materi 10 laktasi dan puerpureum mk. ilmu reproduksi 1lab. reproduksi ternak fapet ub
TRANSCRIPT
Lab. Reproduksi Ternak Fapet UB 1
MATERI 10LAKTASI DAN PUERPUREUM
MK. ILMU REPRODUKSI
Lab. Reproduksi Ternak Fapet UB 2
SUB POKOK BAHASAN
• Proses laktasi (Mekanisme Let down susu)• Peranan Laktasi bagi Reproduksi• Proses Pengembalian organ reproduksi post
partum• Peran hormon prolaktin pada pembentukan
susu dan pengaruhnya terhadap an estrus serta pengaruh oxytosin terharap letdown susu
Learning Objectives
To understand what influences the postpartum interval to rebreeding.
To understand how the postpartum period can be managed to reduce the interval from parturition to conception
Postpartum Period: Time from parturition to 1st fertile estrus.
Sows: Infertile estrus. 3-10 days postpartum 1st fertile estrus after weaning.
Ewes: Non-seasonal ewes. Non-fertile 1st cycle as ewe does not express heat 21 days postpartum approximately 40 days to 1st fertile estrus.
Mares: Foal heat. 5-15 days postpartum (Can be fertile). Next estrus 30 days postpartum. Cows: 1st estrus 30-40 days postpartum in dairy cows and 40- 60 days in beef cattle.
Not very common21 to 35 Days Postpartum
Remember lamb in spring breed in fall. Summer anestrusFirst ovulation there is no visible sign of heat. Need progesteronepriming
Beef cattle can sometimes express short cycles of 12 days longif early in postpartum period (<40 days). Next estrus is OK!Can use SMB (progesterone priming) to remove problem
Factors Affecting the Postpartum Period:
1. Body condition pre- and postpartum
2. Plane of Nutrition
3. Lactation stress
4. Suckling stimulus
5. Photoperiod
6. Temperature
7. Presence of male
Pre is most importantBody condition at calving
Need to be concerned about plane ofnutrition before and after calving based on BCS
Nutritional stress imposed by mammary gland
Blocks release of GnRH which then reducesLH to stimulate ovary follicular development
Seasonal breeders: Mare and ewe
Short expression of estrus
Placement of male with females will decreasetime to estrus. Especially important in theewe (Ram Effect)
Severely emaciated: All ribs andbone structure easily visible andphysically weak. Animals havedifficulty standing or walking.No external fat present by sight ortouch.
Body Condition Scoring System
BCS 1
Emaciated: Similar to 1, but notweakened.
BCS 2
Pictures courtesy of Dr. Robert P. Wettemann
BCS 3
BCS 4
Very thin: No palpable or visible faton ribs or brisket.
Individual muscles in the hind quartersare easily visible and spinusprocesses are very apparent.
Thin: Ribs and pin bones are easilyvisible and fat is not apparent bypalpation on ribs or pin bones.
Individual muscles in the hind quarterare apparent
Pictures courtesy of Dr. Robert P. Wettemann
BCS 6
BCS 5
Moderate: Ribs are less apparentthan in a 4 and have less than1/2 cm of fat on them. Last 2-3 ribscan be felt easily (less then .5 cmof fat). No fat in the brisket.At least 1cm of fat can be palpatedon pinbones. Individual muscles inhind quarter are not apparent.
Good: Smooth appearancethroughout. Some fat deposition inbrisket.Individual ribs are not visible.About 2 cm of fat on the pin bonesand about 1 cm of fat on last2-3 ribs.
Pictures courtesy of Dr. Robert P. Wettemann
BCS 8
BCS 7
Good: Brisket is full, tailheadand pin bones have protrudingdeposits of fat on them.Back appears square due to fat.Indentation over spinal cord dueto fat on each side.One to two cm of fat on last 2-3 ribs.
Obese: Back is very square. Brisket is distended with fat.Large protruding deposits of faton tailhead and pin bones.Neck is thick.Three to four cm of fat on last2-3 ribs.Large indentation over spinal cord.
Wagner et al. 1988.J. Anim. Sci. 66:603 Pictures courtesy of Dr. Robert P. Wettemann
Nutrition of Beef Cows
Estrus Response:
Cows that calve in BCS of 5-6 return to estrus sooner than cows in < BCS 5
It is difficult to put on BCS after calving without allot of expense
Pregnancy Response:
Cows fed to maintain or gain weight from calving through breeding have higher pregnancy rate than cows losing weight
Cows can lose weight after calving and be flushed 2 weeks prior to and through breeding season, achieve a comparable pregnancy rate to cows fed adequately throughout the breeding season.
Calf Performance:
Cows that lose weight after calving wean lighter calves than those cows that maintain or gain weight
This information would be true of cows in low BCS < 5
Suckling Effects: Inhibits FSH and LH release.
Sows - Normal weaning 21-35 days postpartum
Weaning Days to
Days Postpartum Estrus Littersize
10 12 10.5
15-21 7 11.5
24 5 11.7
Too early- Smallerlitter (2 less)
Normalsynchronized heatin 4-7 days.
Sows which do not express estrus by 6 days can betreated with P.G. 600
Cattle - Postpartum interval to 1st estrus.
12-74 Days Dairy cows milked 2x/Day
46-104 Days. Suckled Beef Cows
~14 Days. Mastectomized Cows.
Average = 35 Days
Average = 60 Days
Difference cause bynutrition and suckling
Removal of mammary gland
Weaning is essentially the same effect!
Endocrine changes for 1st postpartum estrus in cattle:
in tonic LH causes progesterone
Source of progesterone?
1. Ovary 2.Adrenal (?)
Progesterone primes the brain 1. For behavior estrus 2. For surge of LH
- Need a in progesterone for 1.For behavioral estrus 2.For LH surge - With progesterone, follicular growth and estrogens increase to cause LH surge.
- Luteinized follicle
Stimulates activity
Synchromate B may functionin similar fashion. Anestruscows stimulated withprogesterone injection or implant . Need to be close to cycling to respond. Deepanestrus has no effect
Management techniques to shorten the postpartum interval:
Feed intake of sows (flushing) after weaning helps.
Maintain animals in moderate to good body condition.
Avoid weight loss unless over conditioned.
Early weaning to remove suckling effect
Sows at 21 days postpartum
Cows at ~50 days postpartum
Calf separation for 48 hours at 40-50 days postpartum.
Once a day suckling.
Increase energy prior to estrus (7days) then backto normal after heat. Increase ovulation rate
Beef cattle before calving
Beef cattle after calving
Only as last choice
Part of Synchromate B system
Allow suckling for only 2 hours/day!
Effect of once-daily suckling on reproductive performance of Brahman x Hereford heifers and their calves Treatment Criteria Normal Suckling Once-daily Suckling
Number of cows 16 19
Percentage of cows in estrus by 90 days 6 74 after calving
Interval from calving to first estrus (days) 168±14 69±6
Weaning weights of calves (lbs) 323±11 324±10
Adapted from Randel, 1981. J. Anim. Sci. 53:755-757
Hereford Heifers Weaned at 6-8 weeks Not weaned
# of heifers 31 32
Days from calving to conception 70 90.5
% heifers pregnant during breeding season 97 59
7 month weaning weights 374 lbs 372 lbs
Lusby et al., 1981. J. Anim. Sci. 53:1193-1197
Learning Objective
To understand the anatomy of a mammary gland, how the mammary gland develops, how it secretes milk, what controls milk secretion and why colostrum is important
Anatomy of the Mammary Gland
COW
Cow: 4 Glands 1 gland/teatEwe & Doe: 2 Glands 1 gland/teat
Synthesis of Milk
Storage area100-400 g ofMilk
Opening
LobeLobule which contains
Alveoli
Alveoli
Primary and SecondaryDucts (Non-secretory)
Teat Meatus
TeatCistern
GlandCistern
Redrawn from Bearden, H.J. andFuquay, J.W. (1997) Applied Animal Reproduction
Suspension of the Mammary Gland
Lateral SuspensoryLigament
Medial Suspensory Ligament
From Swett et al. 1942. J. Agric Res. 65:19-42
Anatomy of the Mammary Gland
COW
TeatCistern
GlandCistern
Alveolia
From Swett et al. 1942. J. Agric Res. 65:19-42
Mammary Gland of Sow and Mare
Sow: 10-14 teats 2 glands/teatMare: 2 teats 2 glands/teat
Gland CisternTeat Cistern
Streak Canal
Alveoli
Bloodflow isvery importantBrings substratesfor milk production500 liters of bloodneeded to produce1 liter of milk
Arteriole
EpithelialCells
Lumen
Oxytocin stimulates
contractionDuct
Passage of milk togland cistern
Venuole
Myoepithelium
Capillary
Synthesize milk
Redrawn from Bearden, H.J. andFuquay, J.W. (1997) Applied Animal Reproduction
Comparison of Colostrum to True Milk Approximate composition of colostrum and normal Holstein milk
First-Milk 2nd and 3rd Day Colostrum Colostrum MilkConstituent (percent) (percent) (percent) Fat 6.0 3.5 3.5
Nonfat solids 22.3 12.5 8.8
Protein 18.8 7.5 3.25
Immune globulins 13.1 1.0 0.09
Lactose 2.5 4.0 4.60
Decreasewith time
Decreasewith time
Calf can absorb immunoglobulins with decreasing efficiencyup to 24 hours after birth
Calf's immune system not functional until 1-2 months postpartum
Antibodies - absorption in gut decreases with time especiallyafter gut is stimulated.Example: Milk given without colostrum will stimulate gut closure for absorption of immunglobulinsImmunoglobins in calf are as high as dam within a few hours
Colostrum provides passive immunityNeed to give newborn calf at 5% of body wt in colostrumFoal may also need extra colostrum - Check IgG in blood 18-36 hrs from foaling Test IgG Blood Levels Failure of immune transfer < 400 mg/DL Partial transfer 400-800 mg/DL Normal > 800 mg/DLTreatment if deficient: Colostrum from other mares Infuse serum or plasma IgG i.v.
True Milk Production: 500-1000 liters of blood pass through gland to produce 1 liter of milk.
Blood precursors of the milk constituents in the ruminant Milk constituent Blood Precursor Water Water Lactose Glucose Protein Casein Amino Acids ß-Lactoglobulin Amino Acids a-lactalbumin Amino Acids Milk serum albumin Blood serum albumin Immune globulins Immune globulins Fat Fatty acids Acetate, ß-hydroxybutyrate, blood lipids Glycerol Glucose, Glycerol from triglycerides Minerals Minerals Vitamins Vitamins
Unique to milk
Epithelium of Alveolus
Capillary Myoepithelial Cell
EndoplasmicReticulum
Fat Droplet
Golgi
ProteinSecretion
Mitochondria
Nucleus
Maintenance of Milk Production:
Metabolic hormones involved Thyroxine & Triiodothyroine (Thyroid) Insulin and Insulin-like Growth Factor IGF-I
Corticosteroids
Growth hormone
Nutrition is also important
Note: Prolactin is important forfirst secretion of milk but mayplay only a minor role after thestart of lactation
Can utilize Bovine Somatotropin (BST) - Trade-name Posilacto increase milk production (5-15 lb/day). Growth Hormonestimulates IGF-I from liver which affects milk production. It increases metabolism of body fat stores and bloodflow to mammary gland.Dairy cows start at 63 days of lactation (9th week of lactation)
Need suckling stimulus + removal of milk oxytocin - milk let down As gland fills, pressure shuts off milk secretion Example: Milk a cow 2x vs. 3x/Day, Get a 15-20% in milk production
Problems with milk-let down: Fear or Stress Causes adrenalin which inhibits oxytocin release
Response of myoepithelial cells to oxytocin
Vasoconstricts - oxytocin supply to gland
Stimulates myoepithelial cells ofalveolus
Fills usually within 6 hours
Milk 305 days - 60 days dry-off period. Allows time fortissue to regenerate itself. When wean calf gland fills stopping secretion byepithelium which degenerate and are absorbed. New cells develop underprolactin stimulation in late pregnancy