Abstract #T176
Section: Production, Management and the Environment
Session: Production, Management & the Environment II
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Exhibit Hall B
Session: Production, Management & the Environment II
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Exhibit Hall B
# T176
Milk yield and somatic cell score of northeastern United States organic dairy farms during the grazing and non-grazing seasons.
J. G. B. Galvao Jr.*1, A. F. Brito2, A. H. N. Rangel3, J. B. A. Silva4, A. F. Benson5, A. N. Hafla6, H. M. Darby7, K. J. Soder6, R. Kersbergen8, 1Instituto Federal de Educação, Ciencia e Tecnologia do Rio Grande do Norte, Ipanguaçu, RN, Brazil, 2University of New Hampshire, Durham, NH, 3Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil, 4Universidade Federal do Semiarido, Mossoro, RN, Brazil, 5Cornell University Cooperative Extension, Cortland, NY, 6USDA-ARS, University Park, PA, 7University of Vermont, St. Albans, VT, 8University of Maine, Orono, ME.
Key Words: grazing season, milk somatic cell score, organic dairies
Milk yield and somatic cell score of northeastern United States organic dairy farms during the grazing and non-grazing seasons.
J. G. B. Galvao Jr.*1, A. F. Brito2, A. H. N. Rangel3, J. B. A. Silva4, A. F. Benson5, A. N. Hafla6, H. M. Darby7, K. J. Soder6, R. Kersbergen8, 1Instituto Federal de Educação, Ciencia e Tecnologia do Rio Grande do Norte, Ipanguaçu, RN, Brazil, 2University of New Hampshire, Durham, NH, 3Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil, 4Universidade Federal do Semiarido, Mossoro, RN, Brazil, 5Cornell University Cooperative Extension, Cortland, NY, 6USDA-ARS, University Park, PA, 7University of Vermont, St. Albans, VT, 8University of Maine, Orono, ME.
The objective of this study was to evaluate milk yield and composition of organically-certified dairy herds during the grazing season (GS) and non-grazing season (NGS) in the Northeast region of the United States. Dairy Herd Improvement records of Holstein, Jersey, and Holstein-Jersey crossbred cows from May 2012 to June 2015 were obtained monthly from 14 herds in the states of New Hampshire (n = 3), Vermont (n = 3), Maine (n = 3), New York (n = 2), and Pennsylvania (n = 3). The length of GS averaged 160 d (May to November). A total of 14,246 observations including milk yield, 4% fat-corrected milk (FCM), concentrations of milk fat and true protein, and somatic cell score (SCS) were obtained. Seasonal effects (GS vs. NGS) were compared using the PROC GLM procedure of SAS. Herds averaged (mean ± SD) 38 ± 18 lactating cows, 21.3 ± 8.04 kg/d of milk, 21.7 ± 7.52 kg/d of FCM, 4.26 ± 0.98% milk fat, 3.28 ± 0.45% milk true protein, and 2.54 ± 1.80 SCS. Days in milk was similar and averaged 143 ± 89 (GS) and 152 ± 85 (NGS). All milk variables (mean ± SEM) analyzed herein were affected by season, except SCS, which averaged 2.50 ± 0.04 vs. 2.52 ± 0.03 for the GS and NGS, respectively. Milk yield (22.0 ± 0.15 kg/d vs. 20.8 ± 0.12 kg/d, FCM (22.1 ± 0.14 kg/d vs. 21.4 ± 0.12 kg/d), and concentration of milk true protein (3.32 ± 0.01% vs. 3.29 ± 0.01%) were greater during the GS than NGS, which may be explained by improved forage nutritional value when comparing pasture with conserved feeds. Milk fat concentration was greater in the NGS (4.35 ± 0.01%) vs. GS (4.17 ± 0.02%). This increased milk fat concentration may have been caused by replacing pasture for conserved feeds with greater fiber content, or by a dilution effect caused by decreased milk volume (−1.20 kg of milk/d) during the NGS. Herd SCS suggest adequate year-round milking procedures and preventative mastitis protocols. However, farmers should adopt better supplementation strategies or implement forage-crop practices that improve conserved feed nutritional value to mitigate milk yield losses during the NGS.
Key Words: grazing season, milk somatic cell score, organic dairies
