Supplementing Intensively Grazed Late-Gestation and Early-Lactation Dairy Cattle with Chromium

• Published in: Journal of dairy science 2004-12, Vol.87 (12), p.4269-4277
• Main Authors: Bryan, M.A., Socha, M.T., Tomlinson, D.J.
• Format: Article
• Language: English
• Subjects: Animal Feed; Animal Nutritional Physiological Phenomena; Animal productions; Animals; Biological and medical sciences; blood lipids; Cattle - metabolism; Cattle - physiology; chromium; Chromium - administration & dosage; dairy cattle; dairy cows; dietary mineral supplements; Dietary Supplements; dry period; Fatty Acids, Nonesterified - blood; feed additives; Female; Food industries; free fatty acids; Fundamental and applied biological sciences. Psychology; intensive grazing; Lactation - drug effects; Lactation - metabolism; Liver - metabolism; Milk - chemistry; Milk - secretion; Milk and cheese industries. Ice creams; Nutritional Requirements; Poaceae; Pregnancy; Pregnancy Rate; Pregnancy, Animal - drug effects; Pregnancy, Animal - physiology; rotational grazing; Terrestrial animal productions; Vertebrates
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(04)73571-7

Two hundred thirty-two primiparous and multiparous cows were assigned to a study to determine the effect of supplementing 0 or 6.25 mg/d of Cr from Cr Met on lactation and reproductive performance. Cows received treatments from 6 wk precalving through 21 wk postpartum. Precalving, treatments were incorporated into a pelleted grain mixture and group-fed. Post-calving, cows received treatments via an individual oral drench once a day after the a.m. milking. Grazed herbage was the primary diet constituent for lactating cattle. Blood was collected from a predetermined group of cows before and immediately after calving. On 4 occasions during the treatment period, milk yield was recorded and samples collected for determination of composition. Chromium supplementation had no effect on yield of milk and milk components and milk composition. Chromium supplementation decreased serum nonesterified fatty acids (NEFA) concentration (0.60 vs. 0.68 mmol/L), with chromium supplementation having the greatest impact on serum NEFA concentrations at 1 wk prepartum. Greater percentages of cows supplemented with Cr were observed to be anestrus by dairy personnel (45.5 vs. 32.0%). However, Cr supplementation tended to increase the percentage of cows pregnant in the first 28 d of the mating season (50.0 vs. 39.2%). Results indicate that Cr Met supplementation of intensely grazed, late-gestation and early-lactation dairy cattle decreased serum NEFA concentrations and tended to increase pregnancy rates in the first 28 d of the mating season.