles between genotypes of growing lamb would influence the e×tent to which nutrition and growth may be manipulated. This should be considered when choosing a feeding or growth regime for a particular genotype, or vice versa.

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Differential effects of predation risk and competition over vigilance variables and feeding success in Eurasian siskins (Carduelis spinus)

Behaviour ◽

10.1163/1568539x-00003114 ◽

2013 ◽

Vol 150 (14) ◽

pp. 1665-1687 ◽

Cited By ~ 9

Author(s):

Jordi Pascual ◽

Juan Carlos Senar

Keyword(s):

Food Intake ◽

Predation Risk ◽

Foraging Behaviour ◽

Interference Competition ◽

Ecological Factors ◽

Intake Rate ◽

Similar Length ◽

Feeding Success ◽

High Predation ◽

Food Intake Rate

Many investigations have studied the effects of predation risk and competition over vigilance and feeding success, but they have proven to be difficult to discriminate. Moreover, none of the studies that have avoided the confusion has considered all the vigilance variables, food intake rate and time spent in the foraging patch. In this study, we designed an experiment with Eurasian siskinsCarduelis spinusforaging on three bird table feeders: one with low predation risk and competition, one with low predation risk and high competition and one with high predation risk and intermediate competition. Birds responded to increasing interference competition by increasing mean scan durations (probably due to the birds having to be vigilant for both other flock members and predators) and maintaining the length of mean inter-scan durations, while they responded to increasing predation risk by reducing mean inter-scan durations (probably in order to detect the predator sooner) while maintaining similar length of mean scan durations. Birds were often ejected from the feeder or departed because of disturbances, so time spent on feeders was reduced both because of competition and predation risk. Pecking rates were affected by competition but not by predation risk. Our results clearly show that birds vigilance strategy while foraging might be very different when they are mainly concerned with scanning for predators or when they primarily monitor competing flock companions. In addition, they stress the importance of recording all the vigilance and feeding variables when studying the effect of ecological factors over the foraging behaviour of birds.

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Foraging behaviour of oystercatchers Haematopus ostralegus during a diet switch from worms Nereis diversicolor to clams Scrobicularia plana

Canadian Journal of Zoology ◽

10.1139/z89-314 ◽

1989 ◽

Vol 67 (9) ◽

pp. 2225-2231 ◽

Cited By ~ 15

Author(s):

J. Sherman Boates ◽

John D. Goss-Custard

Keyword(s):

Food Intake ◽

Foraging Behaviour ◽

Capture Rate ◽

Handling Time ◽

Intake Rate ◽

Nereis Diversicolor ◽

Scrobicularia Plana ◽

Haematopus Ostralegus ◽

Food Value ◽

Food Intake Rate

On the mudflats of the Exe Estuary in southwest England, oystercatchers Haematopus ostralegus switched from eating worms Nereis diversicolor to clams Scrobicularia plana during autumn. A decline in the profitability of worms (from 17 to 4 mg/s handling time) and the food intake of oystercatchers eating worms (from 1300 to < 200 mg/15 min) occurred prior to and during the switch to clams. Declines in profitability and food intake rate were due to seasonal changes in the size and food value of worms available to oystercatchers. Capture rate on worms varied little prior to, or during, the switch. Oystercatchers appeared to switch diets in response to changes in the reward offered by worms rather than in response to relative changes in the reward offered by the two prey species. This is because individual oystercatchers were never observed eating a mixed diet of worms and clams, and may explain why it took 6 weeks (11 October to 25 November) for the population to complete the switch.

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Effects of Personality Traits on the Food-Scratching Behaviour and Food Intake of Japanese Quail (Coturnix japonica)

Animals ◽

10.3390/ani11123423 ◽

2021 ◽

Vol 11 (12) ◽

pp. 3423

Author(s):

Xinyu Zhang ◽

Xue Wang ◽

Wei Wang ◽

Renxin Xu ◽

Chunlin Li ◽

...

Keyword(s):

Food Intake ◽

Personality Traits ◽

Japanese Quail ◽

Foraging Behaviour ◽

Coturnix Japonica ◽

Behavioural Syndrome ◽

Foraging Success ◽

Initial Stage ◽

The Impact ◽

Foraging Time

Overall foraging success and ultimate fitness of an individual animal is highly dependent on their food-searching strategies, which are the focus of foraging theory. Considering the consistent inter-individual behavioural differences, personality may have a fundamental impact on animal food-scratching behaviour, which remains largely unknown. In this study, we aimed to investigate how personality traits (i.e., boldness and exploration) affect the food-scratching behaviour and food intake of the domestic Japanese quail Coturnix japonica during the foraging process. The quails exhibited significant repeatability in boldness and exploration, which also constituted a behavioural syndrome. More proactive, that is, bolder and more explorative, individuals scratched the ground more frequently for food and began scratching earlier in a patch. Individuals that scratched more frequently had a longer foraging time and a higher food intake. The correlation between personality traits and temporary food intake during every 2 min varied over time and was sex dependent, with females exhibiting a positive correlation during the first half of the foraging stage and males after the initial stage. These findings suggest that personality traits affect the food-scratching behaviour and, thus, the food intake of quails. Our study provides insights into the impact of personality traits on animal’s foraging behaviour by influencing their food-searching strategies.

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Measuring C. elegans spatial foraging and food intake using bioluminescent bacteria

10.1101/759928 ◽

2019 ◽

Cited By ~ 1

Author(s):

Siyu Serena Ding ◽

Karen S. Sarkisyan ◽

Andre E. X. Brown

Keyword(s):

Food Intake ◽

Foraging Behaviour ◽

Light Emission ◽

Fold Increase ◽

Food Patch ◽

Background Signal ◽

Bioluminescent Bacteria ◽

C Elegans ◽

Tightly Coupled ◽

Lower Background

ABSTRACTFor most animals, feeding includes two behaviours: foraging to find a food patch and food intake once a patch is found. The nematode Caenorhabditis elegans is a useful model for studying the genetics of both behaviours. However, most methods of measuring feeding in worms quantify either foraging behaviour or food intake but not both. Imaging the depletion of fluorescently labelled bacteria provides information on both the distribution and amount of consumption, but even after patch exhaustion a prominent background signal remains, which complicates quantification. Here, we used a bioluminescent Escherichia coli strain to quantify C. elegans feeding. With light emission tightly coupled to active metabolism, only living bacteria are capable of bioluminescence so the signal is lost upon ingestion. We quantified the loss of bioluminescence using N2 reference worms and eat-2 mutants, and found a nearly 100-fold increase in signal-to-background ratio and lower background compared to loss of fluorescence. We also quantified feeding using aggregating npr-1 mutant worms. We found that groups of npr-1 mutants first clear bacteria from each other before foraging collectively for more food; similarly, during high density swarming, only worms at the migrating front are in contact with bacteria. These results demonstrate the usefulness of bioluminescent bacteria for quantifying feeding and suggest a hygiene hypothesis for the function of C. elegans aggregation and swarming.

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Individual differences in sociability and their consequences for foraging behaviour in sheep

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200001307 ◽

2000 ◽

Vol 2000 ◽

pp. 129-129 ◽

Cited By ~ 3

Author(s):

A.M. Sibbald ◽

D.J.F. Smith ◽

R.J. Hooper

Keyword(s):

Spatial Distribution ◽

Individual Differences ◽

Social Behaviour ◽

Foraging Behaviour ◽

Social Motivation ◽

Trade Offs ◽

Nearest Neighbours ◽

Grazing Sheep

The spatial distribution of grazing sheep is influenced by the distribution of vegetation and by social behaviour. Where there are conflicts between grazing preferred vegetation and maintaining normal inter-individual distances, animals may have to make trade-offs based on the relative strengths of their motivation to feed or to be social. Social motivation, or sociability, has been assessed in chickens by measuring the rate at which isolated individuals move towards their companions (Suarez and Gallup, 1983) and in sheep by studying nearest neighbours (Sibbald et al, 1998). The aim of this experiment was to test whether individual differences in sociability affect the foraging behaviour of sheep, when animals have to choose between grazing or remaining close to their companions.

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