Effects of Cornus and Its Mixture with Oregano and Thyme Essential Oils on Dairy Sheep Performance and Milk, Yoghurt and Cheese Quality under Heat Stress

Abstract

The effect of a diet supplemented with a novel cornus extract, enriched with essential oils of oregano and thyme, on the performance of Chios cross-bred dairy sheep was investigated during the summer period. The plant extracts were prepared using a “green” method based on aqueous extraction. A total of 45 lactating ewes were allocated into three equal groups in a randomized block design. The three groups were fed the same feed allowance, roughage based on Lucerne hay and wheat straw and a concentrate based on cereals and oil cakes (the control diet). The diet of two groups was fortified with cornus extract, with or without oregano and thyme essential oils, at a level 0.515 g of plant extract/essential oils per kg of concentrate. Individual milk yield was recorded weekly and feed refusals were recorded on a pen basis daily, during a six-week period of lactation. Milk samples were analyzed for the chemical composition of protein, fat, lactose and solids-not-fat constituents, somatic cell counts and total viable bacteria counts. Moreover, the milk of each group was used for yoghurt and Feta cheese production. The lipid oxidative stability, protein carbonyl content and fatty acid composition of milk, yoghurt and cheese samples were also evaluated. The results showed that the incorporation of novel plant extracts and essential oils increased the milk production per ewe. Dietary supplementation with cornus extracts and essential oils lowered lipid and protein oxidation in milk, yoghurt and cheese samples, compared to the control. However, diet supplementation with herbal extracts did not affect the fatty acid profile in milk, cheese and yoghurt or the serum biochemical parameters. In conclusion, dietary supplementation with cornus in combination with oregano and thyme has the potential to improve feed utilization and the performance of high-yield dairy Chios cross-bred ewes reared under heat stress.

Essential Oils as a Dietary Additive for Small Ruminants: A Meta-Analysis on Performance, Rumen Parameters, Serum Metabolites, and Product Quality

“…Particularly in small ruminants, some studies have evaluated the effect of dietary inclusion of EOs on animal performance [15,16], nutrient digestibility, ruminal fermentation [17,18], blood biochemistry [19,20], and meat quality [21,22], as well as milk production and composition [23,24]. However, no conclusive results have been obtained until now, perhaps due to the variability that exists among these studies regarding the experimental periods, primary bioactive compounds, and the doses of EOs used [25].…”

The Effect of Extruded Feed Additives with Balsamic Poplar Buds on Productivity of Dairy Goats

“…Using extruded feed additives in the diet had a positive effect on the health condition of the goats and their external characteristics, so that the goats of the experimental groups had a visually different coat. With poor feeding, improper maintenance and diseases of animals, wool easily loses its natural shine (Kalaitsidis et al 2021).…”

“…But increasing mixture of additives to 6g/cow per day leads to negative effects. Kalaitsidis et al (2021) studied the effect of Cornus essential oils and its mixture with oregano and thyme essential oils on the productivity of dairy sheep and the quality of milk, yogurt and cheese under heat stress. The results showed that including the plant extracts and essential oils increased milk production.…”

Essential Oil Supplementation in Small Ruminants: A Review on Their Possible Role in Rumen Fermentation, Microbiota, and Animal Production

“…However, the dietary administration of 1200 mg of rosemary extract increased milk performance, considering the high productivity of Valle del Belice ewes, and also sustained body condition score [78]. Moreover, dairy ewes of the Chios cross-breed treated during summer by adding a specific cornus, a Mediterranean plant rich in anthocyanins, gallic acid, and ellagic acid with a high antioxidant activity, into the EO compounds of oregano and thyme, displayed higher milk production, lower milk urea concentration, and SCC [79]. In addition, the supplementation of cornus hydrodistillation extract, as well as oregano and thyme essential oils, improved the oxidative stability of milk, even though it did not affect the milk fatty acid profile.…”

“…Murcia al Vino cheese, without affecting cheese yield, microbiological count, and sensory parameters [83]. The addition of cornus hydrodistillation extract, as well as oregano and thyme essential oils, improved the oxidative stability of Feta cheese and yoghurt, with no effects on their fatty acid profile [79].…”