At this time, most mature cows and first-calf heifers are in the early stages of gestation. Their nutrition needs are relatively low and therefore it makes a starting point for designing a gestation into pre-calving mineral program. Producers have a lot of commercial mineral choices at their fingertips, from buying a standard beef mineral to one that is formulated for special needs. Either way, your own mineral program should focus upon and meet your beef cows macro-and trace-mineral (vitamins included) requirements to promote successful pregnancies throughout the winter.
A beef-gestation mineral program at home should follow a simple outline: (1) Basic mineral requirements of early-to late-gestation beef cows, (2) Review cow challenges (re: health and reproductive) that need improvement, (3) Determine essential minerals already supplied by current feedstuffs, and (4) Identify any special mineral needs due to environment, soil and water conditions.
Most standard or customized beef cow minerals available at your feed store are manufactured from formulas that are based upon scientific mineral and vitamin requirements. These vary with animal age, reproductive performance and health status. Ruminant nutritionists design cow mineral formulas based upon recommendations developed by the National Research Council (NRC). Of all the macro-and trace minerals (with vitamins) vital to beef cows, calcium (Ca) and phosphorus often form a foundation of most home-grown gestation-cow mineral programs.
Consequently, an early gestating beef cow requires about 25 grams of calcium and 18 grams of phosphorus per day, yet these levels dramatically increase to about 50 grams of calcium and 35 grams of phosphorus per head per day by calving. In addition, both of these essential macro-minerals should always be provided in a 2:1 dietary ratio in order to prevent related body dysfunctions (i. e.: water-belly) during gestation and post-calving problems (i. e.: milk fever and retained placentas) as fresh beef cows. It should also be noted that Ca/P ratios of up to 7:1 can fed to gestating beef cows without detrimental effects their health or pregnancy.
Since significant amounts of calcium and phosphorus are in forage- based gestation diets, it usually becomes an exercise of direct implementation of a well-formulated beef cow mineral that supplements remaining calcium and phosphorus needs. Keep in mind that as cows progress toward their second/third trimesters of pregnancy, they will need more calcium and phosphorus to be supplemented in their diets.
Consider the following forage-based cow diets, which are either matched with either a commercial 2:1 (re: 20 per cent Ca/10 per cent P) or 1: 1 (re: 12 per cent Ca/12 per centP) cow mineral:
” Alfalfa diets 12 kg of mixed-alfalfa hay, no grain fed : (supplies 80 g Ca, 15 g P) + 1:1 beef mineral @ 56 g (supplements 7 g Ca, 7 g P) = total dietary 87 g Ca, 22 g P; 4 to 1 Ca/P ratio.
” Grass diets 10 kg of prairie grass, 1 kg of corn-distillers (high in P): (supplies 35 g Ca, 19 g P) + 2: 1 beef mineral @ 42 g (supplements 8 g Ca, 4 g P) = 43 g Ca, 23 g P; 1.9 to 1 Ca/P ratio.
” Straw diets 8 kg of straw, 1 kg of grain fed: (supplies 15 g Ca, 15 g P) + 2:1 beef mineral fed at 70 g (supplies 14 g Ca, 7 g P) = 29 g Ca, 22 g P; 1.3 to 1 Ca/P ratio (note: require more calcium to be fed).
Given this demonstration or actual diets, commercial beef cow minerals not only carry supplemental calcium and phosphorus, but are also formulated with a trace mineral (and vitamin) pack that supplies respective recommended levels for gestating beef cows on a complete feed basis (i. e.: copper 10 ppm, zinc 30 ppm, manganese 40 ppm, cobalt 00 ppm, iodine 00 and selenium 0.3 ppm). The effectiveness of such trace mineral supplementation is not only based on their total level in the overall diet, but upon their biological availability in the beef cow.
Producers who want assurance of optimum metabolism of these essential trace minerals in their beef cow herd often buy beef minerals containing more bio-available organic or chelated trace minerals. They might first feed a less-costly standard cow mineral for the first 90 days of early/mid gestation and then switch to a breeder mineral formulated with organic trace minerals for a remaining 60 days before calving. Some people forgo this two-step mineral program and choose to feed the fortified breeder mineral for the entire gestation period.
Their belief is such mineral assurance of helping the cows meet all their trace mineral requirements costs a nominal $4 surcharge per cow, if the cow herd is placed on a higher plane of mineral nutrition during the entire gestation season (Nov 1 April 1):
” 70 g/head/d of a standard 2:1 beef mineral @ $25/25 kg for the 90 days, followed by a Breeder cow mineral (with organic trace minerals)@ $40/25 kg for 60 days = $ 13.02
” 70 g/head/d of a Breeder cow mineral (with organic trace minerals) @ $40/25 kg for 150 days = $ 16.80.
Aside from the above macro-and trace minerals levels from biologically available sources, we should not overlook to supplement the essential fat-soluble vitamins A, D, and E in both our standard gestation and breeder type minerals. About 100,000 IU of vitamin A, 5,000 10,000 IU of vitamin D and 50 200 IU of vitamin E should be supplied to each beef during gestation.
With such good mineral (and vitamin) nutrition that can be packed into 50 to 100 grams fed to each cow per day of the gestation beef herd, a good gestation cow mineral really does began at home. It might be a standard mineral or a fortified mineral as the cows needs increase toward the end of gestation. Regardless, when the best mineral is chosen, it helps beef cow health and performance, which leads to greater operation revenues.
PeterVittiisanindependentlivestock nutritionistandconsultantbasedinWinnipeg. Toreachhimcall204-254-7497orbyemailat [email protected]