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In this work we report a lipidomics approach to study the effects of two diet systems on the composition of ovine milk. Milk from two groups of Sarda sheep grazing on 40% (P40) and 60% (P60) of pasture were analyzed by a UHPLC-QTOF-MS analytical platform and data submitted to multivariate statistical analysis. Pairwise partial least square discriminant analysis of the lipid profile of the data was carried out to classify samples and to find discriminant lipids. The two dietary groups were characterized by differences in triacylglycerols, phosphocholines and phosphatidylethanolamines levels. Discriminants of the P40 group were TG and PC containing in their backbone saturated medium chain FA thus suggesting greater de novo fatty synthesis in the mammary gland. On the other hand, the P60 group was characterized by TG and PC formed by unsaturated long chain FA originating from the diet or from lipid mobilization.

This work evaluated the reliability of the multivariate statistical analysis to discriminate the feeding system and the species of ruminants using their intramuscular fatty acids (FA) profile. FA composition of 53 meat samples (longissimus dorsi muscle) from animals of different species (sheep and cattle) raised with different feeding systems (pasture and stall-fed) (4 groups overall) was determined and expressed as % fatty acid methyl ester (FAME). A stepwise discriminant analysis (SDA) was applied to the full set of FA to select the variables that best discriminated between feeding systems and animal species. The selected variables were then submitted to a canonical discriminant analysis (CDA) to test the ability of those variables in discriminating against the four groups. Discriminant analysis (DA) was then exploited to classify meat samples. From the 62 initial variables detected in the FA profile, 24 were retained in the SDA. The subsequent CDA developed by using the selected variables, significantly discriminated the four groups (Hotelling's test p

The objective of this study was to evaluate whether dairy sheep during the transition period are affected by their parity numbers with regard to (1) body weight (BW), body condition score (BCS), and production performance (milk yield and composition) and (2) metabolic, inflammation, and stress biomarkers. For this purpose, 30 Sarda dairy ewes [15 primiparous (PRP) and 15 multiparous (MUP) ewes] were recruited on d 90 of gestation. Each group was homogeneous according to age, BW, and BCS. Sampling was carried out at -60, -30, -7, 0, +30, and +60 d from lambing. The MUP ewes showed a higher BW (46.32 vs. 38.71 kg) and larger litter size (1.45 vs. 1.06 kg) but a lower BCS (2.47 vs. 2.70) than the PRP ewes. Furthermore, the MUP ewes had lower concentrations of glucose (3.49 vs. 4.27 mol/L), cholesterol (1.63 vs. 1.81 mmol/L), free fatty acids (0.47 vs. 0.62 mmol/L), and triglycerides (0.22 vs. 0.25 mmol/L) compared with PRP ewes. With regard to inflammation and oxidative stress parameters, the PRP group had higher haptoglobin (0.48 vs. 0.18 g/L) and paraoxonase (187.90 vs. 152.11 U/L) activity than the MUP group. Overall, the MUP ewes were characterized by greater milk production performance and greater feed intake, resulting in a better energy balance, than the PRP ewes. Interestingly, these findings highlighted a different metabolic and inflammatory response over the transition period between PRP and MUP ewes, with the latter displaying lower concentrations of inflammatory-related biomarkers.

Milks obtained from ruminants grazing natural pastures and some forage crops may worth a plus value as compared to milks obtained to stall fed ruminants, due to their putative higher content of beneficial fatty acids (FA). Fourier Transformed Mid-infrared (FT-MIR) analysis of FA can help to distinguish milks coming from different areas and, possibly, different feeding systems. The objective was to discriminate sheep milks sourced from dairy sheep rotationally grazing for 2, 4 or 6 hr/d Italian ryegrass or berseem clover. To test this hypothesis a data-mining study was undertaken using a database of 1230 individual milk spectra. Data were elaborated by Principal Component Analysis (PCA) and analyzed by Linear Discriminant analysis (LDA) with or without the use of Genetic Algorithm (GA) as a variable selection tool with the primary aim to discriminate feeding regimes based on the grass vs those based on the legume, access time (2, 4 or 6 h/d), grazing day (first vs last grazing day during the seven day grazing period) and the milking time (morning vs afternoon morning). The best fitting discriminant models based on FT-MIR spectra were able to correctly predict 100% of the samples differing for the pasture forage, 91.9% of the samples differing for grazing day, and 97.1% of the samples regarding their milking time. The access time to pasture was correctly predicted by the model in 60.3% of the samples, and the classification ability was improved to 77.0% when considering only the 2 h/d and 6 h/d classes.

Monitoring behaviour of grazing animals is important for the management of grazing systems. A study was run to discriminate between the main behaviours (grazing, ruminating and other activities) of sheep at pasture wearing a halter equipped with an accelerometer (BEHARUM device), and to identify the epoch setting (5, 10, 30, 60, 120, 180 and 300 s) with the best performance. The BEHARUM device includes a three-axial accelerometer sensor and a force sensor positioned under the lower jaw of the animal. The halter was fitted to eight Sarda dairy sheep that rotationally grazed either a spatial association (mixture) or a time association of berseem clover (Trifolium alexandrinum L.) and Italian ryegrass (Lolium multiflorum Lam.) for 6 h day−1. The behaviour of the animals was also video-recorded. The raw acceleration and force data were processed for each epoch setting to create 15 variables: the mean, variance and inverse coefficient of variation (ICV; mean/standard deviation) per minute for the X-, Y-, Z-axis and force, and the resultant. Multivariate statistical techniques were used to discriminate between the three behavioural activities: canonical discriminant analysis (CDA), and discriminant analysis (DA). To validate the derived discriminant functions, a bootstrap procedure was run. To evaluate the performance of DA in discriminating between the three activities, the sensitivity, specificity, precision, accuracy and Coehn’s k coefficient were calculated, based on the error distribution in assignment. Results show that a discriminant analysis can accurately classify important behaviours such as grazing, ruminating and other activities in sheep at pasture. The prediction model has demonstrated a better performance in classifying grazing behaviour than ruminating and other activities for all epochs. The 30 s epoch length yielded the most accurate classification in terms of accuracy and Coehn’s k coefficient. Nevertheless, 60 and 120 s may increase the potential recording time without causing serious lack of accuracy.

The effects of the intra-ruminal dosing of a glucogenic mixture including 70% glycerol, 20% propylene glycol and 10% water was studied on thirty late lactation dairy ewes of Sarda breed. The animals were divided in two homogeneous groups receiving by gavage either 200 mL of water (CTR group; body weight 40.9 ± 1.5 kg) or 200 mL of the above mixture (GLY group; body weight 39.4 ± 1.3 kg) twice daily from d 16 to d 19 of the oestrus cycle, synchronised by “ram effect”. The ewes were then mated and their reproductive responses to the synchronised mating evaluated by scanning on d 50 and at lambing. During the treatment, the ewes were housed in an open hut, machine milked twice daily and fed concentrate and hay to meet their nutrient requirements. During the treatment, concentrate intake was markedly reduced in GLY when compared with CTR (P

A device based on a tri-axial accelerometer was used to measure behavioural parameters of dairy sheep at pasture. Short tests were performed in grazing conditions to collect accelerometer data simultaneously with video recordings of sheep behavioural activities (grazing, ruminating and resting). The raw acceleration data was processed to create 12 variables: mean, variance and inverse coefficient of variation (ICV; mean/standard deviation) for the X-, Y- and Z-axis and the resultant at 1-min intervals. A database inclusive of the 12 acceleration variables and the three behavioural activities detected for each minute was then created. Three multivariate statistical techniques were used to discriminate the behavioural activities using the acceleration data: stepwise discriminant analysis (SDA), canonical discriminant analysis (CDA), and discriminant analysis (DA). Based on the acceleration variables selected by SDA, the subsequent CDA significantly discriminated the three behaviours by extracting two canonical functions. The first canonical function (CAN1) discriminated the grazing activity from the resting and ruminating, whereas the second (CAN2) differentiated the grazing from the ruminating behaviour. After bootstrap resampling, the DA correctly assigned 93.0% of minutes to behavioural activities. Stepwise regression analysis was used to estimate the rate of biting(total number of bites/min) using a subset of acceleration data that contained only minutes in which sheep were grazing. In this case, 15 variables were tested and out of them, only one was selected, the sum of X-axis value per minute (SX), which explained 65% of the total variation of the rate of biting .

The aim of this research was to study the effects of dietary supplementation on the composition and fatty acid (FA) profile of milk from grazing dairy sheep. Forty-eight lactating Sarda ewes were randomly allocated to four homogeneous groups: PAS – control group grazing for 22 h/d without supplementation; NFS – group supplemented with a cereal based concentrate; SLNA – group supplemented with a concentrate enriched with sunflower seeds (106 g/kg DM); and SALA, group supplemented with a concentrate enriched with linseeds (105 g/kg DM). Milk from groups receiving the oilseed enriched concentrate (SLNA and SALA) showed increased total C18:2 non-conjugated dienes, C18:1 t 9 and total trans C18:1 by 106% (P c9, t11 , (2.90 vs 2.27 g/100 g of FAME; P c9, t11 in milk, also resulted in some counters effects on milk nutritional quality, compared to grazing without supplementation.

The multipurpose cardoon crop (Cynara cardunculus var. altilis) is also exploited to produce bio-intermediates for biorefinery; the press cake composed by partially defatted seed residue after oil extraction represents an important byproduct. This research was addressed at elucidating feeding value and traits of cardoon press cake to be exploited as a novel supplement for feeding ruminants. Specific aims were: to (i) determine the nutritional profile of press cake and (ii) evaluate the effect of anti-tannic agents on methane production, ammonia level, ruminal volatile fatty acids profile, ruminal biohydrogenation of linoleic and linolenic acids, crude protein (CP) degradation and fiber (NDF) digestion. Cardoon press cake shows moderate level of CP (18.5%) and fat (7.9%) with high level of NDF, and represents a valuable source of both essential amino acids and n-6 fatty acids. The content of phenolics reached 32.7 mg g−1 and could positively affect the transfer of n-6 unsaturated fatty acids (−50% of biohydrogenation) in milk and meat ruminant products without negative effects for CP degradability and NDF digestibility. In addition, it is able to modulate the methane release, in particular 48 h after incubation. A moderate level of the polyphenol oxidase was also detected. In vitro results indicate that cardoon press cake is suitable for animal feeding and for improving their performances and products with potential benefits for human consumers, due to its content of unsaturated fatty acids with a proper amount of phenolic compounds.

The accurate estimation of herbage intake is a key to adequately feed grazing ruminants. Ten dairy Sarda sheep fitted with a halter equipped with an accelerometer (BEHARUM device) were allowed to graze micro-swards of Italian ryegrass (Lolium multiflorum L.), alfalfa (Medicago sativa L.), oat (Avena sativa L.), chicory (Cichorium intibus L.) and a mixture (Italian ryegrass and alfalfa) for six minutes. Accelerometer data and video recordings of behaviour were collected simultaneously. The raw acceleration data were processed to calculate 15 variables: sum, mean, variance and inverse coefficient of variation (ICV, mean/standard deviation) for the X, Y and Z axes and the resultant. A database was created that included the acceleration variables and herbage intake (FMI, DMI, g), intake rate (FMIR, DMIR, g/minute), bite mass (FMBM, DMBM, g) either on fresh (FM) or dry matter basis (DM) and the logarithm of number of bites (LB) and bite rate (LBR) measured during the tests. Partial least square regression analysis (PLSR) was used to verify if acceleration variables could be used as predictors of behavioural traits. The precision and accuracy of PLSR were evaluated implementing the Model Evaluation System, in which predicted values were regressed against observed ones, based on r2 and Dent & Blackie test. The PLSR showed an overall good accuracy (Dent & Blackie test P = ns) and was proven precise for the estimation of LB (r2 = 0.87), LBR (r2 = 0.86), DMI and DMIR (r2 = 0.71). To conclude, BEHARUM can accurately estimate with high to moderate precision number of bites and herbage intake of sheep short term grazing Mediterranean forages.

The aim of this study was to investigate the blood concentrations of L-arginine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and L-homoarginine, which are regulators of nitric oxide (NO) synthesis, in single, twin, and triplet pregnancies in ewes undergoing either a dietary energy restriction or receiving 100% of their energy requirements. From day 24 to 100 of pregnancy, the ewes were fed ryegrass hay and two different iso-proteic concentrates fulfilling either 100% of ewes&rsquo, energy requirements (control group, n = 30, 14 singleton pregnancies, 12 twin pregnancies, and 4 triplet pregnancies) or only 45% (feed-restricted group, n = 29, 11 singleton pregnancies, 15 twin pregnancies, and 3 triplet pregnancies). Blood samples were collected monthly to measure, by capillary electrophoresis, the circulating concentrations of arginine, ADMA, homoarginine, SDMA, and of other amino acids not involved in NO synthesis to rule out possible direct effects of diet restriction on their concentrations. No differences between groups were observed in the circulating concentrations of most of the amino acids investigated. L-homoarginine increased markedly in both groups during pregnancy (p &lt, 0.001). SDMA (p &lt, 0.01), L-arginine, and ADMA concentrations were higher in feed-restricted ewes than in controls. The L-arginine/ADMA ratio, an indicator of NO production by NOS, decreased towards term without differences between groups. The ADMA/SDMA ratio, an index of the ADMA degrading enzyme activity, was higher in controls than in feed-restricted ewes (p &lt, 0.001). Obtained results show that circulating concentrations of L-arginine, of its metabolites, and the ratio between NO synthesis boosters and inhibitors are altered in energy-restricted ewes, and that these alterations are more marked in ewes carrying multiple fetuses.

Simple Summary This paper updates the knowledge on the effects of grazing ruminants on milk quality and cheese with emphasis on unsaturated fatty acids, volatile compounds antioxidant protection degree and phenols. It focuses on the effects of the forage species and its phenological phase on the fatty acid (FA) profile of the forage and the milk/cheese fatty acid profile. In addition, this paper highlights that milk and cheese sourced from grazed herbage is characterized by a higher content of volatile compounds compared to cheese made from sheep fed at stall. The volatile compounds, besides giving a characteristic flavor to the cheese, can also be used as biomarkers because they can be transferred from herbage to the milk. Recent results show that some endogenous plants factors are capable, when properly included into ruminant’s diet, to modulate feed digestion and nutrient uptake, making livestock systems more efficient and environmentally sustainable. Finally, of particular interest is the role of grazing ruminants in land management and landscape re-evaluation for tourism purpose, a key element to prevent the depopulation and degradation of rural areas. Abstract Dairy products from grazing ruminant have numerous positive effects on human health thanks to their higher content essential fatty acids, vitamins, and polyphenols. Compared to livestock fed a conventional maize silage- and/or grain-based diet, grass-fed livestock produce milk with higher levels of n-3 fatty acids, vitamins A, E, carotenoids, and phenols. The effect is even more pronounced if animals are grazing on legume/forbs-rich grasslands. This review argues, based on the available literature, about the effect of grazing ruminant on milk and cheese quality, including the hedonistic aspects, pointing out the link between territory and dairy products quality (Protected Designation Origin; Protected Geografic Origin; namely PDO and PGI labels). Moreover, it points out the main plant biomarkers which can be used to discriminate grazing sourced from stall-fed sourced milk and dairy products. Overall milk and cheese sourced from grazing animals (cows, sheep and goat) showed higher levels (compared to stall system) of FA, vitamins, phenols, putatively beneficial for consumers’ health. FA and plant secondary metabolites can also affect flavor and some nutritional and technological features of dairy products such as their antioxidant protection degree. This would favour a fair pricing of dairy products sourced from grazing systems and the persistence of viable and sustainable extensive production systems.

Background: Research efforts have focused on the evaluation of the bioactive quality of animal products (milk, cheese, meat, and other by-products) contrasting various feeding strategies coming from different ecological zones. The study aimed to describe the fatty acids (FA), polyphenols (P), bioactive compounds (BC), and antioxidant activity (AA) of goat&rsquo, s milk. Methods: Dairy goats were fed with five systems: (1) Grazing, (2) conventional diet (CD), (3) CD + 10% of Acacia farnesiana (AF) pods, (4) CD + 20% AF, and (5) CD + 30% AF. The fatty acid profile, health promoting and thrombogenic indexes were calculated. Milk extracts were evaluated by HPLC to determent phenolic compounds (gallic, caffeic, chlorogenic, and ferulic acids, catechin, epicatechin, and quercetin). Antioxidant activity of goat&rsquo, s milk extract was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH&bull, ), oxygen radical absorbance capacity (ORAC), and the ferric reducing antioxidant power (FRAP) assays. Results: Conventional diet showed the highest content of polyunsaturated fatty acids while grazing showed the best n-6:n-3 and the linoleic:alpha linolenic acid ratio. Similarly, grazing and AF boosted the polyphenol content. Conclusions: Acacia farnesiana inclusion in the goats&rsquo, diets increased the presence of bioactive compounds and the antioxidant activity while diminishing the cholesterol content of goat&rsquo, s milk.

The effect of the level of dietary non-fiber carbohydrates (NFC) on intake, in vivo digestibility, milk production and endocrine-metabolic status was studied in 20 Sarda ewes (mean ± SE, BW 42.5 ± 3.9 kg) at mid-lactation stage (89 ± 1 DIM). Ewes were divided into 2 groups and fed chopped alfalfa hay at 400 g/d and pelleted concentrates ad libitum in metabolic cages during 3 weeks. The concentrates differed in NFC concentration (NFC = 36% of DM: group NFC36; NFC = 23% of DM: group NFC23), due to the substitution of cereal grains with soybean hulls in the low NFC diet. Dry matter intake was higher for NFC23 than for NFC36 (2900 g/d vs. 2555 g/d; P vs. 62.9%, P vs. 56.1%, P P > 0.2). Dietary NFC concentration negatively affected milk yield (1813 ml/d vs. 2110 ml/d, for NFC36 and NFC23 groups, respectively, P vs. 4.51%, P vs. 5.19%, P > 0.2). Body fat increased ( P P P P

a b s t r a c t Diet composition is the major factor influencing the fatty acid composition of meat and milk from ruminants because the fatty acids (FA) which reach the duodenum are, at least in part, of dietary origin as well as the result of rumen microbial biohydrogenation (BH) of dietary lipids. In this review, effects of synthesis of conjugated linoleic (CLA) and linolenic (CLNA) acid isomers in the rumen, effects of the lipids in herbage, and plant endogenous factors on synthesis of nutraceutical fatty acids are discussed. Discovery of beneficial FA in ruminant products, such as CLA and other -3 FA, stimulated many studies in the last 20 years, including those on the roles of minor FA intermediates on rumen BH and mammary gland metabolism. Much of this research was targeted at identifying the intermediates formed during BH as well as the rumen microbial ecology involved in these processes. However, shifting the research to feedstuff endogenous factors which influence lipolysis (LP) and losses of polyunsaturated FA in the rumen may be of interest in identifying nutri- tional strategies to manipulate FA profiles in ruminant products. The presence of FA with healthful properties in milk or meat from ruminants can be enhanced by inclusion of fresh forages in their diet. Hence, there is increasing interest in the crucial role of endogenous LP, plant secondary metabolites (PSM) and polyphenol oxidase (PPO) on ruminal BH. To better understand the pathways through which PSM or PPO impact FA metabolism, char- acterization of lipids in fresh forages suggests the important role of the diet matrix on the ruminal fate of lipids. A critical discussion of the role of odd chain branched FA (OBCFA) is also reported, including potential impacts on rumen microbial metabolism. Finally, new insights into lipid metabolism from in vitro techniques are discussed.

Cabiddu, A., Sallis, L., Tweed, J. K. S., Molle, G., Decandia, M., Lee, M. R. F. (2010). The influence of plant polyphenols on lipolysis and biohydrogenation in dried forages at different phenological stages in vitro. Journal of the Science of Food and Agriculture, 90, (5), 829-835 Sponsorship: University Research Fund; Makira Fund; Livery Guild IMPF: 01.36

The concentration of condensed tannins (CT) in sulla (Hedysarum coronarium L.) is moderate and overall regarded as beneficial. However, the intake of this forage can reduce diet digestibility, particularly during flowering phase. An experiment was run to assess the effect of CT on feeding behaviour, intake, diet digestibility and performance of dairy sheep rotationally grazing sulla at flowering phase. Twenty-four late-lactating sheep were blocked in two homogeneous groups and submitted to the following treatments: i) twice daily drenching with 200 g/day of a 50% w/v water solution of an anti-tannic substance, polyethylene glycol, group PEG; ii) twice daily drenching with 200 g/day of water, group CON (Control group). All the sheep rotationally grazed as a flock two sulla plots from April to June (8 weeks in total). Sward height, herbage mass, botanical and chemical composition of the herbage were measured at the beginning and the end of each grazing period. The feeding behaviour (3 sheep per group) was continuously monitored for 24 h in 6 weeks using the IGER behaviour recorders. Herbage DM intake (DMI), dietary DM digestibility (DMD) and apparent CP digestibility (CPD) were estimated on 8 sheep per group by the n-alkane method. On average, PEG group had longer total grazing (503 ± 12 vs 460 ± 12 min, P

A grazing experiment was undertaken to evaluate the effect of PEG supplementation on the fatty acid composition of milk from Sarda sheep grazing sulla. Twenty-four late-lactating sheep (12 per group), were paired and split into two groups: group control (CON), dosed daily with a quenching gun with 200 ml of water, and group PEG, dosed with 200 ml of a 50/50 w/v water solution of PEG. The sheep grazed two 0.8 ha plots of sulla under a rotational grazing scheme. The contents of c-9, t-11 CLA and t-11 C18:1 in milk fat were on average 40% higher (P

In the light of recent findings in sheep nutrition and feeding behaviour, the diets of grazing dairy sheep should be based on forages encompassing a variety of complementary nutritional values and containing moderate levels of diverse plant secondary metabolites, until recently regarded as “anti-nutritional”. In lactating sheep, pastures of tannin-containing legumes like sulla (Hedysarum coronarium) and chicory (Cichorium intybus) can be integrated with annual grasses for establishing artificial pastures under rainfed conditions. Diets based on these forages, while ensuring high milking performance, can mitigate the unbalance of CP to energy ratio of grazing sheep. By grazing sulla and Italian ryegrass (50:50 by area) as spatially adjacent monocultures or in timely sequence (complementary grazing) sheep eat more and perform better than by grazing the ryegrass pasture only. Concentrate supplementation of lactating sheep should be preferably based on sources rich in digestible plant fiber (soyhulls or beet pulps), particularly from mid-lactation onwards and when supplementation levels are high. Milk urea concentration is confirmed as a useful monitoring tool to balance protein nutrition and curb the waste of N at animal and system level. Finally, challenging tasks for future research on dairy sheep grazing management and nutrition are on-farm application of recent technological advances, such as image-based estimation of pasture biomass and quality, evaluation of sheep dietary quality by faecal Near Infrared Reflectance Spectrometry, and establishment of remote control systems. © 2008 Elsevier B.V. All rights reserved.

The effects of supplemental polyethylene glycol (PEG) on feeding behaviour, diet composition, intake and milk production were studied in late lactating Sarda goats browsing on a lentisk-based bushland with different herbage cover. The goats were allotted to two groups that browsed 7 h daily on 2 plots characterised by different cover proportions of woody and herbaceous species. These proportions were 90% woody vs. 10% herbaceous species in one plot (W — woody, close bushland with low herbage cover) and 70% woody vs. 30% herbaceous species in the other plot (H — herbaceous, open bushland with high herbage cover). Each group was divided into two sub-groups: one fed with 50 g day − 1 of PEG 4000 MW (PEG + ) and the other receiving no PEG supplementation (PEG − ). The feeding behaviour was different between groups; goats in herbaceous plot (H-goats), had a longer grazing time, expressed as percentage of total observation time than the counterparts (64% vs. 58%, P P = 0.12). The average daily milk production was 473, 591, 541 and 589 ml, respectively in W-PEG −, W-PEG + , H-PEG − and H-PEG + sub-groups with significant effect of herbage cover × PEG dose interaction ( P P P

Sixty-four Sarda dairy sheep fed fresh forage based diets were allocated to eight groups in early lactation (i.e., 44 days in milk, winter period, growing stage of the forages) and at mid-lactation (i.e., 98 days in milk, spring period, reproductive stage of the forages) to evaluate effects of corn grain or beet pulp based supplementation on milk and cheese fatty acid (FA) composition. Four forage species were compared, being: annual ryegrass (RY; Lolium rigidum Gaudin), sulla (SU; Hedysarum coronarium L.), burr medic (BM; Medicago polymorpha L.) and crown daisy, (CD; Chrysanthemum coronarium L.). The supplements differed in carbohydrate composition consisting either of 600 g/kg (dry matter basis) corn grain (concentrate C) or 400 g/kg sugar beet pulp (concentrate BP) and were offered at a fixed rate (C, 500 g/day; BP, 530 g/day) to provide a similar metabolizable energy and crude protein supply. Forage species affected (P

An experiment was carried out to evaluate the effect on milk and cheese fatty acid composition of the inclusion of Chrysanthemum coronarium L., (Asteracea) into dairy sheep diet. Plots sown either with a binary mixture consisting of Lolium rigidum Gaudin and Medicago polymorpha (LM) or a ternary mixture including the above species and C. coronarium were (LMC) grazed by groups of Sarda dairy ewes during May. The botanical composition of diet, as measured by n-alkane method, showed that 34% of LMC group diet consisted of Chrysanthemum flowers and leaves. Exposure of sheep to this non-conventional forage did not affect animal performance and milk composition (fat and casein, P > 0.05) but resulted in different milk and cheese fatty acid composition. In particular conjugated linoleic acid, vaccenic acid and linoleic acid were all higher in LMC than LM groups (P

Two experiments were undertaken to evaluate the effect on milk and cheese fatty acid composition of feeding different fresh forages to dairy sheep both in winter (experiment 1, growing stage of the forages, early lactating ewes) and in spring (experiment 2, reproduction stage of the forages, midlactating ewes). Four forage species were compared: annual ryegrass (RY, Lolium rigidum Gaudin), sulla (SU, Hedysarum coronarium L.), burr medic (BM, Medicago polymorpha L.), and a daisy forb (CH, Chrysanthemum coronarium L.). The forages were cut twice daily and offered ad libitum to 4 replicate groups of Sarda dairy sheep (groups RY, SU, BM, and CH). The CH forage was particularly rich in linoleic acid in both periods, whereas BM and SU forages were rich in linolenic acid in winter and spring, respectively. Milk fatty acid composition was affected by the forage in both experiments. Milk conjugated linoleic acid and vaccenic acid contents were higher in CH and BM groups (winter) and CH group (spring) than in the other groups. No differences were observed when comparing fatty acid profile between milk, 1-d-old cheeses, and 60-d-old cheeses within experimental groups, suggesting that the fatty acid recovery rates during cheese making and ripening were not affected by the feeding regimens. After stepwise discriminant analyses of the pooled data, the milks and cheeses sourced in the different feeding regimens differed among them. Based on these results, we conclude that it is possible to manipulate the fatty acid profile of sheep dairy produce to maximize the content of beneficial fatty acids by the use of appropriate fresh forage-based regimens.

This paper updates our knowledge on the effects of the botanical composition and management of Mediterranean pastures on the fatty acid composition of sheep milk and cheese. It focuses on the effects of the forage species and its phenological phase on: (i) the fatty acid profile of the forage, and (ii) the milk fatty acid composition. Here we refer specifically to putatively beneficial fatty acids (mono- and poly-unsaturated fatty acids (PUFA)), including conjugated linoleic acid (CLA, C18:2 c-9, t-11) and vaccenic acid (C18:1 t-11). A database was set up compiled from the results of various studies carried out by our research group and this was statistically analysed. Both the forage species ( P < 0.05) and its phenological phase (P < 0.08) affected the content of linoleic acid, a precursor of CLA in the forage. The PUFA level in milk was higher in ewes grazing pure legumes and grass–legume mixtures than in those grazing pure grass pastures. When the pasture mixture also contained a daisy plant (Chrysanthemum coronarium ), the CLA and vaccenic acid levels were even higher. Linoleic (C18:2; c-9, c-12) linolenic (C18:3; c-9, c-12, c-15) CLA (C18:2; c-9, t-11) and vaccenic acid (C18:1; t-11) levels in milk decreased from the vegetative (early-mid lactation) to the reproductive phase (late lactation). The � 9 desaturase activity (estimate by C14:1/C14:0 ratio), which is involved in the conversion of vaccenic acid to CLA in the mammary gland, supports the hypothesis that the lower the substrate supply the higher the endogenous CLA synthesis. Finally, no marked differences were found in the fatty acid composition of milk and cheese from dairy sheep. Guidelines for managing the nutrition of grazing sheep to increase the unsaturated fatty acid content in milk are discussed. © 2005 Elsevier B.V. All rights reserved.

The nutritional value of sown safflower (Carthamus tinctorius L.) annual pastures for Mediterranean dairy sheep was investigated in the Northern Negev Desert of Israel (250 mm of rainfall) with Awassi hoggets and in Sardinia (Italy, 590 mm of rainfall) with Sarda milking ewes. Safflower (termed “Saf”) was compared with barley (“Bar”) in Israel, and with chicory (Cichorium intybus L., termed “Chi”) and burr medic (Medicago polymorpha L., termed “Bm”) in Sardinia. In Israel, hoggets grazed more DM (1.8 kg d−1 versus 1.5 kg d−1, P

Three experiments were carried out to assess the feeding value of sulla ( Hedysarum coronarium L.) as complementary grazing source for Sarda dairy sheep basically fed on annual ryegrass ( Lolium rigidum Gaudin) pasture. In experiment 1 (E1), non-pregnant (D) and pregnant (P) ewes were allotted into three groups allocated for 9 h daily, respectively, on plots of sulla (S9), annual ryegrass (R9) or sulla for 3 h in the morning and annual ryegrass for the remaining time (S3R6). In experiment 2 (E2), the treatments were sulla (S22), ryegrass (R22) and two “time mixtures” consisting, respectively, of 3 (S3R19) or 6 h allocation on sulla (S6R16). In experiment 3 (E3) only R22 and S6R16 were compared. In both E2 and E3, milked ewes were used and the total time on the plots was 22 h daily. In E1, the total digestible herbage intake (DDMI), measured by the n -alkane method, was affected by the interaction between sheep physiological state and grazing system ( P P P

Sixty four Sarda dairy sheep fed with diets based on fresh forage were allocated to eight groups to evaluate the effect of corn or beet pulp based supplementation on milk fatty acid composition. Four forage species were compared: annual ryegrass (RY, Lolium rigidum Gaudin), sulla (SU, Hedysarum coronarium L.), burr medic (BM, Medicago polymorpha L.), and garland, a daisy forb, (CH, Chrysanthemum coronarium L.). The supplements were iso-nitrogenous but differed in carbohydrate composition consisting either of 60% (DM) of corn (concentrate C) or 40% sugar beet pulp (concentrate BP). The supplementation was iso-energetic (500 and 530 g/d, respectively). Overall during winter period (growing stage of the forages) SU and RY groups showed higher levels of atherogenicity index and C16:0. In winter period BP outperformed C for palmitic acid. In spring AI showed a trend similar to that of winter. Moreover C concentrate gave a better level of AI and myristic acid than BP. This study confirms that forage species and, to a lesser extent, carbohydrate source in the supplement markedly affect mediumchain FA profile and hence atherogenicity index in sheep milk.

A trial on different fatty acid supplementation was run in grazing dairy sheep. Forty-eight lactating Sarda ewes were randomly allocated to four homogeneous groups: PAS, control group grazing for 22h/d without supplementation; NOF, group supplemented with a cereal based non-fat enriched concentrate; C182, group supplemented with a concentrate rich in sunflower seeds; and C183, group supplemented with a concentrate rich in linseeds. The results showed that the concentrates, based on oilseeds from both sunflower and linseed sources determined high C18:1 t11 and CLA c9 t11 cheese fat content. Moreover linseeds supplementation improved the concentration in the cheese of other beneficial fatty acids such as LN and PUFAω3.

The effect of polyethylene glycol (PEG) on intake and digestibility in Sarda goats either fed in metabolic crates or browsing a Mediterranean scrubland, featured by tannin-rich species, was studied. In metabolic cages (Experiment 1) nine dry goats were fed ad libitum with foliage of lentisk (Pistacia lentiscus L.) supplemented with 200 g per day of a concentrate and either 0, 25 or 50 g per day of PEG. In the scrubland (Experiment 2), with lentisk as main species, 20 goats at the end of lactation, were supplemented with hay and concentrate, receiving 0 or 50 g per day of PEG. In both experiments the PEG did not affect the diet intake. The in vivo CP digestibility of the diet raised from 37% without PEG to 71% with 50 g of PEG in Experiment 1( P

A study has been carried out in the centre-east area of Corsica (altitude 850 m a. s. l.) in three goat herds (Corsican local breed) browsing a Mediterranean shrubland without any additional feed supply. The practical usefulness of BCS and metabolic profile in order to assess the nutritional conditions of goats during the milking period (80 to 120 days of lactation) was investigated on a sample of 18 goats selected in each herd. BCS, metabolic profile, and milk yield/quality were individually measured. A negative overall correlation was found between the mean BCS and milk yield ( r =−0.24, P P P >0.05) were found. Blood P and Mg values indicate a sufficient intake of these minerals. Our results indicate that, under the specific conditions of this study, goats browsing a Mediterranean shrubland can produce a fairly good quantity of milk with good composition, without a significant depletion of fat reserves or marked metabolic imbalances. Under extensive husbandry conditions, BCS and to a lesser extent blood parameters, can help in explaining the differences in milk yield between goat herds.

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