Physicochemical Characteristics of Yogurt from Sheep Fed with Moringa oleifera Leaf Extracts

This study determined the effect of feeding Moringa oleifera (MO) leaf extracts to lactating ewes on the physicochemical composition of their milk and yogurt during storage (4 °C for 14 days) and the sensory acceptance of the yogurt. Over 45 days, 24 multiparous lactating Pelibuey and Katahdin ewes (two days in lactation) were randomly assigned to four groups: MO-0, basal diet (BD) + 0 mL MO; MO-20, BD + 20 mL MO; MO-40, BD + 40 mL MO; and MO-60, BD + 60 mL MO. In the milk, an increase of 6% in protein, 26% in leucine, 14% in ash, and 1% in the pH (6.71) was observed with MO-60. The density values decreased by 0.3% at a higher dose of MO compared to MO-0, while the nonfat solids (NFS) in the milk were similar between the treatments. In the yogurt, an increase of 5% in protein, 113% in leucine (MO-20), 9% in NFS, and a reduction of 2% in moisture with MO-60 was observed. The acidity reflected an inverse relationship to the pH, as did the moisture and NFS with MO-60. In conclusion, dietary supplementation with MO in lactating ewes did not have negative effects on the chemical composition of their yogurt during storage (14 days). Overall, feeding sheep with 20 mL of MO positively influenced the physicochemical composition of their milk and yogurt during storage.

How much does it cost? Teaching physiology of energy metabolism in mice using an indirect calorimetry system in a practical course for veterinary students

In endothermic mammals total energy expenditure (EE) is composed of basal metabolic rate (BMR), energy spent for muscle activity, thermoregulation, any kind of production (such as milk, meat or egg production) and the thermic effect of feeding. The BMR is predominantly determined by body mass and the surface to volume ratio of the body. The EE can be quantified either by direct or indirect calorimetry. Direct calorimetry measures the rate of heat loss from the body, whereas indirect calorimetry measures oxygen consumption and carbon dioxide production and calculates heat production from oxidative nutrient combustion. A deep and sustainable understanding of EE in animals is crucial for veterinarians in order to properly calculate and evaluate feed rations, during special circumstances such as anaesthesia or in situations with increased energy demands as commonly seen in high yielding livestock. The practical class described in this manuscript provides an experimental approach to understand how EE can be measured and calculated by indirect calorimetry. Two important factors that affect the EE of animals (the thermic effect of feeding and the effect of ambient temperature) are measured. A profound knowledge about the energy requirements of animal life and its measurement is also relevant for education in general biology, animal and human physiology and nutrition. Therefore, this teaching unit can equally well be implemented in other areas of life sciences.