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The effects of Cysteamine on rumen fermentation, microbial protein synthesis, and bacterial abundance in lactating dairy cows

Wednesday, March 18, 2015
Grand Ballroom - Posters (Community Choice Credit Union Convention Center)
Hong Liu , College of Animal Science and Technology, Yangzhou University, Yangzhou, China
Hongbo Yang , College of Animal Science and Technology, Yangzhou University, Yangzhou, China
Miao Lin , College of Animal Science and Technology, Yangzhou University, Yangzhou, China
Haitham Mohammed Babekir , College of Animal Science and Technology, Yangzhou University, Yangzhou, China
Guoqi Zhao , College of Animal Science and Technology, Yangzhou University, Yangzhou, China
Tingting Ma , College of Animal Science and Technology, Yangzhou University, Yangzhou, China
Zhiyuan Chen , College of Animal Science and Technology, Yangzhou University, Yangzhou, China
Abstract Text:

Forty mid-lactation Holstein cows (average body weight = 550 ± 22 kg; parity=1 to 2; days in milk = 152 ± 23 d; milk yield =18.8 ± 2.4 kg) were used in a completely randomized block design to investigate the effects of cysteamine (CS, supplied by Shanghai Walcom Biology Co., Ltd.) supplementation on rumen fermentation, microbial protein synthesis, and bacterial abundance. CS was added to the basal total mixed ration at doses of 0 (CON), 15, 30, 75, and 150 g/d. The experiment was conducted over a period of 10 weeks, including 2 weeks for adaptation and 8 weeks for data collection. Rumen fluid samples were collected before morning feeding at the end of week 4, 6, 8 and 10. Data were analyzed using PROC MIXED in SAS 9.0. Rumen pH (P=0.422) and acetate concentration (P=0.744) were not affected by treatments. Rumen ammonia-N concentration in the 75g/d treatment was greater than CON and the 15g/d treatment (P=0.001). Total volatile fatty acid concentration in CON and 15g/d treatment were higher compared with 75g/d and 150g/d treatments (P=0.007). Cows fed 15g/d CS had the lowest proportion of propionate (P=0.026) and the highest acetate: propionate ratio (P=0.004), compared with the other treatments. The concentration of protozoa protein (P=0.018) and total microbial protein (P=0.041) in the 75g/d treatment were lower than CON. When considering rumen bacteria abundance, through real-time PCR test we observed that, the relative abundance of P. ruminicola in the 75g/d treatment was higher than CON (P=0.001). 30g/d CS supplementation upregulated B. fibrisolvens abundance (P<0.001). F. succinogenes levels of 30g/d and 75g/d treatment were upregulated, but that of 150g/d group was downregulated (P<0.001). Adding 75g/d and 150g/d reduced R. albus levels (P<0.001). The R. flavefaciens abundance of the 15g/d, 30g/d and 150g/d were lower than CON (P<0.001). Based on the results of this study, low doses (0~30g/d) of CS were useful for increasing rumen fermentation. However, 75g/d CS supplementation reduced protozoa protein concentration, and 150g/d CS reduced F. succinogenes, R. albus and R. flavefaciens abundance, which indicated that high levels of CS inhibited the microbial activity.

Keywords:

rumen fermentation, microbial protein synthesis, bacteria abundance

See more of: Ruminant Nutrition 2
See more of: Ruminant Nutrition
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