Basic Anatomy and Reproductive Physiology of Chickens Flashcards
Introduction
Unique and distinct to mammals
Differences among species and breeds
Distinct function and relationship
Production focus
Age. Highlights
0-6 weeks - dev of internal organs (brain, liver, lungs, kidney, heart, git)
7-14 weeks - dev of bones
15 weeks - sexual maturity (ovary and oviduct)
Feathers
Features and Functions
Identification
Protection
Thermoregulation
Reproduction
Skin
Features and Functions
Converts provitamin D3 to vitamin D3 (dietary absorption)
Others
Features and Functions
Scales, uropygial gland, comb, wattle
Feathers
Types
Contour
- Wing - remiges
- Tail - retrices
Semiplume
Filoplume
Down
Wing Feathers
Primaries - terminal phalanx, basal phalanx, metacarpus, ulnare
Secondaries - radiale, ulna, radius
Tertiarls - humerus
Blade of scapula, coracoid
Feathers
Parts
Rachis - parang sternum
Barb - parang rib
Barbules - ribs ng rib
Inferior umbilicus -> calamus or quill -> rachis (A flight feather, vane or blade
Musculoskeletal
Descriptions
Spinal column fused in thoracic to sacral except for T6
7 pairs of ribs
Tarsal bones are fused
- males have metatarsal spur
Prominent keel bone
Neck bones are flexible with light skull (23 bones)
Musculoskeletal
Description
Largest muscle - pectoral (15‐20% of bw)
- supracoracoideus - raise wing (up stroke)
- pectoralis - down stroke
Pectoral girdle is well developed with scapula, coracoid bone, clavicle (wishbone)
Muscle fiber - white and dark
Pectoralis Major and Minor
Pectoralis Major (pulls wing down)
Pectoralis Minor (pulls wing up)
Digestive
Description
Beak without teeth and soft palate
- taste buds (no sweet because no T1R2 receptor)
Presence of crop
Stomach (2 regions)
- proventriculus (true stomach)
- ventriculus (gizzard)
Paired ceca
Feces empty through cloaca or vent
Ceca and Meckel’s Diverticulum
Paired
Respiratory and Excretory
Description
Rigid with non expandable lungs
Syrinx
9 air sacs (bellow)
- cervical, anterior thoracic, posterior thoracic, abdominal (paired)
- interclavicular (nonpaired)
Metabolic alkalosis due to
Excess loss of CO2 = soft-shelled eggs
Effects of dietary glutamine on heat induced oxidative stress
High respiratory rate, CO2 exhalation; corticotropin releasing hormone; water intake, FCR; heart rate, hypertension, blood pH; ROS, fat deposition; nerve sensitivity; inflammation; corticosterone, epinephrine
Low feed intake, weight gain; muscle growth, meat quality; gut integrity, microbiome diversity
Heat stress
High panting, drinking, sitting, wings elevated, temp, HR, RR; pH, cortisol, TNF-a, IL-6
Low egg prod, egg quality, large follicle, LH, FSH, Calbindin expression, HCO3, Ca2 absorption
Dekalb body weight development
Reproductive
Organs -> Skeletal and Muscle -> Reproductive tract
Ca increase at prelay 15-16 wks
Reproductive
Only ____ is functional
Left
- FSH, LH
- weight of yolk varies per species
Egg formation
Funnel 15 mins entry point
Magnum 3 hr albumen
Isthmus 1 hr membranes
Shell gland 21 hr water, shell, pigment
Cloaca <1 min exit point
Main systems responsible for egg prod
Nervous
Endocrine
Skeletal
Reproductive
Lighting program
Purpose
Control the age at point of lay and remove influence of natural day length variations
- influences growth and sexual maturity during rearing
Varies depending on developed layer/breeder strain
Sample lighting program
At 15 weeks, increase
Summary
Age weeks lighting
1-69 1-9 24 hours
70-139 10-19 0 hours
140-146 20 5:30-6 AM
…
189+ 27 4-6 AM, 6-8 PM
