Calving (parturition) 10/24&26

Parturition - the process of giving birth
3 stages - Preparatory, Birthing, Placenta

Some signs of impending parturition
Distended stomach
Mammary (udders) begin to fill with milk

Anorexia

Swollen Vulva
Restlessness
Separation from the herd

Stage 1 - Dilation of the cervix begins, Rhythmic uterine contractions, the calf will rotate to the upright position, then the water sac is expelled.

Stage 2 begins with increased rate of contractions with abdominal pressing. the calf and placentas are pushed through the vagina. The proper presentation of the calf is forelegs first with the nose resting on the legs. 

Most cows calve at night (mostly to piss us off when we spend hours looking for them in zero degree weather) due to the inherited instinct that they can hide the newborns from predators better at night. One way to influence the calving time to better suit us is the Konafel Method

Feed from 11-noon and 930-11pm to cause cows to calve during the day. start about 1 month ahead of first due date. this method varies from 10% effectiveness to 80% effectiveness.

To induce a cow into labor - do not do before last 7-14 days of the gestation period.

use Dexamethasone- calving will occur in approx. 48 hours. 20-50mg/IM

Inducing causes a high incidence of retained placentas and lowers post partum fertility.

Azium mixed with 25mg of Lut will also induce a cow in 35 hours.

Induce sheep with 8-20 mg of Dex , 24-72 hours, no retained placenta.

Birthing times for cattle (normal)

heifers - 1-3 hours post water sac

cows 1-2 hours post water sac

Stage 3 - Placenta expulsion- The uterine contractions push the placenta out usually within 12 hours in cattle nd 8 - 24 hours in ewes.

Dystocia/Calving problems

Causes : High birth weights and most importantly calf shape (broad shouldered, big boned)

Presentation problems (breech, head back, legs tucked)

or Multiple Births.

10% in cows and a higher rate in heifers

Factors affecting calf size - High levels of feed and protein intake by the cow, selection of growth rate in the sire leads to a high correlation with birth weights. The breed of the dam and sire are also factors. The sire determines the gestation length usually. Age of dam, heifers average 8lb lighter calves. and finally, the size of the pelvic opening.  

The King Of Dystocia

Heat Wave

After a delay in delivery, you should conduct a pelvic examination while wearing an OB sleeve.

Determine the position of the fetus

Examine size of the calf relative to the birth canal

Then attach a pulling device (I prefer a soft rope, but most use chains)

Cesarian Section - Occurs when the calf is simply to big to go through the birth canal or is in an unmanipulative position. First the area is shaved and sanitized then anesthesia is administered 

Fetalectomy - Surgical extraction through the vagina, if the calf is too large and already dead (this is where the calve is cutup inside and pulled out, piece by piece)

Retained Placenta - failure to expel placenta, wait 48 hours then give injectible antibiotics with a uterine bolus. If placenta doesn't come out, you can pull it out, but be gentle.

Uterine Prolapse 

the uterus comes out thought the vagina, inverted. caused by a difficult birth and too much traction, subclinical milk fever and should be treated as an emergency .

Newborn calf care - look for normal respiration, free airway of mucus and phlegm. roll the calf onto sternum as this allows the calf to breathe easier. Dry and rub the calf vigorously to stimulate circulation. Dip the naval in Iodine to prevent a disease called naval ill.

Monitor colostrum intake - colostrum is the first milk the calf gets from the mother, it contains all the antibodies and nutrients to kickstart the calfs immune system. Studies show that calves who never get colostrum do poorly through life. after 24 hours, gut closure occurs and the immunglobins can't be absorbed. this is crucial. calves should receive 10% of their body weight in colostrum milk in first 24 hours.

HHEEEEYYYY

its nice to know some people actually do read this thing who are in the same class. Tell your friends and their friends too.

Hormone Flow Chart

Embryo Development

Capacitation  in cattle takes roughly 6 hours, while ovulation in cattle occurs 25-32 hours after the onset of standing heat.
Semen sexing - sex is determined by an X(female) and Y(male) chromosomes in sperm cells. A FACS machine is used to determine and separate the individual sperm based on their chromosome. They actually look at each individual sperm at a time.

Gestation Management 
Day 1- Fertilization of sperm and egg, happens in the oviduct (fallopian tubes), immediately after fertilization, cell division begins.
Different stages of development (zygote, marula, blastacyt, embryo)

Days 2-5 - Zygote passes down the oviduct and enters the uterus by day 5 post breeding.

Day 6 - Cell differentiation - different organ and tissue cells begin developing.
Ectoderm - Skin, Nervous System - External Layer
Endoderm - Lungs, thyroid, pancreatic - inner layer
Mesoderm - Muscle, skeletal system - middle layer

Maternal Recognition of Pregnancy 
recognition of pregnancy doesn't involve any conscious recognition by the mother, rather a chemical hormonal signal. The window for recognition is very narrow.

Interferon Tau is the hormone that signals a pregnancy. In sheep, (ovine) interferon  tau is released around day 12-13 and in cattle (bovine) interferon tau is released in days 15-16.

Int. Tau inhibits the production of pgf2a (prostaglandin, which destroys the CL [corpus luteum] that maintains pregnancy) no prostaglandin means a safe CL which means a stable pregnancy.

In humans - the fetus produces chorionic gonadatropin hCG - similar to LH, it binds LH receptors on the CL and stimulates progesterone production. Pregnancy tests look for hCG.

Day 14 - Embryo elongation - the embryo helps to establish its own room or space in the uterus, especially in hogs and sheep because of the multiple embryos, by elongating the cells inside.

Day 30-35 - implantation and attachment - the embryo attaches itself to the uterine wall and can now receive nutrients directly from the mother. Before implantation, the embryo had to receive nutrients from the uterine fluids.

The First Trimester - most differentiation happens while the 2nd and 3rd trimester experience mainly growth.

Fetal Growth
Bone development - day 70
Extensive Bone Development - 180
Teeth - 110
Hair, eyes, muzzle - 150
Hair on the entire body - 230
More than 50% f fetal weight comes in the last 2 months of pregnancy

Pregnancy Detection
There are several methods to detect a pregnancy in cattle. Detecting pregnancy is essential to main a productive cow herd, as it costs money every day to feed and maintain them. Non-Productive days = days when a cow isn't raising  calf or is pregnant.
Estrus detection - Cheap, easy, fairly accurate, and quick. Sometimes though, cows can display a false heat.
Rectal Palpation - most common, can be performed around day 45 of pregnancy. The vet or other person is feeling around the uterus for the fetus its self or later on can feel the weight in the uterus. Sometimes its not always accurate and can also cause abortions, not to mention it can be expensive.
Ultrasound - Detects the developing embryo as early as 25 days, extremely accurate, but the ultrasound machines are expensive.
Blood/Milk Progesterone Test - Measure the level of progesterone in in either the milk or progesterone, must be performed between 18-21 days. accuracy = 61-88 %
BioPryn - Blood pregnancy test - tests for a protein called Pregnancy Specific Protein B (PSPB) which is produced by the placenta. Can be used as early as 28 days post breeding, 90 days post calving. 99% Accurate, costs $2.40 per sample + supplies.

Artificial Insemination Basics and Estrus 10/12

Today we covered mostly things about AI. pretty basic for us show calf producers but you wouldn't believe the amount of farm kids who didn't have a clue about breeding a cow, heat detecting, semen freezing...

Semen standards for Rams

percent motility - 30% - 70%

percent normal morphology - 30%-50%

White blood cells >5

Brucella Ovis  - Negative

10-15 % of Rams fail a BSE

Male : Female ratio for breeding

18-1 for yearling bulls (1 bull for 18 cows)

30-1 for mature bulls

35to 50 - 1 mature rams

15-30 for ram lambs

Synchronized matings 1:5 or 1:10 (sheep)

Estrous Synchronization

Why synch cattle?

1. With AI, decrease time and expense of time & labor for detection of estrus

2. Success of Embryo Transfer , especially with fresh eggs. Recips have to be in the same exact level of estrus as the donor cow for fresh, non frozen implants.

3. Uniform groups of calves, calving in the same time frame. Groups of uniform animals bring higher prices at the sale and its a hell of a lot easier/less worrisome to calve in a 3 week window vs a 3 month window.

4. Labor Savings - calving can be strenuous and a pain in the ass, but its easier to make it last a shorter time vs. a longer drawn out time.

Methods of Synchronization 

1. Natural method - weaning will cause the estrous cycle to start (especially true in sows)

2. hormonal - induce or suppress estrus (Lutalyse(prostaglandin) and CIDR's)

CIDR - controlled internal drug release - suppresses estrus with progesterone, progesterone maintains a pregnancy, so if she thinks she's bred, she won't come into heat right? Once progesterone levels drop (after the CL is killed, estrogen levels come up and result in a standing heat)

Why is AI used?

1. Maximize genetic improvement. - we can use virtually any bull in the world today for a small cost and can dramatically improve the herd with ease. a $20 straw of semen cost less than a big money bull + feed + transportation + vet bills.

2. Control reproductive diseases. All bulls collected are tested for leptospirosis.

3. The use of dead or injured sires. We can use bulls from 50 years ago thanks to freezing semen. there is always semen to be had on an old bull who is still popular today (Meyer 734 for example)

Keys to Success with AI

The detection of estrus is essential to having a successful AI program. can be detected with behavioral changes and of course, standing to be bred.

2. Proper timing of insemination, having viable sperm at the time of ovulation so the sperm is alive and ready to make some babies. Breed towards the end of estrus (8-12 hours afar standing, or use the AM/PM rule)

3. Technician Skill - conception rates depend heavily on the guy putting the semen in. for instance, if he's breeding through the rectum.... he might not be the right guy for the job. the cervix is the hardest part and some techs are better at getting through it than others.

Estrus Detection

Primary Characteristic of Estrus - Standing heat. 

Secondary Characteristic of Estrus - Restlessness, chin resting, bellowing, red swollen vulva, discharge from the rear, flehman response  from bulls (lip curl) fighting, riding other cows, less feed intake. Theres quite a few ways to detect estrus even if no standing heat is observed.

most breeding mounts occur between 7pm and 7am, so check right at dark and first light.

Female Reproductive System ... from 10/7

First off, all hormone systems are the same as bulls, so reference that for the beginnings of the female system.
FSH goes to the ovaries, where it stimulates the follicle to become larger, and as it matures, it produces estrogen.
Infundibulum surrounds the ovary, catches the egg, and guides it to the oviduct.
LH (Lut) causes ovulation.
Corpus Luteum - forms where the follicle breaks open (to release the egg) . Produces Progesterone which protects the pregnancy.

ovary_l.jpg
images

Cysterella = GnRH
Lutalyse = Prostaglandin

Lut kills the Corpus Luteum, which in turn, will terminate the pregnancy.


Superovulation - excess FSH is given to produce multiple follicles to in turn, produce more eggs (for flushing)

oviduct - transports the egg and sperm to the site of fertilization, transferred by cilia
Uterus - transports the sperm from the cervix to oviduct, site of embryo implantation, where the calf develops... produces prostaglandin

Vagina and vulva... we know what those are.

Hormones
Estrus - in standing heat, willing to be bred. Due to increased concentrations of estrogen
Estrous Cycle - period of time from one estrus to the next , average of 21 days for cows, 17 for ewes

estrus period - cow 12-18 hours, ewe 24-36 hours

Axis.jpg
http://beef.unl.edu/learning/estrous.shtml

Reproductive Systems! ...from 10/5

I'm skipping over the sheep breeds lecture notes...

Male Reproductive System
GnRH Gonadotropin-releasing hormone (GnRH), also known as Luteinizing-hormone-releasing hormone (LHRH) and luliberin, is a tropic peptide hormone responsible for the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary. GnRH is synthesized and released from neurons within the hypothalamus. The peptide belongs to gonadotropin-releasing hormone family.


starts in the hypothalamus, goes to pituitary gland and releases FSH and LH.


Luteinizing hormone (LH, also known as lutropin^[1]) is a hormone produced by the anterior pituitary gland. In females, an acute rise of LH called the LH surge triggers ovulation^[2] and development of the corpus luteum. In males, where LH had also been called interstitial cell-stimulating hormone (ICSH),^[3] it stimulates Leydig cell production of testosterone.^[4] It acts synergistically with FSH.


Follicle-stimulating hormone (FSH) is a hormone found in humans and other animals. It is synthesized and secreted by gonadotrophs of the anterior pituitary gland. FSH regulates the development, growth, pubertal maturation, and reproductive processes of the body. FSH andLuteinizing hormone (LH) act synergistically in reproduction.

Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles,^[1]birds,^[2] and other vertebrates. In mammals, testosterone is primarily secreted in the testes ofmales and the ovaries of females, although small amounts are also secreted by the adrenal glands. It is the principal male sex hormone and an anabolic steroid.

]

In men, testosterone plays a key role in the development of male reproductive tissues such as thetestis and prostate as well as promoting secondary sexual characteristics such as increasedmuscle, bone mass and the growth of body-hair.^[3] In addition, testosterone is essential for health and well-being^[4] as well as the prevention of osteoporosis.^[5]

Testosterone is observed in most vertebrates. Fish make a slightly different form called 11-ketotestosterone.^[7] Its counterpart in insects is ecdysone.^[8] These ubiquitous steroids suggest that sex hormones have an ancient evolutionary history.^[9]

Leydig cells, also known as interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle. They produce testosterone in the presence of luteinizing hormone (LH). Leydig cells are polyhedral in shape, display a large prominent nucleus, an eosinophiliccytoplasm and numerous lipid-filled vesicles. They are responsible for sperm production, semifonius tubules, spermatogenia .

Testosterone Aids in muscle building and LIBIDO (sex drive)

Oxytocin is best known for its roles in female reproduction. It is released in large amounts 1) after distension of the cervix and uterus during labor, and 2) after stimulation of the nipples, facilitating birth and breastfeeding. Recent studies have begun to investigate oxytocin's role in various behaviors, including orgasm, social recognition, pair bonding, anxiety, and maternal behaviors.^[2] For this reason, it is sometimes referred to as the "love hormone".^[3]


oxytocin causes contractions in smooth muscle in the scrotum, causing ejaculation.


Epidymis - where the sperm matures, takes 45-50 days, 7 days in the epidymis


Vas deferens - transports sperm from testes during ejaculation, connects to urethra


ACCESSORY SEX ORGANS
Seminal Vesical
prostate gland
bulbourethral (Cowpers) gland


functions of ASO
Add fluid volume, nutrients, and alkaline buffers to semen
sperm plus ASO fluid = SEMEN


Carrier proteins - Albumin - protects the sperm


Anti-biotics are put into semen extenders to protect the sperm, cows, and offspring from common breeding diseases like Leptospirosis 


PENIS
the bulls penis is fibroelastic, and is a sigmoid flexure type (S shaped) it extends upon erection , allowing forextension. found in boars, bulls, and rams.
g02016art01.jpg

ejaculation
Bulls - 5ml - 1.1billion per ml. - low volume, high concentration

the head of the sperm carries genetic info
Aerosome, contacts egg and releases chemicals to dissolve the jelly coat around egg.
The tail pushes the sperm into the egg. it does NOT "swim all the way there"

Bulls reach sexual maturity at 12 months or a 26cm Scrotal Circumference