Causes of pig infertility and its management

Pig rearing amongst the tribals of Nagaland is one of the most integral parts of source of livelihood for rural people. The demand for pork meat is very high and challenging to fulfill at the same time.

There are many constraints that hinder piggery development as piggery development depends upon the availability of quality breeds, quality piglets, quality feeds, and effective disease control measures.

Infertility issues in pigs play a major role in hindering piggery development as the success of pig farming depends largely on the number of piglets produced at the farm or at the farmers’ backyard piggery.

Some of the issues related to infertility in pigs and its management are discussed for better productive efficiency of pigs.

1. Poor heat detection
Poor detection of heat in female pigs is one of the causes of poor breeding management in piggery production. Females come into heat for the second time after 18 to 24 days and the same interval for the third heat when she is ready to be served. The female should not be mated in the early stages of the third cycle but wait until she stands rigid when back pressure test is carried out by pressing with palms of both hands over the loin region and if the animal stands motionless with cocked ear, it indicates that the animal is in proper heat. The best time to mate the sow is 12 – 36 hours after onset of heat and if she is still on heat next day also, rebreeding on second day is also recommended as it will give extra one or two piglets as compared to just one breeding.

2. Mycotoxin contamination in feed and bedding materials
Mycotoxins are the poison caused by mouldy growths (fungal growths that occurs on damp or wet surfaces) which are present in grain and straw beddings. Mycotoxins can damage the placenta and cause abortion and still birth. Feeds should be kept in well-ventilated room to avoid growth of moulds in the feeds. Feeding trough and water trough should be cleaned every day before feeding the animals. Wet straws or straws that has been baled in damp conditions should never be used as bedding material for breeding pigs and youngstock.

3. Poor management at mating
Improper planning on breeding program will lead to poor fertility and low productions. Sows are likely to be served between four and six days after their piglets have been weaned. There should be well lighted room to activate the sows hormones within the service area. The sows should be kept stress free environment and service records should be kept for reference like the date of service and the due date for farrowing.

4. Incorrect body condition score
Feeding must be spot on before mating because if the metabolism progresses to a state of negative energy from underfeeding or unbalanced nutrition, the sow may fail to implant adequate numbers or viable young embryos. Sows that are too thin or too fat can lead to infertility issues by affecting ovulation, conception and embryo development.

5. Too young at first service
Gilts that are mated too young often fail to ever catch up. Their performances will be poor in subsequent litters. One should consider age at puberty for breeding gilts, age at first breeding, body weight at first breeding and number of estrus at first breeding.

6. Temperature extremes
High temperatures have a profound effect on fertility by lowering the desire in boars to mate. In sows it causes decrease in conception rates as it negatively affects oocyte quality, follicular development and embryo survival. It can be real issue for outdoor breeding herds where temperatures cannot be controlled. Pigs should have access to an ad-lib supply of drinking water. Wallows should be maintained and adequate shade and hut ventilation provided.

Dr. Sarendi Walling
ACTO (Animal Science), KVK, Mokokchung