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THE MOO NEWS

Newsletter of Penn Dutch Cow Care                                           May 2003

  Hi Folks,

            Spring is finally here! The grass is lush and growing fast and the cows are enjoying it. Since ‘Dr. Green’ is a great health care provider, actual health problems won’t be discussed much here. Since the vast majority of my farmers are graziers to varying degrees, I’d like to share some pointers I’ve picked up. Much of this is from Penn State ’s grazing group, headed by Dr. Larry Muller.

            First- what is a grazing system? It can be high input, using pasture to supplement indoor feeding. It can be medium to high input, using increased pasture and less feed inputs in the barn. Or it can be low input, using the most possible pasture for dry matter intake. Well-managed intensive grazing systems have been shown as a viable alternative to remain competitive for herds with less than 300 cows. To meet income needs, since there’ll be lower production, there is usually an increase in herd size along with needed improvement of management of cows and pastures. Grazing does not mean less management since ‘any cow knows how to eat grass.’ No, grazing takes true management to be successful. However, for those of you who do not now utilize existing pasture to its fullest extent, even if it’s only 5 acres, there are some things that you can still do. For starters, break up an area of continuous pasture area into smaller areas (paddocks). Try 1 acre paddocks, divided up by single-strand polywire, and keeping the cows on them for 1-2 days. You will need a source of water and a water line - a 50-gallon trough is easy to dump out and move with quick couples off your water line. Clip pastures a day or two after grazing to splatter out manure paddies (this is free fertilizer) so the worm larvae get killed. If you’re not used to grazing much, and don’t have a lot of dedicated pasture, this is a start. The cows will like having some fresh greens to eat.

            The cost of pasture as a nutritional component of the diet is generally accepted to be about 1-3 cents/lb. DM; whereas totally feeding in the barn is generally 6-7 cents/lb. DM. With the low milk prices, a cheap source of feed to supplement barn feeding seems worthy of consideration.

            If you are already more committed to grazing in general, here are a few tips to keep in mind. During our usual hottest time of the year, regular cool season grasses go dormant, more or less. One way to help them “jump” when a rain does come, is to not let pastures be grazed down too short. By keeping the height no less than 3”, there is enough plant mass available for rapid re-growth when moisture comes along during the hot spell.

            As crop insurance (non-governmental kind), plant sorghum sudan grass for July and August heat. Sorghum sudan grass is a warm season grass that loves the heat. Plant it during the last 2 weeks of May, but not much past the 1st week of June (in southeastern Pa). The soil needs to be about 60 degrees and drill it in no deeper than ½” deep. If the soil is too cold or it’s planted too deep, it won’t grow as it can. Try to “stagger” planting it- 3 acres one week and 3 acres in another 10 days. Since it comes up so fast and lush, this will help to not let it get ahead of you and the cows. Generally no herbicide is needed if planted correctly because of its fast growth. Graze it when it is 18” or higher to avoid prussic acid. It can also be cut and ensiled and is at least equivalent, if not better, than corn silage as far as energy. It is also more digestible with more effective fiber.

            Remember that cows on pasture get more than enough protein, but energy is an issue. When there is a lot of green fresh pasture in the cow’s rumen, there is lots of ammonia which must be excreted. It is converted to urea and then to urine and out it goes. But it takes energy to do this in the cow. By feeding medium quality hay with molasses on it (so the cows will eat it), you are not only providing energy (by the molasses) but also effective fiber. Cows really don’t need to all be pouring out thick pea soup-like manure when on pasture. If they are, you are not getting efficient absorption of pasture nutrients- it is simply running through the rumen extremely fast and not helping with the cow’s basic metabolic needs and her needs to keep body condition so she can make milk and get bred back. Cows also use energy by walking. The further they walk to get to a paddock, the less energy they have to make milk.

            Energy can be found in pasture, especially in clovers. Cows love clover! Clover needs to be managed correctly so it’s not shaded out by grasses and not left too exposed to the hot sun, otherwise its stolons (runners) will wither. Energy also can be found in grain. Feeding a low protein grain concentrate will help to decrease excess ammonia in the rumen and help keep condition on the cows. The New Zealand method of no to very little grain feeding makes sense- in New Zealand . Their climate does not allow for grain farming, so it is simply not economical to feed it. We are not in New Zealand here and grain is relatively cheap. Our pasture season is more like Australia , Ireland and the Netherlands . They do feed grain to the grazing cows. I think we should, too, and not just a “whiff” of it.

            The previous part of this newsletter is based on my own experience and thoughts, as my newsletters usually are. The next small part is taken right out of literature, just to give an idea of possible grain mixes. From Morrison’s Feeds and Feeding (1949), when grazing cows was an integral part of dairy farming, a 12% protein grain mix is for cows on excellent pasture: (A) Ground corn 1160 lbs, ground oats 500 lbs, wheat bran 200 lbs, soybean oil mean or cottonseed meal 120 lbs, salt 20 lbs (makes 1 ton) or (B) Ground corn 1130 lbs, ground oats 500 lbs, wheat bran 200 lbs, linseed meal 150 lbs, salt 20 lbs. or (C) Ground barley 1030 lbs, ground oats 700 lbs, wheat bran 250 lbs, salt 20 lbs.

            A 14% protein grain mix for a very good pasture would be (A) Ground corn 1055 lbs, ground oats 500 lbs, wheat bran 200 lbs, soybean oil meal 225 lbs, salt 20 lbs, or (B) Ground corn 980 lbs, ground oats 500 lbs, wheat bran 200 lbs, linseed meal 300 lbs, salt 20 lbs. or (C) Ground barley 1090 lbs, ground oats 600 lbs, wheat bran 200 lbs, soybean oil mean or cottonseed meal 90 lbs, salt 20 lbs. Use a salt like Redmonds, loaded with trace minerals.

            Notice corn and barley were never in the same mix, not even at the 20% protein level (not shown), probably because of possible rumen acidosis (which is still possible when grazing).

            So how much grain to feed to grazing cows? Well, do notice that when cows are fed grain, they will reduce their DMI from pasture, OR, to put it differently, if there’s not enough DMI from pasture, they will gladly eat offered grain to meet their needs. First, try not to feed more than 20 lbs of grain in a day- especially if you are still feeding some corn silage into the summer since corn silage is part grain itself (leads to rumen acidosis). If you feed corn silage, keep it less than 10 lbs. per day. Generally the following guideline from Penn State applies: (Assume 1300 lb BW. Guidelines based on high quality grass pasture available in adequate quantities):

                                    Spring                           Summer                        Fall

Production                    lb.        G:M*                lb.        G:M                 lb.        G:M

>80                              20        1:4-1:5              22-24    1:3                    20        1:4-1:5

70                                15-18    1:4-1:5              19-21    1:3.5                 16-18    1:4-1:5

60                                11-13    1:5                    15-18    1:4                    12-14    1:5

50                                8-10     1:5-1:6              10-12    1:4.5                 8-10     1:4-1:5

<40                              6-8       1:6-1:7              8-10     1:5                    6-8       1:6-1:7

*G:M = grain:milk ratio

            Remember to test pastures for nutrient value (using wet chemistry, not NIR) and learn how to accurately estimate the dry matter in paddocks.

Happy Grazing!

 

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