Animal Welfare Challenges in Broiler Breeders with Special Focus on Restricted Feeding and Behaviour

Transcription

1 Animal Welfare Challenges in Broiler Breeders with Special Focus on Restricted Feeding and Behaviour W. Bessei Institut für Tierhaltung und Tierzüchtung Fachgebiet Nutztierethologie und Kleintierzucht Universität Hohenheim

2 Comparison of performance of parent stocks under restricted and ad lib. feeding regimes Criteria restricted ad libitum Source Live weight (kg, 20/40 weeks) Feed intake (g/bird/day) 140/160 >200 2,0 / 3,0 5 / 5 Bruggeman et al. (2005) Laying rate (%) 79,1 52,4 Puterflam et al. (2006) Multiple egg yolks (n) 2,5 7,6 Puterflam et al. (2006) Erratic oviposition /defective egg syndrom Robinson and Wilson (1976) Mortality (%) 5 (7) 30 (68) Puterflam et al. (2000) Sacher (2008)

3 Definition of hunger Hunger is a negative subjective state experienced by an animal that is chronically under nourished D`Eath et al. (2009)

4 Methods of feed restriction Quantitative restriction (from %) Qualitative restriction Dilution with fiber or sand Suboptimum CP contents Reduction of access to water Appetit reducing substances (Ca-proprionate, Na- Monensin)

5 Physiological criteria used to assess hunger in broiler breeders Criteria Glucose NEFA (non-esterified fatty acids) Glucose /NEFA-ratio Stress Corticosteron Heterophile:Leucocyte ratio (H/L) Basophile; Monocytes Creatinkinase Response to antigens Heart rate Electroencephalogramme (EEG) Comments These criteria have an important role to play in feed intake regulation. There are, however, controversial results under restrictive feeding conditions The glucocorticosteroids are important for the metabolic turnover and respond changes in nutrient supply; their relation to psychic stress is covered by the changes of the metabolic rate under restrictive feeding idem not sufficiently investigated

6 Behavioural criteria Criteria Feed intake/feeding behaviour Difference between ad lib. and restricted feeding Intensity of feed intake (speed) Duration of meals Compensatory feed intake Operant feed intake Conditioned preference of feeding place Other behaviours Locomotor activity, litter pecking (exploration) Water intake/drinking berhaviour Object pecking (feeder, drinker, walls, pen mates) Aggression Preening Reactivity/Fear Stereotyped behaviours Behavioural sequences Detrented Fluctuation Analysis (DFA) T- Pattern Comments Behaviours do not change proportionally to the level of feed restriction Changes may occur as compensatory activities; stereotyped behaviour is considered the most prominent indicator of compromised welfare Variability of behaviour is considered an indicator of welbeing

7 Time budget in broiler breeders under restricted and ad lib. feeding regimes during rearing before feeding (Puterflam et al., 2006) ad libitum restricted 9,6 4,1 12 9,7 10 Standing 32,5 13,1 11,8 5,2 4,7 Standing 44,3 4, ,1 15,7

8 Time budget of broiler breeders under ad libitum und restricted feeding during the feeding time (rearing period) (Puterflam et al., 2006) Ad lib. Restricted 5,4 11,3 1,9 0,8 1,1 3,1 10,3 Food Pecking 66,1 9,1 1 5,2 0,9 3,1 3 3,5 Food pecking 74,3

9 Time budget of broiler breeders under ad libitum und restricted feeding after the feeding time (rearing period) (Puterflam et al., 2006) ad lib. restricted 3,3 7,6 3,7 4,6 19,9 5,4 4,4 14,1 29,4 Sitzen 20,4 Sitzen 5,7 24,8 4,4 0 31,4 20,8

10 Time budget of broiler breeders under ad libitum und restricted feeding during the feeding time (laying period phase 1) (Puterflam et al., 2006) ad lib. restricted 4,9 13,7 8,2 1,2 6,4 3,1 31,2 2,2 12,8 12,6 1,1 7,6 3 43,3 27,9 18,6

11 Time budget of broiler breeders under ad libitum und restricted feeding during the feeding time (laying period phase 2) (Puterflam et al., 2006) SA SR 0,1 2,7 8,5 4,6 2,6 21,5 1,3 0,5 4,8 5,2 2,7 20 5,1 42,5 14,5 54,5

12 Time budget of broiler breeders under ad libitum und restricted feeding during the feeding time (laying period phase 3) (Puterflam et al., 2006) ad lib. restricted 6,6 1 5,1 6,5 2,6 19,7 6,5 12,4 3,1 22,2 7,6 26,1 20 7,1 17,4 16,4

13 Behavioural sequencies of parent stocks under ad lib. feeding (Merlet et al., 2005) ad libitum restricted

14 Time (mean ± S.E.M.) spent by broiler breeders at the age of 6 weeks on foraging behaviour, sitting and pecking at the feeder during eight observation periods between 07:30 and 15:00 h in the light period (de Jong et al. 2005)

15 Regulation of feed intake in the Domestic Fowl (Grossmann, 1986) Pre-absorptive phase Absorptive phase Post-absorptive Phase Short increase of glucagen und insulin, peak within 1 the decline Action of Cholecystokinin, gastrin and sekretin Secundary excretion of insulin Peak ca. 45 min. after start of the meal Decline of insulin und glucagon Increase of somatostatin

16 Conclusions Hunger is a subjective feeling and cannot be directly assessed by physiological and ethological criteria The physiological criteria which are involved in the regulation of feed intake and metabolix turnover have shown no clear responses towards different levels of feed restriction The most accentuated response of behaviour to feed restriction is the increase of feeding intensity and the reduction of time spent feeding Depending on severity of restriction and age the time spemt feeding varies between 0,5 and 5 hours and is highly concentrated in the time after feed allocation. In ad lib. fed birds the time spemt feeding is much longer and scattered over the hole light (and dark) period The shorter feeding time is compensated by pecking at the litter, feeders, drinkers and other objects. This behaviour is adopts often a stereotyped pattern and is considered an indicator of poor welfare

17 Conclusions (continuation) Attempts to extend the tiem spent feeding in feed restricted birds have not been successful so far (the methods were either not efficient in controlling the body weight, or not efficient in reducing stereotyped behaviour) It has beed proposed to redirect food pecking towards explorative litter pecking, which is a normal behaviour This strategie has to focus on the time immediately after the termination of the ration The applicability under practical condidions has to be explored more in detail