Reproduction

1
Reproduction

• Dr. Les Anderson
• Dr. George Heersche, Jr.
• Dr. Bob Coleman
• Dr. Richard Coffey
• Introduction to Animal and Food Sciences Agent
  In-Service

2
Who Cares?

• Reproductive efficiency is the primary
  determinant of gross income in most animal
  industries.

3
Lecture Outline

• Terminology
• Anatomy
• Reproductive States
• The Estrous Cycle
• Periods of Anestrus
• Pregnancy
• Parturition

4
Gender Terms

• Cow, Bull, Heifer, Steer
• Ewe, Ram (Buck), Ewe lamb, Wether
• Sow, Boar, Gilt, Barrow
• Mare, Stallion, Colt, Filly, Gelding
• Doe, Buck, Kid

5
Reproduction Classifications

• Seasonal vs nonseasonal
• Sheep short day breeders
• Horses long day breeders
• Cattle no effect
• Swine no effect
• Cyclic vs acyclic
• Poultry
• Other species

6
Reproductive Tract - Cow

• Vu Vulva
• AV Ant. Vagina
• CX Cerix
• UH Uterine Horn
• OD Oviduct
• O Ovary
• UB - Urinary Bladder

7
Reproductive Tract - Sow

• Vu Vulva
• AV Ant. Vagina
• CX Cerix
• UH Uterine Horn
• OD Oviduct
• O Ovary
• UB - Urinary Bladder

8
Reproductive Tract - Ewe

• Vu Vulva
• AV Ant. Vagina
• CX Cerix
• UH Uterine Horn
• OD Oviduct
• O Ovary
• UB - Urinary Bladder

9
Reproductive Tract - Mare

• Vu Vulva
• AV Ant. Vagina
• CX Cerix
• UH Uterine Horn
• OD Oviduct
• O Ovary
• UB Urinary Bladder

10
Reproductive 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

11
Reproductive 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

12
Reproductive 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

13
Reproductive 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.

14
Estrous 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

15
Estrous 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

16
Ovarian Cycle

• Def Changes in the structures on the ovary that
  result in the cyclic reproductive activity of a
  female.

17
Ovarian Structures

• Follicles
• Balloon-like structures
• Contain the oocyte (egg)
• Produces estrogen
• Corpus Luteum (CL)
• Solid structure
• Produces progesterone

18
The Ovarian Cycle
Heat
19
Cyclic Hormonal Changes
PG
Progesterone ----
Estrogen ____
Heat
Heat
20
Cyclic Hormonal Changes
PG
Progesterone ----
Estrogen ____
Heat
21
Anestrus

• When?
• Prior to Puberty
• After Parturition
• Season

22
Puberty

• 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.

23
Postpartum 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.

24
Postpartum 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

25
Postpartum Reproductive Activity Cow

Heat
Heat
Heat
Heat
Calve
Ovulation
26
Postpartum 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).

27
Postpartum 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.

28
Seasonal 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.

29
Seasonal 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.

30
Seasonal 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.

31
Pregnancy

• 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.

32
Pregnancy

• 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

33
Anatomy of Pregnancy
34
Pregnancy

• Gestation length
• Cattle 283 days
• Sheep 148 days
• Swine 114 days
• Horses 335 days

35
Pregnancy

• Parturition (birthing)
• Stimulated by the fetus
• fetus cortisol
• placenta Prostaglandin F
• ovary CL regresses, releases
• oxytocin
• Uterus contractions begin

36
Poultry Reproduction
37
Anatomy
38
The Ovary
39
Egg Production
40
Egg Production
41
Egg Production
42
Egg Production
43
Egg 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

44
Managing Reproduction
45
Managing 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

46
Managing Reproduction

• How?
• Control the onset of a fertile estrus
• Hormones
• Light
• Weaning
• Major obstacle to overcome
• Anestrus
• Lactational, nutritional, seasonal, pubertal

47
Controlling the Onset of Estrus

• What is estrus?
• How can we regulate its onset

48
Estrus Behavior
49
Signs 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

50
Mobility Increases
51
Vocalization Increases
52
Reproductive Tracts Changes

• Swollen, red vulva
• Cervical mucous is produced and excreted.

53
Signs 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

54
Signs of Estrus (Standing Heat)

• Tail held high to fully expose vulva.

• Characteristic rigid stance and ear popping
  response to back pressure.

55
Standing Estrus
56
Checking 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.

57
Checking Estrus - Cattle
58
Checking 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

59
Effects on Standing Response
60
Checking Estrus - Mares

• Done daily during the breeding season
• Involves bringing a male to the breeding pastures
• Called Teasing

61
Teasing
- Critical part of the breeding program - Done
daily - Very observant - Keep good records
62
(No Transcript)
63
(No Transcript)
64
(No Transcript)
65
Estrus Synchronization
66
Products 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.

67
What 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

68
What 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

69
What 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

70
What 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

71
EAZI-BREED CIDR Cattle Insert
72
Products 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!!!

73
Products 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

74
Beef and Dairy Cattle Estrus Synchronization
Protocols
75
The 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
76
Hybrid 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
77
CO-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
78
Addition of a CIDR to CO-Synch
66
59
51
51
Stevenson et al., 1999
79
Typical Results (Beef) - KY
Percentage
80
Artificial Insemination
81
What is the Goal?

• To put the optimal number of sperm cells in
  contact with ovulated egg(s) from the female.

82
Successful A.I. Depends On

• Females displaying cyclic activity
• Identification of individual heat periods
• Timing of insemination
• Quality of semen
• Proper insemination techniques

83
AI 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

84
AI In Cattle
85
AI in Swine
86
Which Pipette to Use?

• Disposable vs. reusable
• Smooth edges
• Molded vs. glued-on tip

• Closed cell foam vs. sponge
• Spiral tip vs. plug shape

87
Female Reproductive Tract
88
Inserting 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)

89
Inserting 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)

90
Inserting 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.

91
Depositing 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).

92
Depositing 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.

93
Things 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.

94
Timing of Insemination
95
Timing of Insemination for GILTS with Twice Daily
Heat Detection
Gilts may show visible signs of heat
Standing Heat
OVULATION
Matings
96
Timing of Insemination for SOWS with Twice Daily
Heat Detection
Sows may show visible signs of heat
Standing Heat
OVULATION
Matings
97
Timing 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!!!

98
Timing of Inseminations
99
Artificial Insemination in Sheep
100
Sheep AI Very difficult

• Cervix is small and cervical canal is difficult
  to transverse.
• Over-the-Rail method is typically used.

101
Insemination/Breeding in Mares
102
AI 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.

103
AI in Mares
104
AI in Mares
105
Reproductive Management
106
Beef Cattle
107
Enhancing 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

108
First 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.

109
Calving Distribution
110
180-Day Calving Season
18,614 lbs Avg 443 lbs
111
Goals Reached
29,874 lbs Avg 554 lbs
11,260 lbs!
112
Controlled 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

113
Controlled Calving Season

• Disadvantages
• Increased labor over short calving period
• Increased management requirements

114
Tools to Enhance Percent Calf Crop Weaned and
Calving Distribution

• Estrus synchronization
• Proper heifer development
• Proper young cow development
• Proper bull management and selection

115
Simple Reproductive Management System
116
Estrus 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
117
Estrus 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

118
Estrus 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 )

119
Return on Investment

• 15 increase in pregnancy rate
• 40 extra pounds at weaning per calf
• Estimated return on investment 100 per cow

120
Estrus 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.

121
Reproductive Management in Dairy Cattle
122
Dairy 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

123
WE HAVE TRIED TO FOOL MOTHER NATURE
124
Mothers original plan get pregnant give
birth to live calf produce milk for calf do
it again...
125
Mothers nutritional priorities

• Growth and maintenance of mother
• Growth and maintenance of the fetus
• Milk for the calf
• Reproduce again

126
We ask cows to be super females produce large
amount of milk reproduce regularly be
trouble free be happy about the whole deal
127
Mother and AI Humans heat detection
challenged Successful A.I. Requires
management Hassle and requires
diligence Worth the effort
128
Trying to accomplish things not in Mothers
original plan for the cow or us. Strive to do
the best we can.
129
Reasonable FertilityCows 40 2.5
S/CHeifers 75 1.3 S/C
130
Manage 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
131
Manage 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
132
Heat 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
133
Make A.I. Work talented players good
coaching
134
A.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
135
Inefficient 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

136
Heat 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
137
Proper Timing of Insemination ovulation 28h
egg lives lt 12h sperm lives 24h
capacitation goal a.m. - p.m./p.m.- a.m.
1x
138
High-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
139
High-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
140
Health Care involve veterinarian
vaccination program lepto hardjo-bovis
mastitis foot problems
141
Reproductive Management in Swine
142
Swine 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

143
Critical 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)
144
Estrous Synchronization in Gilts
145
MATRIX 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.

146
Equine
147
Breeding Basics
148
Reproduction Rate
Biological Rate 100
Theoretical Rate 95
Industry Rate 70
Foal Registration 55
149
Low Reproductive Efficiency ? Due to
Operational vs Physiological breeding
season Poor Heat Detection Poor Selection
Procedures Record keeping
150
Estrous Cycle
Estrus - 5 7 days - period of receptivity -
ovulation
151
Estrous Cycle
Diestrus - 14 - 16 days - rejection of the
stallion
152
Transition
Period of time before normal cycles start.
Normal Estrus is when you have 4 days estrus 8
days of diestrus
153
Breeding 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

154
Rebreeding

• 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

155
Reproductive Management
Purpose - enhance pregnancy rate - schedule
breeding
How - lights - hormones - combination of both
156
Light 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
157
Hormonal Therapy
Regumate - 12 -15 day treatment - flexible
Post - Treatment - 3 - 6 days estrus - 8 - 12
days ovulation - use PGF last treat day
158
Hormonal Therapy
Prostaglandin (PGF) - luteolytic (regression of
CL) - need a CL - day 4 - side
effects sweating colic
diarrhea
159
Hormonal Therapy
Prostaglandin (PGF)
Short Cycle - return to estrus - day 4 - 5 post
ovulation - estrus day 2 - 5 - ovulation day
7 - 12 - saves 1 week
160
Hormonal Therapy
Prostaglandin (PGF)
Why?? - retained CL - short cycle after foal
heat - missed ovulation - twins - wrong
stallion
161
Hormonal Therapy
Control Ovulation - hCG pre ovulatory
follicle ovulation in 48 hrs - GnRH
ovuplant inplant hasten ovulation
162
Breeding Procedures

• Artificial Insemination
• - very controlled mating system
• - regulated by breed associations
• - safety
• - use of stallions can be improved
• - requires additional equipment

163
Reproductive Management in Sheep
164
Altering Season

• Three management schemes that can alter seasonal
  breeding
• Breed
• Light
• Hormones

165
Breed

• 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.

166
Daylight

• 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.

167
Hormone 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

168
Male Reproduction
169
Reproductive 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.

170
Reproductive Management of Males

• BSE has three components
• scrotal circumference
• physical exam
• semen evaluation

171
Reproductive 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

172
Seminal Output
n 1944
Percentage
Scrotal Circumference
173
Reproductive 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.

174
Reproductive 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.

175
Reproductive Management in Males

• Management factors that affect male fertility
• Health, especially high fever
• Injury
• Nutrition

176
Nutritional 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??

177
Serving 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.

178
Serving Capacity

• Rams
• Mature rams 130 Ram lambs 1
• Boars and Stallions
• Hand mated or collected

179
Stallions

• Puberty at 14 months of age
• Reproductive maturity at
• 6 10 years of age
• Respond to day length

180
Stallion
Normal production 54 57 days
181
Stallion
Production is affected by - season - frequency
of use - age - testicular size
182
Appendix
183
Estrus Synchronization Protocols - Beef
184
MGA-PG Systems
185
The 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
186
The MGA-PG Hybrid System
GnRH and AI
PG
Heat and AI
33 34 35 36
37
Day of Treatment
187
MGA-PG System

• Advantages
• easy to administer
• inexpensive
• results in normal fertility
• induces anestrous females
• Disadvantages
• long time of administration
• Synchrony of heat not ideal

188
Cow Systems
189
Select Synch
0 1 2 3 4 5 6 7 8 9
10 11 12 13 14
Day of Treatment
190
Addition 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
191
GnRH-PG Systems

• Advantages
• easy to administer
• excellent synchrony of heat
• results in normal fertility
• induces anestrous cows
• Disadvantages
• Somewhat expensive
• Not effective in heifers!

192
Swine Extras
193
A.I. Technician Effect
194
Effect of Number of Sows Bred Consecutively by
Technician
W.L. Flowers, NCSU (2000)
195
Optimal Timing of A.I. In Relation to Onset of
Estrus
196
Intra-Uterine Insemination
197
Intra-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

198
Intra-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.

199
Results of Intra-Uterine A.I.
GP Goldepig catheter (regular catheter)
DGP DeepGoldenpig catheter
(intra-uterine catheter)
200
Important 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

201
Length of Estrus vs. Weaning-to-Estrus Interval
Adapted from J. Anim. Sci. 74944 (1996)
202
Time of Ovulation vs. Length of Estrus
Adapted from J. Reprod. Fert. 10499 (1995)
203
Time of Ovulation After Onset of Estrus
204
Quality of Semen
205
Semen 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

206
Semen 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

207
Sperm Morphology
208
Sperm Morphology
Most likely infertile
May be acceptable if no more than 40 of sperm
count
209
Microscopes
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
210
Length of Lactation Effects
211
Recovery 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

212
Problems 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

213
Problems 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.

214
Problems 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.

215
Problems 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.

216
Effect 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.

217
Weaning-to-Estrus Interval Effects
218
Factors 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.

219
Factors 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)

220
The Period from Fertilization to Embryo
Implantation
221
Problems 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.

222
Problems 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.

223
Factors Affecting Fertilization and Embryo
Implantation

• Timing of matings

Late Estrus
Normal Estrus
Early Estrus
224
Factors 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.

225
Effect of Season on Reproductive Traits
North Carolina State University study
226
Horse Extras
227
(No Transcript)