PRE-LAYING BEHAVIOR AND NEST SELECTION OBSERVATIONS FOR HENS RAISED IN FLOOR PENS Is the pre-laying behavior and nest selection the same each time the hen lays an egg? Lori Rivera Animal Science Major Animal Behavior and Welfare Department

INTRODUCTION Nesting area selection is strongly dictated by the immediate environment and tends to follow a consistent pattern after the first few eggs are laid.¹ Pre-laying behavior, including searching for a suitable nest site and the inspection of potential nests, is one of the most important behavioral patterns in a hen’s life.² One nest box is recommended for every 4-5 hens³. Many factors influence the final nest selection.

H YPOTHESIS Is the pre-laying behavior and nest selection behavior the same each time the hen lays an egg?

OBJECTIVE The objective of this experiment is to observe the relationship between various components of the pre-laying behavior of the hen, her position in the nest box, and the lag time to lay the egg.

T YPICAL P RE - LAYING BEHAVIOR Ο About an hour prior to the egg being laid, the hen exhibits pre- laying behavior and remains fairly consistent. Moves away from the flock, fluttering its wings in a way it may appear to want out of the pen, and gives a pre-laying call Will perform feeding, preening, and sleeping activities Will examine nests by inserting her head into them As time progress’ more of the body enters the nest until she is completely entered and sits down The hen may enter and leave several times before making a final selection

T YPICAL N ESTING BEHAVIOR Nesting behavior begins when a final nesting site is selected If a pen is not available, the hen will choose a corner of the pen to lay her egg Hen firmly sits down and begins nest building by scratching with her feet making a hollow spot to sit in She will begin to throw nesting materials upon her back and around herself to make a rim She will hold her head high and bottom low then begins to quiver

T YPICAL N ESTING BEHAVIOR CONTINUED … О She will stay in this position until the egg has been laid, which takes about a minute Ο Once an egg is laid, the hen may sit a few minutes or will immediately leave the nesting area О Most hens will immediately perform a post-laying gakel call to announce the egg

ETHOGRAM BEHAVIORDESCRIPTIONCODE Dust BathingThrowing dust or straw onto back in or out of nest box or nesting area DB Nest ExaminationExamines several nest sites. Starts when head enters nest box NE Restless WalkingRestless walking around pen, trying to get in other cage or out of cage RW Nest SelectionEntire body enters nest box or nesting area and sits down NS Nest BuildingScooping movements with head gathering straw around herself NB Laying BehaviorHead up, Rear down, Quivering LB Nest ExitEntire body leaves nest box or nesting area. Only occurs after egg has been laid EX Laid Egg Egg has been laid and is visible in nest box or nesting area LE Post Laying Vocalization Loud clucking to announce egg has been laid. Varying frequencies and duration PV

MATERIALS AND METHODS Ο This study was carried out from July 15-July 28, О Nine flocks of hens (10 hens per flock) were housed in small floor-pens. О One type of nest box was used. О Each individual nest contained wood-shavings and straw for nesting material. О The 9 pens were divided into 3 groups. First group- (pens 5, 20, 29), had a hay bale in the pen Second group- (pens 4, 13, 28), had a plastic box in the pen Third group- (9, 12, 21), was the control group

MATERIALS AND METHODS Ο The hens were marked with livestock marker on their backs for identification purposes. Ο The Purple hen and the Red hen were observed in each pen selected. Ο The hens were observed during live visits. Ο Observation times varied per pen and continued until an egg was laid.

Picture of Nest Boxes at the MSU Poultry Farm Eggs laid in Nest Box Eggs laid on floor

Pictures of Pens at the MSU Poultry Farm

Hay Bale Treatment Box Treatment Control Treatment TrtPens Hay2, 5, 8, 11, 17, 20, 23, 26, 29, 32 Box1, 4, 7, 10, 13, 16, 22, 25, 28, 31 Control3, 6, 9, 12, 15, 18, 21, 24, 27, 30 5 HAY 13 BOX 21 CONTROL 29 HAY 4 BOX 12 CONTROL 20 HAY 28 BOX CONTROL 1725 PEN LAY-OUT

RESULTS Laying Behavior Averages (minutes) Dust Bathing19.0 Nest Exit17.5 Laying Behavior15.3 Laid Egg16.5 Nest Building 9.1 Nest Examination20.4 Nest Selection20.3 Post Vocalization18.6 Restless Walking11.1 o The hens spent a majority of their time Examining and Selecting their nests o Dust Bathing and Post Vocalization followed closely behind o The least amount of time was spent on Nest Building

Nest Selection / Nest Examination Averages (minutes) o The Pens with the Hay Bale Treatment had spent the least amount of time selecting and examining nests prior to laying o The Pens with the Box Treatment spent the most amount of time selecting and examining nests

DISCUSSION All hens exhibit nesting behavior. Hens are more motivated to lay their eggs in a nest box. The gakel call increases, which indicates frustration when nesting behavior is hindered by hens blocking access to the nest. The motivation to get access to a nest box, to lay an egg, is determined by how hard a hen will push through a small gap in order to get in.

DISCUSSION CONTINUED … Motivation increases at the time of actual egg-laying. Some hens are less motivated to gain access to nest boxes and therefore lay eggs on the floor. This shows a more relaxed pressure to select a nest site. Some hens lay on the floor because they are not able to effectively compete for nests against the more aggressive hens. Even when nest boxes were provided, some hens lay their eggs outside the nest. If the hen is motivated to lay in a nest, but cannot find an appropriate site, then the hen will lay on the floor.

CONCLUSION Synchronization was an issue when hens performed the same behavior at the same time each day causing several hens to crowd into one nest box at a time. Though two nest boxes were provided, the hens preferred the nest furthest from the door. Pre-laying behavior seemed to be consistent in all nine pens. Most of the time was spent in nest selection and nest examination.

REFERENCES Freire, Rafael, Appleby, Michael C., Hughes, Barry, (1996) Effects of Nest Quality and Other Cues for Exploration on Pre-laying Behaviour. Volume 48, pg ³Leeson, S. and Summer J.D., Broiler Breeder Production. eBook Download, Guelph, Ontario, Canada ²Lentfer, Tine L., Gebhardt-Henrich, Sabine G., (2011). Influence of Nest Site on the Behavior of Laying Hens. Applied Animal Behaviour Science, Volume 135, pg L.J. Keeling Department of Animal Environment and Health, Swedish University of Agricultural Sciences. Chapter 19. ¹Rietveld-Piepers, B., Blokhuis, H.J. (1985). Egg-Laying Behavior and Nest-Site Selection of Domestic Hens Kept in Small Floor Pens, Applied Animal Behavior Science, Volume 14, pg Struelens, Ester, Van Nuffel, Annelies (2008). Influence of Nest Seclusion and Nesting Material on Pre-laying Behavior of Laying Hens. Applied Animal Behavior Science, Volume 112, pg Wood-Gush, D.G.M.; (1963). The Control of the Nesting Behaviour of the Domestic Hen 1. Animal Science, Volume 11, Issue 2-3, pg