The chemical senses of olfaction
and taste influence many aspects of behavior, especially
selection and consumption of specific food
(McLaughlin et al. 1983). Olfaction was important and
efficient for communication in mammals while pigs
were quite sensitive to food smell (Guiraudie-Capraz
et al. 2005; Kittawornrat & Zimmerman 2011). Food
intake or lack thereof could be determined by olfactory
sensation which provided information before animal
ingestion, and this regulatory effect was particularly
evident in pigs (McLaughlin et al. 1983). Moreover,
Hellekant and Danilova (1999) stated that pigs had a
higher requirement for diet acceptance because they
had three to four times the number of taste buds than
on the human tongue. Flavors were commonly used
to improve diet acceptance and stimulate intake via
taste and olfaction. This theory was further confirmed
in the present experiment that FMA flavor could
improve sow feed intake, and higher feed intake of
sows further improved growth performance of piglets,
resulting in higher individual and litter weaning
weights of piglets. However, maternal body reserve
was not sacrificed for these great effects because there
was no difference in backfat loss between the FMA
and CON groups. Therefore, it is indicated that FMA
flavor could effectively decrease milk yield burden of
primiparous sows.
In this experiment, pre- and post-weaning exposure
to FMA flavor tended to show a faster increase in feed
intake and individual weight gain of weaning piglets
during the first week post-weaning. There are several
explanations for this phenomenon. Animals and their
offspring share similar genetics and the same environment,
which leads to a similar physiological response
to various types of food. Maternal information embedded
in diet, milk, feces and so on could be transmitted
to offspring, affected their specific dietary preferences
when encountering appropriate food sources
(Morrow-Tesch & McGlone 1990; Galef 1996). Additionally,
familiar odors associated with the mother
could enhance safety and reduce related stress of their
offspring when experiencing a new environment
(Oostindjer et al. 2011). It has also been proven that
weaning animals tend to seek and prefer their preference
food by the feed experience during the lactation
period (Galef & Giraldeau 2001). Therefore, FMA
flavor could alleviate weaning stress, and then stimulate
feed intake and reduce weight loss.