Effects of supplementation with a phytobiotics-rich herbal mixture on performance, udder health, and metabolic status of Holstein cows with various levels of milk somatic cell counts

Antibiotic treatment of udder health and associated conditions is in the spotlight because of possible resistance by pathogens, but also because of the world-wide trend to move away from antibiotics. In South Africa the group of Prof Mark Laing at UKZN is evaluating bacteriophages and bacteriocins as alternatives to antibiotic treatment. Another method is through potent products that can be supplemented in the feed. In this context Dr F Hashemzadeh-Cigari and co-workers investigated a herbal mixture. Their study, entitled: Effects of supplementation with a phytobiotics-rich herbal mixture on performance, udder health, and metabolic status of Holstein cows with various levels of milk somatic cell counts, was published in theJournal of Dairy Science, Volume 97 of 2014, pages 7487–7497

Their study evaluated the effects of dietary supplementation of a novel phytobiotic-rich herbal mixture (PRHM) on feed intake, performance, udder health, ruminal fermentation, and plasma metabolites in cows with moderate or high somatic cell counts (SCC) in the milk. Twenty-four Holstein dairy cows (about 120 days in milk and producing 45 kg of milk per day at the start of the experiment) were blocked by lactation number and days in milk and split into two groups, based on SCC in the milk; 12 cows with moderate SCC (260,000 to 500,000 cells per mL), and 12 cows with higher SCC (more than 500,000 cells per mL). Within each SCC group, cows were blocked by milk yield and lactation number, and were randomly assigned to two different feeding treatments. Six cows in each SCC group were supplemented with PRHM at 185 g per cow per day, providing 12.4 g of phenolic compounds. The other 6 were not supplemented with PRHM. The experiment lasted 36 days, where the first 24 days were used for adaptation to the diets and the last 12 days for sampling.

The results showed that supplementation with PRHM decreased SCC in the milk, indicating improved udder health of cows with high initial SCC, but not in cows with moderate SCC. The cows supplemented with PRHM consumed more feed DM, produced more milk (both as is and as fat- and energy-corrected milk) in the high SCC group, showed an improvement in feed utilization efficiency and lost more back-fat thickness during the experiment. Milk fat was also reduced, whereas other milk components were not affected by PRHM supplementation. PRHM supplementation, furthermore, decreased the acetate-to-propionate ratio in the rumen fluid, but increased β-hydroxybutyrate and cholesterol concentration in the plasma, irrespective of the initial SCC level in the milk. Other plasma metabolites and liver enzymes were not affected by PRHM supplementation. Apparent nutrient digestibility did not differ among treatments.

Overall, supplementation with PRHM seems to be an effective strategy to enhance performance and lower SCC, particularly in cows having high SCC levels in the milk. Further research is warranted to evaluate long-term effects of PRHM supplementation, especially with regard to metabolic health status and reproduction of the cow.