1,720,982 research outputs found
Effect of linseed supplementation on fatty acid composition and lipid oxidation of Maremmana beef
No full textThe interest in feeding strategies aimed to increase the level of polyunsaturated fatty acid (PUFA) in animal products is growing. Linseed supplementation has been reported as an useful strategy in order to increase PUFAω-3 content. However, less knowledge is available about the effect of PUFAω-3 enrichment on the shelf life of meat. The aim of this work was to evaluate the intramuscular fat oxidative stability of beef obtained from Maremmana young bulls fed a diet supplemented with extruded linseed. 20 Maremmana young bulls were divided in 2 groups: experimental (E- diet supplemented with extruded linseed during fattening) and Control (C- diet without linseed) group. Longissimus dorsi muscles of each animal were sampled, grinded and stored at 4 °C. Fatty acid composition, cholesterol, peroxide, dienes, thiobarbituric acid reactive substances (TBARs), retinol, carotenoids, and cholesterol oxidation products (COPs) levels were determinated at 0, 2 and 6 days of storage. The linseed supplementation led to a significantly increase (+85%) of PUFA ω-3. E group’s beef showed a higher susceptibility to lipid oxidation: TBARs and COPs levels increased by 141% after 2 and 6 days respectively. On the contrary, retinol and carotenoids similarly decreased in beef from both groups. In conclusion, the beef from C group was more stable with regard to oxidation, probably due to the lower levels of pro-oxidant substances and to the proper content of antioxidant substances. In contrast, although the level of antioxidant substances at time 0 was similar between groups, the beef from E group showed a significant increase of oxidation products already after two days. These results suggested that linseed supplementation improves meat quality by increasing PUFAω-3 content, but higher levels of antioxidants than those normally present in the intramuscular fat are needed in order to control the oxidation during the storage
Emission of greenhouses gas in Italy: an inventory for the sheep sector using the Tier 3 of IPCC guidelines
No full textGreenhouses gas emissions (GHG) inventories are often per- formed by using the TIER1/TIER2 of the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC) that applies stan- dard references to perform estimates for all livestock species. The IPCC procedures are not largely detailed for breed aptitude, livestock categories and management systems, especially in the sheep sector. Objective of this work was to assess the GHG emis- sion of the Italian sheep sector by accounting for CH4 from enteric fermentation and, CH4 and N2O from manure manage- ment, both expressed as CO2 equivalents (CO2-eq). Calculations were performed in a spreadsheet file (Excel®). Information about ovine population was obtained by the official national data- base of livestock population (www.statistiche.isz.it). The num- ber of raised mature ewe for milk and meat production in each region (n=20) was obtained by gathering the average data of the year 2012. Regional diffusion, population structure and livestock system of the most representative milk breeds (Sarda, Massese, Comisana) and meat breeds (Bergamasca and Biellese; Appenninica, Laticauda, and Fabrianese; Sopravvissana and Gentile di Puglia) were derived from published literature. A meta-modeling approach was applied, within each animal cate- gory, to estimate: diets and metabolizable energy requirements for maintenance, activity, cold stress and production (Small- Ruminant-Nutrition-System software, www.nutritionalmodels. tamu.edu); emitted methane as a percentage of metabolizable energy intake (INRA, Prod.Anim., 2008, 22:403-418); nitrogen excretion (Option Mediterraneennes, 2011;59:201-209); emis- sion factors for CH4 and N2O from manure (IPPC 2006). Total sheep population accounted for 8.03 million heads of which near- ly 60% and 20% represented mature dairy and meat ewes respec- tively. Sheep were distributed in the whole national territory, but more than 70% in Tuscany, Lazio, Sardinia and Sicily. Total GHG emissions in Italy were 2463, 1792, 671 kiloton of CO-2eq for total, dairy and meat sheep, respectively, representing the 15% of total GHG emission from the Italian livestock sector. In both dairy and meat productive systems, 90% of total emissions derived from enteric fermentation and 10% from manure management. Enteric fermentation was on average 10.96 and 11.28 kg/head/year of methane emitted from milk and meat sheep, respectively. Those values are higher than that proposed by the TIER1 of IPCC (8 kg/head/year)
Methane Emission from Enteric Fermentation: Methanogenesis and Fermentation
No full textRumen fermentation of carbohydrates plays a fundamental role in ruminant metabolism as the main source of energy. Acetic, propionic and butyric acids (namely, volatile fatty acids, VFA) are the main products of the rumen fermentation of structural and nonstructural carbohydrates con- tained in the ruminant’s diet. The metabolic pathways involved in VFA production are strictly linked to methane emission, because hydrogen is actively produced during the fermentation of structural carbohydrates, and it is rapidly metabolised by methanogens, in order to maintain the optimal thermodynamic condition for the metabolism of the microbe consortium in the rumen. Hydrogen plays also a fundamental role in the maintenance of the equilibrium among VFA pathways and in their interconversion. In this chapter, after a brief chemical description of dietary carbohydrates, individual VFA pathways are described in order to put in evidence the thermodynamic control points of each pathway and the production of energy and reductive equivalent. Then, the relationship between hydrogen, VFA and methane production has been reviewed, considering the role of some dietary factors, the substrate competition between different meta- bolic pathways and the models of VFA estimation
Integrazione alimentare con estratto polifenolico da acque di vegetazione nella pecora da latte: effetto sulle performance produttive e stato ossidativo del siero, risultati preliminari
No full textMultivariate analysis of milk fatty acid composition is able to discriminate dairy farm according to feeding regimen and predicted methane emission
No full textDiet composition may change milk fatty acid (FA) profile by modulat- ing the amount of acetate and butyrate for mammary neo-synthesis and influencing the rumen biohydrogenation (BH) of dietary FA. Therefore, milk FA may be considered as a marker of the feeding reg- imen. The aim of this study was to evaluate the ability of linear dis- criminant analysis (LDA) applied on the milk FA composition to dis- criminate the feeding regimen adopted in 29 commercial dairy farms, considering the type of roughage in the diet. LDA was also applied to discriminate the farms on the basis of predicted methane emission (PME) rate (kg CH4/head and day) calculated as follow: (0.37+0.0392 GEI+0.0189 NDF–0.156 EE+0.0014 BW)/55.65, where GEI= Gross Energy Intake (Mcal/d), NDF=%NDF in the diet, EE=% ether extract in the diet, and BW= Body Weight (Kg). A stepwise LDA was applied to select the FA that best discriminated the farms on the basis of roughage used (hay, corn silage, other type of silage) or of the PME (0.48). Only variables with a R2>0.1 were retained at the end of the stepwise procedure. From the 56 initial FA detected in milk, 22 or 23 FA were retained in order to discriminate the farms according to roughage type or PME, respec- tively (P<0.001). The first canonical variable of both LDA explained more than 98% of variance. Results showed that farms adopting feed- ing regimens based on hay (no silage) were clearly discriminated from farms adopting silage as roughage basis of the feeding regi- men, moreover farms with feeding regimen containing corn silage were discriminated from farms adopting other type of silage. The absence of silage in the diet was positive related with the content of α-linolenic acid and CLA and negative related with linoleic acid con- tent in milk. Finally, LDA clearly discriminated also the four predeter- mined group of farms with different PME. High levels of PME were positively related with milk FA originated by rumen metabolism (branched FA and intermediates of rumen BH). On the contrary low levels of PME were related with milk FA originated by mammary metabolism (mainly short chain FA). LDA of milk FA was an effective method to discriminate between farms adopting feeding regimens with different roughage basis. Since this aspect may interfere also with methane emission, LDA may also effectively discriminate farms with different PME
Cholesterol and fatty acids oxidation in meat from three muscles of Massese suckling lambs slaughtered at different weights
Full text linkEighteen Massese male lambs fed mainly with maternal milk were slaughtered at 11, 14 and 17 kg. Samples of Longissimus dorsi (LD), Triceps brachii (TB) and Semimembranosus (Sm) muscles were collected. Total intramus- cular lipids were extracted by means of a mix- ture of chloroform methanol 2/1. Cholesterol content and its oxidation product (COP) were determined by a gas chromatography appara- tus equipped with an apolar 30 m column. Fatty acid oxidation was evaluated by means of thio- barbituric acid reactive substances (TBARS) extracting the sample with aqueous acidic solution. The effect of slaughter weight on oxi- dation of intramuscular lipids was found only in TB muscles. In this muscle the cholesterol content showed a decreasing trend, while the content of COPs significantly increased with the age of animals. Among the COPs, the 7- ketocholesterol and 7β-hydroxycholesterol were the most abundant, followed by α- and β- epoxy-cholesterol and cholestan-triol. The con- tent of TBARS did not vary owing to a similar fatty acid composition of intramuscular fat across weight of slaughter. In any case, the val- ues of TBARS did not reach the threshold of the detection of off-flavour in meat
Effect of different doses of cracked whole soybean on milk fatty acid composition in buffalo
Full text linkIn order to improve the health characteristics of buffalo milk and Mozzarella, the effect of two concentrates differing in linoleic acid (LA) content on milk fatty acid (FA) composition was con- sidered. Dietary LA supplementation, in fact, is the most effec- tive strategy to increase milk content of conjugated linoleic acid (CLA), which has potentially positive effects on human health. Thirty-two buffaloes were randomly allotted in two groups: exper- imental (EG) and control (CG). During the first period (P1, from 26 to 82 days in milk) EG fed a total mixed ratio (TMR) composed by barley silage, alfalfa and grass hay, maize meal and 3 kg of a concentrate composed by 30% cracked whole soybean (WS) and 70% horse bean (HB), which provided 12.6 g/kg DM of LA. During the second period, (P2, from 97 to 152 days in milk), the experi- mental concentrate was 70/30 WS/HB that provided 25.4 g/kg DM of LA. During both periods CG fed a diet based on the same for- age than EG and a concentrate composed by maize meal, soybean meal, and cotton seeds (7.2 g/kg DM of LA). Individual milk sam- ples were weekly collected and data of milk FA composition were analysed by a repeated measures model. At the end of each peri- od, milk from each group was separately processed and six Mozzarella cheese for group were sampled. During P1, LA con- tent of milk from EG was significantly higher than milk from CG (1.85 vs. 1.52% of TL), whereas CLA and vaccenic acid (VA) con- tent did not differ between groups. During P2, the LA content in EG milk was more than two times higher than that in CG milk (3.91 vs. 1.59% of TL). Also CLA (0.59% of TL vs. 0.38% of TL for EG and GC respectively) and VA (1.67%of TL vs. 1.25% of TL for EG and CG, respectively) milk content significantly differed between groups. Oleic acid (OA) content significantly differed between treatments, being higher in milk from EG (+17%). Interestingly, differences were observed also in the substrate/product ratio related to stearoil-CoA desaturase enzyme (SCD). This enzyme acts either on C18:0, that is con- verted in OA, and on C14:0, C16:0 and VA, which are converted in cis9 unsaturated FA. Results suggested a higher affinity of SCD for C18:0. The desaturation index of C18:0, in fact, was more than ten times higher than that of other substrates. The FA com- position of mozzarella reflected that observed in milk, confirm- ing that cheesemaking did not affect the transfer of FA from milk to cheese
Investigating mutual relationship among milk fatty acids by multivariate factor analysis in dairy cows
No full textThe interpretation of mutual relationship among milk fatty acids (FA) is not easy due to the high number of FA contained in milk fat and to the high degree of correlation among them. Multivariate analysis includes different statistical approaches that could help explaining complex pattern of variables. In this study, Multivariate Factor Analysis (MFA) was used to decompose the correlation matrix of 47 FA and milk production traits (milk yield and protein and fat content) measured in 300 Italian Holstein Friesian cows reared in the North of Italy in 23 commercial dairy farms, representative of the intensive dairy system. MFA was able to extract seven latent factors with specific biologic meaning: secretion of Long Chain FA (KLCFA), mammary FA de novo synthesis (Km), rumen biohydrogenation (Kbh), synthesis of odd chain FA (Ko), synthesis of branched chain FA (Kb), mammary desaturation activity (Kd), milk yield (Kmy). According to the pattern of communalities of the factor analysis, C18:3c9c12c15 was the only FA, along with C18:2t11c15, to be uncorrelated with the other variables and it seemed to be excluded by the metabolic pattern described by the seven factors. The desaturation products of the SCD enzyme were independently associated to three latent factors, suggesting new insights in the regulation of SCD activity. Factors were considered as new quantitative phenotypes related to prominent features of milk FA profile. With the aim of evaluating the feeding regimen and animal effects, latent factors were analysed with a mixed model, which considered the fixed effect of lactation stage, parity, some feeding regimen characteristics and the random effect of bull. Lactation stage significantly affected Km and Kmy factors. In perspective, the seven factors extracted by applying MFA analysis to milk FA composition could be considered as new and more informative traits to test the effect of endogenous and exogenous variation factors
Assessment of blood and productive parameters in mid-lactation dairy cows fed different diets: replacement of corn silage with triticale silage
Full text linkCorn crops require large amounts of resources that affect the environmental sustainability of dairy cow farming systems. The aim of the study was thus to investigate the effects of the replacement of corn silage (CS) with triticale silage (TS) by evaluating blood and productive parameters. The study lasted 7 weeks and involved two groups of 20 Italian Holstein Friesian dairy cows that were homogeneous in terms of parity ( [Formula: see text] ), days in milk (DIM) ( [Formula: see text] ), and daily milk production ( [Formula: see text] kg). Chemical analysis of feeds was carried out weekly. Dry-matter intake was estimated daily. At the beginning and end of the trial, haematological, metabolic, and immunological parameters were analysed. At the same, time body weight and body condition score were measured. Milk characteristics were also analysed weekly. Statistical analysis was performed by ANOVA on data of the second sampling, and a non-parametric test was performed to analyse BCS. Regarding the haematological parameters in the two groups, only lymphocyte values were not in the normal range (2.86 and [Formula: see text] L for CS and TS, respectively). Metabolic parameters were in the normal range except for blood ureic nitrogen (BUN; 13.65 and 14.04 [Formula: see text] ), non-esterified fatty acids (NEFAs; 21.40 and 31.93 [Formula: see text] ), and Cl (91.99 and 93.50 [Formula: see text] ). Hair cortisol was low (0.94 and 0.91 [Formula: see text] ), indicating the absence of stress signs, as confirmed by the results of other immunological parameters (serum lysozyme (SL), bactericidal activity (SBA), haptoglobin (HP), and oxygen free radicals (OFRs)). Statistical differences were not found either for haematological or biochemical parameters. The total replacement of CS with TS did not affect milk yield and composition. In conclusion, the replacement of CS by TS did not give rise to significant modifications in the parameters investigated and did not alter the health status of the animals, thus suggesting the feasibility of its introduction into the diet of mid-lactation dairy cows
The content of cla and alpha-linolenic acid in sn-2 of ovine milk triglycerides as affected by dietary lipid supplementation
No full textIn the human intestine, lipids are adsorbed as Sn-2 monoglyc- erides (Sn-2), as effect of the pancreatic lipase action, which hydrolyzes the triglyceride on alpha-position (Sn1-3). Hence, the fatty acids esterified in Sn-2 are preferentially adsorbed. In a pre- vious research we obtained a significant enrichment in Conjugated Linoleic Acid (CLA) and alpha-linolenic acid (ALA) of milk and cheese from sheep fed a diet supplemented with lin- seed. The aim of the present work was to study the triglyceride (TG) composition of the milk of the mentioned study, in order to evaluate the selectivity of CLA and ALA for the Sn-2 position on TG. Sn-2 monoglycerides were obtained by reacting the milk total lipids (TL) from 24 sheep fed with control diet (C) and 24 sheep fed with a diet containing 200 g/die of extruded linseed (L) with swine pancreatic lipase, separated by thin layer chromatography (TLC). The selectivity of individual fatty acids for the Sn-2 posi- tion was evaluated by means of a selectivity index (SI) calculated as FA(Sn-2)/FA(TG); where SI1 in Sn-2. As regard the fatty acid composition of triglycerides, L compared to C, showed a sig- nificant higher content of both ALA and CLA: +45% and +75% respectively (P<0.001). Regarding to the beta-position of TG, ALA was 1.1 g/100g of TL in C and 2.2 g/100 of TL in L (P<0.001), andCLAwas1.2g/100gofTLinCand3.5g/100gofTLinL (P<0.001). As a consequence, in the milk from L group, the con- tent of ALA and CLA increased by 100% and 191%, respectively, than in the milk from C group. These results seemed to indicate a preferential esterification of ALA and CLA in the beta-position of milk triglycerides, probably as a consequence of changes in selectivity of acyl-transferase enzyme (LPAAT). In particular, as regard CLA content, the affinity of LPAAT was inverted: in fact, in C milk, CLA was preferentially esterified in the alpha-position (SI=0.56), while in L milk the SI was higher than 2, suggesting a preferential esterification in the beta position
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