ArticlePDF Available

Comparison of feed proteins for dairy cows takes careful thought

  • Technical Advisory Services
EDITOR’S NOTE: The authors re-
cently took part in a fact-fi nding
mission and visited several feed
mills in Wisconsin. One important fact
that came to light was the diffi culty in
determining how to place a value on pro-
tein ingredients. Many purchasers used
a dollar spread to assess the value of a
protein, and others used a ratio system.
The discussions that ensued revealed a
number of pitfalls in these methods.
ONE of the toughest economic deci-
sions for nutritionists to make is select-
ing dietary ingredients, as each ingredi-
ent contributes more than one nutrient.
For example, barley may have less en-
ergy than corn grain, but it also provides
more protein.
Then, there are ruminal effects: Barley,
which contains less total starch than
corn, may contribute more rumen-avail-
able starch. This becomes even more
complex when proteins are compared.
Should the ingredients be valued on
the basis of cost per ton, cost per unit
of crude protein (CP) or cost per unit of
metabolizable protein (MP)? What about
amino acid profi les of ingredients?
Selecting the wrong metric can make
a considerable difference to the bot-
tom line. The purpose of this article is
to demonstrate that all of these may
be misleading if the value to the ani-
mal is not taken into account, as well
as to provide a more accurate means
of estimating the value of protein in-
gredients in such a way that the pur-
chaser is less vulnerable to mistakes.
Cost per ton of CP
Having data only on the CP content of an
unknown feedstuff tells little about its
MP and amino acid contents. The func-
Feedstuffs, June 5, 2017
© 2017 Feedstuffs. Reprinted with permission from Vol. 89, No.06, June 5, 2017
Comparison of feed proteins for
dairy cows takes careful thought
Nutritionists struggle to estimate the value of protein
ingredients, and selecting the wrong metric can make a
considerable difference to the bottom line.
*Glen Broderick is the president of
Broderick Nutrition & Research LLC,
Madison, Wis. Essi Evans is the president
of Technical Advisory Services Inc.,
Bowmanville, Ont. Brittany Dyck is the
meal manager for the Canola Council of
Canada, Winnipeg, Man.
tion of dietary CP is to supply the cow
with MP as absorbed amino acids, but
any oversupply of dietary CP that does
not contribute to absorbed amino ac-
ids that are used for production will be
largely lost in the urine. Urinary nitrogen
is the most polluting form of excretory
1. Effects of increasing dietary crude protein on milk
production and composition and nitrogen metabolism
parameters (Olmos Colmenero and Broderick, 2006b)
---------------------Dietary CP, % of dry matter---------------------
Milk parameters 13.5 15.0 16.5 17.9 19.4
Dry matter intake, lb./day 47.6b 48.1a,b 49.6a 47.6b 47.8a,b
Bodyweight gain, lb./day 0.49 0.49 0.70 0.57 0.64
Milk yield, lb./day 80.0b 82.0a,b 84.4a 80.7b 81.6a,b
Milk fat, % 3.17c 3.26a,b,c 3.23b,c 3.49a 3.45a,b
Milk fat yield, lb./day 2.51 2.65 2.73 2.71 2.73
3.5% fat-corrected milk, lb./day 75.2b 78.5a,b 80.9a 78.7a,b 79.6a,b
Milk protein, % 3.09 3.15 3.09 3.18 3.16
Milk protein yield, lb./day 2.43b 2.54a,b 2.60a 2.49a,b 2.54a,b
Nitrogen metabolism
Milk N:N intake 0.37a 0.34b 0.31c 0.28d 0.26e
Urea nitrogen excretion, g/day 63.2e 91.0d 128.4c 174.0b 208.1a
a,b,c,d,eMeans in rows without common superscripts are different (P < 0.05).
2. Comparison of protein sources on milk production
(Brito and Broderick, 2007)
--------------------------Added protein source--------------------------
Diet parameters Urea SBM Cottonseed meal CM
Dry matter, % 1.9 12.1 14.1 16.5
Microbial protein, g/day 2,340 2,710 2,710 2,780
RUP, g/day 540 990 1,350 1,150
Protein entering intestine, g/day 2,880 3,700 4,060 3,930
Dry matter intake, lb./day 48.7 54.3 54.5 54.9
Milk yield, lb./day 72.5 88.2 89.3 90.6
Protein yield, lb./day 2.03 2.71 2.60 2.80
Fat yield, lb./day 2.23 2.69 2.60 2.84
3. Calculated effective protein degradation, RUP and
RUP contributed by meals*
Nitrogen Effective protein RUP, % Protein, % RUP, %
solubility, % degradation, % of protein of meal of meal
CM (rapeseed meal) 20 44 56 36.9 20.6
Flax (linseed meal) 59 46 54 26.8 14.5
Lupins 80 56 44 33.8 14.9
Peas 78 71 29 25.0 7.25
SBM 17 73 27 50.6 13.7
Wheat distillers grains 24 79 21 37.5 7.9
*Hedqvist and Uden, 2006.
4. Calculation of available RUP for three ingredients*
CP, RUP (inhibitor Intestinal Available
% of method), digestibility, RUP,
Ingredient DM % of CP % of RUP % of DM
Solvent-extracted SBM 52.8 34.9 89.8 16.5
Expeller SBM 46.9 59.0 88.0 24.2
Solvent-extracted CM 41.6 44.4 76.9 14.2
*Broderick et al., 2016; AminoDat 5.0.
Feedstuffs, June 5, 2017
Numerous studies show that dairy
cows utilize feed CP (nitrogen x 6.25)
much more effi ciently than other rumi-
nant livestock; however, dairy cows still
excrete about two to three times more
nitrogen in manure than in milk, as the
effi ciency values in Table 1 clearly indi-
cate. Supplemental protein sources need
to complement microbial protein in or-
der for cows to be most effi cient.
Cost per ton of MP, amino acids
Microbial protein is “high” quality be-
cause the essential amino acids are pres-
ent in proportions very close to those
required by the cow for the synthesis of
milk proteins. With cows milking more
than ever before, the source and quality
of RUP is becoming as important as the
amount being fed. In the past, protein
quality (the essential amino acid compo-
sition of feed protein) has been consid-
ered much less important to ruminants
because rumen microbes synthesize
high-quality protein out of the lower-
quality protein and the non-protein ni-
trogen in the diet.
So, what has happened to change this
view? Research has shown that, even for
ruminants such as dairy cows, not all
RUP is created equally. The differences
have to do with essential amino acids.
Many of the studies conducted at the
Dairy Forage Research Center compared
solvent SBM with expeller SBM and
roasted soybeans, both of which have
more RUP due to heat treatment. The
expeller SBM had 91% more RUP than
the solvent SBM. In three separate trials,
when these value-added soybean prod-
ucts were fed to supply equal amounts
of CP in the ration, the boost in milk pro-
tein for expeller SBM averaged only 54%
— a substantial improvement, but far
from the 91% increase in RUP.
In addition, similar trials were per-
formed with fi sh meal. The low-soluble,
ruminant-grade fi sh meal had twice as
much RUP as solvent SBM. When cows
were fed this source, their milk protein
yield response was also double that of
cows fed the solvent SBM (Broderick,
1992). Protein utilization was better with
sh meal because of differences in the
protein quality of fi sh meal compared to
This difference is because fi sh meal is
much higher in methionine — one of the
essential amino acids and the one most
often fi rst limiting for milk production.
It was concluded that utilization of soy-
bean RUP is limited by inadequate me-
Ruminant-grade fi sh meal is quite ex-
pensive. Often, the cost is not covered
by the value of its greater protein qual-
ity. However, there are higher-quality
plant proteins that can be used. A recent
study at the Dairy Forage Research Cen-
ter compared four diets based on typi-
cal Midwest feeds (Brito and Broderick,
2007). The diets all contained about
16.5% CP, but the supplemental protein
came from four different sources (Table
5. Calculation of available RUP for three ingredients*
Available Amino Intestinal Available
RUP, Amino acid, % digestibility, amino acid,
Ingredient % of DM acid** of RUP % of RUP g/kg
Solvent-extracted SBM 16.5 Lys 6.17 90 9.16
Met 1.38 92 2.10
Met+Cys 2.84 88 4.13
His 2.63 91 3.95
Expeller SBM 24.2 Lys 6.04 89 13.00
Met 1.34 90 2.92
Met+Cys 2.83 83 5.68
His 2.61 90 5.68
Solvent-extracted CM 14.2 Lys 5.58 73 5.82
Met 1.95 84 2.33
Met+Cys 4.34 77 4.75
His 2.72 81 3.13
*Broderick et al., 2016; AminoDat 5.0.
**Lys = lysine, Met = methionine, Met + Cys = methionine + cysteine, His = histidine.
6. Results from seven studies that compared soybean
meal (SBM) and canola meal (CM)
---Milk yield- -- -Milk protein yield- --Milk fat yield--
Brito and Broderick, 2007 88.2 90.6 2.71 2.80 2.69 2.84
Broderick et al., 2015 84.5 85.8 2.81 2.86 3.52 3.65
Contreras-Govea et al., 2013 80.0 86.2 2.53 2.76 3.00 3.18
Faciola and Broderick, 2013 80.2 82.2 2.42 2.47 3.20 3.22
Broderick and Faciola, 2014 84.3 85.5 2.81 2.85 3.52 3.64
Paula et al., 2015 88.2 91.1 2.76 2.76 3.51 3.62
Moore and Kalscheur, 2016 112.9 122.8
Averages 88.3 92.0 2.67 2.75 3.24 3.36
nitrogen, because much of it is lost as at-
mospheric ammonia or runs into surface
and ground water. In addition, the inef-
cient use of dietary CP increases milk
production costs.
Based on numerous studies conduct-
ed at the Dairy Forage Research Center
in Madison, Wis., some general conclu-
sions can be made about CP. There were
no increases in yield of milk, fat-correct-
ed milk or milk protein with more than
16.5% dietary CP. Lowering protein and
adding rumen undegradable protein
(RUP) to the diet is highly dependent on
the source of the RUP.
In one trial (Olmos Colmenero and
Broderick, 2006a), reducing CP to 15.6%
but adding RUP as heated soybean meal
(SBM) did not support production equal
to 16.5% CP. However, canola meal (CM)
was found to be a more effective source
of MP than SBM or cottonseed meal (Bri-
to et al., 2007; Broderick et al., 2015).
Supplementing rumen-protected me-
thionine has also been shown to be ef-
fective for allowing some reduction in
dietary CP without losing milk yield, par-
ticularly when methionine-poor ingredi-
ents such as SBM form the main source
of supplemental protein (Broderick et
al., 2009; Chen et al., 2011).
Studies conducted at the Dairy For-
age Research Center have demonstrated
that there are no interactions between
energy density or neutral detergent fi ber
(NDF) level and response to dietary pro-
tein sources. Milk yield was increased
by reducing forage from 75% to 62% and
then to 50% of dietary dry matter, re-
sulting in diets with 36%, 32% and 28%
NDF; dietary CP was fed at about 15.1%,
16.7% and 18.4% of dry matter at each
NDF level (Broderick, 2003). The cows
responded to CP the same way at all
three energy levels. Milk and protein
yield both increased with the fi rst CP in-
crement, but there was no difference be-
tween production at 16.7% and 18.4% CP.
Thus, proteins can be reviewed without
being overly concerned about energy in-
This experiment was followed up by a
study that evaluated stepwise increases
of 1.5 percentage units from 13.5% to
19.4% CP in 50% forage diets (Olmos
Colmenero and Broderick, 2006b). As
expected, milk urea nitrogen (MUN),
urinary urea and the milk nitrogen-to-
nitrogen intake (N:N) ratio refl ected the
linear decline in nitrogen effi ciency with
increasing CP (Table 1). Milk production
was highest on the 16.5% CP diet, and a
quadratic response was observed that
indicated that milk and protein yields
were greatest at 16.7% and 17.1% CP, re-
spectively. Overfeeding protein actually
appeared to suppress production.
Ruminants make effi cient use of diets
that are poor in protein content or qual-
ity because rumen microbes synthesize
high-quality protein by capturing recy-
cled urea nitrogen that would otherwise
be excreted in the urine.
Feedstuffs, June 5, 2017
The results obtained in this study can-
not be explained by the RUP supply or
total protein fl ow to the intestines. The
cows receiving cottonseed meal had the
most rumen protein outfl ow, but they
didn’t make as much milk or milk protein
(or fat) as the cows fed CM. The reason
likely was because CM has substantially
more methionine and better amino acid
quality than either SBM or cottonseed
Even more support was provided by
Swedish researchers Hedqvist and Uden
(2006). Their research showed that there
was a low correlation between soluble
protein and degraded protein. CM is high
in soluble protein but also high in RUP
(Table 3).
With this information at hand, how
would one go about determining the val-
ue of available protein? Clearly, if using
CP to purchase meal, a particular protein
source might easily be overvalued or un-
Due to the lack of a relationship be-
tween protein solubility and the RUP that
appears at the duodenum, a method for
determining protein degradation from
in vitro amino acid and peptide release
was developed (Colombini et al., 2011).
This method allows users to calculate a
more accurate value for RUP and shows
that the RUP for solvent-extracted SBM,
expeller SBM and solvent-extracted CM
is 34.9%, 59.0% and 44.4% of the protein,
What is not immediately obvious is
the fact that the digestibility of the RUP
fraction can be different for different in-
gredients. Such values are not frequently
determined for ingredients used in feed-
ing dairy cattle.
However, intestinal digestibility values
have been determined on a routine ba-
sis for swine. One excellent source is a
program produced by Evonik Industries
(AminoDat 5.0). Using these values for
illustration purposes, Table 4 provides
estimations of absorbable RUP for these
three ingredients.
Using this method, it can be seen from
Table 5 that expeller SBM provides 1.46
times per pound as much intestinally
available RUP as solvent-extracted SBM,
while solvent-extracted CM provides
0.86 as much intestinally available RUP.
These values could, therefore, be used to
estimate the worth of ingredients. If SBM
is worth $300 per ton, then expeller SBM
would be worth $438 per ton, and CM
would be valued at $258 per ton.
How about the amino acid profi le? The
same method can be used to calculate
the relative value of meals using amino
As Table 5 shows, there are clear dif-
ferences in the contribution of key amino
acids to the intestinally digested amino
acid pool. For example, solvent-extract-
ed SBM provides 2.10 g/kg of methionine.
Expeller SBM, on the other hand, pro-
vides 2.92 g, or 39% more, of this nutri-
ent. In comparison, CM provides 2.33 g
of methionine, or 11% more methionine
for the same weight of solvent-extracted
Depending upon which nutrient is
most critical to the formulation, the
value of a lower CP, lower available RUP
ingredient might actually be greater than
the standard.
Animal performance effect?
In total, seven studies conducted at the
Dairy Forage Research Center showed
that performance is numerically im-
proved when cows receive CM than when
they receive SBM. A summary of the re-
sults are presented in Table 6. There was
a consistent improvement with the more
balanced protein source.
Lending further support to production
advantages with CM are two recent me-
ta-analyses. Huhtanen et al. (2011) pub-
lished results from 122 studies in which
dietary protein was elevated using either
SBM or CM, and the higher dietary pro-
tein concentrations were achieved by
reducing the grain portion of the diets.
According to the meta-analysis, for ev-
ery 1 lb. increase in CP consumed, milk
production increased by 3.4 lb. when
the added protein was derived from CM
and by 2.1 lb. with SBM, resulting in a net
gain of 1.3 lb. with CM.
Using slightly different selection crite-
ria, Martineau et al. (2013) compared the
effects of replacing other vegetable pro-
teins in the diet with the same amount
of protein from CM. At the average inclu-
sion level (5.1 lb. per day) of CM, milk
yield increased by 3.1 lb. across the 49
studies used in the analysis.
In a continuation of this research,
Martineau et al. (2014) compared the
response in plasma amino acids to
changes in the protein source in the diet.
Essential amino acids were higher and
MUN was lower when cows received CM
compared to all other sources of protein.
What these data show is that calculat-
ing the value of proteins based on their
relative price is not accurate. The calcu-
lation can be somewhat improved by cal-
culating the value on the basis of avail-
able RUP and by comparing the supply
of the most critical amino acid. The val-
ue of improved or reduced performance
also merits consideration.
AminoDat 5.0. 2016. Evonik Industries
Brito, A.F., and G.A. Broderick. 2007.
Effects of feeding different protein supple-
ments on milk production and nutrient utili-
zation in dairy cows. J. Dairy Sci. 90:1816-
Brito, A.F., G.A. Broderick and S.M. Rey-
nal. 2007. Effects of different protein supple-
ments on omasal nutrient flow and microbial
protein synthesis in lactating dairy cows. J.
Dairy Sci. 90:1828-1841.
Broderick, G.A. 1992. Relative value of
fish meal versus solvent soybean meal for
lactating dairy cows fed alfalfa silage as sole
forage. J. Dairy Sci. 75:174-183.
Broderick, G.A. 2003. Effects of varying
dietary protein and energy levels on the
production of lactating dairy cows. J. Dairy
Sci. 86:1370-1381.
Broderick, G.A., and A.P. Faciola. 2014.
Effects of supplementing rumen-protected
met and lys on diets containing soybean
meal or canola meal in lactating dairy cows.
J. Dairy Sci. 97(E-Suppl. 1):751(Abstr.).
Broderick, G.A., S. Colombini, S. Costa,
M.A. Karsli and A.P. Faciola. 2016. Chemical
and ruminal in vitro evaluation of Cana-
dian canola meals produced over 4 years. J.
Dairy Sci. 99:7956-7970.
Broderick, G.A., A.P. Faciola and L.E.
Armentano. 2015. Replacing dietary soy-
bean meal with canola meal improves pro-
duction and efficiency of lactating dairy
cows. J. Dairy Sci. 98:5672-5687.
Broderick, G.A., M.J. Stevenson and R.A.
Patton. 2009. Effect of dietary protein con-
centration and degradability on response
to rumen-protected methionine in lactating
dairy cows. J. Dairy Sci. 92:2719-2728.
Chen, Z.H., G.A. Broderick, N.D. Luchini,
B.K. Sloan and E. Devillard. 2011. Effect of
feeding different sources of rumen-protected
methionine on milk production and N-utili-
zation in lactating dairy cows. J. Dairy Sci.
Colombini, S., G.A. Broderick and M.K.
Clayton. 2011. Effect of quantifying pep-
tide release on ruminal protein degradation
determined using the inhibitor in vitro sys-
tem. J. Dairy Sci. 94:1967-1977.
Contreras-Govea, F.E., S. Bertics, G.A.
Broderick, A. Faciola and L.E. Armentano.
2013. Lactation performance of cows fed
soybean meal or canola meal supplements.
J. Dairy Sci. 96(E-Suppl. 1):34(Abstr.).
Faciola, A.P., and G.A. Broderick. 2013.
Effects of replacing soybean meal with
canola meal for lactating dairy cows fed
three different ratios of alfalfa to corn silage.
J. Dairy Sci. 96:(E-Suppl. 1):452(Abstr.).
Hedqvist, H., and P. Uden. 2006. Measure-
ment of soluble protein degradation in the
rumen. Anim. Feed Sci. Technol. 126:1-21.
Huhtanen, P., M. Hetta and C. Swensson.
2011. Evaluation of canola meal as a protein
supplement for dairy cows: A review and a
meta-analysis. Can. J. Anim Sci. 91:529-543.
Martineau, R., D.R. Ouellet and H.
Lapierre. 2013. Feeding canola meal to
dairy cows: A meta-analysis on lactational
responses. J. Dairy Sci. 96:1701-1714.
Martineau R., D.R. Ouellet and H. Lapi-
erre. 2014. The effect of feeding canola meal
on concentrations of plasma amino acids. J.
Dairy Sci. 97:1603-1610.
Moore, S.A.E., and K.F. Kalscheur. 2016.
Canola meal in dairy cow diets during
early lactation increases production com-
pared with soybean meal. 99(E-Suppl.
Olmos Colmenero, J.J., and G.A. Brod-
erick. 2006a. Effect of amount and ruminal
Feedstuffs, June 5, 2017
degradability of soybean meal protein on
performance of lactating dairy cows. J. Dairy
Sci. 89:1635-1643.
Olmos Colmenero, J.J., and G.A. Brod-
erick. 2006b. Effect of dietary crude protein
concentration on milk production and nitro-
gen utilization in lactating dairy cows. J.
Dairy Sci. 89:1704-1712.
Paula, E.M., M.A.C. Danes, N.E. Lobos,
G.I. Zanton, G.A. Broderick and A.P. Faciola.
2015. Effects of replacing soybean meal with
canola meal or heat-treated canola meal on
performance of lactating dairy cows. J. Dairy
Sci. 98(Suppl. 2):387(Abstr.).
ResearchGate has not been able to resolve any citations for this publication.
Full-text available
Previous research has demonstrated that feeding canola meal (CM) improves milk production and N utilization by lactating dairy cows when replacing solvent-extracted soybean meal (SBM). The objective of the present study was to evaluate whether CM would improve milk yield and components and N utilization, compared with SBM, at different ratios of alfalfa silage (AS) to corn silage (CS) fed to lactating dairy cows. Twenty-four multiparous Holstein cows averaging, at the beginning of the study (mean ± SD), 2.8 ± 0.9 parity, 684 ± 56 kg of BW, 102 ± 41 DIM, and 49 ± 4 kg milk/d, and 24 primiparous cows averaging (mean ± SD) 565 ± 46 kg of BW, 123 ± 30 DIM, and 40 ± 4 kg milk/d were blocked by parity and DIM. A cyclic changeover design with 4 replications of 2 blocks of treatments of 6 cows was used in an arrangement with 4 28-d periods. Dietary treatments were arranged in a 3 × 2 factorial design of 3 proportions of AS to CS as forage source (HAS = high AS, 50% AS to 10% CS; MAS = medium AS, 30% AS to 30% CS; LAS = low AS, 10% AS to 50% CS) and 2 protein supplements (CM vs. SBM). Diets were formulated to contain [dry matter (DM) basis]: 60% forage, 8 to 15% high-moisture corn, 2 to 5% soy hulls, 1.3% mineral-vitamin premix, 16% crude protein, and 31 to 33% NDF. Data from the last 2 weeks of each period were used to compute mean milk yield and composition, and efficiencies of feed conversion, for each cow in each period. Data for the other variables were collected during the last week of each period. All data were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). Regardless of the forage source, replacing SBM with CM improved yields of milk, milk protein, and solids-not-fat. Moreover, milk urea nitrogen concentration and urinary excretion of total N (g/d) and urea N (% of total urinary N) decreased when CM replaced SBM. An interaction effect occurred between forage source and protein supplements for apparent total-tract digestibility, and, overall, this effect was due to small differences in ingredient and chemical compositions of the diets. In addition, these differences had a minor effect on cow performance. Yields of milk and milk components were greatest for cows fed 50% CS, intermediate for 30% CS, and lowest for 10% CS, indicating that, under the conditions of the present study, cows fed 50% CS in the diet (DM basis) had greater production compared with those fed 50% AS.
Full-text available
Previous research suggested that crude protein (CP) from canola meal (CM) was used more efficiently than CP from solvent soybean meal (SBM) by lactating dairy cows. We tested whether dietary CP content influenced relative effectiveness of equal supplemental CP from either CM or SBM. Fifty lactating Holstein cows were blocked by parity and days in milk into 10 squares (2 squares with ruminal cannulas) in a replicated 5 × 5 Latin square trial. Five squares were fed: (1) low (14.5-14.8%) CP with SBM, (2) low CP with CM, (3) low CP with SBM plus CM, (4) high (16.4-16.7%) CP with SBM, and (5) high CP with CM; the other 5 squares were fed the same diets except with rumen-protected Met plus Lys (RPML) added as Mepron (Degussa Corp., Kennesaw, GA) and AminoShure-L (Balchem Corp., New Hampton, NY), which were assumed to provide 8 g/d of absorbed dl-Met and 12 g/d of absorbed l-Lys. Diets contained [dry matter (DM) basis] 40% corn silage, 26% alfalfa silage, 14 to 23% corn grain, 2.4% mineral-vitamin premixes, and 29 to 33% neutral detergent fiber. Periods were 3 wk (total 15 wk), and data from the last week of each period were analyzed using the Mixed procedures of SAS (SAS Institute Inc., Cary, NC). The only effects of RPML were increased DM intake and milk urea N (MUN) and urinary N excretion and trends for decreased milk lactose and solids-not-fat concentrations and milk-N:N intake; no significant RPML × protein source interactions were detected. Higher dietary CP increased milk fat yield and tended to increase milk yield but also elevated MUN, urine volume, urinary N excretion, ruminal concentrations of ammonia and branched-chain volatile fatty acids (VFA), lowered milk lactose concentration and milk-N:N intake, and had no effect on milk true protein yield. Feeding CM instead of SBM increased feed intake, yields of milk, energy-corrected milk, and true protein, and milk-N:N intake, tended to increase fat and lactose yields, and reduced MUN, urine volume, and urinary N excretion. At low CP, MUN was lower and intake tended to be greater on SBM plus CM versus SBM alone, but MUN and N excretion were not reduced to the same degree as on CM alone. Interactions of parity × protein source and parity × CP concentration indicated that primiparous cows were more responsive than multiparous cows to improved supply of metabolizable protein. Replacing SBM with CM reduced ruminal ammonia and branched-chain VFA concentrations, indicating lower ruminal degradation of CM protein. Replacing SBM with CM improved milk and protein yield and N-utilization in lactating cows fed both low- and high-CP diets. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Conference Paper
Full-text available
Abstract Text: Previously, replacing solvent soybean meal (SBM) with equal CP from canola meal (CM) was found to increase milk yield in lactating dairy cows by about 1 kg/d. We tested whether supplementing rumen-protected Met and Lys (RPML) would improve milk and protein yield in cows fed either CM or SBM. Sixteen lactating Holstein cows were blocked by DIM and parity into 4 squares of 4 cows each in a replicated 4 x 4 Latin square. There was a 2 x 2 arrangement of treatments: equal CP supplemented as either SBM or CM, with or without added RPML to provide 10 g absorbed Met/d (Mepron®) plus 22 g absorbed Lys/d (AminoShureL®). Cows within squares were randomly assigned to treatment sequences and fed experimental diets for 3-week periods before switching diets. All diets contained (DM basis) 41% alfalfa silage, 25% corn silage, 2.3% mineral-vitamin premix, 1.4% ground shelled corn and 17% CP. Soybean meal diets contained 22% high moisture corn, 8.7% SBM and 28% NDF; CM diets contained 19% high moisture corn, 11.7% CM and 30% NDF. Data from the last week of each period were analyzed using the mixed procedures of SAS; LS-means are reported in the table. Replacing SBM with CM increased DMI (P = 0.04) and tended to increase yields of energy-corrected milk and fat (P ≤ 0.09), but there were no other affects on production (P ≥ 0.15). Supplementing with RPML did not influence intake or yield (P ≥ 0.15) and no significant of protein x RPML interactions were detected (P ≥ 0.15). These results tended to support previous findings of improved milk yield on CM versus SBM. However, under the conditions of this trial, there were no effects of supplementing with rumen-protected Met plus Lys on either protein source. Table Protein SSBM SSBM CM CM Contrasts RPML - + - + Protein RPML P x R Trait DMI, kg/d 27.1 27.2 27.8 27.5 0.04 0.66 0.36 Milk, kg/d 38.4 38.1 39.1 38.5 0.18 0.27 0.71 Milk/DMI 1.42 1.40 1.41 1.40 0.79 0.38 0.81 ECM, kg/d 39.3 38.7 40.3 39.6 0.09 0.23 0.88 ECM/DMI 1.45 1.42 1.45 1.44 0.54 0.26 0.59 Fat, kg/d 1.62 1.57 1.67 1.63 0.06 0.14 0.90 Prot, kg/d 1.27 1.27 1.30 1.29 0.14 0.65 0.51 MUN, mg/dl 15.2 15.0 15.0 15.0 0.72 0.60 0.73 Keywords: Soybean meal Canola meal Rumen-protected AA
Full-text available
Twenty-five feeds were screened for buffer soluble N (BSN) and its constituent protein N, peptide N, amino acid N and ammonia N. In vitro degradation rates of buffer soluble protein were determined in 11 of these feeds. To estimate rumen in vivo degradation rates, buffer soluble protein from peas or cold pressed rapeseed cake was also given as a pulse dose, together with a liquid marker (CoEDTA), to lactating rumen-fistulated dairy cows. Buffer soluble N ranged from 36 to 802g/kg N. There were also large differences in BSN composition. Buffer soluble protein N ranged from 0 to 874g/kg BSN with peas and lupine seeds containing the highest amounts. There were differences (P
Full-text available
A review and a meta-analysis were conducted to compare the feeding value of soybean meal (SBM) and canola meal (CM) in dairy cows and to evaluate the effects of heat-treatment of CM (TCM) on the performance of dairy cows. The dataset included in total 292 treatment means from 122 studies, in which dietary crude protein (CP) concentration was increased by replacing energy supplements with protein supplements. A mixed model regression analysis with random study effect was used to estimate the marginal production responses to different protein sources. The differences between the slopes were compared by t-test. All protein sources increased dry matter intake, but the responses were greater (P<0.01) for CM and TCM compared with SBM. Feeding CM or TCM produced greater (P<0.01) daily milk yield responses than SBM (3.4±0.19 and 3.7±0.25 vs. 2.1±0.25) kg kg−1 increase in CP intake. Marginal milk protein yield responses (g kg−1 increase in CP intake) were greater (P<0.01) for CM (136±5.4) and TCM (133±8.5) compared with SBM (98±8.0). Smaller response to incremental CP intake can partly be related to the higher average dietary CP concentration in SBM studies. Literature data on rumen ammonia N concentration and omasal protein flow did not support the higher ruminal tabulated ruminal CP degradability of CM compared with SBM. It is concluded that CM can successfully be substituted for SBM on isonitrogenous basis and that most feed evaluation systems overestimate metabolizable protein concentration of SBM relative to CM.
Full-text available
Fish meal was compared with soybean meal in three trials. In trial 1, 20 early lactation cows fed 70% alfalfa silage received an average .46 kg of CP/d from either source in 2 X 2 Latin squares. Rumen protein escapes estimated in vitro were 37% (soybean meal) and 60% (fish meal). Fish meal increased BW gain, milk protein content, yield of milk, FCM, protein, and lactose; lowered rumen propionate; and increased rumen acetate:propionate. In trial 2, 32 midlactation cows fed 89% alfalfa silage were divided into two groups of 16 and supplemented with 0, 1.5, 3.0, or 4.5% CP from either soybean meal or fish meal in 4 X 4 Latin squares. Rumen protein escapes estimated in vitro were 31% (soybean meal) and 67% fish meal). There were linear increases in BW gain and in yield of milk, protein, lactose, and SNF with either protein but no differences between proteins. In trial 3, 32 early lactation cows fed 56% alfalfa silage received no protein supplement or an average .55 kg CP/d from soybean meal, high solubles fish meal, or low solubles fish meal in 4 X 4 Latin squares. Rumen protein escapes estimated in vitro were 27% (soybean meal), 43% (high solubles fish meal), and 63% (low solubles fish meal). Protein increased yield of milk, FCM, fat, protein, lactose, and SNF versus no supplement. Milk protein content increased about .1 percentage unit with both fish meals. Protein yield increased 61, 95, and 130 g/d with soybean meal, high solubles fish meal, and low solubles fish meal versus no supplement. In all trials, fish meal slightly reduced milk lactose content but did not alter milk fat content. Results indicated that greater rumen escape of fish meal protein, relative to soybean meal, increased efficiency of protein utilization in lactating cows fed alfalfa silage.
Extrusion treated canola meal (TCM) was produced in an attempt to increase the rumen-undegraded protein fraction of canola meal (CM). The objective of this study was to evaluate the effects of replacing soybean meal (SBM) with CM or TCM on ruminal digestion, omasal nutrient flow, and performance in lactating dairy cows. To assess performance, 30 multiparous Holstein cows averaging (mean ± SD) 119 ± 23 d in milk and 44 ± 7 kg of milk/d and 15 primiparous cows averaging 121 ± 19 d in milk and 34 ± 6 kg of milk/d were blocked in a randomized complete block design with a 2-wk covariate period and 12-wk experimental period (experiment 1). Dietary ingredients differed only in protein supplements, which were SBM, CM, or TCM. All diets were formulated to contain (dry matter basis) 30% alfalfa silage, 30% corn silage, 4% soy hulls, 2.4% mineral-vitamin premix, and 16% CP. The SBM diet contained 25% high-moisture shelled corn and 8.6% SBM; the canola diets contained 22% high-moisture shelled corn and either 11.2% CM or 11.4% TCM. To assess ruminal digestion and omasal nutrient flow, 6 rumen-cannulated cows were blocked into 2 squares of 3 cows and randomly assigned within blocks to the same 3 dietary treatments as in experiment 1 in a replicated 3 × 3 Latin square design (experiment 2). Data were analyzed using the MIXED procedure of SAS (SAS Institute, Cary, NC). Orthogonal contrasts were used to compare effects of different protein supplements: SBM versus CM + TCM and CM versus TCM. In experiment 1, compared with SBM, apparent total-tract digestibilities of dry matter and nutrients were greater in cows fed both CM diets, and there was a tendency for nutrient digestibilities to be higher in cows fed CM compared with TCM. Diets did not affect milk yield and milk components; however, both canola diets decreased urinary urea N (% of total urinary N), fecal N (% of total N intake), and milk urea N concentration. In experiment 2, compared with SBM, both canola diets increased N intake and tended to increase rumen-degraded protein supply (kg/d) and N truly digested in the rumen (kg/d). Diets did not affect ruminal digestibility, efficiency of microbial protein synthesis, and rumen-undegraded protein flow among diets. Results from this experiment indicate that replacing SBM with CM or TCM in diets of lactating cows improved digestibility and may reduce environmental impact. Moreover, under the conditions of the present study, treating CM by extrusion did not improve CM utilization.
An initial meta-analysis on isonitrogenous experiments where a protein source was replaced by canola meal (CM) showed that CM feeding increased yields of milk and milk protein and apparent N efficiency. The objective of the current study was to determine if these responses were related to increased changes in plasma AA concentrations. Although only half of the experiments of the initial meta-analysis reported concentrations of plasma AA and could be used in the current meta-analysis, lactational responses to CM feeding were similar to those reported previously. In the current meta-analysis, CM feeding increased plasma concentrations of total AA, total essential AA (EAA) and all individual EAA, but decreased concentrations of blood and milk urea-N. The current meta-analysis suggests that CM feeding increased the absorption of EAA, which would be responsible for the increased milk protein secretion and the increased apparent N efficiency.
The objective of this meta-analysis was to determine the effects of the substitution of a protein source by canola meal (CM) on lactational responses (CM minus control) in dairy cows. The study included 49 comparisons of isonitrogenous (±1.0% dietary CP content) dietary treatments published since 1975 (27 experiments). The CM intake ranged from 1.0 to 4.0 kg/d (standard deviation = 0.65). Regressions were forced through the origin, weighted by sample size, and controlled for changes in dry matter intake and in dietary concentrations of CP and ether extract. Milk yield and milk protein yield responded positively to the substitution of a protein source by CM. The response in milk protein yield was affected by the type of protein source that was substituted; the positive response was half less when CM was substituted for soybean meal compared with substitution of CM for other protein sources. The latter effect was in part related to a positive response on milk protein percentage when CM replaced protein sources other than soybean meal. The response in efficiency of N utilization (milk N yield/N intake) was positive to the substitution of a protein source by CM. Negative changes in supply of metabolizable protein (MP) estimated from the 2001 National Research Council model were associated with positive responses in milk protein yield with CM substitution, a finding contrary to the expected positive relationship between supply of MP and milk protein yield. In conclusion, current results suggest that a protein supplement can be substituted by CM with positive effects on milk and milk protein production. These data also suggest an underestimation of MP supply associated with CM inclusion in dairy rations using the National Research Council model.