The ruminal redox potential (Eh) can reflect the microbiological activity and dynamics of fermentation in the rumen. It might be an important indicator of rumen fermentation in combination with pH. However, the rumina...The ruminal redox potential (Eh) can reflect the microbiological activity and dynamics of fermentation in the rumen. It might be an important indicator of rumen fermentation in combination with pH. However, the ruminal Eh has been rarely studied in dairy cows due to the difficulty of its measurement, and the relationship between ruminal Eh and pH is not clear. The objective of this study was to investigate the relationship between ruminal Eh and pH of dairy cows by meta-analysis of systematic measurements from different experiments. A database was constructed from 22 experiments on cannulated dairy cattle including 57 dietary treatments. The ruminal pH and Eh were measured without air contact between 0 and 8 h post-feeding. The results demonstrated a quadratic correlation between ruminal Eh and pH with a reliable within-animal variation (Eh = -1697 + 540.7 pH -47.7 pH2, nobservation = 70, nanimal = 26, P Eh, but not always to the same extent. Some of them still influenced the relationship between ruminal Eh and pH. While the mechanism of the interaction between ruminal Eh and pH remains to be elucidated, it would be interesting to associate Eh to microbial profile, ruminal VFA concentration and milk production performance in future studies.展开更多
Probiotic yeasts are used widely today in the diets of dairy cows with a high production potential. Various studies have researched the effects of live yeasts, in particular Saccharomyces cerevisiae, on digestion, met...Probiotic yeasts are used widely today in the diets of dairy cows with a high production potential. Various studies have researched the effects of live yeasts, in particular Saccharomyces cerevisiae, on digestion, metabolism and performance in dairy cows. The present study aims at evaluating the beneficial effects of using probiotic yeast in dairy cattle farms as a means of improving the breeding performance of milking cows. A group of 14 dairy cattle farms, with at least 40 dairy cows, was selected for the study, all of them using artificial insemination (AI) and that had not used probiotics in the two milking years preceding the study. On these farms, the lactating cows received probiotic yeast supplementation (5 g/cow/day, Actisaf®, Saccharomyces cerevisiae Sc47-CNCM I-4407, 1.1010 CFU/g, Phileo Lesaffre Animal Care, Marcq-en-Baroeul, France) over 13 months including a 4-week period of adaptation to the product and then the observation period lasting a full year. The analysis was therefore based on 2421 Holstein females inseminated with a total of 4230 doses of conventional Holstein semen at 14 farms over three consecutive years: the period of observation and the two preceding years stated as reference period. Use of daily supplementation with probiotic yeast resulted in a significant improvement of 4 points on average in the success rate of artificial insemination and of 5 points in the success rate of first artificial insemination in multiparous dairy cows. The number of inseminations required to obtain a pregnancy was therefore reduced from 3.1 in the reference period to 2.7 in the probiotic yeast supplementation period (p = 0.007). In parallel, the fat and protein yield by these same animals tended to improve (+5%, p = 0.07) between these two periods, demonstrating that it is possible to combine milk performance and maintenance of an effective reproductive system.展开更多
文摘The ruminal redox potential (Eh) can reflect the microbiological activity and dynamics of fermentation in the rumen. It might be an important indicator of rumen fermentation in combination with pH. However, the ruminal Eh has been rarely studied in dairy cows due to the difficulty of its measurement, and the relationship between ruminal Eh and pH is not clear. The objective of this study was to investigate the relationship between ruminal Eh and pH of dairy cows by meta-analysis of systematic measurements from different experiments. A database was constructed from 22 experiments on cannulated dairy cattle including 57 dietary treatments. The ruminal pH and Eh were measured without air contact between 0 and 8 h post-feeding. The results demonstrated a quadratic correlation between ruminal Eh and pH with a reliable within-animal variation (Eh = -1697 + 540.7 pH -47.7 pH2, nobservation = 70, nanimal = 26, P Eh, but not always to the same extent. Some of them still influenced the relationship between ruminal Eh and pH. While the mechanism of the interaction between ruminal Eh and pH remains to be elucidated, it would be interesting to associate Eh to microbial profile, ruminal VFA concentration and milk production performance in future studies.
文摘Probiotic yeasts are used widely today in the diets of dairy cows with a high production potential. Various studies have researched the effects of live yeasts, in particular Saccharomyces cerevisiae, on digestion, metabolism and performance in dairy cows. The present study aims at evaluating the beneficial effects of using probiotic yeast in dairy cattle farms as a means of improving the breeding performance of milking cows. A group of 14 dairy cattle farms, with at least 40 dairy cows, was selected for the study, all of them using artificial insemination (AI) and that had not used probiotics in the two milking years preceding the study. On these farms, the lactating cows received probiotic yeast supplementation (5 g/cow/day, Actisaf®, Saccharomyces cerevisiae Sc47-CNCM I-4407, 1.1010 CFU/g, Phileo Lesaffre Animal Care, Marcq-en-Baroeul, France) over 13 months including a 4-week period of adaptation to the product and then the observation period lasting a full year. The analysis was therefore based on 2421 Holstein females inseminated with a total of 4230 doses of conventional Holstein semen at 14 farms over three consecutive years: the period of observation and the two preceding years stated as reference period. Use of daily supplementation with probiotic yeast resulted in a significant improvement of 4 points on average in the success rate of artificial insemination and of 5 points in the success rate of first artificial insemination in multiparous dairy cows. The number of inseminations required to obtain a pregnancy was therefore reduced from 3.1 in the reference period to 2.7 in the probiotic yeast supplementation period (p = 0.007). In parallel, the fat and protein yield by these same animals tended to improve (+5%, p = 0.07) between these two periods, demonstrating that it is possible to combine milk performance and maintenance of an effective reproductive system.
