Colostrum and milk production - The Gestating and Lactating Sow - page 165

is not required until 16 to 24 h postpartum (Atwood et al. , 1995; Theil et al. , 2006).
Consistently, no correlation was found between litter size or litter weight at birth and
colostrum yield or piglet growth during early lactation (Devillers et al. , 2007; Quesnel,
2011). On the other hand, colostrum yield was positively correlated with mean piglet
birth weight (Devillers et al. , 2007). Together, these results suggest that colostrum yield
may be influenced by the global vitality of the litter at birth and largely depends on the
capacity of the sow to produce colostrum.
Sow parity
Devillers et al. (2007) reported that sows of parities 2 and 3 tended to produce more
colostrum (4.3 kg) than primiparous (3.4 kg) and older sows (3.6 kg). Decaluwé et al.
(2013) reported greater colostrum yield for sows of parities 1 to 3 than sows of parities
4 to 7 (3.7 versus 2.8 kg). Furthermore, greater colostrum yield was observed for sows
of parities 1 and 2 than for sows of parities 3 and more (3.7 versus 3.2 kg, Quesnel,
unpublished data). Despite some discrepancies regarding sows of parity 1 or 3, it seems
consistently that older sows (at least parity 4 and more) produce less colostrum than
younger sows.
Mammary gland development
One aspect which is neglected when discussing factors with potential impact on
colostrogenesis in sows is mammary development. As is discussed in Chapter 4 (Farmer
and Hurley, 2015), sow milk yield is dependent on the number of milk-producing cells
present in mammary glands at the onset of lactation (Head and Williams, 1991) and it
is most likely that this is also the case for colostrum production. Yet, this needs to be
substantiated with further studies.
Sow endocrine status
In swine, the prepartum peak of prolactin is essential for lactogenesis (Farmer et al. ,
1998) and is brought about by the drop in progesterone concentrations (Taverne et al. ,
1982). In primiparous sows, delays in progesterone decrease and in prolactin increase
relative to the onset of parturition were associated with a strongly reduced yield of
colostrum (Foisnet et al. , 2010). Furthermore, the relative concentrations of prolactin and
progesterone during the peripartum period were recently shown to influence colostrum
yield. Primiparous sows that had lower progesterone concentrations associated with
a tendency for greater prolactin concentrations (high prolactin to progesterone ratio)
during the two days before and the day of parturition produced more colostrum (+0.6
kg) than sows that had a low prolactin to progesterone ratio (Loisel, 2014). Finally, piglet
growth rate and survival during the 3 or 5 days postpartum were reduced when sows
had greater circulating concentrations of progesterone immediately after farrowing (De
Passillé et al. , 1993; Quesnel et al. , 2013). It is worth noting that primiparous sows have
lower peripartum concentrations of prolactin than older sows (Quesnel et al. , 2013).
Prolactin concentrations therefore seem to be related to colostrum yield within parity
but not among sows of various parities.