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Milk production responses of dairy cows to fatty acid supplements with different ratios of palmitic and oleic acid in low- and high-fat basal diets.

A. M. Burch

Events

06-23-2020

Abstract:

175
Milk production responses of dairy cows to fatty acid supplements with different ratios of palmitic and oleic acid in low- and high-fat basal diets.
A. M. Burch*1, J. de Souza2, A. L. Lock1. 1Michigan State University East Lansing, MI, 2Perdue AgriBusiness Salisbury, MD.

We evaluated the effects of fatty acid (FA) supplements with different ratios of palmitic (C16:0) and oleic (C18:1) acids in low and high fat basal diets on production responses of dairy cows. Thirty-six multiparous Holstein cows (50.2 � 5.8 kg milk/d; 160 � 36 d DIM) were used in a split-plot Latin square design. Cows were blocked by milk yield and allocated to a main plot receiving either a low fat (LF) basal diet (n = 18) containing cottonseed meal and cottonseed hulls or a high fat (HF) basal diet (n = 18) containing whole cottonseed. Diets were balanced for similar NDF (30.0% DM), starch (28.5% DM), and CP (17.5% DM). Within each plot a 3x3 Latin square arrangement of treatments was used with 3 21 d periods. Treatments were: 1) control (CON; no FA supplementation), 2) FA supplement containing 80% C16:0 + 10% C18:1 (PA), and 3) FA supplement containing 60% C16:0 + 30% C18:1 (PAOA). FA supplements were fed at 1.5% DM and replaced soyhulls in CON. The statistical model included the random effect of cow within basal diet, and the fixed effect of treatment, basal diet, period, and their interactions. Treatment by basal diet interactions were observed with FA treatments increasing lactose yield (P = 0.01) and tending to increase milk yield (P = 0.14) in LF but not in HF. Basal diet had no effect on DMI (P = 0.66) or milk yield (P = 0.62). Compared with LF, HF increased 3.5% FCM (46.7 vs. 50.2 kg/d; P = 0.04) and milk fat yield (1.65 vs. 1.83 kg/d; P = 0.02) and tended to increase ECM (47.1 vs. 50.0 kg/d; P = 0.07). Results for FA treatments are presented in the following order: CON, PA, and PAOA. PAOA decreased DMI (33.0, 33.1, 32.0 kg/d; P < 0.01). FA treatments increased 3.5% FCM (47.4, 48.9, 49.0 kg/d; P < 0.01), ECM (47.8, 49.0, 48.9 kg/d; P < 0.01), and milk fat yield (1.69, 1.76, 1.76 kg/d; P < 0.01) compared with CON but there was no difference between FA treatments. In conclusion, a high fat basal diet had positive production responses while the addition of fat supplements increased milk fat yield, 3.5% FCM, and ECM regardless of basal diet.

Keywords: fat supplementation, basal diet, milk fat.

Biography: Alycia grew up in Jeddo, Michigan and attended Michigan State University where she received a B.S. in Animal Science. She decided to continue her education by pursuing a master's degree with Dr. Adam Lock where her research focuses on the impacts of 16- and 18-carbon fatty acids on nutrient digestibility and production responses of lactating dairy cattle. After the completion of her M.S., she plans on continuing with a PhD. In the end, her goal is to work as a dairy nutrition consultant.