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Submitted to: Montana State University Beef Newsletter
Publication Type: Popular Publication Publication Acceptance Date: 1/15/2004 Publication Date: 2/15/2004 Citation: Waterman, R.C. 2004. A new concept in range cow supplement formulation. Montana State University Beef Newsletter 9(3):6-7. Interpretive Summary: Cattle grazing dormant New Mexico rangelands show yearly variation in response to supplementation. This reaction maybe partially due to differences in glucose (blood sugar) availability and metabolism, which maybe altered by forage conditions. Unlike people, cows absorb no sugar from their diet and must make all of their sugar in the liver. Nutritional status of young cows with suckling calves varies by year depending upon the onset and magnitude of green forage growth. A study at the Corona Range and Livestock Research Center during two dry years 2000 and 2001 (driest) evaluated range protein supplements differing in source and quantity of ingredients that could be used for glucose production in a cow. Supplements fed to forty-two black baldie 2-year-old post-partum cows at 2 lbs per day and provided 0.7 lb crude protein (CP) per day. Three supplements all 36% crude protein were tested and they differed in ingredients that could be used to make glucose by the cows. The first supplement treatment was a traditional good quality cottonseed meal based cube (36 % CP) that has a low glucose potential (logluc). The second contained cottonseed meal and bypass proteins (blood and feather meal) which would have a moderate glucose potential (midgluc) and lastly the midgluc supplement with a propionate salt (NutroCal ™ Kemin Industries Inc) added giving it a high glucose potential (higluc). Supplements were individually fed 2 times per week at 11:00 am on Mondays and Fridays for approximately 90 d after calving. Cows rotationally grazed three pastures during the study. Cow and calf body weight change, milk production, days to first estrus, pregnancy rate and glucose tolerance were measured during the study. The effect of year and treatment (supplements) did not interact so the data was pooled for both years Logluc Midgluc Higluc Probability Cow wt change (calving-breed) 46.0 lb 22.5 lb 38.3 lb P > 0.1 Milk production 11.9 lb 14.3 lb 13.2 lb P > 0.1 Calf weaning wt 465 lb 480 lb 469 lb P > 0.1 Days to 1st estrus 119 114 110 P < 0.08 Fall pregnancy % 83 92 83 P > 0.1 Glucose ½ life 100 min 69 min 56 min P < 0.08 Table1. Young cows fed range supplements with higher glucose potential cycled sooner. Although fall pregnancy rates were similar for cows fed each supplement the cows fed the higluc supplement cycled 9 days earlier than the cows consuming the logluc supplement. The lowered glucose half-life (44 minutes lower) in the higluc supplemented cows compared to the logulc fed cows may partially demonstrate an improvement in glucose condition of these cows. Technical Abstract: Cattle grazing dormant New Mexico rangelands show yearly variation in response to supplementation. This reaction maybe partially due to differences in glucose (blood sugar) availability and metabolism, which maybe altered by forage conditions. Unlike people, cows absorb no sugar from their diet and must make all of their sugar in the liver. Nutritional status of young cows with suckling calves varies by year depending upon the onset and magnitude of green forage growth. A study at the Corona Range and Livestock Research Center during two dry years 2000 and 2001 (driest) evaluated range protein supplements differing in source and quantity of ingredients that could be used for glucose production in a cow. Supplements fed to forty-two black baldie 2-year-old post-partum cows at 2 lbs per day and provided 0.7 lb crude protein (CP) per day. Three supplements all 36% crude protein were tested and they differed in ingredients that could be used to make glucose by the cows. The first supplement treatment was a traditional good quality cottonseed meal based cube (36 % CP) that has a low glucose potential (logluc). The second contained cottonseed meal and bypass proteins (blood and feather meal) which would have a moderate glucose potential (midgluc) and lastly the midgluc supplement with a propionate salt (NutroCal ™ Kemin Industries Inc) added giving it a high glucose potential (higluc). Supplements were individually fed 2 times per week at 11:00 am on Mondays and Fridays for approximately 90 d after calving. Cows rotationally grazed three pastures during the study. Cow and calf body weight change, milk production, days to first estrus, pregnancy rate and glucose tolerance were measured during the study. The effect of year and treatment (supplements) did not interact so the data was pooled for both years Logluc Midgluc Higluc Probability Cow wt change (calving-breed) 46.0 lb 22.5 lb 38.3 lb P > 0.1 Milk production 11.9 lb 14.3 lb 13.2 lb P > 0.1 Calf weaning wt 465 lb 480 lb 469 lb P > 0.1 Days to 1st estrus 119 114 110 P < 0.08 Fall pregnancy % 83 92 83 P > 0.1 Glucose ½ life 100 min 69 min 56 min P < 0.08 Table1. Young cows fed range supplements with higher glucose potential cycled sooner. Although fall pregnancy rates were similar for cows fed each supplement the cows fed the higluc supplement cycled 9 days earlier than the cows consuming the logluc supplement. The lowered glucose half-life (44 minutes lower) in the higluc supplemented cows compared to the logulc fed cows may partially demonstrate an improvement in glucose condition of these cows. |
