1760
Effect of feeding yeast culture (YC) on lactation performance of dairy cows fed diets differing in rumen fermentability

Tuesday, July 22, 2014
Exhibit Hall AB (Kansas City Convention Center)
Andre LG Dias , Department of Animal Sciences, University of Florida, Gainesville, FL
Rafael A Azevedo , Department of Animal Sciences, University of Florida, Gainesville, FL
Jose A Freitas , Department of Animal Sciences, University of Florida, Gainesville, FL
Beatriz Micai , Department of Animal Sciences, University of Florida, Gainesville, FL
Thiago V Silva , Department of Animal Sciences, University of Florida, Gainesville, FL
Gabriel C. Gomes , Department of Animal Sciences, University of Florida, Gainesville, FL
Eduardo S. Ribeiro , Department of Animal Sciences, University of Florida, Gainesville, FL
Leandro F. Greco , Department of Animal Sciences, University of Florida, Gainesville, FL
Pedro M. Leopoldo Junior , Department of Animal Sciences, University of Florida, Gainesville, FL
Josť E.P. Santos , Department of Animal Sciences, University of Florida, Gainesville, FL
Abstract Text: Objectives were to evaluate the effect of feeding YC (Saccharomyces cerevisiae, Rumen Yeast, ICC, Brazil) on lactation performance of dairy cows fed diets with two concentrations of starch. Fifty-six Holstein cows at 42 d postpartum were blocked by parity and milk production and randomly assigned to 1 of 4 treatments, low starch no YC (22% starch and control; LSC), low starch and YC (22% starch and 15 g/d of YC; LSYC), high starch no YC (28% starch and control; HSC), and high starch with YC (28% starch and 15 g/d of YC; HSYC). The study lasted 13 weeks and milk yield, body weight, and dry matter intake were measured daily. Milk samples were collected weekly to determine concentrations of milk components and somatic cells. Data was analyzed by ANOVA for repeated measures using the MIXED procedure of SAS. Results are presented in Table 1. Feeding high starch improved yields of milk and milk protein, whereas inclusion of YC improved yields of milk and all milk components regardless of starch in the diet.

Table 1. Effect of YC and level of starch on lactation performance of dairy cows

 

Treatment

 

P

Variable

LSC

LSYC

HSC

HSYC

SEM

Starch

YC

Starch x YC

Milk yield, Kg/d

38.7

40.4

40.4

41.7

1.2

0.09

0.09

0.81

3.5% FCM, Kg/d

40.2

41.9

40.3

43.3

1.3

0.57

0.05

0.62

Milk fat, %

3.90

3.84

3.64

3.82

0.09

0.10

0.49

0.17

Fat yield, Kg/d

1.47

1.53

1.43

1.57

0.05

0.96

0.05

0.41

Milk protein, %

2.90

2.84

2.97

3.04

0.05

0.01

0.95

0.12

Protein yield, Kg/d

1.09

1.12

1.16

1.24

0.03

0.01

0.04

0.40

Milk NEL, Mcal/d

27.2

28.2

27.5

29.4

0.9

0.28

0.04

0.51

Body condition

2.85

3.00

2.89

2.92

0.05

0.70

0.06

0.21

LSC: low starch and no YC; LSYC: low starch and YC; HSC: high starch and no YC; HSYC: high starch and YC. 

Keywords: dairy cow, lactation, yeast culture.