1. Pre-natal losses in piglets (classifying, causes)

What are pre-natal losses in swine?

The death of piglets before parturition, during intrauterine development

What are the classifications of pre-natal losses in swine according to time?

Gametopathies, embryopathies, or fetopathies

What are the critical stages of embryonic loss?

1. Day 9: when the blastocyst begins to expand

2. Day 13: around implantation

How can gametopathies be divided?

1. Gametopathy

2. Blastopathy

3. Disruption of implantation, loss of fertilised egg between zygote formation and implantation

What occurs during gametopathies in swine?

Injury to ova and sperm before fertilisation

What is blastopathy in swine?

Injury of fertilised ova or the blastocyst after fertilisation until implantation in the uterus, before the 12th day

What happens during embryopathy in swine?

Loss between day 13-35 of pregnancy due to disruption of organogenesis and reabsorption of the embryo

1. Early Embryonic Death: occurs before maternal recognition <35 & result in resorption & return to oestrus

2. Late Embryonic Death: result in prolonged oestrus. If four piglets remain, pregnancy continues.

What is fetopathy in swine?

Loss between day 36-115 of pregnancy

What are the types of fetopathies in swine?

1. Mummification

2. Abortion

3. Stillbirth

What is mummification in swine?

Loss of the foetus after ossification of bones, typically after day 35

What is abortion in swine?

Termination of pregnancy by the expulsion of a foetus from the uterus prior to viability

What is stillbirth in swine?

When the foetus dies shortly before birth, having reached full term

What are the types of causes of prenatal losses of piglets according to origin?

1. Endogenous

2. Exogenous

What are endogenous causes of pre-natal losses in swine?

Genetic or hereditary causes, often involving recessive inheritance

What are exogenous causes of pre-natal losses in swine?

Hazards of the environment

1. Physical/mechanical causes

2. Chemical/toxic causes

3. Infectious causes

4. Non-infectious

What are examples of physical or mechanical causes of pre-natal losses in swine?

1. Trauma (particularly first month after insemination)

2. Extreme temperatures, drafts, wet pens, excessive fan speeds

3. Torsion of the uterus

What are chemical causes of pre-natal losses in swine?

1. Toxins: Exposure to pesticides, heavy metals, solanine (green potatoes), organophosphates, high CO2 levels, mycotoxins (mouldy feed, aflatoxins)

2. Drugs: corticosteroids and sedatives, hormones, vaccines (e.g. lepto)

3. Teratogens

What are the effects of teratogens on embryos and foetuses?

Have major effects during embryonic stage. In foetal stage they affect late developing systems (palate, cerebellum, heart, urogenital system) - 90%

What are some infectious causes of pre-natal losses in swine?

1. Bacteria

2. Virus

3. Parasites

What are examples of bacterial causes affecting reproduction in swine?

1. Brucella suis

2. Erysipelothrix rhusiopathiae

3. Leptospira species (interrogans pomona, grippotyphosa, bratislava, icterohemorrhagica, canicola)

4. Mycoplasma suis

5. Septicaemia (E. coli, Streptococcus, Staphylococcus, Pseudomonas)

What are examples of viruses causing pre-natal losses?

1. Aujeszky’s disease

2. Parvovirus

3. Porcine Reproductive & Respiratory Syndrome (PRRS)

4. Porcine Circovirus-2 (PCV-2)

5. CSF

6. ASF

7. Enterovirus

What does SMEDI stand for in swine reproduction?

Stillbirth, Mummification, Embryonic Death, Infertility

What is the cause of SMEDI?

Parvovirus, porcine enterovirus

What happens if a pig is infected by parvovirus or porcine enterovirus during different pregnancy stages?

• <30 days: embryo resorbed;

• 30-70 days: mummification;

• >70 days: dead or weak, but may survive normally

What parasite can cause pre-natal losses in swine?

Toxoplasma gondii

What impact does fever have on pre-natal losses in swine?

Any disease raising body temperature can contribute to pre-natal losses

What are examples of non-infectious causes of pre-natal losses?

1. Stress

2. Poor preparation of animals for breeding

3. Insufficient selection of breeding animals (musculoskeletal problems, susceptibility to stress, etc.)

4. Incorporating fattening pigs into breeding

5. Insufficient nutrition

What is the role of environmental stress in pre-natal losses in swine?

It raises blood cortisol levels, which can contribute to losses

What nutritional deficiency can contribute to pre-natal losses in swine?

Malnutrition of sows and deficient feed rations, leading to deficiencies of essential amino acids, vitamins and minerals

What are examples of vitamin and mineral deficiencies contributing to pre-natal losses?

1. Choline

2. Vitamin A

3. Magnesium

4. Vitamin C

5. Zinc

What role does choline play in pre-natal development in swine?

It supports nerve function, brain, and muscle development; deficiency can lead to congenital splay leg

What is the impact of vitamin A deficiency in pre-natal losses in swine?

It can cause hydrocephalus, anencephalus, anophthalmia, microphthalmia, and atresia ani

What is the impact of magnesium deficiency in pre-natal losses in swine?

It can cause arthrogryposis (A congenital condition characterized by joint contractures, where the joints are permanently fixed in a bent or straight position (mobility issues))

What role does vitamin C play in swine pre-natal development?

It is essential for maintaining blood vessels; deficiency can cause neonatal haemorrhagic anaemia

What effect does zinc deficiency have in swine during parturition?

It can lead to delayed parturition and umbilical bleeding

Stages of piglet loss:

When is parvovirus more dangerous to developing embryo/foetus?

< 70 days due to no immunity