Milk composition in Damascus, Mamber and F1 Alpine crossbred goats under grazing or confinement management

Direct effects of phenolic compounds on the mammary gland: In vivo and ex vivo evidence

We assessed the potential of Pistacia lentiscus (lentisk) phenolic compounds to enhance production of milk composition in lactating goats and caprine primary mammary epithelial cells (MEC). Damascus goats were given a lentisk infusion (LI) or fresh water (FW) to drink, in a crossover design. Milk from LI vs. FW goats was 0.43% richer in fat and 30% in omega 3 fatty acids. Lentisk infusion enhanced antioxidant capacity of plasma and milk by 37% and 30% respectively, and induced transcriptional activation of antioxidant genes. To assess the direct effect of polyphenols on milk quality in terms of composition and antioxidant capacity, we used plasma collected from goats fed hay (HP) or browsed on phenolic compounds-rich pasture (primarily lentisk; PP) as a conditioning medium for primary culture of MEC. PP increased 2-fold cellular triglyceride content and 2.4-fold intracellular casein, and increased ATP production and non-mitochondrial oxygen consumption. Taken together, the results imply that lentisk phenolic compounds affect blood, MEC and milk oxidative status, which increase fat production by the mammary gland.

Pistacia lentiscus extract enhances mammary epithelial cells' productivity by modulating their oxidative status

We assessed the potential of phenolic compounds from Pistacia lentiscus (lentisk) to enhance production of milk constituents in bovine mammary epithelial cells (MEC). MEC were exposed to 0 (control), 1 or 10 ppm of polyphenols from lentisk ethanolic extract (PLEE) for 24 h. PLEE were absorbed by the MEC plasma membrane, but also penetrated the cell to accumulate in and around the nucleus. PLEE increased triglyceride content in the cell and its secretion to the medium, and significantly increased intracellular lipid droplet diameter. Compared to control, PLEE increased dose-dependently the lactose synthesis, secretion of whey proteins, and contents of casein. To evaluate mitochondrial activity under pro-oxidant load, MEC were preincubated with PLEE and exposed for 2 h to H₂O₂. Exposure to H₂O₂ increased the proportion of cells with impaired mitochondrial membrane potential twofold in controls, but not in PLEE-pre-treated cells. Accordingly, proton leakage was markedly decreased by PLEE, and coupling efficiency between the respiratory chain and ATP production was significantly enhanced. Thus, lentisk polyphenols divert energy to production of milk fat, protein and lactose, with less energy directed to cellular damage control; alternatively, PLEE enables MEC to maintain energy and oxidative status under extreme metabolic rate required for milk production and secretion, and reduces the limitation on energy required to support production.

Fighting the Deadly Helminthiasis without Drug Resistance

Helminthiasis is a very costly management problem in the sheep and goat industry, because the gastrointestinal parasites develop resistance against all chemical products that are discovered and produced by the pharmaceutical industry. The use of natural herbal contents of tannin as especially in Sericea Lespedeza (SL; Lespedeza cuneate) is very promising. Utilizing genetic differences in resistance among the different goat and sheep breeds is a promising alternative, with limited success to date. Totally eliminating the offending parasites from re-infesting by plowing under affected pastures for some seasons, or scheduling rotational pastures, or feeding fresh (grazed) or dried forms of the perennial warm-season legume sericea lespedeza to the infected sheep and goats, or using elevated housing with slatted floors are the most promising alternatives to the ancient tradition of herding and managing ruminants by transhumance. An elevated slatted floor housing is desirable, and deserves wider attention because of its potential in controlling helminthiasis. Slatted floors are already used in the sheep and goat industries in Sweden, Norway, Malaysia and Guatemala.

Lipidome changes, with a focus on phospholipids, due to feeding systems and processing in goat milk

We evaluated the effects of processing - pasteurization and yoghurt manufacturing - on some health-promoting lipidome components in milk from two feeding treatments - brushland grazing or hay-feeding in confinement - in dairy goats. The contents of fat and protein were higher, and of urea, lower, in grazing goats. Fatty acid composition - at the exception of saturated fatty acids - was affected by dietary management and milk processing. Phospholipid contents was lower in confined goats, with little effect for processing. The phospholipid-to-triglyceride ratio was decreased by pasteurization. Sensitivity to pasteurization of phospholipid composition differed between feeding treatments. The percentage of sphingomyelin increased following pasteurization, with no response for fermentation to yoghurt. These results can be exploited to modulate health-promoting fats in dairy products.

Dietary pomegranate peel improves milk quality of lactating ewes: Emphasis on milk fat globule membrane properties and antioxidative traits

Concentrated pomegranate peel extract (CPE) was supplemented to ewes, and milk yield and fat content-fatty acid (FA) and phospholipid (PL) composition-were monitored. CPE-fed ewes had higher milk yield, and fat, protein and lactose contents than controls. Milk PL content-20% higher in the CPE-supplemented group-was regulated by treatment and not by total fat content; milk phosphatidylethanolamine and phosphatidylcholine increased by 22 and 26%, respectively, in CPE-supplemented vs. control ewes. Milk saturated FA concentration was higher, and total polyunsaturated and monounsaturated FA content lower in the CPE vs. control group, regardless of milk total fat content. CPE supplementation increased milk antioxidant capacity, suggesting antioxidant transfer from dietary source to milk, increasing stability and nutritive value. Our study provides first evidence for milk quality improvement in terms of antioxidants and PL enrichment without compromising total milk fat, suggesting strategies to improve dairy animals' milk composition without compromising total production.

Atrazine-induced toxicity in goat spermatozoa is alleviated to some extent by polyphenol-enriched feed

Atrazine (ATZ) is one of the most extensively used herbicides to control growth of broadleaf and grassy weeds in crops. ATZ and its metabolites have deleterious effect on sperm quality. ATZ is also known for its ability to induce oxidative stress. Pistacia lentiscus (PL) is an evergreen shrub, with a high content of polyphenols in leaf extracts, with a known anti-inflammatory and antioxidant properties. The protective effect of PL or its extracts against ATZ-induced damage have not been yet evaluated. We examined the harmful effects of atrazine (ATZ) exposure on male reproductive system, using goat (Capra hircus) model spermatozoa and the protective effects of PL and PL ethanolic extract (PLE). In in-vivo experiments, male goats were fed a standard ration or one supplemented with 15 mg ATZ/kg body weight daily, for 6 months. Exposure to ATZ impaired the spermatozoa's morphology, viability, mitochondrial membrane potential and cell lipid composition. These alterations may in turn lead to reduced fertilization competence of the exposed spermatozoa. In an ex-vivo experiment, spermatozoa from male goats fed a standard ration or one supplemented with PL or PLE for 90 days and then were exposed to 1 μM ATZ or 10 μM of its major metabolite diaminochlorotriazine (DACT) through in-vitro capacitation. Prefeeding with PL or PLE partially attenuated the harmful effects of ATZ and DACT. Dietary supplementation with polyphenol-enriched feed can protect, to a certain extent, spermatozoa in males exposed to environmental toxicants.