Fertility

Failure to cycle

Causes:

·    Failure to observe oestrus *

·    Metabolic disease, e.g. NEB, vitamin deficiencies

·    Pregnancy – always check before giving PGF2a

·    Uterine infection

·    Cystic ovarian disease

·    Calf at foot – more of an issue in beef

Failure to conceive

Causes:

·    Improper insemination

·    Infectious causes, e.g. uterine infection prior to insemination, infection at breeding ® early embryonic death

·    Toxins, incl. mycotoxins, endotoxins

·    Iatrogenic

·    Sire choice

Early embryonic death

Causes:

·    BVD – causes EED, ovarian damage, delayed return to oestrus, reduced conception rate

·    IBR – temporary ovarian necrosis, follicular damage ® reduced conception rates

·    Leptospirosis – poor fertility and EED due to endometrial inflammation ® reduce conception rate and long return to service, zoonotic

·    Brucella – poor fertility and epididymitis/orchitis in males, reduced conception rate in cows, zoonotic and NOTIFIABLE

·    Campylobacter – causes endometritis, failure to conceive, EED, abortion, irregular oestrus cycle and long return to service

·    Trichomonas – causes EED, pyometra and endometritis, long return to service

·    Q-fever

Issues with oestrus detection *

·    Ability of cow to express oestrus behaviour

o  Good environment (e.g. if slippy, cow cant mount)

o  No lameness

o  Correct nutrition

o  Genetics

·    Errors with detection

o  Time observing

o  Timing of observation

o  Training

o  Use of bull

o  Heat detection aids, e.g. pedometers, chalk, synchronisation protocols

Factors affecting conception rate

·    Nutrition: NEB, macronutrients, SARA, excess protein

·    AI related: technique, semen quality/storage, thawing/handling of semen, timing of AI

·    Disease: lameness, herd level infectious disease, uterine bacterial disease, venereal disease

·    Bull: true infertility, lameness, lack of libido

Infertility in the male

·    Conditions affecting fertility:

o  Scrotum: orchitis (brucella), dermatitis (chorioptic mange)

o  Testicles: hypoplasia, cryptorchid, neoplasia

o  Epididymis: floppy, lumpy, epididymitis

o  Prepuce: phimosis, paraphimosis, FB, trauma, urolithiasis, infectious balanitis, laceration

o  Penis: neoplasia, persistent frenulum, rupture at sigmoid plexus, trauma

o  Accessory sex glands: seminal vesiculitis

·    Infectious causes of infertility in bulls:

o  Viral: BVD, IBR, blue tongue, EBL (enzootic bovine leukosis)

o  Bacterial: brucella (notifiable), campylobacter, Johne’s, mycoplasma, leptospirosis

o  Protozoal: trichomonas

·    Causes of abnormal sperm production: heat, stress

Anoestrus

·    Absence of oestrus cycles

Causes:

·    Unobserved oestrus

·    Metabolic/nutritional disease

·    Uterine disease (e.g. chronic metritis, pyometra), cystic ovarian disease

·    Pregnancy, suckling beef calves present

·    In heifers – not reached puberty, reproductive tract abnormalities (freemartinism, mucometra)