Essential oils for dairy calves: effects on performance, scours, rumen fermentation and intestinal fauna

Abstract

The first cause of death of dairy calves is often diarrhea which is mainly caused by pathogenic bacteria, which can result in excessive use of antibiotics. However, facing the increase concern by the industry and consumers, the use of antibiotics not only to control pathogens, but also to manipulate growth, has become a challenge. Alternative additives, such essential oils, have the potential to decrease antibiotic use, without reducing performance or increasing mortality of dairy calves. The objective of this study was to evaluate the use of a commercial blend of essential oils, incorporated into the calf starter and/or milk replacer to monitor the effect on overall calf performance, fecal scores and rumen fermentation parameters. A total of 30 Holstein calves received 6 l/day of a liquid diet, consisting of a commercial milk replacer containing 20% CP : 15% fat (EE). Calves had free choice access to water and calf starter. Weaning occurred at week 8, and calves were followed until the 10 th week of age. Calves were assigned to one of the three treatment groups in a randomized block design. Treatments: (1) control without essential oils supplementation (C); (2) essential oils blend in the milk replacer at 400 mg/kg (MR) and (3) essential oils blend in the milk replacer (200 mg/kg) and starter feed (200 mg/kg) (MRS). From the 2 nd week, calves were weighed and body measurements were taken, while concentrate intake and fecal scores were monitored daily. Blood samples were drawn weekly for determination of glucose and β-hydroxybutyrate. Fecal samples were collected weekly and analyzed for lactic acid bacteria and Enterobacteria; and ruminal fluid for determination of pH, short chain fatty acids, ammonia-N and counts of amylolytic and cellulolytic bacteria, and protozoa. Performance, fecal scores and intestines microorganisms were not affected by the essential oils supplementation. Ruminal and blood parameters were also not affected, with the exception the rumen ammonia-N concentration, with higher values when essential oils were supplemented in a combination of milk replacer and starter feed. Most of the evaluated parameters were affected by age of calves, mainly as a response to the increase in concentrate intake as animals' aged. Essential oils are promising substitutes for antibiotics. However, the dose and routes of administration deserve further studies, allowing a better animal performance and health to be achieved.

Effect of supplementation of calf starter with fennel powder on performance, weaning age and fermentation characteristics in Holstein dairy calves

“…Santos et al. () supplemented dairy calves with essential oils and observed no significant effects on pH. In another study, Busquet et al.…”

“…According to Santos et al. (), ruminal ammonia nitrogen concentration increased when essential oils were supplemented in a combination of milk replacer and starter feed. Benchaar et al.…”

OreganoExtract Added into the Diet of Dairy Heifers Changes Feeding Behavior and Concentrate Intake

“…The inclusion of spices, especially those containing essential oils, into the diet of ruminants is increasing due to their effects on ruminal fermentation [5, 6] and animal health [10, 24, 25], although there are reduced evidences of spices' effects improving animal performance [26]. In nonruminants, essential oils have been used in a wide scale due to their potential as replacement of antibiotics [27, 28].…”

“…Bampidis et al [9] did not find positive effects of feeding dried Oregano leaves to growing lambs on intake, feed conversion, weight gain, body development, oxidative stress, and meat quality. Supplementation with distinct blends containing Oregano for dairy calves did not affect intake and body weight gain [10] but reduced dry matter intake (DMI) of cows in early lactation without affecting milk production [11]. Many factors may determine the variability of the published results: complex gastrointestinal tract of ruminants, impact of the basal diet on the relationship between rumen microbiota; intrinsic variability of plants extracts; extrinsic conditions that may affect concentration and bioavailability of phytochemicals such as weather conditions, harvest season, dose, extraction method, and presentation form [6].…”

Desempenho e parâmetros sanguíneos de bezerros em sistema de desaleitamento precoce suplementados com probiótico de bactérias ruminais

“…Os sistemas de produção leiteira vêm aumentando a inclusão de aditivos que tenham efeito positivo no desempenho animal (SILVA et al, 2011;SANTOS et al, 2015). O uso de antibióticos como aditivo, para melhorar o desempenho animal, pode tornar bactérias patogênicas mais resistentes e consequentemente difíceis de serem combatidas (MOTA et al, 2005).…”