A high somatic cell count (SCC) impacts dairy quality to a large extent. The goal of this work was to investigate differences in goat milk composition and technological parameters according to SCC cut-off (600, 700, 800, and 1000.103/mL). Thirty-four individual milk samples of White Shorthair goats in a similar stage of lactation were investigated. The first differences in milk quality appeared already at SCC cut-off of 600.103/mL (5.58 LSCS-linear somatic cell score), yet the most striking differences were found for SCC over 1000.103/mL (6.32 LSCS), which was expressed by lowering heat stability (126 vs. 217 s, p = 0.034), increasing protein (3.41 vs. 3.04%, p = 0.009), casein (2.80 vs. 2.44%, p = 0.034) and chloride (164 vs. 147 mg/100 mL, p = 0.004) levels, as well as non-fat dry matter (8.79 vs. 8.45%, p = 0.045). It has been shown that low levels of Staphylococcus spp. bacteria (120–1600 CFU/mL) in the mammary gland correlated with decreased lactose content (4.60 vs. 4.47 g/100 g, p = 0.022). Since our results indicate that even low SCC values may significantly affect the technological properties of goat milk, SCC should therefore be routinely screened and reported to dairy manufacturers to assure the consumer of high end-product quality.

The content of hippuric acid in raw goat's and sheep's milk and the content of benzoic acid in model fermented milk drinks prepared using different cultures of bacteria of milk fermentation were determined. All fermented milk drinks contained benzoic acid in the range 5.0-78 mg kg-1. Higher quantity of benzoic acid in fermented sheep's milk drinks corresponded also to significantly higher quantity of hippuric acid in raw sheep's milk. No significant differences among used cultures of bacteria of dairy fermentation and the quantity of benzoic acid in fermented milk drinks were recorded. In addition, the quantity of benzoic acid in various commercial goat's and sheep's cheeses produced directly in farms was analyzed. The contents of benzoic acid in cheeses ranged from 5.1 to 90 mg kg-1. No significant difference in the quantity of benzoic acid from goat's and sheep's cheeses was found, whereas significant differences were registered in the quantity of benzoic acid in cheeses produced in individual farms.

ABSTRACT:This study was conducted to evaluate changes in composition of whey proteins of Czech White Short-haired goat and East Friesian ewe milk and their comparison throughout lactation. Some differences in composition between ewe and goat milk were found. The results showed that the mean total protein (%), whey protein (g/100 g), and β-lactoglobulin (β-Lg, g/100 g) contents of goat milk were 2.75, 0.433, and 0.119 respectively and of ewe milk 6.36, 1.11, and 0.732 respectively. The contents of total protein as well as acid whey proteins in goat milk were nearly constant throughout the lactation period and fluctuated around the mean value while the contents of total protein as well as acid whey proteins in ovine milk were dependent on the period of lactation. The total protein content in ovine milk continuously increased during the lactation period. A higher content of ovine acid whey proteins was noticed at the beginning and in the final period of lactation. The average ratio of whey to total protein was 15.8 ± 2.61% in goat milk and 17.4 ± 2.68% in ewe milk and ranged from 13.0 to 20.4% in goat and from 14.0 to 20.8% in ewe milk. The total contents of two major whey proteins. α-lactalbumin and β-lactoglobulin (α-La + β-Lg = AG), averaged 87% of total whey protein, 92% in ovine milk. The main component of acid whey proteins in goat milk was α-La while in ovine milk the main component of acid whey proteins was β-Lg, however, at the end of the lactation period the content of β-Lg for both kinds of milk increased steeply, and the β-Lg/α-La ratio reached a maximum value of 1.94 in goat milk and of 9.74 in ewe milk. In addition, goat milk contains a similar amino acid profile to ewe milk but the amino acid pattern in whey proteins differs from that in milk. Total essential amino acids were approximately 40% of the total amino acids in goat and ewe milk as well as in goat and ewe whey.

Iodine deficiency and related risks of medical and/or developmental disorders in humans are a worldwide problem. In the last years, Czech endocrinologists and paediatricians have observed a significant increase in the occurrence of goitre in children and adolescents caused by a low dietary intake of iodine. Given the low consumption of seafood, milk and dairy products are the main sources of iodine in theCzechRepublic. Iodine contents of milk of dairy cows of different breeds from seven farms located in Central andNorthern Bohemia were studied over a period of 17 months (April 2000 through August 2001). Iodine content was determined by high-performance liquid chromatography with electrochemical detection (HPLC-ECD) based on IDF Standard 167 (1994), following alkaline mineralization of the sample. An analysis of the certified reference material CRM 063 was used to examine the accuracy of determination. Two-way analysis of variance (ANOVA) with and without replications, including Scheffe’s comparison at a 5% level of significance, was used for statistical evaluation of experimental data. The iodine content of milk ranged from 147 to 605 µg/kg (mean 251  110 µg/kg) during the winter season, and from 35 to 484 µg/kg (mean 212  104 µg/kg) during the summer season. The mean iodine concentration in all samples of milk during the studied period was 225  109 μg/kg.The wide range of iodine concentrations is connected with differences in iodine saturation of dairy cows and it is a result of multiple factors. Iodine reserves in the soil play an important role and influence the content of iodine in feeds for dairy cows and thereby the iodine levels in milk. The presence of goitrogenic substances in feed for dairy cows is another important factor. The iodine content was found to be statistically significantly lower in the milk from dairy cows fed a diet enriched with rapeseed cakes compared to that of dairy cows on a diet without rapeseed cake. Dairy cows on farm F6, which were fed maize silage without added rapeseed cake during winter, had a statistically higher iodine content in milk during the winter season compared to summer, when they were fed fresh fodder. Fresh fodder is supposed to contain goitrogenic substances which significantly reduce iodine levels in milk. This opinion is supported by experimental findings that the date of milk sample collection has no statistically significant influence on milk iodine levels if the dairy cows are fed a diet containing added rapeseed cake (farms F1, F2, F3, and F4) throughout the year. Compared to the other farms, statistically significantly higher milk iodine content was found on farm F5. The mean iodine content in milk from farm F5 was 425  74 μg/kg during the studied period. The main cause is probably that the diet contained no rapeseed cake.  

Michlová T., Dragounová H., Horníčková Š., Hejtmánková A. (2015): Factors influencing the content of vitamins A and E in sheep and goat milk. Czech J. Food Sci., 33: 58-65.The content of lipophilic vitamins A and E was determined in samples of sheep and goat milk of different breeds coming from 9 farms in central, eastern, and southern Bohemia. Samples were collected throughout the period of lactation (from April to September). Vitamins A and E were determined by HPLC using DAD and FLD detectors. Vitamin A was determined in all samples but only α-tocopherol (out of various forms of vitamin E) was detected in all samples. The total average content of vitamins A and E in raw milk of all sheep breeds during lactation was 0.93 ± 0.07 and 2.93 ± 0.87 mg/kg, levels of these vitamins in goat milk were 0.79 ± 0.08 and 1.29 ± 0.35 mg/kg, respectively. The results showed a significantly medium and strong correlation between the content of vitamin A and E and the content of fat (R 2 = 0.57 and 0.75, respectively). The year did not have any statistically significant influence on the content of monitored vitamins. The content of both vitamins is dependent on the phase of lactation. The levels of vitamins A and E were significantly lower in the early phase and significantly higher in the late phase of lactation. The amount of monitored vitamins slightly decreased during pasteurisation. A strong decrease in the content of both vitamins was observed during the first two weeks after milk storage in a freezing box at the temperature of -20°C (about 11-55%).