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Amylase – A radical innovation
in dairy cow nutrition
Dr. Irmgard Immig
Global Category Manager Ruminants at DSM
HEALTH • NUTRITION • MATERIALS
Amylase – A radical innovation
in dairy cow nutrition
Find out more about
RONOZYME® RumiStar™ >
Dr. Irmgard Immig, Global Category Manager Ruminants at DSM
Corn silage and corn grain inclusion rates in the daily ration of cows are on the rise. No other crop
has such a high availability of supply, energy density and consistency. Corn silage has a high
palatability and delivers a considerable amount of starch that by-passes the rumen. By-pass
starch is digested in the intestine and is more efficient as a glucose source for early lactating
dairy cows, than broken down to volatile fatty acids in the rumen.
Wheat and barley are both poor sources of by-pass starch because they are very rapidly degraded
in the rumen – only 5-10% leave the rumen unfermented. Corn starch, on the other hand, is a
slowly degradable energy source and is more likely to by-pass the rumen. In fact, up to 30% of
the corn starch can leave the rumen undigested. A cow in early lactation yielding 40 kg of milk per
day has a glucose requirement of about 3 kg for milk production1 (Table 1). Therefore, corn starch
that by-passes the rumen can easily match about 60% of the daily glucose requirement for milk
production (Table 2).
Table 1: Milk constituent and glucose requirements to produce 40 kg of milk (Matthé et al, 2000)
Milk composition
Constituents in 40 kg milk (kg/day)
Protein (3.2%)
1.3
Fat (4.0%)
1.6
Lactose (4.8%)
1.9
Glucose requirement
2.85
Table 2: By-pass starch from corn can deliver up to 60% of the daily glucose requirement
of a high yielding dairy cow
Corn
Wheat
Grain intake (g/hd/d)
8,000
8,000
Starch intake (g/hd/d)
5,600
5,300
Rumen degradablity (%)
70
90
By-pass starch (g/hd/d)
1,680
528
60
19
In % of daily glucose requirement
Dairy producers are therefore not only investing in cow genetics but also in corn hybrid genetics.
Modern corn hybrids that are grown for silage and/or corn grain should deliver the most from
every hectare in terms of energy from starch but also from the forage part. In order to achieve high
energy concentration in the feed, special attention has to be paid to the starch content and its
rumen degradability, as well as on the fiber content and its digestibility.
1
2
Matthé et al, 2000
Degradability and digestibility
Ruminal corn starch degradability is strongly influenced by which corn hybrid is used in the feed,
and its maturity. Varieties with almost all hard or vitreous endosperm are called flint, while those
with a softer or flourier endosperm are called dent hybrids. The proportion of starch from corn that
is fermented in the rumen can therefore vary considerably - between 50 to 95% depending on corn
varieties and maturity2 (Figure 1).
Figure 1: Site of starch digestion in dairy cows receiving high moisture ear corn of increasing
maturity (Brandt et al, 1986)
Feces
Losses
Ground corn grain
Hindgut
Late dough
Medium dough
Preferred
sites of
digetion
Early dough
Duodenum
Rumen
0
(Brandt et al. 1986)
10 20 30 40 50 60 70 80 90 100
Starch degradation (%)
Decreased corn starch degradability in the rumen shifts starch digestion more
towards the intestines. Going beyond the duodenum leads to starch losses and
loose feces.
Undegraded starch from the rumen will flow into the small intestine, where it will be digested
by endogenous enzymes produced by the cow. Although the increased intestinal starch flow
can increase the direct absorption of glucose, being an important precursor of lactose for high
producing dairy cows, the capacity of the small intestine to digest large quantities of starch is
limited. Therefore, some undigested starch can move through the duodenum towards the hindgut
and is then lost via feces, having a negative impact on feed utilization and incurring costs for the
dairy producer (see figure 1).
Another undesirable effect that can result from feeding high amounts of very slowly degradable
starch is a limited availability of oligosaccharides or rapidly available energy in the rumen directly
after a meal. This leads to a lack of energy for the fiber colonizing and digesting bacteria and will
therefore limit the capacity and the speed of the microbes to degrade the dietary fiber (NDF) of the
ration. Moreover, microbial biomass and thus microbial protein yield might be compromised, due
to the lack of more readily available energy. Synchronizing energy and protein metabolism in the
rumen is, however, the key for maximizing microbial protein output, for optimum feed utilization
and thus performance.
2
3
Brandt et al, 1986
Modulating starch degradability
The rate and site of starch digestion in the gastro-intestinal tract can be modified by various grain
processing methods, by harvesting corn at the right maturity and dry matter content. Recently
it was proven that feed enzymes can also have an impact on starch degradability in the rumen.
In vitro experiments using buffered rumen fluid showed that the addition of an alpha amylase
enzyme to different grain varieties increased gas production as an indicator of fermentation
intensity. The strongest effect was on corn grain where the alpha amylase showed a higher
fermentation intensity of almost 80%3 (Figure 2). In addition, different corn varieties reacted
differently to the alpha amylase. For example, fermentation intensity is higher in flint corn than
in dent corn hybrids.
Figure 2: Corn responds much better to an alpha amylase in vitro than other starch sources
(DSM/BioPract, 2006)
After 4 hours of incubation
% additional gas production
compared to untreated control
80
70
60
50
40
30
20
10
0
Corn
meal
Barley
meal
Rye
meal
Wheat
meal
Oat
meal
Potato
meal
Feed enzymes for the rumen
Feed enzymes are a radical innovation in dairy cow nutrition and one in particular can be used
as a new approach to maximize corn starch utilization and fiber digestion in early lactation.
RONOZYME® RumiStar™ is registered as a feed additive and is currently the only enzyme for dairy
cows on the market that works in the rumen. RONOZYME® RumiStar™ catalyzes the hydrolysis of
corn starch to oligosaccharides in the rumen without compromising on pH4 (Figure 3).
3
4
DSM/BioPract, 2006
4
Bach, 2011
Average rumen pH values throughout the day
Figure 3: Although RONOZYME® RumiStar™ increases the fermentation of slowly degradable
starch in the rumen it does not lower ruminal pH (Bach, 2013)
6.45
6.40
6.35
6.30
Control
6.25
RONOZYME®
RumiStar™
6.20
6.15
6.10
6.05
6.00
0
10
Source: Bach 2013
20
30
40
50
60
70
Measurement within a day
Oligosaccharides can be used as an energy source by the fiber degrading microbes – also
known as “cross-feeding”. The time it takes for fiber to be digested can be reduced when there
is more energy available to the fibrolytic microbes. It has been demonstrated that RONOZYME®
RumiStar™ almost doubled the ruminal degradation rate of starch and fiber (NDF) in situ5 (Figure
4). The degradation of the organic matter in the rumen therefore increased, leading to an overall
improvement of the total tract digestibility of the ration. A higher total tract organic matter
digestibility exploits the energy potential of the ration and leads to better animal performance.
Figure 4: RONOZYME® RumiStar™ enhanced ruminal degradation rate in situ and shifts digestion
more to the rumen thus increasing ruminal feed degradability (Bach 2010; Nozière et al)
Degradation rate/h
Control
RONOZYME®
RumiStar™
Corn grain
Starch
0.049a
0.088b
Corn silage
Fiber (NDF)
0.010a
0.020b
P<0.10
Bach (2010)
5
5
Bach et al, 2013
Rumen degradability (%)
Control
RONOZYME®
RumiStar™
Organic matter (OM)
64.6
67.3*
Fiber (NDF)
44.6
47.5
Starch
73.9
81.1**
* p<0.05; ** p<0.01 Noziere et al., 2012
The increased digestibility of the diet results in more energy that is available to the cow for
milk production. This was shown in a trial conducted at the University of Delaware in the US.
RONOZYME® RumiStar™ improved the digestibility of dry matter, of organic matter and fiber (NDF)
in a corn-based diet and this also resulted in a 9% increase in fat corrected milk yield or +3.6 kg
per cow per day6 (Figure 5).
Figure 5: RONOZYME® RumiStar™ improved digestibility and milk yield in high producing dairy
cows (Klingerman et al, 2009)
45
3.5% FCM (kg/d)
43.0
40
39.4*
35
Control
RONOZYME® RumiStar™
* p<0.05
Adding RONOZYME® RumiStar™ to a typical diet in the north of Italy increased not only milk yield
but also milk fat content, leading to 15% more fat corrected milk (FCM) of 4.4 kg per cow per day in
early lactating cows (<150 days in milk)7 (Table 3).
Table 3: Effect of RONOZYME® RumiStar™ in early lactating cows in Italy (Masoero et al., 2011)
Cows in early lactation
Control
RONOZYME®
RumiStar™
Difference
Milk yield (kg/d)
42.9a
46.0b
+3.1
Milk fat (%)
3.17a
3.35b
+0.18
4% FCM (kg)
37.1A
41.5B
+4.4
a, b: P< 0.01
A, B: P< 0.001
6
6
Klingerman et al, 2009
7
Masoero et al., 2011
Commercial field trials, as well as University trials, were conducted over several years in North
America, Latin America and Europe. They show that RONOZYME® RumiStar™ increased the milk
yield of cows in diets that contained 20 – 30% of corn starch on average by about 2 kg per cow
per day, ranging from 0.5 to 4.4 kg per cow per day (Figure 6). Moreover, the additive could also
alleviate the typical energy gap in the first 150 days of lactation, allowing the cow to recover more
rapidly from energy deficiency during this critical period8.
Figure 6: Fifteen out of 16 trials that show that RONOZYME® RumiStar™ has a positive
effect on milk yield
2.3
Germany, Field trial
Klingerman, USA
Azem & Meda, Mexico
Pereira, Brazil
Toth, Hungary
Bach, Spain
Masoero, Italy
Vargas-Rodriguez, USA
Gengoclu, Turkey
Brazil, Field observation
Spain, Field trial
CA Field I, USA
CA Field II, USA
CA Field III, USA
CO Field I, USA
CO Field II, USA
3.6
1.4
0.8
1.3
1.5
4.4
0.5
2.2
3.8
3.8
-0.8
3
1.2
1.3
0.9
-1
0
1
2
3
4
5
Effect of RONOZYME RumiStar compared to control (Δ milk kg/hd/d)
®
™
A trial conducted in Spain (IRTA, Barcelona) showed that RONOZYME® RumiStar™ also has an
effect on the intermediary metabolism of the cow. Cows fed the enzyme gained increased blood
glucose levels and the insulin/glucose ratio became higher. This is a very interesting observation
because it indicates that the enzyme is also active in the small intestine helping the cow’s
endogenous pancreas amylase to digest the by-pass starch9 (Table 4).
Table 4: RONOZYME® RumiStar™ increased glucose and the insulin over glucose ratio
(Bach, 2012)
Control
RONOZYME® RumiStar™
Glucose mg/dl
38.2a
43.0b
Insulin µg/l
0.20
0.22
Insulin/glucose
1.98a
3.64b
8
9
7
Bach, 2010
Bach, 2012
Cows have a limited capacity to digest starch that is entering the duodenum and this can lead to
considerable amounts of starch excreted via the feces. A simple calculation shows the financial
dimension of this loss: in a dairy herd of 500 cows with a daily intake of 5.6 kg of corn starch at
a digestibility of 95% the cows excrete the equivalent of 21 Mton of corn grain in the first 100
days of lactation. This is an extra need for growing 2.5 ha more corn. At the current price level
this is a financial loss of € 3,000. If such a herd was to increase milk production by 2 kg when
supplemented with RONOZYME® RumiStar™ per cow per day, in the first 100 days of lactation,
this would account to 100,000 kg more milk, and at a current milk price of 0.28 €/kg the total
gain would be €31,000.
Conclusion
Currently, dairy farmers are struggling because milk prices are very low and will continue to stay
low throughout 2016. There is therefore little desire to further increase milk production. However,
attitudes towards increased milk production would perhaps shift with the knowledge that the
same amount of milk could be produced with less cows. Dairy producers can achieve this by
turning to innovative new approaches for feed, such as the use of specific feed enzymes. This
would result in a significant rise in herd efficiency, as well as better rumen health and would also
allow for maximum profit to be achieved from every hectare of corn grown.
Find out more about
RONOZYME® RumiStar™ >
8