Title: Reproduction
1Reproduction
- Dr. Les Anderson
- Dr. George Heersche, Jr.
- Dr. Bob Coleman
- Dr. Richard Coffey
- Introduction to Animal and Food Sciences Agent
In-Service
2Who Cares?
- Reproductive efficiency is the primary
determinant of gross income in most animal
industries.
3Lecture Outline
- Terminology
- Anatomy
- Reproductive States
- The Estrous Cycle
- Periods of Anestrus
- Pregnancy
- Parturition
4Gender Terms
- Cow, Bull, Heifer, Steer
- Ewe, Ram (Buck), Ewe lamb, Wether
- Sow, Boar, Gilt, Barrow
- Mare, Stallion, Colt, Filly, Gelding
- Doe, Buck, Kid
5Reproduction Classifications
- Seasonal vs nonseasonal
- Sheep short day breeders
- Horses long day breeders
- Cattle no effect
- Swine no effect
- Cyclic vs acyclic
- Poultry
- Other species
6Reproductive Tract - Cow
- Vu Vulva
- AV Ant. Vagina
- CX Cerix
- UH Uterine Horn
- OD Oviduct
- O Ovary
- UB - Urinary Bladder
7Reproductive Tract - Sow
- Vu Vulva
- AV Ant. Vagina
- CX Cerix
- UH Uterine Horn
- OD Oviduct
- O Ovary
- UB - Urinary Bladder
8Reproductive Tract - Ewe
- Vu Vulva
- AV Ant. Vagina
- CX Cerix
- UH Uterine Horn
- OD Oviduct
- O Ovary
- UB - Urinary Bladder
9Reproductive Tract - Mare
- Vu Vulva
- AV Ant. Vagina
- CX Cerix
- UH Uterine Horn
- OD Oviduct
- O Ovary
- UB Urinary Bladder
10Reproductive Tract - Bull
- T Testis
- TE Tail of the Epid.
- DD Vas Deferens
- VG Sem. Vesicles
- BP Prostate
- SF Sigmoid Flexure
- RPM Ret. Penis Muscle
- PS Penis
11Reproductive Tract - Boar
- T Testis
- TE Tail of the Epid.
- DD Vas Deferens
- VG Sem. Vesicles
- BP Prostate
- SF Sigmoid Flexure
- RPM Ret. Penis Muscle
- PS Penis
- GP Glans Penis
12Reproductive Tract - Stallion
- T Testis
- TE Tail of the Epid.
- DD Vas Deferens
- A Ampulla
- VG Sem. Vesicles
- BP Prostate
- SF Sigmoid Flexure
- RPM Ret. Penis Muscle
- PS Penis
- GP Glans Penis
13Reproductive States
- Cyclic
- Def Females that have or are exhibiting estrous
cycles of normal length - Estrous Cycles
- Def The period of time from one estrus to the
next. - Acyclic (anestrous)
- Def Females that are not exhibiting estrous
cycles - Observed before puberty ( 12 months of age),
after parturition, and due to season.
14Estrous Cycles
- Duration of estrus
- Specie Range Average
- Cattle 6-36 h 24 h
- Swine 48-72 h 60 h
- Horse 4-8 days 6 d
- Sheep 24-36 h 30 h
15Estrous Cycles
- Length of the estrous cycle
- Specie Range Average
- Cattle 17-23 d 21
- Swine 17-23 d 21
- Horse 17-23 d 21
- Sheep 15-18 d 17
16Ovarian Cycle
- Def Changes in the structures on the ovary that
result in the cyclic reproductive activity of a
female.
17Ovarian Structures
- Follicles
- Balloon-like structures
- Contain the oocyte (egg)
- Produces estrogen
- Corpus Luteum (CL)
- Solid structure
- Produces progesterone
18The Ovarian Cycle
Heat
19Cyclic Hormonal Changes
PG
Progesterone ----
Estrogen ____
Heat
Heat
20Cyclic Hormonal Changes
PG
Progesterone ----
Estrogen ____
Heat
21Anestrus
- When?
- Prior to Puberty
- After Parturition
- Season
22Puberty
- Animals attain the ability to reproduce at
puberty. - Puberty occurs when the brain becomes less
sensitive to hormonal feedback and begins to
produce the hormones necessary to drive the
ovarian cycle. - Age at puberty is an important production
parameter for beef, dairy, and swine. Equine and
ovine are seasonally regulated. - Females that are earlier at puberty are generally
more fertile during their first breeding season.
23Postpartum Anestrous
- Postpartum (After Parturition)
- Most females undergo a period of anestrous after
parturition. - The length of this period determines reproduction
efficiency in most species. - Typically, the presence of the offspring
initiates anestrous. Other factors influence the
length of the anestrous period.
24Postpartum Reproductive Activity
- Cattle
- After parturition, cattle remain anestrus (ie no
estrus) for 30-120 days. - Factors that regulate the length of the
postpartum anestrus period are - Nutrition
- Age
- Dystocia
- Calving season
- Management
25Postpartum Reproductive Activity Cow
Heat
Heat
Heat
Heat
Calve
Ovulation
26Postpartum Reproductive Activity
- Swine
- Anestrus until weaning
- Historically, sows would exhibit estrus 3-5 days
after weaning, but this is not predictable now
because of the young ages at weaning (14-17 days).
27Postpartum Reproductive Activity
- Sheep
- Lamb in spring, and seasonal regulation of
cyclicity shuts down their reproductive activity - When day length shortens, ewes begin to cycle.
- Horses
- Approximately 6-7 days following parturition,
mares will be in estrus (foal heat). Afterwards,
they begin to cycle normally.
28Seasonal Anestrous
- Reproductive activity in sheep, goats, and horses
are greatly influenced by season. - Darkness stimulates the release of the hormone
melatonin from the pineal gland in the brain.
More darkness more melatonin. - Melatonin alters (inhibits) the function of the
centers in the brain that regulate estrous cycles.
29Seasonal Anestrous
- Sheep and goats
- Short day breeders
- Activity begins in fall (August/September) and
continues until Winter (January/February). - Some breeds of sheep are less sensitive to the
influence of daylight and will lamb twice per
year. However, they are less fertile during the
off season.
30Seasonal Anestrous
- Horses
- Long-day breeders
- Reproductive activity begins in spring
(March/April) and continues until fall
(September/October). - Major industry related to helping mares conceive
early in order to foal in January.
31Pregnancy
- Begins with fertilization
- Def union between the male germ cell (sperm)
with the female germ cell (oocyte). - Fertilization occurs in the oviduct at the
junction between the ampulla and the isthmus. - Once fertilized the new cellular product is
called an embryo. - Embryos pass from the oviduct to the uterus 5, 3,
3, 7 days after estrus in cattle, swine, sheep,
and horses, respectively.
32Pregnancy
- Stages
- Embryo - fertilization to app. D 30
- Fetus - Day 30 of pregnancy to parturition
- Components of a pregnancy
- Fetus/embryo
- Placenta
- membranes responsible for the protection and
nourishment of the fetus
33Anatomy of Pregnancy
34Pregnancy
- Gestation length
- Cattle 283 days
- Sheep 148 days
- Swine 114 days
- Horses 335 days
35Pregnancy
- Parturition (birthing)
- Stimulated by the fetus
- fetus cortisol
- placenta Prostaglandin F
- ovary CL regresses, releases
- oxytocin
- Uterus contractions begin
36Poultry Reproduction
37Anatomy
38The Ovary
39Egg Production
40Egg Production
41Egg Production
42Egg Production
43Egg Production
- Photosensitivity controls reproduction
- Sexual maturation (egg production) begins at
about 8-10 weeks - Eggs are produced in clutches until the
production falls off (usually get 300) - Hens are force molted to rest.
- 8-12 weeks later, egg production resumes
- Production is less (egg quality and quantity) in
recycled hens
44Managing Reproduction
45Managing Reproduction
- General Goal
- Increase number of offspring born each year
- Examples
- Increase pregnancy rate from 80 to 90 in a beef
herd - Increase the number of pigs/lambs born
- Control the time (season) of parturition
- Examples
- Calve beef cows in March and April
- Dual season breeders in sheep
- Foaling in January and February in horses
46Managing Reproduction
- How?
- Control the onset of a fertile estrus
- Hormones
- Light
- Weaning
- Major obstacle to overcome
- Anestrus
- Lactational, nutritional, seasonal, pubertal
47Controlling the Onset of Estrus
- What is estrus?
- How can we regulate its onset
48Estrus Behavior
49Signs of Pre-Estrus
- Swollen vulva, often red (gilts up to 72 hr
before estrus, sows less than 24 hr)
- Vocalization
- Restless movement
- Climbing
- Looking for male
- Bar biting
- Riding other females
50Mobility Increases
51Vocalization Increases
52Reproductive Tracts Changes
- Swollen, red vulva
- Cervical mucous is produced and excreted.
53Signs of Estrus (Standing Heat)
- Off feed, not eating
- Restless movement
- Elevated temperature
- Quivers
- Riding other females
- Mucus discharge (initially feels slick, but
becomes tacky and stringy after exposure to air.)
- Dark, red on inside of vulva
54Signs of Estrus (Standing Heat)
- Tail held high to fully expose vulva.
- Characteristic rigid stance and ear popping
response to back pressure.
55Standing Estrus
56Checking Estrus - Cattle
- Industry Standard Visual observation
- 2 times per day (early AM, late PM) for 20-30
minutes. - Fertility greatly determined by heat checking
accuracy - Electronic systems (Heat Watch) available that
greatly improve the accuracy of heat detection.
57Checking Estrus - Cattle
58Checking Standing Estrus - Swine
- Use a boar to check heat
- Nose-to-nose contact is females in stalls (limit
to 4-5 stalls at a time refractory response) - In pen if sows are group penned
- Check heat twice daily
- House boars away from females
- Females can become sensitized to smell and sounds
of boars
59Effects on Standing Response
60Checking Estrus - Mares
- Done daily during the breeding season
- Involves bringing a male to the breeding pastures
- Called Teasing
61Teasing
- Critical part of the breeding program - Done
daily - Very observant - Keep good records
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65Estrus Synchronization
66Products Used to Control Heat
- Prostaglandins
- Action regress CL
- Drugs names include Lutalyse, Estrumate,
Prostamate, and In-Synch. - Progestins
- Action Imitates CL
- Drug names include melengestrol acetate (MGA),
Regumate, CIDRs (control internal drug release)
and progesterone.
67What is MGA?
- Melengestrol Acetate
- Orally active, synthetic progestogen
(progesterone-like compound) - Effective dose .5 mg/head/day
- Key
- If the females are not eating the feed containing
MGA it is not working! - Available in complete feeds, pellets, range
cubes, protein supplements, and others
68What is Regumate/MATRIX?
- Orally active, synthetic progestogen
(progesterone-like compound) - Uses
- Synchronize estrus (swine and equine)
- Induce estrus in seasonally anestrus mares
- Maintain pregnancy in mares with placental
deficiencies - Suppress estrus in show mares
69What is Regumate/MATRIX?
- Administer 6.8 mL (15 mg altrenogest) per gilt
once a day for 14 consecutive days. - Treat gilts individually by top-dressing on feed.
- Treated gilts express estrus 4-9 days after
treatment - Administer .044 mg/kg BWT/day for 10-15 days
- Oral dose or as feed additive
70What is a CIDR?
- Controlled Internal Drug Release
- T-Shaped plastic device that is coated in
progesterone (1.38 g). Has a tail. - Inserted into the vagina
- Tail sticks out and is used to remove CIDR
- Original use was to induce estrous cycles in
anestrous cows - Being developed for swine and sheep
71EAZI-BREED CIDR Cattle Insert
72Products Used to Control Heat
- Gonadotropin-releasing hormone (GnRH)
- Action causes formation of CL
- Drug names include Cystorelin, Fertagyl and
Factrel - Synthetics include Buserelin and Deslorelin
- Also generic products available but they do not
have a preservative!!!
73Products Used to Control Heat
- Human Chorionic Gonadotropin (hCG)
- Action causes formation of CL
- Estradiol Cypionate (ECP)
- Action stimulates estrus and/or ovulation also
regulates follicle growth and increases uterine
involution
74Beef and Dairy Cattle Estrus Synchronization
Protocols
75The MGA-PG Hybrid System
Heat and AI for 72 hours. All animals NOT in
heat receive GnRH and are inseminated at 72 hours
MGA Feeding
0 2 4 6 8 10 12 14 16 18 20
22 24 26 28 30 32 34 36 38 39
Day of Treatment
76Hybrid Select Sync
PG
GnRH
Heat and AI
0 1 2 3 4 5 6 7 8 9
10 11 12 13 14
Day of Treatment
77CO-Synch and Ov-Synch
Co-Synch GnRH and AI simulatenously Ov-Synch
AI 16 hours after GnRH
GnRH
0 1 2 3 4 5
6 7 8 9 10
Day of Treatment
78Addition of a CIDR to CO-Synch
66
59
51
51
Stevenson et al., 1999
79Typical Results (Beef) - KY
Percentage
80Artificial Insemination
81What is the Goal?
- To put the optimal number of sperm cells in
contact with ovulated egg(s) from the female.
82Successful A.I. Depends On
- Females displaying cyclic activity
- Identification of individual heat periods
- Timing of insemination
- Quality of semen
- Proper insemination techniques
83AI In Cattle
- Key
- Accurate detection of estrus
- Insemination should occur 8-14 hours after
female first allows mounting - Once-a-Day Breeding in dairy
- All cattle bred in AM have not observed
difference in pregnancy rate
84AI In Cattle
85AI in Swine
86Which Pipette to Use?
- Disposable vs. reusable
- Smooth edges
- Molded vs. glued-on tip
- Closed cell foam vs. sponge
- Spiral tip vs. plug shape
87Female Reproductive Tract
88Inserting Pipette
- Clean vulva area
- Use some lubrication (non-spermicidal lubricant
or a few drops of semen) - Point tip upward at 35o angle for first 4-5
inches (avoid urethra and bladder)
89Inserting Pipette (cont.)
- When past urethra, hold pipette in more
horizontal position and push forward another 6-9
inches (or until you feel the resistance of the
cervix)
90Inserting Pipette (cont.)
- Spiral pipettes with slight inward pressure,
gently turn counterclockwise to penetrate cervix - Foam tipped pipettes
- with slight inward
- pressure, slightly rotate
- left to right.
- Muscles of cervix will tighten around pipette
when positioned.
91Depositing Semen
- Invert bottle 2-3 times to mix semen.
- Semen should be deposited slowly (3-10 minutes).
- Sometimes uterine contractions occur very
rapidly, allowing for fast depositions. Other
times uterine contractions are much slower,
requiring more time for depositions. - If great deal of resistance to flow of semen,
reposition the catheter (may be lodged against a
cervical flow). - Watch for excessive backflow (either not
positioned right or going too fast).
92Depositing Semen
- Females need to know they are being bred.
- Providing stimulus helps initiate contractions
that moves sperm to site of fertilization. - Ways to provide stimulation when inseminating
- Presence of boar
- Apply back pressure
- Rub flanks
- Remove pipette when completed
- Rotate clockwise while gently pulling out.
93Things to Avoid
- Getting females excited or nervous
- Has a big negative effect on semen transport and,
therefore, fertilization. - Prolonged boar exposure before inseminating the
female (can lead to refractory response). - Re-using disposable pipettes.
- Having wrong person do the breeding.
- Breeding too many sows before taking a break.
94Timing of Insemination
95Timing of Insemination for GILTS with Twice Daily
Heat Detection
Gilts may show visible signs of heat
Standing Heat
OVULATION
Matings
96Timing of Insemination for SOWS with Twice Daily
Heat Detection
Sows may show visible signs of heat
Standing Heat
OVULATION
Matings
97Timing of Inseminations With Once Per Day Heat
Detection
- If heat detection performed once per day, matings
should be done - 1st service when found in heat
- 2nd service 12 to 24 hours later
- ONCE PER DAY HEAT DETECTION NOT RECOMMENDED!!!
98Timing of Inseminations
99Artificial Insemination in Sheep
100Sheep AI Very difficult
- Cervix is small and cervical canal is difficult
to transverse. - Over-the-Rail method is typically used.
101Insemination/Breeding in Mares
102AI in Mares
- Estrus lasts 5-7 days
- Normally breed daily or alternate days from the
onset of estrus until the end - Hard to determine the timing of ovulation
- Can regulate by injection of GnRH, Buserelin,
Deslorelin, or hCG. Can also use ECP.
103AI in Mares
104AI in Mares
105Reproductive Management
106Beef Cattle
107Enhancing Reproductive Performance
- Goal
- Ideal every cow calve on the first day of the
calving season - Realistic 60-70 day calving season, gt90 calf
crop weaned, 80 calve in the first 30 days
108First Step
- Control the breeding/calving season
- Scenario
- 60 females calved from March to August.
- All calves weaned on November 1st.
- 42 calves weaned from 60 females.
- Very typical Kentucky producer.
109Calving Distribution
110180-Day Calving Season
18,614 lbs Avg 443 lbs
111Goals Reached
29,874 lbs Avg 554 lbs
11,260 lbs!
112Controlled Calving Season
- Advantages
- More uniform calf crop
- Heavier weaning weights
- Increased labor efficiency
- Increased production efficiency
- Faster post weaning gain
- Older heifers available for use as replacements
- Early born heifers are more productive and
- profitable
113Controlled Calving Season
- Disadvantages
- Increased labor over short calving period
- Increased management requirements
114Tools to Enhance Percent Calf Crop Weaned and
Calving Distribution
- Estrus synchronization
- Proper heifer development
- Proper young cow development
- Proper bull management and selection
115Simple Reproductive Management System
116Estrus Synchronization for Natural Service -
Experiment
No treatment
Turn in bulls
Control
Turn in bulls
MGA feeding
MGA
Lutalyse
MGA-Lutalyse
Turn in bulls
MGA feeding
Day 1
Day 7
117Estrus Synchronization and Natural Service -
Results
- Average Calving
- Treatment Calving date Rate 1st 40 d
- Control 57 81 89
- MGA 52 93 100
- MGA-Lutalyse 52 100 100
118Estrus Synchronization and Natural Service Expt
2
-
- Treatment Numbers Preg Rate 1st 30 d
- Control 621 83 47
- MGA 614 93 78
- BullCow range from 123 to 142 (91 PR )
119Return on Investment
- 15 increase in pregnancy rate
- 40 extra pounds at weaning per calf
- Estimated return on investment 100 per cow
120Estrus Synchronization and Natural Service
- Recommendations
- Do NOT need to change bullcow ratio.
- BUT
- Use an 18 month old bull or older (1 seasons
experience. - Bull should have at least a 35 cm scrotal
circumference as a yearling.
121Reproductive Management in Dairy Cattle
122Dairy Cattle Reproductive Goals
- Get cows and heifers pregnant via artificial
insemination - In a reasonable amount of time
- Using a reasonable amount of semen
- At a reasonable cost
123WE HAVE TRIED TO FOOL MOTHER NATURE
124Mothers original plan get pregnant give
birth to live calf produce milk for calf do
it again...
125Mothers nutritional priorities
- Growth and maintenance of mother
- Growth and maintenance of the fetus
- Milk for the calf
- Reproduce again
126We ask cows to be super females produce large
amount of milk reproduce regularly be
trouble free be happy about the whole deal
127Mother and AI Humans heat detection
challenged Successful A.I. Requires
management Hassle and requires
diligence Worth the effort
128Trying to accomplish things not in Mothers
original plan for the cow or us. Strive to do
the best we can.
129Reasonable FertilityCows 40 2.5
S/CHeifers 75 1.3 S/C
130Manage breeding, feeding and cow comfort to
minimize the negative influence of factors which
lower fertility incorrect transition period
management inaccurate heat detection
heat and humidity sloppy semen handling and
insemination techniques incorrect timing
of insemination
131Manage breeding, feeding and cow comfort to
minimize the negative influence of factors which
lower fertility negative energy balance
high blood urea nitrogen infected fescue
mycotoxins in feed mastitis
132Heat and Humidity Decrease cow activity
Decrease heat detection efficiency Do not
decrease fertilization Decrease embryo
survival Keep cows cool Turning in the bull
wont solve
133Make A.I. Work talented players good
coaching
134A.I. Dairy Heifers increase the number of
genetically superior heifers available for
herd replacement or sale genetic edge
predictable results cash crop higher
fertility calving ease DBH/SCE/DCE
135Inefficient Heat Detection is Devastating
- 20 21 not bred and 48 not PG by 200 d 30
32 not PG by 200 d - Too often solution is turn in the bull
136Heat Detection is Part of Your LifeDeal With
It programmed breeding works cows not PG on
programmed breeding often fall through the
cracks continue to check herd for heat
program first insemination only Heersche synch
137Proper Timing of Insemination ovulation 28h
egg lives lt 12h sperm lives 24h
capacitation goal a.m. - p.m./p.m.- a.m.
1x
138High-Maintenance Females cows with high
production potential demand more from us than
other cows to be happy demand more than we
have to offer some of us are better at keeping
high- maintenance cows happy
139High-Maintenance Cow Keys get off to good
start stay healthy feel good eat well
do not lose a lot of weight transition and
early lactation program
140Health Care involve veterinarian
vaccination program lepto hardjo-bovis
mastitis foot problems
141Reproductive Management in Swine
142Swine Reproductive Management
- Maximize the number of litters per year
- Maximize the number of live pigs born and pigs
weaned each litter - Basically want to get as many pigs as possible
out of your sows
143Critical Periods for Successful Breeding and
Gestation
Lactation (14-28 days)
Stress Increases Stillborns (day 84-114)
Farrowing
Weaning-to-Estrus (4-? days)
Weaning
Fertilization (day 0)
Breeding
Gestation (114 days)
Embryos Free Floating (day 1-12)
Pregnancy Detection (day 21-42)
1st Maternal Recognition of Pregnancy (day 10-12)
2nd Maternal Recognition of Pregnancy (day 15-20)
Gestation Weight Gain (day 30-114)
Implantation of Fetus to Uterus (day 14-30)
144Estrous Synchronization in Gilts
145MATRIX Product
- Produced and marketed by Intervet.
- MATRIX is an altrenogest solution (synthetic
progestagen). - Same as REGUMATE used in horses.
- Used to synchronize estrous in cycling gilts.
- Administer 6.8 mL (15 mg altrenogest) per gilt
once a day for 14 consecutive days. - Treat gilts individually by top-dressing on feed.
- Treated gilts express estrus 4-9 days after
treatment.
146Equine
147Breeding Basics
148Reproduction Rate
Biological Rate 100
Theoretical Rate 95
Industry Rate 70
Foal Registration 55
149Low Reproductive Efficiency ? Due to
Operational vs Physiological breeding
season Poor Heat Detection Poor Selection
Procedures Record keeping
150Estrous Cycle
Estrus - 5 7 days - period of receptivity -
ovulation
151Estrous Cycle
Diestrus - 14 - 16 days - rejection of the
stallion
152Transition
Period of time before normal cycles start.
Normal Estrus is when you have 4 days estrus 8
days of diestrus
153Breeding Procedures
- Hand Mating mare and stallion are handled by
one or more persons - Pasture Mating stallion turned out with mares
for entire breeding season - Artificial Insemination
- very controlled mating system
154Rebreeding
- Vet checked after foaling
- If no complications, start teasing day 4 or 5
post parturition - Breed on foal heat
- Continue normal breeding procedures
- Adhere to recommended feeding program
155Reproductive Management
Purpose - enhance pregnancy rate - schedule
breeding
How - lights - hormones - combination of both
156Light Therapy
- 16 hours of light (fixed) - 200 watt bulb -
read a newspaper in the stall - start Nov or
Dec - 60 - 90 days to first ovulation -
transition does occur
157Hormonal Therapy
Regumate - 12 -15 day treatment - flexible
Post - Treatment - 3 - 6 days estrus - 8 - 12
days ovulation - use PGF last treat day
158Hormonal Therapy
Prostaglandin (PGF) - luteolytic (regression of
CL) - need a CL - day 4 - side
effects sweating colic
diarrhea
159Hormonal Therapy
Prostaglandin (PGF)
Short Cycle - return to estrus - day 4 - 5 post
ovulation - estrus day 2 - 5 - ovulation day
7 - 12 - saves 1 week
160Hormonal Therapy
Prostaglandin (PGF)
Why?? - retained CL - short cycle after foal
heat - missed ovulation - twins - wrong
stallion
161Hormonal Therapy
Control Ovulation - hCG pre ovulatory
follicle ovulation in 48 hrs - GnRH
ovuplant inplant hasten ovulation
162Breeding Procedures
- Artificial Insemination
- - very controlled mating system
- - regulated by breed associations
- - safety
- - use of stallions can be improved
- - requires additional equipment
163Reproductive Management in Sheep
164Altering Season
- Three management schemes that can alter seasonal
breeding - Breed
- Light
- Hormones
165Breed
- Some breeds are less sensitive to the length of
daylight. - Example Dorset v Suffolk
- Typically, the closer the origination point of
the breed is to the equator, the less sensitive
they are to daylight.
166Daylight
- Seasonal breeding activity increases in sheep as
the length of the day decreases (fall/winter
breeders) - Estrous activity begins approximately in August
and ends in January/February. - Can alter sensitivity by putting animals in barn
for one hour in the middle of the day.
167Hormone Administration
- Out-of-season breeding can be stimulated by
administration of progesterone. - Used ½ of a norgestomet implant but.
- CIDR devices being developed for small ruminants
and should be available soon. - Lutalyse is also used to regulate the regression
of the CL
168Male Reproduction
169Reproductive Management of Males
- Reproductive management of males is the most
important aspect of reproductive management of a
herd/flock!! - Most important tool for reproductive management
in bulls is subjecting the male to a breeding
soundness exam (BSE) 30-60 days prior to the
breeding season.
170Reproductive Management of Males
- BSE has three components
- scrotal circumference
- physical exam
- semen evaluation
171Reproductive Management in Males
- Scrotal circumference
- highly correlated with semen output and quality
- The larger the yearling scrotal circumference the
larger the seminal output, the larger the serving
capacity, and the higher the quality of semen - Makes up 50 of BSE Score
172Seminal Output
n 1944
Percentage
Scrotal Circumference
173Reproductive Management in Males
- Physical exam
- Visual evaluation of the structural correctness,
health and well being of the bull. A health
history should also be taken. Illness that
results in a high fever or other heat stress can
reduce fertility for 60 days. - Rectal palpation of the accessory glands
- Electro-stimulation to observe extension of penis
and if any abnormalities exist.
174Reproductive Management in Males
- Semen evaluation
- Sperm morphology
- Sperm motility
- Evaluation
- Classified as Satisfactory, unsatisfactory, or
the classification is deferred - Only use bulls that grade satisfactory. Minimal
scrotal circumference is 30 cm at 12 months of
age.
175Reproductive Management in Males
- Management factors that affect male fertility
- Health, especially high fever
- Injury
- Nutrition
176Nutritional Management in Bulls
- Bulls fed moderate energy diets had a 52 higher
semen output than bulls fed high energy diets. - Lower fertility the result of increased fat
deposition in the scrotum and spermatic cord. - A negative correlation exists between back fat
thickness and fertility in range bulls. - Should we feed our bulls to gain gt3 lbs per day
from weaning to yearling??
177Serving Capacity
- As males mature their serving capacity increases
- Traditional
- mature bulls 130-40 cows, yearlings 110-20.
- Research indicates that bullcow ratio can be as
high as from 144 to 160 and not reduce
pregnancy rates.
178Serving Capacity
- Rams
- Mature rams 130 Ram lambs 1
- Boars and Stallions
- Hand mated or collected
179Stallions
- Puberty at 14 months of age
- Reproductive maturity at
- 6 10 years of age
- Respond to day length
180Stallion
Normal production 54 57 days
181Stallion
Production is affected by - season - frequency
of use - age - testicular size
182Appendix
183Estrus Synchronization Protocols - Beef
184MGA-PG Systems
185The MGA-PG System
0 2 4 6 8 10 12 14 16 18 20
22 24 26 28 30 32 34 36 38 39
Day of Treatment
186The MGA-PG Hybrid System
GnRH and AI
PG
Heat and AI
33 34 35 36
37
Day of Treatment
187MGA-PG System
- Advantages
- easy to administer
- inexpensive
- results in normal fertility
- induces anestrous females
- Disadvantages
- long time of administration
- Synchrony of heat not ideal
188Cow Systems
189Select Synch
0 1 2 3 4 5 6 7 8 9
10 11 12 13 14
Day of Treatment
190Addition of a CIDR
- Options
- check heat and AI
- use the Hybrid method
- use CO-Synch method
CIDR
0 1 2 3 4 5 6 7 8 9
10 11 12 13 14
Day of Treatment
191GnRH-PG Systems
- Advantages
- easy to administer
- excellent synchrony of heat
- results in normal fertility
- induces anestrous cows
- Disadvantages
- Somewhat expensive
- Not effective in heifers!
192Swine Extras
193A.I. Technician Effect
194Effect of Number of Sows Bred Consecutively by
Technician
W.L. Flowers, NCSU (2000)
195Optimal Timing of A.I. In Relation to Onset of
Estrus
196Intra-Uterine Insemination
197Intra-Uterine Insemination
- Tip of regular A.I. catheter
- Small, specialized catheter that passes through
regular A.I. catheter. - Tip of specialized catheter penetrating the
uterus body
198Intra-Uterine Insemination
- Very difficult to use with gilts (especially if
first estrus cycle). - Increased risk and frequency of bleeding in
gilts. - Can be difficult to use in sows that have had
previous traumatic births (scar tissue in
cervix). - Sanitation is critical (catheters must be
wrapped, sealed, and irradiated). - Requires training for breeding technicians.
- Only value is if low sperm doses need to be used.
199Results of Intra-Uterine A.I.
GP Goldepig catheter (regular catheter)
DGP DeepGoldenpig catheter
(intra-uterine catheter)
200Important Time Considerations
- Once semen is deposited, it takes 2-3 hours for
sperm to gain ability to fertilize egg. - Life span of sperm in female reproductive tract
is about 24 hours. - Life span of egg after ovulation is about 6-8
hours. - Time of ovulation (after onset of estrus)
- Gilts 24 to 36 hours
- Sows 36 to 48 hours
201Length of Estrus vs. Weaning-to-Estrus Interval
Adapted from J. Anim. Sci. 74944 (1996)
202Time of Ovulation vs. Length of Estrus
Adapted from J. Reprod. Fert. 10499 (1995)
203Time of Ovulation After Onset of Estrus
204Quality of Semen
205Semen Characteristics
- Gross evaluation
- General appearance milky to creamy appearance,
free of any foreign material. - Color grayish white to white color
- Pink blood contamination
- Yellow urine contamination
- Smell little odor if any
206Semen Characteristics
- Microscopic evaluation
- Motility closely related to sperm viability
(live sperm cells). - Should warm up to get true picture of motility.
- If hyper-osmotic extender used (Androhep), will
need to use caffeine coated microscope slide. - Good motility doesnt always mean good fertility
207Sperm Morphology
208Sperm Morphology
Most likely infertile
May be acceptable if no more than 40 of sperm
count
209Microscopes
Binocular Microscope 10x, 20x, 40x, 100x
objectives Built-in illuminator Mechanical
stage 800-1,000
Monocular Microscope 10x, 40x, 100x
objectives Built-in illuminator 300-400
210Length of Lactation Effects
211Recovery Process
- The length of lactation can effect the
weaning-to-estrus interval if it is so short that
it interferes with the recovery process. - After farrowing, the reproductive system requires
some time to recover from pregnancy before
another mating can take place. - There are 3 primary organs involved with the
recovery process - Ovaries
- Brain
- Uterus
212Problems with Recovery
- Sows become anestrus (absence of estrous
behavior) . - Can occur if weaning is done very early in the
recovery process (7-10 day weaning) - Brain not capable of producing sufficient LH and
FSH - Final stages of follicular growth and ovulation
do not occur. - Follicles on ovary never get large enough to
produce adequate estrogen (needed for normal
estrous cycle behavior). - Sows never cycle again
213Problems with Recovery
- Sows experience nymphomania (abnormally long and
erratic estrous period) - Can occur if weaning is done late in the recovery
process (10-14 day weaning) - Brain can produce enough LH and FSH for final
stages of follicular growth, but lacks sufficient
amounts for ovulation to occur. - Follicles grow and produce adequate estrogen for
standing reflex. - Sows will conceive when bred, but they will not
conceive because no eggs are ovulated.
214Problems with Recovery
- Anestrus and nymphomania conditions fairly easy
to detect because they are deviations from normal
estrous behavior after weaning. - More difficult to diagnose is when the brain
recovery is complete, but uterus recovery is not.
In this case - Estrus is normal.
- Sows can be bred and will conceive.
- Pregnancy is not maintained because uterus is not
sufficiently recovered to fully support embryonic
development. - May experience repeat breeders, low farrowing
rates, and (or) reductions in litter size.
215Problems with Recovery
- In general, if sows are well managed and lactate
at least 14-16 days, then the ovaries, brain, and
uterus are fully recovered. - However, the sow may experience several things
that can delay the recovery process. - Significant loss of weight and condition (less
nutrients available for recovery) low feed
intake or poor condition at farrowing. - Too few pigs to cause quieting effect of nursing
on LH and FSH secretion from brain. - Litters of small pigs that lack the sucking
intensity needed for quieting effect on brain.
216Effect of Lactation Length on Estrus and Ovulation
- Lactation lengths 14 days or greater had little
effect on duration of estrus or the
estrus-to-ovulation interval.
217Weaning-to-Estrus Interval Effects
218Factors Affecting the Weaning-to-Estrus Interval
- Poor body condition at farrowing.
- Inadequate feed intake during lactation.
- Fighting of group-housed sows following weaning.
- Inadequate feed intake immediately following
weaning. - Most sows are in a negative energy balance
following weaning. - Offer plenty of feed.
219Factors Affecting the Weaning-to-Estrus Interval
- High temperatures.
- Keep sows cool ( 85o F) ventilation, drippers,
etc. - Normal respiration rate 15-25 breaths/minute
(risk of heat stress if above 35 breaths/minute)
220The Period from Fertilization to Embryo
Implantation
221Problems with Fertilization
- Under normal circumstances, problems with
fertilization are almost exclusively and external
rather than an internal problem. - Poor detection of estrus
- Improper timing of matings
- Poor semen quality
- Poor insemination techniques
- Improper handling of sows
- Heat stress
- Etc.
222Problems with Fertilization
- One exception to this is problems that can occur
if sows are bred late in the heat period (close
to or after ovulation). - Late in the heat period a post-breeding
inflammatory response occurs in the uterus to
remove non-fertilizing sperm and bacteria
(involves white blood cells entering the uterus
to digest sperm and other debris). - Uterine contractions also occur late in the heat
period to help physically remove products of
inflammation. - If these pus-filled white blood cells are still
present in the uterus when the fertilized eggs
arrive from the oviduct, the process can be
compromised.
223Factors Affecting Fertilization and Embryo
Implantation
Late Estrus
Normal Estrus
Early Estrus
224Factors Affecting Fertilization and Embryo
Implantation
- Early embryos in the oviduct are susceptible to
stressors on the sow. - Avoid heat stress (high temperatures).
- Minimize unnecessary sow movement if sows are
to be group-housed, mix sows right after weaning. - If gilts are flushed (fed high level of energy)
prior to breeding, return to normal level of
feeding after breeding. - High energy intake during the first 30 days
following breeding can lead to high embryo
mortality in gilts (negative effect on
implantation). - Avoid heat stress and moving or comingling sows
during periods when implantation occurs (days
14-30 post-mating). - Negative impact on implantation.
225Effect of Season on Reproductive Traits
North Carolina State University study
226Horse Extras
227(No Transcript)