| Autor: |
B.M. Goetz, J. Lefler, M.A. Abeyta, E.A. Horst, E.J. Mayorga, M. Al-Qaisi, S. Rodriguez-Jimenez, C. Martino, A. Izzo, R. La, H.B. Green, C.E. Moore, M. Embree, L.H. Baumgard |
| Jazyk: |
angličtina |
| Rok vydání: |
2021 |
| Předmět: |
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| Zdroj: |
JDS Communications, Vol 2, Iss 3, Pp 118-122 (2021) |
| Druh dokumentu: |
article |
| ISSN: |
2666-9102 |
| DOI: |
10.3168/jdsc.2020-0002 |
| Popis: |
This study evaluated the effects of a microbial feed supplement (MFS; Galaxis, Ascus Biosciences Inc.) comprising 2 native rumen microbes on performance parameters in mid-lactation dairy cows. Forty-six lactating primiparous and multiparous Holstein cows [629 ± 62 kg of body weight, mean ± standard deviation (SD); parity 1.64 ± 0.49; 119 ± 38 days in milk; 45.11 ± 3.81 and 52.73 ± 4.77 kg/d of milk yield for primiparous and multiparous, respectively] were enrolled in a study containing 3 experimental periods (P). During all periods, enrolled cows were fed the same base total mixed ration (TMR) ad libitum once daily. During P1 (7 d), baseline data were obtained for covariate analysis. At the beginning of P2 (60 d), cows were assigned to 1 of 2 dietary treatment groups in a randomized complete block design to balance for milk yield (MY), parity, and days in milk: (1) a control diet (CON; base TMR; n = 23), or (2) a control diet supplemented with 5 g/d of MFS (MFS; n = 23). Sample size was determined based on previous, unpublished results involving this MFS; a 3-kg difference between groups with a SD of 3.5 kg could be detected with sufficient power (0.81) using a total sample size of 46 cows. Treatment was top-dressed and hand-mixed into the top one-third of the TMR. During P3 (7 d), no treatment was administered, and all cows were fed the base TMR. When analyzing all cows in the data set, MFS had little to no effect on performance. However, modeling revealed that the fixed effect of covariate milk production level had a significant effect on the response of MY and ECM, and further investigation of the data revealed that treatment effectiveness in P2 correlated with milk production during P1. Cows were retrospectively categorized into 2 milk production groups (MPG) balanced for parity: MPG1 (i.e., |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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