Bovine Repro Drugs

What is cystorelin and feragyl?

Gonadorelin diacetate tetrayhydrate

What was Gonadorelin diacetate tetrahydrate originally approved for?

Ovarian follicular cysts in dairy cattle but also approved for use in combination with cloprostenol sodium

What is a clinical nuance of GnRH?

There are conflicting results in clinical trials comparing types of GnRH

What is Lutalyse HighCon?

High concentrations PGF2alphaa that is only approved in cattle

What is cloprostenol sodium?

PGF2alpha

What is PGF2alphas approved for?

Treatment of pyometra or chronic endometritis, luteal cysts, estrus synchronization, treatment of mummified fetus

When do you need to remove P4 implants?

After 7 days

What are some clinical nuances of P4 implants?

CIDRs will keep P4 within their matrix after use (re-use is not inferior)

Progesterone can be absorbed through skin of humans

Blue tail on the end should be cut out because heifers like to pull CIDRs out

What is the only P4 implant approved in the US?

EAZI-BREED CIDR

What is melengesterol acetate?

P4 analogue used for growth promotion and suppression of estrus

Can also be used to synchronize cattle b pulling the drug at the same time

Must wait until second estrus to breed

What are some clinical nuances of P4 medicated articles like melengestrol acetate?

Cheaper and less labor than CIDR

What does P4 do during pregnancy?

Secreted from CL and placenta inhibiting myometrial contraction (P4 block)

What does E2 do during pregnancy?

Secreted from placenta signaling early parturition and increases cervical and vaginal secretions

What does cortisol do during pregnancy?

Secreted by fetus to tell the placenta to convert P4 to E2 decreased P4 levels and removing the block.

This causes the placenta to synthesize PGF2a

What is PGF2alpha during parturition?

Lyses CL and drops P4

Stimulates relaxin

Stimulates myometrial contractions indirectly

What does oxytocin do during parturition?

Released from posterior pituitary in response to afferent neuron stimulation from cervix

Causes myometrial contractions

What drugs are used to manage pregnancy and parturition?

Progesterone, corticosteroids, prostaglandin F2alpha, oxytocin, lidocaine, epi

How can you induce parturition?

Dexamethasone and PGF2alpha late in gestation but will increase risk of retained placenta

Should not be given until after 270 days gestation

What regulates lactation

hormonal signals

What is lactogenesis?

Development of mammary gland and initiation of milk production in gland

What is galactopoiesis?

Maintaining milk production once it has started

What are lacto ang galactopoiesis dependent on?

Prolactin and somatropin

What is domperidone?

Dopamine antagonist that induces prolactin release

What does melatonin supplementation do to lactation?

Decreases prolactin production

What is oxytocin approved for?

Precipitate labor

Accelerate parturition

Evacuation of uterine debris

Contraction of uterus after C-section and control hemorrhage

Can be used to contract smooth muscle in mammary gland to induce milk let-down if udder is in proper physiological state

Where can ovarian cysts be?

Follicular (responds to gonadorelin)

Luteal (responds to prostaglandin)

Can just treat with each if unsure the type

What are the uterine diseases?

Pyometra

Endometritis

Metritis

What are the types of dystocia?

Malpresentation

Fetal-maternal mismatch

How do you treat pyometra/endometritis?

PGF2alpha

What antibiotic is labelled for lactating dairy cattle?

Ceftiofur cystalline free acid (Excede)

What antibiotics are not prohibited for use in lactating dairy cattle?

Ceftiofure hydrochloride

oxytet

What is the most common disease in dairy cattle?

Mastitis also most common use of antibiotics in diaries

What is the most commonly used drug to treat mastitis?

Cephalosporins

What should you do every time you have to treat mastitis?

Discuss diagnosis, prevention, and management too

What happens to a follicle after ovulation?

Fills with blood and becomes and corpus hemorrhagicum until it is becomes a CL

What does CL release?

Progesterone

What does estrogen levels mimic?

Size of follicles

What occurs during metestrus?

Estrogen levels fall and follicle undergoes luteinization

What occurs during diestru?

High progesterone

What happens during proestrus?

Progesterone falls and estrogen rises

CL lyses

What happens during estrus?

Ovulation and high levels of estrogen

What is Gonadorelin hydrochloride?

Synthetic GnRH analog approved for ovarian cysts and synchronization

0 day withdrawal

What is the difference between GnRH products?

Conflicting study results. Some say Factrel is worse than others, one says no difference,

What is the difference between detecting a difference and showing non-inferiority?

Easier to prove there is not a difference

Non-inferiority has a null hypothesis that says this drug is not worse

(metestrus)

Nothing, just started a follicular wave

Diestrus

No effect on CL but will leutanize dominant and subordinate follicles starting a new follicular wave

(estrus)

More narrow ovulation window impacting late ovulators

What is PGF2alpha (lutalyse) used for?

Induce luteolysis to synchronize estrus or induce abortion

Stimulate uterine contractions (pyometras)

What are the clinical nuances of PGF2alpha

Can absorb through skin and cause abortion in humans

Can induce bronchospasms in asthmatics

Can make dogs and camelids sick

Metestrus

No effect on corpus hemorrhagicum

Diestrus

Luteolysis and a drop in p4

If dominant follicle is present then CL will form soon

Estrus

Nothing

What is OvSynch?

Combine GnRH and PGF2alpha to synchronize cycles in cows using a single GnRH shot

What happens if you give GnRH in the first few days of cycle during OvSynch?

Little effect but they are where you want them to be anyway

What happens if you give GnRH during diestrus with OvSynch?

Antral follicles and dominant follicles will luteinize starting a new follicular wave

What happens if you give GnRH to a cow that is during proestrus/estrus during OvSynch?

Ovulation of dominant follicle that with luteinize starting a follicular wave

What are the steps of OvSynch?

Give GnRH

PGF2alpha 2 days after to cause ovulation

All cows will be in synch

What happens if you put in a CIDR then give PGF2alpha?

Will increase progesterone so a CL is ready to lyse then PGF2alpha will lyse it when you want

Does not matter when you put in CIDR

Can you give CIDR, GnRH, and PGF2alpha at once?

Technically off label so no

What is the main difference between MGA and a CIDR?

The first oocyte after an MGA is less fertile than first oocyte on CIDR so need to wait for the second cycle

What secretes pregnancy specific protein B?

Chorionic binucleate giant cells

Used to diagnose pregnancy

What produces lactogens?

Placenta and fetus

Prepare udder for lactation

T/F evidence supporting P4 supplementation to improve pregnancy retention in cattle is conflicting?

True

How do we use P4 to manipulate pregnancy in a cow?

Decrease it using PGF2alpha (abortion)

How do you induce abortion before 150 days?

PGF2alpha

How do you induce abortion after 150 days?

PGF2alpha with dexamethasone

What drugs are used to manipulate lactation?

recombinant bovine somatotropin (rBST)

Oxytocin

What does rBST (recombinant bovine somatotropin) do?

Partitions nutrients towards lactations and augmentation galactopoiesis. Was not used until E. coli was able to be modified to create it instead of mice

0 day milk and meat withdrawal

HOWEVER, it is not used due to pushback by human health concerns despite no evidence supporting it

What is happening to cattle and calves inventory?

Decreasing because we have better genetics so total milk production is still increasing

Describe responsiveness to oxytocin on the uterus?

More responsive near parturition

Less responsive after parturition until 72 hours after there is no effect

T/F utility of clearing fetal membranes with oxytocin is debatable?

True

What is the only intramammary lincosamide for mastitis?

Pirlimycin

What anti-inflammatories are used for mastitis?

Banamine (flunixin)

What drugs are commonly used off label for bacteremia associated with mastitis and you should check with FARAD?

Ceftiofur

Penicillin G procaine

Oxytetracycline

T/F lidocaine has not been found by FDA to be safe and effective and labeling is not approved?

True, but it is not enforced yet

What is the toxic dose of lidocaine for a 500kg cow?

250 mL (20mg/mL)