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Value of maize fed to dairy cows
Australian Grains Industry Conference Melbourne 29th July 2015
Steve Li@le BVSc MANZCVS Dip. Agribus. Principal Consultant
Capacity+ Ag ConsulKng
In this session…… • Feeding grains to dairy cows • Nutrient value of maize grain compared to other grains • Possible applicaKons for maize grain in dairy cow diets • Processing maize grain prior to feeding to dairy cows
Grain supports intensifica7on of the dairy industry
Grain fed per cow per year Today, grains support 25-‐30% of all milk produced in Australia Predominant grains: • 1980s & 90s: Barley and
triKcale • 2000s: Wheat Other grains fed to dairy cows: • Maize, sorghum
(Dairy Australia 2015)
(Dairy Australia 2015)
Today, grains support 25-‐30% of all milk produced in Australia Predominant grains: • 1980s & 90s: Barley and
triKcale • 2000s: Wheat Other grains fed to dairy cows: • Maize, sorghum 0
100
200
300
400
500
600
Avg. herd size
Avg. kgs Milksolids/cow
Grain/concentrate fed per cow per year
Grain supports intensifica7on of the dairy industry
4%
19%
64%
7% 5% 1% 3%
11%
68%
8% 7% 3%
0%
10%
20%
30%
40%
50%
60%
70%
% of farms
% of producKon
(Dairy Australia 2015)
Grain is fed to dairy cows in a range of feeding systems
Dairy cows are ruminant animals
1 2
3
Feeds are digested and absorbed in the rumen, small and large intesKnes
Nutrient value of maize grain compared to other grains
Maize grain: • Marginally higher in energy (ME)
Grain type Energy density (MJ ME/kg DM)
Maize 13.5 (12-‐16) Wheat 13 (12-‐14) Barley 12 (11.5-‐13.5) Oats 11 (9-‐13) Sorghum 11 (7-‐13) Sorghum (steam-‐flaked) 12 (9-‐14)
Nutrient value of maize grain compared to other grains
Maize grain: • Marginally higher in energy (ME) • Higher in starch
Grain type Energy density (MJ ME/kg DM)
Starch content (% DM)
Maize 13.5 (12-‐16) 70-‐75 Wheat 13 (12-‐14) 65-‐70 Barley 12 (11.5-‐13.5) 55-‐60 Oats 11 (9-‐13) 45-‐50 Sorghum 11 (7-‐13) 65-‐70 Sorghum (steam-‐flaked) 12 (9-‐14) 65-‐70
Nutrient value of maize grain compared to other grains
Maize grain: • Marginally higher in energy (ME) • Higher in starch • Slower rate of rumen fermenta7on
Grain type Energy density (MJ ME/kg DM)
Starch content (% DM)
Rate of rumen fermenta7on (+ = slow,
+++++ = fast) Maize 13.5 (12-‐16) 70-‐75 + Wheat 13 (12-‐14) 65-‐70 +++++ Barley 12 (11.5-‐13.5) 55-‐60 +++ Oats 11 (9-‐13) 45-‐50 ++ Sorghum 11 (7-‐13) 65-‐70 + Sorghum (steam-‐flaked) 12 (9-‐14) 65-‐70 ++
Nutrient value of maize grain compared to other grains
Maize grain: • Marginally higher in energy (ME) • Higher in starch • Slower rate of rumen fermenta7on
0
20
40
60
80
100
120
140
0 12 24 36 48
Gas
pro
duct
ion
(mL)
Time (h)
Wheat Maize
Example showing effect of grain type on rate of in vitro rumen digesKon
Rate of fermentaKon varies with culKvar For maize grain: • Vitreous – slower • Floury -‐ faster
Nutrient value of maize grain compared to other grains
Maize grain: • Marginally higher in energy (ME) • Higher in starch • Slower rate of rumen fermentaKon • Lower in crude protein (CP) Grain type Energy density
(MJ ME/kg DM) Starch content
(% DM) Rate of rumen fermenta7on (+ = slow,
+++++ = fast)
Crude Protein content (% DM)
Maize 13.5 (12-‐16) 70-‐75 + 9.5 Wheat 13 (12-‐14) 65-‐70 +++++ 12-‐13 Barley 12 (11.5-‐13.5) 55-‐60 +++ 12-‐13.5 Oats 11 (9-‐13) 45-‐50 ++ 11.5-‐12 Sorghum 11 (7-‐13) 65-‐70 + 10.5 Sorghum (steam-‐flaked) 12 (9-‐14) 65-‐70 ++ 11.5
Designing diets for dairy cows Step 1 – Calculate cow nutrient requirements Step 2 – Consider feeds available and their costs Step 3 – EsKmate cow’s voluntary feed intake Step 4 – Formulate diet
Designing diets for dairy cows Step 1 – Calculate cow nutrient requirements Step 2 – Consider feeds available and their costs Step 3 – EsKmate cow’s voluntary feed intake Step 4 – Formulate diet
Simple diets: • Formulated on:
• Metab. Energy • Crude Protein
• Typical concentrates fed:
• Straight grain (e.g. wheat)
More complex diets: • Formulated on:
• Metab. or Net Energy • Metab. Protein or Amino Acids • Rates and extents of digesKon • Minerals
• Typical concentrates fed: • Wheat + some Maize grain • Canola meal, other protein sources
Possible applica7ons for maize grain in dairy cow diets
I. As a complementary grain to wheat when grain is fed at high levels per cow per day
Recent research feeding more complex diets including maize grain
Flexible Feeding Systems project (Dept. of Ag. & Food, WA)
Control PMR diet: • 3.6 kg DM lupins (fed in dairy) • 8 kgs DM pasture silage • 6 kgs DM wheat
Complex PMR (PMR+) diet: • 3.6 kg DM lupins (fed in dairy) • 8 kgs DM pasture silage • 2 kgs DM wheat • 2 kgs DM maize grain • 2 kgs DM canola meal
plus ad-‐lib access to lucerne haylage
(fed as PMR)
(fed as PMR)
2 groups of 39 milking cows. 12 weeks
(McDonnell and Staines, 2015. Unpublished)
Recent research feeding more complex diets including maize grain
Flexible Feeding Systems project (Dept. of Ag. & Food, WA)
Results:
(McDonnell and Staines, 2015. Unpublished)
18
19
20
21
22
23
24
20 40 60 80 100 120
DM In
take (k
g/cow/d)
Days in Milk
Total Dry Mafer Intake
Control PMR+
Recent research feeding more complex diets including maize grain
Flexible Feeding Systems project (Dept. of Ag. & Food, WA)
Results:
(McDonnell and Staines, 2015. Unpublished)
1
2
3
4
5
6
20 40 60 80 100 120
Kg
DM
/cow
/d
Days in Milk
Lucerne haylage DM Intake
Control PMR+
Recent research feeding more complex diets including maize grain
Flexible Feeding Systems project (Dept. of Ag. & Food, WA)
Results:
(McDonnell and Staines, 2015. Unpublished)
Complex PMR resulted in 3 kg more milk per cow per day
22
24
26
28
30
32
20 30 40 50 60 70 80 90 100 110
Mean weekly MY (L/d)
Days in Milk
Milk Yield Control PMR+
Recent research feeding more complex diets including maize grain
Flexible Feeding Systems project (Vic-‐DEDJTR, Ellinbank)
Control PMR diet: • Grazed pasture • 75% Barley (fed in dairy) • 25% Pasture silage
PMR 1 diet (Simple mix): • Grazed pasture • 75% Barley • 25% Pasture silage (fed in paddock)
(fed as PMR)
3 groups of 72 milking cows
(Auldist et al, 2013)
PMR 2 diet (Complex mix): • Grazed pasture • 25% Barley • 30% Maize grain • 25% Lucerne hay • 20% Maize silage
(fed as PMR)
All 3 diets were equal in energy density
All cows received same pasture allowance Supplement was fed at 6, 8, 10, and 12 kg DM/cow/day
Recent research feeding more complex diets including maize grain
Flexible Feeding Systems project (Vic-‐DEDJTR, Ellinbank)
16 18 20 22 24
6 7 8 9 10 11 12 13 Supplement intake (kg DM/cow/d)
Energy corrected
milk yield (k
g/cow/d)
Control
Results:
PMR1
PMR2
(Auldist et al, 2013)
Possible applica7ons for maize grain in dairy cow diets
II. Whenever cows are at increased risk of ruminal acidosis
Hour 05:00 09:00 13:00 17:00 21:00 01:00 05:00
Rum
en fl
uid
pH
5.0
5.5
6.0
6.5
7.0
TMR
PMR
Pasture only
Pasture + grain
(Courtesy of W Wales, Vic-‐DEDJTR)
Risk factors include: • Younger cows • Freshly calved cows • Wheat • High grain feeding rate/ cow/day • Low dietary fibre content • Young, lush, leafy pasture • Low pH silages • No buffers in diet • Heat stress
Recent research feeding more complex diets including maize grain
Flexible Feeding Systems project (Vic-‐DEDJTR, Ellinbank)
(Greenwood et al, 2014)
Metabolism experiment: Control diet: Barley + forage PMR: Maize-‐based PMR
Possible applica7ons for maize grain in dairy cow diets
III. For freshly calved cows
Rumen wall of dry cow Rumen wall of peak lactation cow
At calving, a dairy cow’s rumen papillae have not yet fully developed
(Lean and DeGaris, 2010)
Possible applica7ons for maize grain in dairy cow diets
III. For freshly calved cows At calving, a dairy cow’s appeKte is suppressed Feeding maize can help cow overcome this, thereby: • Reducing negaKve energy balance in early lactaKon • Improving cow ferKlity
Possible applica7ons for maize grain in dairy cow diets
IV. In hot weather
Primary cow cooling strategies are shade & evaporaKve cooling However, feeding maize can help: • reduce the risk of ruminal acidosis • reduce heat load on cow • maintain energy intake for milk
producKon
Dairy cows are ruminant animals
1 2
3
Rate and extent of starch digesKon in cow’s gut also depends on grain’s parKcle size
(Courtesy of D Huggins, Ridley)
Dairy cows are ruminant animals
Rate and extent of starch digesKon in cow’s gut also depends on grain’s parKcle size
Bypass starch!!
Normal manure
Processing maize grain prior to feeding to dairy cows
Rate and extent of starch digesKon in cow’s gut also depends on grain’s parKcle size
(Sopade et al, 2011)
Commonly used mills and the forces they apply to grain kernels
Processing maize grain prior to feeding to dairy cows
Rate and extent of starch digesKon in cow’s gut also depends on grain’s parKcle size
Example showing effect of grain parKcle size on rate of rumen digesKon
Processing maize grain prior to feeding to dairy cows
Rate and extent of starch digesKon in cow’s gut also depends on grain’s parKcle size
Feeding trial: Daily milk yield of cows grazing ryegrass/prairie grass pastures and supplemented with 6 kg of maize-‐based concentrate
(Granzin, 2002)
Key messages…… • Grains provide cows with starch for energy • Compared to other grains, maize grain is marginally higher in energy,
higher in starch, has a slower rate of rumen fermentaKon and is lower in protein
• Maize has several possible applicaKons in dairy cow diets • To opKmise milk responses from maize grain, processing prior to
feeding needs to carefully control parKcle size
Thank you. Any ques7ons?
Steve Lifle Capacity+ Ag Consul7ng
Mobile: 0400 004 841 Email: [email protected]
Key messages…… • Grains provide cows with starch for energy • Compared to other grains, maize grain is marginally higher in energy,
higher in starch, has a slower rate of rumen fermentaKon and is lower in protein
• Maize has several possible applicaKons in dairy cow diets • To opKmise milk responses from maize grain, processing prior to
feeding needs to carefully control parKcle size
