Abstract The objective of this research was to evaluate the physicochemical quality of milk and cheese from goats-fed diets containing different concentrations of flaxseed oil in replacement of corn. Eight multiparous Saanen goats weighing 51.0 ± 8.0 kg and 67.0 ± 18.0 days of lactation were used. According to the concentrations of linseed oil inclusion in the diet, the goats were randomly distributed in a latin square (4 x 4), according to the concentrations of linseed oil inclusion in the diet (0, 1, 2, and 3%). Milk samples from each animal were collected twice a day, at regular times, during the three days of data collection in each period, for subsequent physicochemical and fatty acid profile analysis employing gas chromatography. The non-fat solids (P = 0.0302) and density (P = 0.0327) variables sgnificantly affected linseed oil in the goats' feed. Regressive effects (linear and quadratic) were not observed for other variables studied, except for lactose and density. Thus, 20 fatty acids have been identified in goat milk, which gives us an essential source of information about animal diet and milk quality concerning human health benefits. Furthermore, there were changes in the lipid profile of milk, decreasing saturated fatty acids and increasing unsaturated fatty acids, resulting in health-promoting effects.

Abstract The objective of this research was to evaluate the production, milk quality, consumption and financial analysis of milk from goats consuming diets with different levels of double-distilled glycerin. Twelve multiparous Saanen goats, weighing 40 ± 6 kg and 30 ± 5 days of lactation, kept in a confinement system for 60 days were used. The goats were randomly distributed in a Latin square (4 x 4), according to the levels of double-distilled glycerin. The ingredients used were tifton hay, ground corn grain, soybean meal, vitamin/mineral supplement, urea, and double-distilled glycerin levels (0, 6, 12 and 18%) to replace corn in the diets. The milk fat of goats fed with double-distilled glycerin in the diet showed a decreasing linear regressive effect (P = 0.001). Dry matter intake showed a quadratic regressive effect (P = 0.033). Evaluating the total cost of each diet, it was observed that the level containing 0% glycerin was the diet with the lowest cost per kilogram. The use of double-distilled glycerin in the feeding of dairy goats can be recommended up to the level of 18% of corn replacement without harming milk production, however, it is necessary to verify the economic viability, considering that there will be losses in the quality of the milk produced.

Abstract The objective of this study was to evaluate the effects of replacing corn by double-distilled glycerin, a co-product of the biodiesel industry, on goat curd cheese in terms of physical-chemical, microbiological and sensory aspects. Twelve multiparas Saanen goats weighing 47.07 ± 2.41 kg and at 90 ± 5 days of lactation. The experimental design was completely randomized with two treatments (0 and 15% inclusion of glycerin). The physicochemical parameters analyzed were: fat (%), non-fat solids (%), protein (%), lactose (%), salts (%), relative density at 15/15 °C (gmL-1), index cryoscopic (°C), electrical conductivity (mScm-1), pH and acidity. The milk from each treatment was used to make the rennet cheese. The fat had a significant effect (P < 0.05) with inclusion of glycerin in the diet. The physicochemical characteristics of the cheese were influenced (P < 0.05) by feeding up to 15% of glycerin. Regarding sensory attributes, only firmness was influenced (P < 0.05) by the inclusion of glycerin in the diet of dairy goats. Bidistilled glycerin, when inserted in the diet of dairy goats at a level of 15%, causes a reduction in the lipid content of milk and cheese, consequently affecting the cheese yield, and the parameter of firmness in the sensory of the evaluated cheeses.