Composition of sow colostrum and milk - The Gestating and Lactating Sow - page 189

Sow milk also contains complex carbohydrates, including 29 distinct oligosaccharides
(Tao et al. , 2010). Concentrations of these oligosaccharides are highest in colostrum, and
then decline during lactation before increasing again by day 24. In addition, the profiles
of oligosaccharides in sow milk vary with stage of lactation.

9.5.2 Diet

Gestation diet composition might be expected to affect colostrum and possibly milk
lactose content. However, lactose concentration in colostrum or milk is not affected by
gestation diets supplemented with energy in the form of oils (Jackson et al. , 1995; Laws
et al. , 2009), nor is it affected by gestation diets supplemented with conjugated linoleic
acid (Krogh et al. , 2012) or with the leucine metabolite β-hydroxy β-methyl butyrate
(Flummer and Theil, 2012). Gestation diets with high dietary fiber content (23.4%) do
not affect colostrum or milk lactose concentrations (Loisel et al. , 2013).

Feeding supplemental dietary fat during lactation has no effect on milk lactose content
(Coffey et al. , 1982; Lauridsen and Danielsen, 2004; Theil et al. , 2004). Lactose concentration
in sow milk is not affected by protein level, lysine level or branched chain amino acid
levels in lactation diets (Dourmad et al. , 1998; King et al. , 1993; Richert et al. , 1997).
However, lactose content of sow milk is affected by energy source, with feeding starch
resulting in a higher lactose percentage than feeding tallow (Van den Brand et al. , 2000).
Lactose concentration in milk at day 22 is higher in sows fed high fructose diets during
lactation compared with control or high dextrose diets (White et al. , 1984). Lactation diets
supplemented with glycerol increase milk lactose content (Schieck et al. , 2010).

Dietary folic acid supplementation has been observed to decrease milk lactose at day 7 of
lactation (Wang et al. , 2011), however, it should be noted that lactose concentrations in
that study were lower than typically reported by others (Table 9.3). Lactose concentration
of milk at day 10 to 12 of lactation is not affected by dietary electrolyte balance (DeRouchey
et al. , 2003).

9.5.3 Other factors

Zou et al. (1992) noted lower lactose concentrations in colostrum of first lactation
Meishan sows compared with Yorkshire sows. Concentrations of lactose in milk were
reported not to be different among those breeds (Alston-Mills et al. , 2000; Zou et al. ,
1992), however, were found to be greater in milk from 50% Meishan crossbred sows
compared with Yorkshire sows (Farmer et al. , 2001). Lactose concentration in sow
colostrum is associated positively with colostrum yield (Foisnet et al. , 2010a). Similarly,
lactose content of milk at day 22 of lactation is positively correlated with milk yield
(r=0.33, P <0.1; White et al. , 1984). Lactose concentrations of sow milk are not affected
by parity (Baas et al. , 1992; Goransson, 1990: Klobasa et al. , 1987), sow body condition
(Klaver et al. , 1981), or ambient temperature (Renaudeau and Noblet, 2001).