Agriculture Reference
In-Depth Information
at levels that satisfy the requirements of the
most demanding pigs and, therefore, most of
the pigs receive more nutrients than they
really need to express their growth potential
(Hauschild
et al
., 2010). This is because for
most nutrients, underfed pigs will exhibit
reduced growth performance, while the over-
fed ones will exhibit near optimal perform-
ance. Providing growing animals with excess
nutrients to avoid reducing herd perform-
ance has become a common, if not a univer-
sal practice in commercial swine operations.
The use of these safety margins has to be
seen as an admission of our inability to pre-
cisely estimate the animal's nutritional re-
quirements and the factors that may modu-
late them (Patience, 1996). Nonetheless, in
the context of feeding populations of pigs,
nutrient requirements should be seen as the
balance between the proportion of pigs that
are going to be overfed and underfed (Brossard
et al
., 2009; Hauschild
et al
., 2010), acknow-
ledging that this proportion will change within
each feeding period.
Precision farming or precision agricul-
ture is an agricultural management concept
that relies on the existence of in-field vari-
ability. Precision feeding is based on the
fact that animals within a herd differ from
each other in terms of age, weight and pro-
duction potential and, therefore, each pig
has different nutrient requirements. The
precision feeding concept herein proposed
is applied to individual animals and con-
cerns the use of feeding techniques that pro-
vide each pig of the herd with a daily diet
that contains the optimal concentration of
nutrients. To provide these daily and indi-
vidually tailored diets, precision feeding
needs to include the following essential
elements (Pomar
et al
., 2009b):
New developments in the real-time determin-
ation of nutrient requirements along with some
preliminary results comparing individual pre-
cision feeding with conventional group feeding
systems are described in the following sections.
Estimating Nutrient Requirements
in Growing Animals
Body growth results from the net synthesis
of body components and depends on an ad-
equate supply of energy and essential nutri-
ents used by producing animals for body
maintenance, growth, reproduction and lac-
tation. Growing pigs must be provided with
these essential feed resources in adequate
amounts and in forms that are palatable and
efficiently utilized for optimal growth (NRC,
1998). These nutrients are provided by feed
ingredients the nutritive value of which is
estimated based on their nutritive compos-
ition, digestibility, metabolic availability and
fate, taking into consideration the addition
of enzymes, feed physical treatments and
other factors (Noblet and van Milgen, 2004;
Stein
et al
., 2007; NRC, 2012). The precise
evaluation of the nutritional potential of
feed ingredients is an essential element for
livestock precision feeding.
For specific nutrients (e.g. essential
amino acids), and when all other nutrients
are provided at adequate levels, nutrient re-
quirements can be defined as the amount of
nutrients needed for specified production
purposes, which in farm animals are pro-
duction outputs such as growth rate, protein
deposition, milk yield, etc. (Fuller, 2004).
Depending on the production purpose and
the nutrient, this required nutrient amount
can be considered as the minimum amount
that will prevent signs of deficiency and
allow the animal to perform its necessary
functions in a normal manner. Nutrient re-
quirements are modulated by factors that are
related to the animal (e.g. genetic potential,
age, weight and sex), the feed (e.g. nutrient
composition, digestibility and anti-nutritional
factors) and the environment (e.g. temperature
and space allowance) (Noblet and Quiniou,
1999), and they are estimated for a given
• The precise evaluation of the nutri-
tional content of feed ingredients.
• The real-time determination of individ-
ual nutrient requirements.
• The formulation of balanced diets limit-
ing the amount of excess nutrients.
• The concomitant adjustment of the
dietary supply of nutrients that will
match the evaluated requirements of
each individual within the herd.
