Invited review: Human, cow, and donkey milk comparison: Focus on metabolic effects.

Milk is an important food of the daily diet. Many countries include it in their dietary recommendations due to its content in several important nutrients that exert beneficial effects on human health. Human milk is a newborn's first food and plays an important role in the growth, development, and future health of every individual. Cow milk is the type of milk most consumed in the world. However, its relatively high content of saturated fats raises concerns about potential adverse effects on human health, although epidemiological studies have disproved this association. Indeed, dairy consumption appear to be linked to a lower risk of mortality and major cardiovascular disease events. In the last few years many researchers have begun to focus their attention on both the production and quality of cow milk as well as the analysis of milk from other animal species to evaluate their effect on human health. The need to investigate the composition and metabolic effects of milk from other animal species arises from the adverse reactions of individuals in several groups to certain components of cow milk. It has emerged that donkey milk compared with that of other animal species, is the nearest to human milk and an excellent substitute for it. Milk from various animal species shows substantial differences in nutritional composition and distinct metabolic effects. In this review, we discussed the main compositional features and metabolic effects of 3 types of milk: human, cow, and donkey milk.

In vitro evaluation of Saccharomyces cerevisiae cell wall fermentability using a dog model.

Six Saccharomyces cerevisiae cell wall samples were tested by the in vitro gas production technique using dog faeces as inoculum. In particular, the substrates resulted from three different production processes (alcoholic_A, bakers_BA and brewers_BR) and were characterized by two different carbohydrates (mannans + glucans) concentrations nitrogen-free extract (NFE high and low). Gas production of fermenting cultures was recorded for 72 hr to estimate the fermentation profiles. The organic matter degradability (OMD), fermentation liquor pH, short-chain fatty acids (SCFA) and ammonia (NH3 ) productions were also measured. All substrates presented a high percentage of OMD (>92%) and moderate fermentability in terms of cumulative volume of gas related to incubated OM (OMCV >50 ml/g) and short-chain fatty acids production (>25 mmol/g), proving their functional properties. Comparing the substrates, it seems evident that the production process affects the chemical composition of the yeast cell wall in terms of crude protein, ether extract and ash content. Consequently, the in vitro fermentation process was significantly different among substrates for volume of gas, SCFA and ammonia production. Regarding the fermentation rate profiles, the production process influenced mainly the curve shape, whereas the NFE concentration affected the quantity of gas produced per hour. In particular, both S. cerevisiae_BR showed very high percentage of OM degradability, gas and SCFA productions and a fast fermentation process due to their high content of fermentable carbohydrates. On the contrary, both S. cerevisiae_BA yeast cell walls appeared to be less degradable and fermentable, probably due to their high content of ether extract. Regarding both S. cerevisiae_A, the high protein content of these substrates could explain the contrasting in vitro results (high degradability with low gas and SCFA production).

Nutritional management of search and rescue dogs.

Dogs used for search and rescue (SAR) may experience continuous micro-traumas that predispose them to skeletal disorders. The aim of the present study was to evaluate the effect of diet on osteo-articular apparatus in healthy SAR dogs. A total of sixteen SAR dogs were divided into two groups (low supplementation (LS) and high supplementation (HS)) and were fed for 3 months with two experimental diets, characterised by the same protein and energy density, but different in n-3 PUFA (6·2 v. 8·4 % of metabolisable energy), chondroitin sulfate (219·8 v. 989·0 mg/kg DM) and glucosamine (769·2 v. 1318·7 mg/kg DM) in the LS and HS groups, respectively. At recruitment all dogs showed no joint inflammation signs, except four that showed mild symptoms. Haematology and serum biochemistry were performed every 30 d. Joint status was scored by physical and lameness evaluations. The sampling effect analysis showed potential beneficial effects by a decrease in a specific marker of membrane integrity (creatine kinase; CK). Comparing groups, glucose was significantly higher and CK was significantly lower in the HS group; however, in both cases the levels of these parameters fell in the normal range. At the end of the experiment, erythrocytes, Hb and packed cell volume were significantly higher in the HS compared with the LS group. These could result in an improvement in dogs' performance, even if this aspect was not investigated in the present study. Concerning joint evaluation (pain on manipulation, lameness and range of motion), no statistically significant differences were detected between the groups and within the experimental period.

Comparison of nutritional and antinutritional traits among different species (Lupinus albus L., Lupinus luteus L., Lupinus angustifolius L.) and varieties of lupin seeds.

In order to promote the use of lupin in pig nutrition, in this research the nutritional characteristics (i.e. dietary fibre, alkaloid and fatty acid profile) and the in vitro gas production of 12 lupin varieties grown in the Mediterranean basin and belonging to three lupin species (Lupinus albus, Lupinus angustifolius and Lupinus luteus) were assessed. Four varieties of L. albus (Asfer, Lublanc, Lutteur and Multitalia) were grown in South Campania. Three varieties of L. luteus (Dukat, Mister and Taper), three of L. angustifolius (Jindalee, Sonet and Wonga) and two of L. albus (Rosetta and Luxor) were grown in Eastern Sicily. Lupinus albus varieties showed interesting nutritional and dietetic characteristics (i.e. high protein and low fibre content); the lipid fraction, rather elevated, is well represented by monounsaturated fatty acids (544 g/kg), whereas saturated fatty acids (SFAs) are less represented (167 g/kg) and the n-3/n-6 ratio (0.510) is the most favourable. Lupinus luteus varieties presented the most remarkable dietetic aspects, in terms of polyunsaturated fatty acid (PUFA) content (569 g/kg), n-6 PUFA series (490 g/kg), UFA/SFA (5.24) and PUFA/SFA (3.56) ratios and atherogenic (0.059) and thrombogenic (0.100) indices and very low alkaloid content (1.07 mg per 100 g). Lupinus angustifolius varieties showed the least interesting nutritional and dietetic characteristics: low protein and fat content, high fibre level, high SFA amount (248 g/kg) and the lowest favourable nutritional indices (IA: 0.164 and IT: 0.334). Regarding the fermentation process, in L. albus, the tendency to increase the rate of gas production during the early stages of fermentation suggests that the high presence of alkaloids did not affect the in vitro degradability, production of short-chain fatty acids and fermentation process, probably due to their concentration and/or water solubility. Lupinus angustifolius and L. luteus showed intermediate and slightly worse in vitro fermentation patterns respectively. From a nutritional and dietetic point of view, lupin may represent an interesting alternative to soya bean in pig feeding.

Regulation of Stearoyl Coenzyme A Desaturase 1 Gene Promoter in Bovine Mammary Cells.

Stearoyl-Coenzyme A desaturase 1 (SCD1) belongs to the fatty acid family of desaturases. In lactating ruminants, the SCD1 protein is highly expressed in the mammary gland and is relevant for the fatty acid composition of milk and dairy products. Bovine mammary epithelial cells (BME-UV1), cultured in vitro, have been proposed as a model to reproduce the biology of the mammary gland. The present study was designed to investigate the responsiveness of bovine SCD1 promoter to serum, insulin, oleic acid, and NFY transcription factor in BME-UV1 cells. A luciferase-based reporter assay was used to monitor the transcriptional activity of the SCD1 promoter region in BME-UV1 cells treated or not with insulin and/or oleic acid. The level of endogenous SCD1 mRNA was evaluated by Real time PCR. Insulin (20 ng/mL) induced a 2.0 to 2.5-fold increase of SCD1 promoter activity. Additionally, the effect of insulin was inhibited by oleic acid, serum components, and NFY enforced expression. Serum and NFY showed no synergistic or additive effect on SCD1 promoter activity suggesting that they repress SCD1 transcription through the same responsive element.

Meat quality of buffalo young bulls fed faba bean as protein source.

Sixteen Italian Mediterranean Buffalo young bulls were divided into two groups fed isoprotein and isoenergy diets and only differing for protein source of concentrate: faba bean (FB) vs soybean (SB). Animals were slaughtered at 350 kg BW. Meat from FB group showed significantly lower fat, protein, cholesterol and saturated fatty acids than SB group. Significant differences were also found between the three muscles analysed [Longissimus thoracis (LT), Semitendinosus (ST) and Iliopsoas plus Psoas minor (IP)]. ST showed the most favourable fatty acids profile: lower SFA, higher PUFA, MUFA, ω-3, ω-6, CLA and, consequently, lower values for both atherogenic and thrombogenic indexes. Results showed that faba bean can be used as a protein source alternative to soybean in the diet of young buffalo bulls for the production of high quality meat.

Fermentation kinetics of sainfoin hay with and without PEG.

The in vitro gas production technique was applied to evaluate the biological activity of tannins in sainfoin (Onobrychis viciifolia Scop.) hay cut at four progressive phenological stages. The buffalo (Bubalus bubalis) rumen fluid was used as inoculum, polyethylene glycol (PEG) was added as specific binding agent and an alfalfa hay (AH) was used as control. All samples were analysed for chemical composition and condensed tannin (CTs). According to the phenological stage of sainfoin, crude protein gradually decreased [from 219 to 122 g/kg dry matter (DM)] and neutral detergent fibre (NDF) increased (from 391 to 514 g/kg DM). Condensed tannins showed the highest value at the first phenological stage [31.5 mg catechin equivalents (CE)/g DM], and their level significantly decreased at the subsequent growth stages. Gas production and fermentation rate were significantly affected by substrate type and PEG addition. The first stage of sainfoin showed the lowest value of gas and volatile fatty acids production and the slowest fermentation kinetics compared with the other samples, when incubated without PEG, because of the CTs effect. The incubation with PEG improved the fermentation process of the first stage of sainfoin, but no effect was registered on AH, where CTs were not detected. Among the sainfoin samples, the slowest kinetics with PEG was observed in the hay harvested at the fourth stage, probably due to its chemical composition. The use of PEG allowed to verify the effect of tannins on the in vitro fermentation characteristics of sainfoin hay.

Influence of replacing corn silage with barley silage in the diets of buffalo cows on milk yield and quality.

A 150-day trial was carried out on 40 Italian Mediterranean buffalo cows that, immediately after calving, were equally divided into two homogeneous groups (M and O) based on the number of calving events and previous milk yield. The animals were fed (16 kg dry matter (DM)/head) two isoenergy/isoprotein diets (NEl: 6.39 MJ/kg DM; 15.4 CP% DM), composed of corn (diet M) or barley silage (diet O) concentrate, alfalfa hay, and a vitamin-mineral supplement. The fermentation characteristics of both silage diets were evaluated by an in vitro gas production technique, and their nutritional values were calculated as follows: NEl (MJ/kg DM) = 0.54 + 0.0959 GP + 0.0038 CP + 0.0001733 CP(2), where GP is the gas production after 24 h of incubation (ml/200 mg DM) and CP is the protein content of silage (g/kg DM). The nutritional values of the silages were slightly different (4.16 vs. 4.14 MJ/kg DM for M and O, respectively) likely due to the high content of hemicellulose in the O diet (22.0 vs. 16.9%). Average milk yield did not differ between the groups; instead, milk fat (8.39 vs. 9.06%; P < 0.01) and protein (4.41 vs. 4.60%; P < 0.01) levels were significantly higher in the O group. The results elicit great interest in southern Italy where corn cultivation is adversely affected by the high cost of irrigation.

Identification and validation of reference genes for gene expression studies in water buffalo.

In gene expression analysis, a key step to obtain informative data from reverse transcription quantitative PCR (RT qPCR) assay is normalization, that is usually achieved by ratio to correct the abundance of the gene of interest against that of an endogenous reference gene. The finding of such reference genes, ideally expressed in a stable way in multiple tissue samples and in different experimental conditions, is a non-trivial problem. In this work, a set of genes potentially useful as reference for gene expression studies in water buffalo has been identified and evaluated. In the first step, a publicly available Bos taurus expressed sequence tags database has been downloaded from the TIGR Gene Index and mined by some simple frequency algorithms to find out which tentative consensuses are present in a remarkable number of different cDNA libraries and, consequently, are more suitable to be included in a starter set of candidate reference genes. To validate the potential of such candidates for their use as normalizers in buffalo gene expression analysis, an RT qPCR analysis has been carried out, in which the expression stability of these genes has been evaluated on a panel of buffalo tissues and organs. Our results indicate that ribosomal proteins L4 and L5 and Gek protein encoding genes can be useful as normalizers to compare gene expression levels across tissues and organs in buffalo.

Fate of transgenic DNA and evaluation of metabolic effects in goats fed genetically modified soybean and in their offsprings.

The presence of DNA fragments in blood and milk from goats fed conventional (control) or Roundup Ready® soybean meal solvent extracted (s.e.; treated) was investigated by using a polymerase chain reaction approach. The same investigation was carried out on blood, skeletal muscle and organs from kids of both groups fed only dams' milk until weaning. Moreover, the possible effects on cell metabolism were evaluated by determination of several specific enzymes in serum, heart, skeletal muscle, liver and kidney. Fragments of the multicopy chloroplast (trnL) gene were found in blood and milk samples from goats of both groups. In kids, the chloroplast fragments were found in samples of both groups. In samples, which proved positive for the presence of chloroplast DNA, fragments of the specific soybean single copy gene (lectin) were detected in several blood and milk samples. The same fragment was also found in control and treated groups of kids. Transgenic fragments were not found in those samples, which were found positive for chloroplast fragments of control groups of either goats or kids. On the contrary, in blood and milk of treated goats, fragments both of the 35S promoter and the CP4 epsps gene were detected. These fragments were also found in treated kids with a significant detection of the 35S promoter in liver, kidney and blood, and of the CP4 epsps gene fragment in liver, kidney, heart and muscle. A significant increase in lactic dehydrogenase, mainly concerning the lactic dehydrogenase-1 isoenzyme was found in heart, skeletal muscle and kidney of treated kids, thus suggesting a change in the local production of the enzyme. Finally, no significant differences were detected concerning kid body and organ weight.