Pig rearing amongst the tribals of Nagaland is one of the
most significant sources of livelihood for rural people. The demand for pork is
very high and challenging to fulfill at the same time. There are many
constraints that hinder piggery development as it depends on the availability
of quality breeds, quality piglets, quality feeds and effective disease control
measures. Infertility issues in pigs plays a major role in hindering piggery
development as the success of pig farming depends largely on the numbers of
piglets produced, be it at farm or farmers’ backyard piggery. Some of the
issues related to infertility in pigs and its management are:
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 the next day, 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 have 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 programme 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 in stress-free environment and service records should be kept for
reference like the date of service and the due date for farrowing.
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.
