Agriculture Reference
In-Depth Information
adapting nutrient content (amino acids, min-
erals, vitamins, etc.) according to gestation
stage and/or parity; although in practice the
most common strategy is still to use the same
diet for all sows. Indeed, amino acid and
mineral requirements decrease with parity
and also vary according to gestation stage.
Feeding the same diet to all pregnant sows
results in an oversupply of nutrients in many
situations and a risk of undersupply in late
gestation, especially for primiparous sows.
This could be improved by using two differ-
ent gestation diets or multiphase feeding. The
role of such strategies in the reduction of ni-
trogen and phosphorus excretion will be de-
scribed in the next section.
During lactation, nutrient requirements
are mainly affected by milk production and
appetite of sows. It is clear from the results
presented in
Table 4.1
that young sows have
a lower appetite and should be fed a diet
more concentrated in nutrients, especially
amino acids and minerals. In practice, the
appetite of lactating sows varies widely ac-
cording to parity, ambient temperature and
body condition, etc. Moreover the potential
for milk production varies among sows, in-
creasing the variability of the requirement.
Using individual data of litter growth
rate (LGR) and feed intake from a farm with
average LGR of 2970 g/day and feed intake
of 6.5 kg/day, we calculated the digestible
lysine requirement according to InraPorc.
Average requirements for parities
1
to
4
amounted to 8.20 ± 2.68, 7.81 ± 2.53, 7.60 ±
2.44 and 7.10 ± 2.15 g/kg digestible lysine,
respectively. However, because of the vari-
ability, higher supplies are required to meet
the requirements of all sows as illustrated in
Fig. 4.4
. For instance, to meet the require-
ment of 80% of all sows, a diet with 9.3 g/kg
digestible lysine should be fed. From these
results, the question could be raised of the
possibility of feeding a specific lactation
diet to first parity sows.
Improving Nutrient Utilization and
Reducing Excretion
The first task in improving the efficiency of
nutrient utilization and consequently redu-
cing excretion is to ensure an adequate
protein and amino acid supply over time
according to the production potential and
physiological status of the animals (Rigolot
et al
., 2010). In sows, nitrogen and phos-
phorus excretion can be reduced by 20% to
25% when specific diets are provided
120
100
80
Parity
4
Parity
3
Parity
2
Parity
1
60
40
20
0
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
11.0
Standardized ilal digestible lysine (g/kg)
Fig. 4.4.
Effect of digestible lysine content on the percentage of lactating sows from different parities with
their requirements met. (Dourmad, 2013, unpublished data.)
