Ahmed Gargouri

Analysis of Raw Milk Quality at Reception and During Cold Storage: Combined Effects of Somatic Cell Counts and Psychrotrophic Bacteria on Lipolysis

The objective of the article was to analyze the influence of psychrotrophic bacteria counts (PBCs) and somatic cell counts (SCCs) on the extent of lipolysis in bulk samples of cows milk at reception and during cold storage. Samples of milk were analyzed on the day of sampling and subsequently during cold storage. The acidity, fat, density, chloride content, electrical conductivity (EC), bulk milk SCCs (BMSCC), and PBC values were analyzed on the day of sampling and the levels of acidity, EC, SCC, and PBC were analyzed during cold storage at 4 °C for 72 h. The SCC value 869 × 10(3) mL(-1) was higher than the recommended threshold. Lipolysis level at sampling day was related more closely with SCC than with PBC. There was no significant correlation between milk acidity and PBC among others parameters, while the milk mean density was only significant (P < 0.01) correlated with the fat content. The EC and chloride content were consistently correlated (P < 0.001) with BMSCC that allowed them to be used as indicators of mammary gland infection. The milk acidity, EC, PBC, and lipolysis levels increased in relation to the storage time at 4 °C. The lipolysis level during storage was in closer relation to the SCC, but not relation to the PBC. Effects of SCC and PBC on lipolysis decreased throughout the chilling period. It was concluded that initial lipolysis level and intrinsic milk lipoprotein lipase appear more effective than SCC and PBC on the development of lipolysis during storage.

Total and differential bulk cow milk somatic cell counts and their relation with antioxidant factors

In the present study, the relationship between total bulk milk somatic cell counts (BMSCC), differential BMSCC (macrophage, lymphocyte, and polymorphonuclear leukocytes), and antioxidant enzymes was investigated. Forty-three samples of bulk milk were selected randomly from eight dairy farms in the region of Sfax (Tunisia) in winter, from November 2005 to February 2006. Bulk milk samples were analyzed for antioxidant enzymes such as catalase, SOD and GSHPx activity and differential SCC. After that, milks were allotted according to their total SCC to: group 1, bulk milk with SCC below 1000x10(3) ml(-1); group 2, bulk milk with SCC from 1000x10(3) to 1500x10(3) ml(-1); group 3, bulk milk with SCC above 1500x10(3) ml(-1). BMSCC levels ranged from 400x10(3) to nearly 4000x10(3) ml(-1). Lymphocytes were the predominant cell type in all groups, but their proportion declined with the total BMSCC. Catalase and GSHPx activities were found to be significantly (P<0.001) correlated with total BMSCC and with the PMN population. In contrast, a weak correlation between the activity of the SOD and total or differential bulk milk somatic cells was observed. It has been suggested that milk cells, especially PMN, could generate a situation of oxidative stress in the mammary gland. Specifically, hydrogen peroxide and hydroxyl radicals were probably the most important reactive oxygen metabolites released by PMN.

Evaluation of Tunisian milk quality in dairy herds: Inter-relationship between chemical, physical and hygienic criteria

The objective of this paper was to evaluate the global milk quality in Tunisian dairy herds. Samples of milk were analyzed for chemical, physical and hygienic parameters. Milk total solids, fat content and density were consistently correlated and one of them can be used as a chemical indicator of milk quality. The somatic cell count value of 689 × 10(3) /mL was higher than the recommended threshold. All milk samples were positive for the major pathogen Staphylococcus aureus. These hygienic parameters were related more closely with chloride content, minerals and electrical conductivity, which allows them to be used as indicators of mammary gland infection. It was concluded that milk producers have at hand rapid and easy tools for assessing the overall quality of milk.

Beneficial effects of fermented camel milk by lactococcus lactis subsp cremoris on cardiotoxicity induced by carbon tetrachloride in mice

Carbon tetrachloride (CCl4) is a xenobiotic present in the environment, can cause harmful effects on human health. In the present study, we attempted to elucidate the cardiopreventive potential of the fermented camel milk by lactococcus lactis subsp cremoris (FCM-LLC) against the toxic effects of acute exposure to CCl4 on heart tissue of mice. Twenty-eight mices were divided into four groups of seven each: group (C) served as control; group (FCM-LLC) received only 100mgL of FCM-LLC/kg body weight daily for 15days; group (CCl4) was administered by a single dose of CCl4 (10mL/kg in 0.3% olive oil, i.p) at day 14 and group (FCM-LLC+CCl4) pretreated with FCM-LLC and received a single dose of CCl4 on day 14. The exposure to a single dose of CCl4 caused cardiotoxicity expressed by an increase in lipid peroxidation (TBARS), protein carbonyls (PC) levels and in antioxidant markers (superoxide dismutase (SOD), catalase (CAT), gluthathione peroxidase (GPx), glutathione (GSH) and Vitamin C levels) in the CCl4-treated group when compared with the untreated group. Furthermore, treatment with CCl4 significantly elevated the cardiac toxicity markers while increasing of alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase MB (CKMB) and Troponin I activities. The pre-treatment of experimental mices with FCM-LLC has allowed an improvement through lowering oxidative stress and attenuating cardiac toxicity. These modifications were further evident through histopathological aspects of the heart. Overall, the present data provide evidence of the beneficial effects of fermented camel milk by lactococcus lactis subsp creemoris clearly revealed through the reduction of the CCl4 induced heart oxidative damages.

Cardiopreventive effects of camel milk against carbon tetrachloride induced oxidative stress, biochemical and histological alterations in mice

Abstract The present study was designed to examine the preventive effects of camel milk (CM) against the toxic effects of acute exposure to carbon tetrachloride (CCl4) on the heart tissue of mice. Administration of a single dose of CCl4 caused cardio toxicity as monitored by an increase in lipid peroxidation (thiobarbituric acid reactive substances), protein carbonyl level and antioxidant markers (superoxide dismutase, catalase, glutathione peroxidase, glutathione and vitamin C) in the heart tissue. Moreover, CCl4 caused a distinguished rise of plasma aspartate aminotransferase, lactate dehydrogenase, troponin I, and creatine kinase activities. Furthermore, CM ameliorated biochemical and histological parameters as compared to CCl4-treated group. Overall, this study indicates that CM is efficient in inhibiting oxidative stress induced by CCl4 and suggests that the administration of this milk may be helpful in the prevention of cardio-toxicity complications.

Effects of Zeolite supplementation on dairy cow production and ruminal parameters – a review

Abstract In recent years, the use of both natural and synthetic zeolites in livestock feeds fed to lactating cows has increased, mainly to improve their performance, health, and to protect against mycotoxins intoxication. Data of scientific literature were compiled to analyze the effects of the incorporation of non-nutritional adsorbent zeolite on production performance and ruminal environment parameters of lactating cows. At moderate levels (200–400 g/cow/day), milk yield was increased by zeolite. Milk fat and protein contents and DMI were not altered and all ruminal parameters were improved: acetate was enhanced, propionate was reduced and consequently, acetate to propionate ratio was increased. The rumen pH was increased and rumen ammonia nitrogen was reduced. When the level of zeolite exceeded 400 g/d/cow, all production and ruminal parameters were negatively altered. These data suggest that zeolite level in the diet has a significant effect on the response of dairy production and ruminal environment characteristics.