3Feeding high yield dairy cows and maintain milk yield and fertility Dietary energy sources fed to the lactating cow can have a profound influence on her subsequent fertility, Professor Phil Garnsworthy of the
University of Nottingham, UK, told the
online feed forum. Trials with high-yielding
Holstein Friesian cows have shown that
they respond differently to the energy
source at different stages of their reproductive cycle.
The indicator used to measure this effect is the insulin status of the cow’s blood.
Feed formulation for dairy cows needs
to take account of how much a cow eats,
said Professor
Garnsworthy,
and this depends
on various
factors including
availability;
feeding ad
libitum should
mean giving
110% of appetite
so there is no artificial restriction on daily
intake.
From the research evidence, for good-quality oocytes and the right blastocyst
development, we need to feed the cow a
low-insulin diet. This means a formulation
high in fat and low in starch.
Before that, however, it has been
demonstrated that the exact opposite
of a high-insulin feed improves follicular
development in early lactation.
A multidiet approach might, therefore,
be the answer to maximising fertility, if it
could be accommodated within the management of the dairy herd. At the same
time, Professor Garnsworthy warned,
avoid extremes of fat or starch – or of
protein – in any of the diets, as an excess
could be as detrimental as a deficiency.
4Feed Manufacturing: Altering the nutritional value and increasing output with process efficiency
A different approach to handling feed
particle size requirements in broiler diets
was covered by Dr. Leland McKinney of
Kansas State University. There is good
evidence from research that the particle
size obtained by grading grains such as
maize and sorghum will have an impact
on the growth rate and the feed:gain
There is good evidence from research that
the particle size obtained by grading grains
such as maize and sorghum will have an
impact on the growth rate and the feed:gain
ratio of commercial broilers.
ratio of commercial broilers. A procedure
now being used in feed manufacturing to
maximize the effect involves taking meal
to a sifter or sieve after grinding in order
to separate fine and coarse particles so
they can be handled differently.
Whereas the finer material goes to the
mixer, the more coarse particles are returned only after the mixing and pelleting
stages. Adding the cracked corn to broiler diets post-pelleting has been shown
Will Henry of Extru-Tech Inc showed this
example of the structure of an extruded
product that
resulted from
a 5.84 ratio
between thermal
and mechanical
energy in the
extrusion process.
by Kansas State University research to
bring no significant change in growth
performance or feed efficiency. What it
does achieve, however, is opening up
the potential for the mill to increase its
total weekly feed production by almost
one-third and to reduce its operating
hours by nearly one-quarter. Against that
must be set the possible disadvantage
that the larger particles have not gone
through the heat of pelleting and therefore may be less acceptable from the
viewpoint of feed sterilization.
In the context of a practical situation,
such as the high-capacity extrusion of
floating aquatic feed, the usage of utilities for power can represent as much as
8% of the total production cost, said Will
Henry, R&D Director at Extru-Tech Inc.
This illustrates why energy management
has become such a hot topic among
extruder operators and why the most
common goal today is to improve the
process efficiency of extrusion while, at
the same time, increasing its output.
5Mycotoxin Control: Dismissing myths, achieving control Dr. Jules Taylor-Pickard, solutions deployment team leader, Alltech
Europe, shared that mycotoxin feed
direct losses are around 1 billion metric
tons of food and food products.
When undertaking a mycotoxin
analysis consider the sampling plan.
For example, how many samples per
lot of feeds are submitted, the type of
analysis, the extraction method, and
the sensitivity of the analytical technique
need to be considered. However, she
cautioned, that a negative result does
not, necessarily, mean that no mycotoxins are present. Masked mycotoxins and
mycotoxons are not evenly distributed
throughout a batch of grain. We will
never totally eliminate mycotoxins from
the food and feed chain, but use of mycotoxin sequestering agents can play a
pivotal role in combating mycotoxosis
in animals.
Dr. Gerd Schatzmayr of Biomin covered practical ways of achieving effective
control of mycotoxins in feed materials. Mycotoxins are more prevalent in
livestock production than assumed in
the past. According to the FAO, 25% of
animal feed is contaminated. Biomin’s
2009 World MycotoxinSsurvey found
that approximately 40% of feed was
contaminated with more than one
mycotoxin. To minimize the impact, an
effective intervention strategy is needed.
Dr. Schatzmayr recommends prevention
during feed production, decontamination during feed processing and deactivation during feed digestion. [FM]
