Pigs Flashcards
Describe which animals health records should be kept for and what information should be recorded
Per animal for gilts, sows and boars, per little in the farrowing house, per pen or room for weaners, per pen or house for growers/finishers. Information recorded includes: problem ,number treated, date treatment given, dose per pig, dose per pen or house. this information can be used to complete the medicines record book accurately, number of death or culls, routine treatments such as wormers and vaccinations eg what used and date given.
What can production records in pigs be used for?
The data is produced as figures for the last month and a rolling average figure for a defined interval eg last 3 6 or 12 months. comparisons can also be given with the same month or interval the previous year. such figures identify problem areas which can be acted on at early stage. actual performance data are compared with the target and interference level data. if any performance figure hits the interference level data or approached them then the producer needs to focus attention on this area and determine the cause of poor performance.
What are action records?
These indicate management tasks to be done and when. these cover many areas for example sows due to be served, dates for checking return to oestrus dates for pregnancy testing, dates of expected farrowing. Such records are valuable for good management and ensure tasks are done at the correct tme or that the required observations etc are carried out.
Where is most of a pig farms income derived fomr? what is the average price for pigs?
On a percentage basis farm income is derived from feeding herd sales - either pigs finished at slaughter weight or pigs sold as weaners - 96%, OR sow/boar sales - adults culled on account of age, poor performance or other reasons. pig prices swing from 75-80p/kg to £1.55/kg dead weight for finishing pigs. the break even price is 90p/kg deadweight. the major cost for the producer is feed.
Describe the measures a pig farm should take to ensure good biosecurity?
Location - preferably an area of low pig density at least 3km from another pig unit, in hilly country and or on the coast, secure perimeter fence, isolation facilities off site for incoming stock, well constructed loading bay, draining towards the lorry, with gates preventing lorry drivers entering the unit from the loading bay, washing and disinfection facilities at the loading bay, transport - lorries arrive at the farm t collect pigs should be empty, clean and disinfected. lorries with a part load of pigs sitting in close proximity to pigs on the unit, present a serious health risk, visitors - should park away from the unit, ring for attention, wear boots and clothing belonging to the unit. some units require visitors to be pig clean (to have not been to another unit in the past 2,3 or 4 days), feed lorries should remain out with the perimeter fence. Rodent and fly control should be effective. feed stores should be netted to prevent birds gaining access. personnel should not come into contact with other pigs. pork products should not be brought onto the unit. dead pigs should be disposed of safely and hygienically.
What is a specific pathogen free pig herd?
Also known as minimal disease pigs - used to describe pigs in herds that are free from a specified list of diseases. the health status is checked regularly through abattoir screening and laboratory testing. these herds are free from enzootic pneumonia (mycoplasma hyopneumoniae), porcine reproductive and respiratory virus infection (PRRS), pleuropneumonia (actinobacillus pleupneumoniae), atrophic rhinitis (toxigenic pastuerella multocida), swine dysentery (brachyspira hyodysenteriae), streptococcal meningitis (streptococcus suis type II), mange (sarcoptes scabei).
What is a high health status herd?
Herds are free of major infectious diseases listed under SPF with one or possibly two exceptions that are otherwise well controlled e.g m. hypopneumoniae positive controlled by vaccination.
What is a conventional health status pig herd?
there is no guarantee of freedom from any of the above diseases.
Describe the environmental actors which affect the health an performance of sows?
Insufficient lying area for sows, poorly drained floors rough floors, protrusions in pens which can injure pig, poor building and farrowing crate design, poor light intensity, fluctuating light, fluctuating temperatures, draughts, temperatures above higher critical temperature without cooling devices or a wallow, below lower critical temperatures with insufficient bedding and shelter, stony ground, unduly muddy, wet ground, poor water availability.
What management factors can affect the health and performance of sows?
Poor methods of introducing sows and gilts into groups reuslting in aggression, allowing vices to develop e.g vulva biting, by failure to identify causes, poor Stockmanship - no empathy with the pigs, failure to clean, disinfect buildings at adequate intervals, failure to vaccinate, worm and mange treat sows, mechanically transferring infections between sows, continuous throughput of buildings.
What factors should be considered in relation to sow disposal?
Herd culling policy - indoor herds have an average target of 38%, outdoors 45%. individual sows reproductive performance, sows body condition, number of functional teats, health problems eg lameness, availability of gilts (pig flow on the unit), mortality rate in sows. The target for culling sows is 6-7 parity as there are increasing problems as the sows get older such as prolonged farrowings - increased stillbirth rate, more piglets overlain, variable litter size and birth weights, problems with lactation arising from chronic mastitis and non functional teats, greater likelihood of poor fertility, lameness, endometritis, vulval discharge, cystitis/pyelonephritis.
Describe the main important indicators of reproductive performance in sows?
Reduced farrowing rate:: farrowing rate is the number of sows which farrow to the number of services in a given period expressed as a percentage.
Reduced litter size.
What are the causes of reproductive failure? when can failure occur?
failure can occur at conception or implantation - sows/gilts will return to oestrus at 21 days. post implantation - irregular returns or sows/gilts come through not in pig. maturation - abortion or mummification occurs. causes may be single or multiple problems and causes, problems differe between indoor and outdoor units, majority of problems are non infectious ie managemental or environmental causes are common. viral and bacterial infections may be implicated.
Describe the management and environmental factors to consider which may effect reproductive performance in sows?
Condition - level of nutrition, suitability of diet, feeding system. Service management - boar contact, heat detection, number of servings, timing supervision, hygiene. Boar use - frequency, sow:boar ratio, health of boars, supervision of young boars. AI usage - timing, oeprator experience, handling of semen, quality of semen. Seasonal effects - autun reproductive syndrome, winter anoestrus, adverse temperature and weather conditions especially for outdoor sows. Farrowing house management and environment - hygiene, all in all out policy, sow comfort, farrowing supervision, speed of farrowing, neonatal care, suitable conditions for piglets, health. culling policy - parity, health problems, sow deaths. Gilt replacement - genetic suitability for unit, home breeding, selection defects. Efficiency and accuracy of data recording.
What is anoestrus? Define the criteria of anoestrus.
One of the most common reproductive disorders of sows and gilts. criteria of anoestrus are;
gilt - at least 8 months of age without showing oestrus, cessation of oestrus cycles in the absence of pregnancy.
Sow - weaned at least 10 days without showing oestrus, cessation of oestrus cycles in the absence of pregnancy or lactation. Anoestrus is a presenting sign which is commonly interpreted as indicating inactivity of the ovaries, however many supposedly anoestrus pigs prove to be pregnant, cyclic or have abnormal gonads. Ddx of anoestrus - inactive ovaries, rpegnancy, undetected oestrus cycles, irregular oestrus cycles due to persistent corpora lutea or cystic follicles, intersexuality, defects. Is it true anoestrus? examine tracts of cull sows at slaughter - no developed follicles or corpora lutea, ovaries small and flattened. Consider the use of hormonal therapy in truly anoestrus a nimals.
Describe the faults in housing which can lead to inactivity of the ovaries?
Inadequate space for drinking, feeding sleeping, inadequate photostimulation, wet cold conditions, inadequate diet, inadequate energy and protein intake, poorr palatibility or spoilage of food, inadequate stimulation by boar sight sound contact and variety, poor genetic selection, management problems eg large groups, competitive stress, bullying, badly matched groups, illness or parasitism. Serious problem for outdoor units during winter months.
What are cystic ovaries? What is the cause?
follicular or luteal cysts are seen quite commonly but their effect on fertility is uncertain as can be seen in normal pregnant animals. They are caused by high progesterone concentrations from adrenal cortex induced by environmental stress or exogenous ACTH inhibits positive feedback mechanism of oestrogens on the pituitary gland thus inhibiting pre ovulatory surge of LH. examine for causes of environmental stress.
What are the possible problem areas if a sow returns to oestrus at 21 days?
Failure to conceive or implant. consider - accuracy of oestrus detection, timing of services or AI, boar factors - possible infertility, testicular size and consistency, penile defects or injuries, sow to boar ratio, boar usage, quality of service, experience of AI operator, handling and storage of semen used for AI, suitability of service area - floors, space, temperature. Previous reproductive diseases -v aginal discharges post service, possible endometritis.
What are the possible problem areas if the sow has irregular returns to oestrus?
Loss during the embryonic phase up to 35 days leading to resorption or the foetal stage > 35 days leading to abortion. consider seasonal effects - august to october months associated with increased rates of resorptio/abortion - autumn reproductive syndrome. overuse of baors leading to small number of embryos - foetuses resorbed at approximately 35 days, vaginal discharges/endometritis, infectious reproductive diseases - PRRS, parvo, enteroviruses etc. Other acute illnesses - swine influenza, erysipelas, actinobacillus pleuopneumoniae etc.
What is abortion? What are some of the possible causes?
Abortion occurs when pregnancy control mechanisms cease i.e luteal function ceases, ovarian progesterone production falls and premature farrowing is initiated. In contrast when foetuses undergo resorption or mummifications the maternal pregnancy state usually continues. Sporadic abortions occur in most herds. check the abortion rate against target and action figures to assess the significance. there are many potential causes of abortion including inadequate or unsuitable diet, cold, draughts, wet conditions, parisitism > falling energy level > catabolism > luteolysis.. Inadequate lighting > luteolysis. Stress, no boar contact, decreasing daylight, toxin circulation eg accidental in feed toxins, carbon monoxide, PRRS, aujeszky, swine fever swine influenza, parvo, enterovirus, erysipelas, leptospirsis, brucellosis, actinobacillosis.
What is the difference between type I and type II stillbirths?
Type I - foetuses die before the end of gestation and are classified as pre partum deaths. often due to infectious causes eg Parvovirus or PRRS infection. Type II - foetuses die during parturition usually due to non infectious causes eg duration of farrowing - high interval between piglets 13-18 minutes: low stillbirth rate, 45-55 minutes: high still birth rate, small litters <4 piglets or very large litters, high parity sows, position of foetus occur in the last third of the litter, anoxia, umbilical rupture, impeded blood flow, carbon monoxie, high ambient temperature in late gestation (sow fatigue). Intrapartum anoxia stimulates CNS respiratory centres and can lead to inhalation of amniotic fluid and debris. it also causes relaxation of anal sphincter with release of meconium into amniotic fluid. piglets can be examined for these signs of foetal distress.
How can parturition be induced?
By injection of prostaglandin. farrowing commences 18-36 hours later. small doses of oxytocin can be given from 20 hours post prostaglandin or once farrowing commences in order to speed up the farrowing. single large doses of oxytocin are contra indicated as this has been shown to cause dystocia. oxytocin will not induce farrowing in sows and gilts.
What is the cause of small litter sizes in pigs?
Genetics. management factors post weaning - ad lib feeding and boar contact recommended, number of services, recommended at least 2 with 24 hour interval or 3 at 12 hour intervals. single services - small litters. age of gilt at first mating. small litters when bred before 220 days. young boars <10 months old can leave small litters - overuse of boars, poor sow condition, infections such as endometritis, parvovirus, enteroviruses, PRRS.
Describe intersexuality in pigs, what is a hermaphrodite and a male pseudohermaphrodite?
Common in pigs - approx 1% of females the conditions have a genetic basis. true hermaphrodite - both ovarian and testicular tissue in gonads with female external genitalia. vulva often upturned and clitoris prominent. male pseudohermaphrodite - testicles for gonads with female external genitalia similar to hermaphrodites. Uterine horns can be hypoplastic or aplastic. other tubal anomalies can occur eg aplasias of vagina, cervix or uterine horns duplications of any of the tubal structures.
Describe group type I, II and III infectious causes of reproductive disorders in pigs?
I - ubiquitous micro organisms that occur as common commensals eg arcanobacterium pyogenes, E. coli, strep, salmonella.
II - contagious microorganisms which are present in a high proportion of pig herds - PRRS, porcine parvovirus, leptospira.
III - infections associated with severe reproductive diseases which are uncommon in the UK.
What is reproductive failure associated with vaginal discharge in the sow after service?
Insidious onset discharge, seen in 10-20 days post service. May persist for weeks/months if untreated or resolve spontaneously after 1-2 weeks. Discharge may arise from vagina, uterus, bladder or kidney inflammation. quantity of discharge varies from slight to copious - 500ml per day. typically up to 10% of served sows can show discharges and farrowing rates can be reduced to 75% due to regular or irregular returns to service and abortions. higher prevalence in higher parity sows >4 parity. Aetiology - mixed population of ubiquitous organisms e.g A pyogenes, E. coli, streptococci, pseudomonas eubacterium suis common in cystitis or pyelonephritis. Environmental factors are important - poor hygiene in sow/boar accommodation or service area. infection probably introduced at service when genitalia contaminated. the boars preputial diverticulum can also harbour infection.
What is the treatment and control options for vaginal discharge in the sow
Not all discharging sows return to service, some remain pregnant. if discharge is copious, sows are unlikely to be pregnant. treat discharging sows promptly with long acting broad spectrum antibiotic by injection or instillation via AI catheter. A slight discharge in the first week after service is of no pathogenic significance - usually due to seminal debris. do not re serve sows while discharging. once recovered, use AI for next service. avoid possible boar contamination. if discharging recurs or sow returns for a second/third time - cull. Cull sows at parity 7. Adopt stringent hygiene for boar pens, service pens and sow stalls/Accommodation especially that is used in the first 21 days post service - plenty of clean straw. boars can be treated with long acting broad spectrum antibiotic by injection and infuse prepuce with Intramammary tubes daily for 5 days. some units treat boars on a quarterly basis. If the problem is widespread - in feed antibiotic medication can be given to sows post weaning up to 28 days post service and to boars intermittently. treatment of a discharge problem needs to be maintained for approximately 6 months until all the sows have received a course of medication. prophylactic antibiotic treatment of sows at service eg long acting penicillin is useful when a discharging problem is detected in the early stages.
What is coliform mastitis?
mastitis caused by a variety of coliform bacteria for example E col, kelbsiella, enterobacter, bacterial species common in the sows environment. Organisms come in contact with the teats through indequate hygiene or via piglets oral flora. Endotoxaemia is considered to be the cause of agalactia. septicaemia does not develop. Coliform mastitis does not appear to result in protective immunity (Recurrence at subsequent pregnancies has been recognised. Clinical signs seen at day 1 or 2 post farrowing, temperature response up to 42 C, listless, weak, loss of interest in piglets, prefer sternal recumbency, may become weak and comatose, reduced feed and water intake, signs last 2-33 days. Piglets gaunt and hungry looking, continually trying to feed, restless. skin over mammary area redenned. Subcutaneous oedema. udder may be hardened and paiinful. secretion from nipple may show evidence of mastitis. Some sub complexes may be unaffected causing secretion to appear normal. Treatment is broad spectrum antibiotics, NSAIDS, oxtocin. care for piglets, cross fostering/milk substitue. Prevent by good hygiene. Use of sulpha trimethoprim in feed from day 112 for 4 days is helpful when agalactia is becoming a more serious problem. Vaccines against enteric strains of coliforms not thought to prevent agalactiae.
What is porcine reproductive and respiratory syndrome? (PRRS, Blue ear)
Caused by an RNA virus- different strains occur. the acute phase of the disease lasts approx 4-16 weeks. features are : reproductive losses in pregnant stock, increased pre weaning mortality and influenza like illness affecting all ages of pigs. A common progression in breeding herds: non specific illness in sows, 1-2 weeks later reproductive losses followed by unthriftiness, respiratory illness and morality in piglets of all ages and growing stocks. blue ears, snout and vulva are only seen occasionally. reproductive problems include infertility, premature farrowing, stillbirths and weakly piglets born. No non porcine hosts identified. pig to pig transmission occurs readily through airborne spread, semen, fomites. Incubation period is 1-7 days, farrowing abnormalities and neonatal deaths follow after 14-28 days, foetal infection can occur following maternal challenge in late pregnancy resulting in pre and post natal disease, abortions may result from purely maternal illness. Diagnosis - clinical featurs, serology, rising titres but be aware of vaccination status, virus isolation from aborted stillborn or non viable piglets, PCR test for virus from blood, semen throat swabs. Prophylaxis management - buy replacements and AI semen from sero negative herds, ensure thorough biosecurity, apply vaccination policy if present in herd.
What is swine influenza?
Four strains of influenza A occur in pigs. Acute phase lasts 4-16 weeks. influenza like illness, affecting al ages of pigs, reproductive losses in pregnant stock and increased pre weaning mortality. Clinical signs very similar to PRRS except respiratory signs are more widespread and severe especially if there are other endemic respiratory diseases on the farm. The virus enters the respiratory tract, multiplies rapidly in bronchial epitheliuum, virus disappears by 9-10 days post infection. animals can become viraemic. transplacental infection occurs. Infection can persist in units for many months causing persistent or recurring losses. virus is carried by pigs. maternal immunity demonstrable for up to 4 months and can interfere with development of active immunity. Management strategies - do not allow staff or visitors who are suffering from influenza to have contact with pigs. if free of swine influenza buy replacements from sero negative herds. Prevent introduction via vehicles etc. If present in herd: disinfection, expose gilts to breeding sows before pregnancy to establish immunity. Vaccine for pigs available in the UK: gripovac.
What is porcine parvo virus? Describe the clinical signs and how it is spread.
It is associated with SMEDI syndrome along with a number of enteroviruses. all reproduction associated clinical signs: stillbirths, mummification,embryonic death, infertility, irregular returns to oestrus, small litters. In non pregnant gilts and boars infection is of no consequence. signs depend on stage of pregnancy: 70 days gestation, stillbirths, live but weakly piglets. Spread by oronasal or venereal routes, viraemia, transplacental spread approx 10-14 days post infection. Spreads into boar reproductive organs and semen from approx 7-21 days post infection. Virus adheres to eggs, embryos and foetuses until they reach immunocompetence at approx 70 days gestation. Virus kills foetuses up to approx 70 days but pregnancy is maintained and piglets all mummified at birth or mixed mummified, stillborn and live piglets born. In immunocompetent piglets, virus causes endothelial damage and placentitis. live born piglets are either immune or infected imunotolerant. Vaccinate susceptible stock - incoming gilts sows and boars. Annual vaccination recommended, though not always done as producers often prefer to keep active infection in the herd to boost natural immunity.
What is porcine leptospirosis? What are the clinical signs and the pathogenesis?
L bratislava of most importance. More common in out door units. Causes abortion, stillbirths, weak piglets of reduced viability, abortion in last trimester common. Infertility, increased returns to service. Infection is by oro nasal, veneral routes. Bacteraemia, localised in renal tubules, shed in urine. Transplacental infection occurs, localises in uterus, foetal invasion, abortion 10 days - 4 weeks post infection. Infection can persist in both urinary and genital tract of sows and boars. subclinical infection common in hers. Treatment of individual animals is seldom justified. in feed medication of sows (chlortetracycline) for 1 month in spring and 1 month in autumn found to be beneficial. prevent contact with free living vectors.
What is porcine circo virus type 2?
Primarily associated with post weaning multisystemic wasting syndrome. most herds in the UK are endemically infected. when entering naive herds or infecting naive gilts it can cause reproductive problems including transient infertility, foetal re absorption and increased regular and irregular returns to oestrus. A vaccine is available for breeding age pigs and can be used if PCV2 is thought to be affecting the herds reproductive performance.
Describe the clinical signs of Neonatal E. coli diarrhoea and the pathogenesis of this infection
PAthogenic E. coli - ETEC adhere to the mucosa of the small intestine by means of fimbiral adhesins. they colonise the small intestine and produce one or more enterotoxins. both neonatal and post weaning colibacillosis are most commonly cause by ETEC producing heat labile toxin or vero toxigenic E. coli producing heat stable toxins. both act in the gut and stimulate hypersecretions of mucin and electrolytes resulting in acute diarrhoea and dehydration. Infection of newborn pigs is by faecal oral route. Lack of colostrum and management factors such as low ambient temperatures reduce the vigour and feed intake of piglets leading to increased susceptibility to diarrhoea. Clincal signs are watery darrhoea, dehydration, metabolic acidosis, vomiting and depression or sudden death. most common in pigs 0 -4 days of age and can appear as early as 2-3 hours after birth.
What is the treatment and prevention measures for neonatal E. coli diarrhoea?
Treatment should consist of oral rehydration fluids and antibiotics. oral antibiotic treatment for piglets. maternal vaccination is effective if sufficient colostrum of good quality is consumed within the first hours of life, but good management, hygiene, ensuring adequate ambient temperature and colostrum intakes are also very important. selective breeding for resistance to K88+ and perhaps F18 fimbrial adhesins could have effect. Susceptibility to E. coli is dominant over resistance.
Describe the pathogenesis and clinical signs of rotavirus in pigs? How can rotavirus be prevented?
Rotaviruses replicate predomiantly in the cytoplasm of differentiated small intestinal epithelial cells. It results in small intestinal villous atrophy and severe enteritis. pigs become infected 7-40 days of age, via fecal oral route. adequate colostrum and milk intake will provide newborn piglets with maternal antibodies that persist 3-4 weeks. contaminated environment and adult animals serve as sources of infection. Signs range from mild diarrhoea and dehydration to severe fatal diarrhoea. diarrhoea affects piglets mainly between 5-14 days of age and lasts from 2-5 days. rotavirus can be detected in fecal samples using PAGE. Treatment should consist of electrolyte/fluid replacement. prevention and control depens on excellent hygiene and disinfection of the farrowing house. peroxygen disinfectant (virkon S) is effective. others are not. move sows and piglets into a different cleaned and disinfected farrowing crate at 4-5 days post farrowing which reduces the level of virus challenge.
