Theme 3: social learning

LB

Energy intake around weaning

Change from milkk intake to solid food intake

drop and then increase day 28

Problems associated with weaning of pigs

health and performance

• low nutrient intake

• poor growth rate or even weight loss

• impaired intestinal functioning, diarrheo

• use of antibiotics

welfare

• stress response

• maladaptive behaviours

  • decreased play behaviour

Weaning - schematic overview of changes

Learning of feeding and foraging behaviour

omnivores: few inborn restrictions → learning

learning what to eat

• food neophobia

• recognition by flavours (taste + retronasal olfaction)

• flavour + postingestive effects → preference or avoidance

• generalization (preference/avoidance of similar food items)

• sensitive periods

food neophobia

reluctance to try unfamiliar food items

mechanism to protect against toxins or other negative effects

Factors influencing food neophobia

personality

stress and fear

unfamiliar environment increases food neophobia

food neophobia in piglets

food neophobia higher in unfamiliar environments and in high fear/stress situations

better to expose piglets to (novel) solid food before weaning, in safe familiar environment

Offering creep feed before weaning

feed intake before weaning low and variable

several strategies tried, feed quality, palatability, but often not sucessful

Lessons from nature, feed exploration

Stable

• weaning abrupt event

• at 3-4 weeks

• little eexperiece with solid feed

nature

• weaning: gradual process

• ends at 8-20 weeks

  • feed exploration starts early

feed presentation: diversity infeed

day 11 before weaning

\2 times more eatesr at day 11,100% eaters at wenaing

not so much piglet feed

feed presentation larger feed pellets

before weaning, preference large pellet first 2 weeks, 181 vs 91 gfram per pen

after weaning

• pigletrs fed 12 mm pellet before weaning, growth +26% until day 10 postweaning, feed intake +14%

irrespective of pellet size after weaning

Feed presentation: play feeder

before weaning

• more play with feeder

• more early eaters

• no effect on overall intake

after weaning

= growth +15% 2 weeks

less body lessions and damage to ears and tails\

feed intake +30% first 4 hours, +15% first 2 weeks

lessons from nature: sow-piglet interaction

stable

• limited ocntact

• eating separately

• different feed

nature

• lots of contact

• eating together

• same feed items

social learning

learning that is influenced by observation of or interaction with another animals or its products

crucial during developmetn of feeding (weaning transition)

• trial and error learning risky

  • trial and error learning time consuming

social learning in weanling pigs

feed intake sitmulated by eating pen mates and eoghbours

non-eaters preweaning, after weaning housed with

• experienced postweaning eater

• neighbour eaters

• eaters one pen in between

moter more imporat than dry ewe for learning

social learning

mothers

mothers best likely models (vertical transmission)

genetically related

same environment

most attention directed at mother

information transmission may start early in life, even before birth

prenatal flavour learning

animals prenatally exposed to flavoiurs

• via foetal blood streama dn amiotic fluid

evidence of prenatal flavour learning inmany species

prenatal learning may facilitate transiton from prenatal environment ot environment after birth

• e.g. location of nest, nipple, kin (familY) recognition

  • dietary preferences and acquisiton of independent feeding

prenatal flavour learning

maternal die3ts

maternal diets affects prenatal environment

• pregnant ladies during third trimester were given carrot juice, enhanced acceptance of carrot flavoured meal

postnatal learning

lactating mothers diet

rat example

rat mothers fed palatable diet or unpalatale diet during lactation

rat pups from mother unpalatable diet consumed 10x more unpalatable feed at d17

Effects of lactating mother (diet)

around weaning (rats, mice, rabbits, humans)

• initial dietary choice

• preference for similarly flavoured feed

  • increased intake or liking if diet matches with mother’s feed

even in later life - goats

• faster acceptance and increaed intake of rice straw at 6 motnhs

effects of lactating mothers diet - how

observational learning (direct social learning)

• but also information transfer if mother is fed in asbsence of sucklins

flavour learning by exposure to maternal diet

• through mother skin, breath, body, faeces, air

  • milk

learning via exposure to flavours in milk

flavour changes in milk are perceived by sucklings

flavouor learning through milk more effective than via other routes e..g breath mother, air

• swalling facilitates retronasal perception

• association of flavours with reinforcing conditions

  • positive consequences

    • suckling → warmth. tactile contact

perinatal flavour learning in piglets

experiment

flavour exposed pilgets before birht showed more interst in the anise flavour

flavour exposed piglets showed less escape attempts and vocalization sin the prsence of anise

recognition of flavours from mothers feed

• prenatally exposed piglets experiemtn

recognition of falvour form mothers feed after birth

reduced fear/sttress in the presence of this flavour

flavour learning and performance postweaning

• prenatally and pre+postnatally exposed piglets

experimetn

higher feed intake d2-3 and hgiehr growth, d2. d5

less damaging behaviours during 2 weeks

less diarrhoea during 2 weeks

if flavour was present in postweaning environment

diarrheoa during first 2 weeks postweaning

perintal flavour weaning

prenatal flavour weningimporves performance of weanling piglets if the flavour is present in the pstweaning environment

no preference for flavoured feed

familiar flavour (prenatal exposure)

schematic overview

flavour learning and performance postweaning

anise experiment

perinatally exposed piglets postweaning

lower coritsol levels at 4h and 7h

ate faster

played more

showed less damaging behaviours

had less stressrelated vocalisations

if flavour was present in postweaning environment, in either air or feed

conclusions perinatal flavour learning

perinatal flavour learnign enahnces piglets performance at weaning if the flavour ispresent in the postweaning environment

stress reducing effects of familiar flavour at weaning

so effect not due to reduced food neophobia and generaltization alone

but

effects may dpeend on chosen flavour

dosage effects

indivual differences

direct forms of social learning

learning what, when, where how to forage

multiple cues or signs involved

• olfactory and gustatory

• audtory

• visual

• combinations

chickens”: acoustic and visual cues

direct

specific food call

ground pecking

scratching

high quality food: more intnse and longer food calls

more food pecking and scratching by mother if chicks eat wrong foods

social learning: process

true imitaiotn

• goal-directed, purposeful copying of behaviour of a demonstrator

social facilitation (contagious behaviour)

• initation or increase of behaviour due to presence of another animal displaying that behaviour

local or stimulus enhancement

• demonstrator directs attention to part of environment (place or stimulus)

  • social transfer, not true imitation (even presence anesthesized rat induces preference of rat pups for feeding site)

delayued vs immediate reinforcement

paticipating with demonstrator (immediate) may be more effective than observing only (delayed)

no delay between observation and performing behaviour

direct reinforcement: link between cues/behaviour and post-ingestive consequences (NUTRIENTS)

many animals are able to learn with delayed reinforcement, but the shorter the delay, the betterr

food neophobia test

in the presence of their mother, piglets

were faster to touch the food 19 s vs 111s

consumed more food items 6.3 vs 4..6

were more likely to try both types of food

more interaction with the sow

piglets with loose housed sow

higher growth d15 until weaning, likelyu due to higher feed intake

less damaging behaviours after weaning

more play beavhioura fter waning

\

improved coping wth weaning transiton?

delayed vs immediate reinformance experiment

observing or participating sow

observing sow and particpating with sow effective

• faster at feeder than controls

• higher feeed itnake than controls

• preference for sows feed (flavour) and feeder

demonstrating is better than self leaning

• even wihout own experience with feed (observation)

• why participation not etter than observation?

  • location

social learning in piglets

learning form mother is effective in stimulating feed intake in piglets

more effective than own exposure to food (self learnign)

observing sow and particpating both effective, piglets also use information with delayed reinforcmeent

piglets prioritze type of sows food (flavour) over location, but location is also important

mother-offspring information transfer plays a role in the development of independent feeding

true

increasing opportunties for sow-piglet information transfer improves performance and welfare of piglets after weaning

several ways of information transfer are effective (perinatal flavour learning; observatinal learnign)

reduce weaning problems by

providing piglets same flavour before and after birth and after weaning

\allowing piglets to observe (see, smell) what the sow is eating

allowing piglets and sow to eat together

providing piglets and sows the same food in early lactation