Abstract #95
Section: Production, Management and the Environment (orals)
Session: Production, Management, and Environment I
Format: Oral
Day/Time: Monday 10:45 AM–11:00 AM
Location: Ballroom C
Session: Production, Management, and Environment I
Format: Oral
Day/Time: Monday 10:45 AM–11:00 AM
Location: Ballroom C
# 95
Effects of fully acidified close-up diets and dietary calcium content on production and milk composition of transition dairy cows.
Kristen M. Glosson*1, Xiangfei Zhang2, Scott S. Bascom3, Angie D. Rowson3, James K. Drackley1, 1University of Illinois, Department of Animal Sciences, Urbana, IL, 2Institute of Animal Nutrition, Key Laboratory of Low Carbon Culture and Safety Production in Cattle in Sichuan, Sichuan Agricultural University, Chengdu, Sichuan, China, 3Phibro Animal Health Corp, Teaneck, NJ.
Key Words: fully acidified close up diet, production, calcium
Effects of fully acidified close-up diets and dietary calcium content on production and milk composition of transition dairy cows.
Kristen M. Glosson*1, Xiangfei Zhang2, Scott S. Bascom3, Angie D. Rowson3, James K. Drackley1, 1University of Illinois, Department of Animal Sciences, Urbana, IL, 2Institute of Animal Nutrition, Key Laboratory of Low Carbon Culture and Safety Production in Cattle in Sichuan, Sichuan Agricultural University, Chengdu, Sichuan, China, 3Phibro Animal Health Corp, Teaneck, NJ.
Dry cow dietary strategies of decreasing dietary Ca and using acidogenic diets with a negative dietary cation-anion difference (DCAD) vary in effectiveness to reduce subclinical hypocalcemia (SCH). The objective of this study was to determine the effects of 3 dietary strategies for close-up dry cows on dry matter intake (DMI) and production in multiparous Holstein cows (n = 81). Cows were assigned to 1 of 3 treatments during the close-up dry period (−28 d to calving): (1) a positive DCAD diet with low dietary Ca (0.4% DM; CON); (2) a fully acidified DCAD diet (urine pH 5.7) with low dietary Ca (0.4% DM; LOW); or (3) a fully acidified DCAD diet (urine pH 5.7) with high dietary Ca (2.0% DM; HIGH). The DCAD was decreased by addition of a commercial anionic product (Animate; Phibro Animal Health) and Ca was increased by adding CaCO3. All cows were fed CON during the far-off dry cow period (−50 to −28 d) and then all groups were fed the same lactation diet postpartum. Cows were milked 3x/d and production was summarized by week. Intake was recorded daily and DMI was calculated weekly. Milk composition (3 consecutive milkings) was determined once weekly during the fresh period. The MIXED procedure in SAS was used to contrast: 1) CON vs the average of LOW and HIGH; and 2) LOW vs HIGH. Cows receiving CON had greater close-up DMI (P < 0.01). After calving, cows fed LOW or HIGH had greater DMI (18.9 and 19.5 kg/d) and greater milk yield (44.6 and 45.2 kg/d) when compared with cows fed CON (17.0, P < 0.01 and 42.0 kg/d, P < 0.05, respectively). Cows given CON had a greater milk fat percentage (P < 0.01), but protein (%) and component production (kg/d) did not differ among treatments (P > 0.10). Milk fat and protein were used to calculate the fat to protein ratio (FPR), which indicates subclinical ketosis (SCK) when above 1.4. Cows given CON had a higher FPR (1.57) than those given LOW or HIGH (1.36 and 1.28), while cows given LOW or HIGH had greater postpartum DMI and milk yield. Prepartum dietary Ca did not affect these variables in cows fed a negative DCAD close-up diet.
Key Words: fully acidified close up diet, production, calcium
