Arianna Buccioni

Effect of kind of dietary fat on the quality of milk fat from Italian Friesian cows

Four diets, supplemented with different fats of vegetable origin, were compared in a 4×4 Latin square design with eight primiparous Italian Friesian cows (two cows per cell). The four fats were: toasted full fat soy bean in diet WS; toasted full fat linseed in diet WL; calcium soap of palm oil in diet PS; and calcium soap of olive oil in diet OS. Scope of the trial was to study the effect of the four different fat sources on milk yield and composition and on the quality of milk fat in terms of safety for the consumer health, with particular attention to trans fatty acids and to conjugated linoleic acid isomers (CLA). Diet OS induced the highest milk yield (P<0.05), while diet PS gave the fattest milk (P<0.05), and the highest milk content of both saturated and medium chain fatty acids (P<0.05). Saturated to unsaturated ratio of milk fat was decreased when cows were fed diet WS (P<0.05), while the ratio was increased with cows fed on diet PS (P<0.05). With a closely similar behaviour milk CLA content was enhanced with diet WS and strongly depressed (P<0.05) with diet PS. Diet OS increased total CLA as well, probably as a consequence of the bio-hydrogenation process of large amounts of oleic acid, transformed into trans isomers of C18:1, including vaccenic acids. Full fat soy bean promoted some milk fatty acids with beneficial effects on consumer health, but calcium soap of olive oil similarly improved the fatty acid profile of milk fat, while meeting the cows’ requirements as an energy supplement.

Genetic parameters for conjugated linoleic acid, selected milk fatty acids, and milk fatty acid unsaturation of Italian Holstein-Friesian cows.

The objective of this study was to estimate genetic parameters for conjugated linoleic acid (CLA) and other selected milk fatty acid (FA) content and for unsaturation ratios in the Italian Holstein Friesian population. Furthermore, the relationship of milk FA with milk fat and protein content was considered. One morning milk sample was collected from 990 Italian Holstein Friesian cows randomly sampled from 54 half-sib families, located in 34 commercial herds in the North-eastern part of Italy. Each sample was analyzed for milk percentages of fat and protein, and for single FA percentages (computed as FA weight as a proportion of total fat weight). Heritabilities were moderate for unsaturated FA, ranging from 0.14 for C16:1 to 0.19 for C14:1. Less than 10% of heritability was estimated for each saturated FA content. Heritability for index of desaturation, monounsaturated FA and CLA/trans-11 18:1 ratio were 0.15, 0.14, and 0.15, respectively. Standard errors of the heritability values ranged from 0.02 to 0.06. Genetic correlations were high and negative between C16:0 and C18:0, as well as between C14:0 and C18:0. Genetic correlations of index of desaturation were high and negative with C14:0 and C16:0 (-0.70 and -0.72, respectively), and close to zero (0.03) with C18:0. The genetic correlation of C16:0 with fat percentage was positive (0.74), implying that selection for fat percentage should result in a correlated increase of C16:0, whereas trans-11 C18:1 and cis-9, trans-11 C18:2 contents decreased with increasing fat percentage (-0.69 and -0.55, respectively). Genetic correlations of fat percentage with 14:1/14 and 16:1/16 ratios were positive, whereas genetic correlations of fat percentage with 18:1/18 and CLA/trans-11 18:1 ratios were negative. These results suggest that it is possible to change the milk FA composition by genetic selection, which offers opportunities to meet consumer demands regarding health aspects of milk and dairy products.

Butyric acid glycerides in the diet of broiler chickens: effects on gut histology and carcass composition

Abstract Aim of the study was to verify the effects of butyric acid glycerides, as a supplemental ingredient in the diet, on live performance of broiler chickens and on the morphology of their small intestine, since short chain fatty acids are known as selective protection factors against intestinal microbial parasites, potent growth promoters of the gut wall tissues, also in terms of immune modulation response. An experiment was carried out on 150 Ross 308 female chickens, allotted to 5 treatments, over a 35 d ays period: the control, with soybean oil as the energy supplement, and 4 treatments with increasing amounts (0.2, 0.35, 0.5, 1% mixed feed) of a mixture of butyric acid glycerides (mono-, di- and tri-glycerides). Treated animals showed a higher live weight at slaughtering (P<0.05) with a better feed conversion rate. The carcase characteristics were not influenced, but the small intestine wall resulted slightly modified with shorter villi, longer microvilli (P<0.01) and larger crypts depth in jejunum (P<0.01), only with lowest concentration of the supplement (0.2%). It is concluded that butyric acid glycerides are an efficient supplement to broilers’ diets, deserving particular attention as a possible alternative to antimicrobial drugs, which have been banned in Europe.

Effect of soybean oil supplementation on milk fatty acid composition from Saanen goats fed diets with different forage:concentrate ratios

Abstract Twelve lactating Saanen goats were randomly assigned to four experimental diets, which differed in terms of forage:concentrate ratio and soybean oil supplementation. A 4×4 Latin square design was used. On a dry matter (DM) basis, forage:concentrate ratios were 63:37 (‘high-forage’ diet) and 35:65 (‘low-forage’ diet/high beet pulp). These diets were given either with oil (100 g·d-1) or without. The inclusion of soybean oil in the diet resulted in a significant increase in milk yield (but with HF diet) and in milk fat yield and concentration (P<0.05). Milk protein content remained unchanged across the diets. Milk protein yield was, however, higher for the high-forage diet containing added oil (forage × oil interaction, P<0.05). Soybean oil in the diet modified the milk fatty acid composition, reducing the levels of medium-chain and saturated fatty acids and increasing the levels of C18:2 n-6 and conjugated linoleic acid (CLA). The addition of soybean oil to the diet resulted in a significant increase in rumenic acid (cis-9, trans-11 CLA) and vaccenic acid (trans-11 C18:1) content in the milk fat. Interactions between forage and oil resulted in a significant increase in rumenic acid and vaccenic acid in animals fed a high-forage plus oil diet, and in trans-10 C18:1and trans-10, cis-12 CLA in animals fed a low-forage plus oil diet, probably due to a shift in the rumen’s biohydrogenation of linoleic acid.

Conjugated Linoleic Acid (CLA) content of meat from three muscles of Massese suckling lambs slaughtered at different weights

Eighteen Massese male lambs, fed mainly maternal milk were slaughtered at 11, 14 and 17kg. Samples of Longissimus Dorsi (LD), Triceps Brachii (TB) and Semimembranosus (Sm) muscles were collected. Milk from the lambs dams was sampled weekly. Fatty acid composition of milk and meat was determined. TB was the fattest muscle, Sm the leanest one and LD showed an intermediate value of total lipids, while the weight at slaughter did not influence total intramuscular fat content in any muscle. Although slaughter weight slightly affected overall fatty acid composition of muscles, rumenic acid and total CLA content in TB and Sm, but not in LD, significantly increased with slaughter weight. As regard milk fatty acid composition, the contents of total CLA, RA and others minor CLA isomers decreased during the first four weeks after lambing and then increased at the last control (five weeks). The animals slaughtered at a live weight of 14 and 17kg showed a greater SCD enzyme activity (estimated by product/substrate ratio) and a higher rumen activity (estimated by means of branched chain and odd chain fatty acid content in meat) than animals slaughtered at 11kg. Cis-7, trans-9 CLA content significantly increased with the slaughter age in TB and SM, while trans-7, trans-9 CLA, only increased in TB, and cis-8, cis-10 CLA, only increased in SM. Further studies are needed in order to verify weather the different behaviour of RA in LD muscle may be due to differences in muscle metabolism or fatty acid utilisation.

Milk fatty acid composition, rumen microbial population, and animal performances in response to diets rich in linoleic acid supplemented with chestnut or quebracho tannins in dairy ewes

The aim of the study was to evaluate milk fatty acid (FA) profile, animal performance, and rumen microbial population in response to diets containing soybean oil supplemented or not with chestnut and quebracho tannins in dairy ewes. Eighteen Comisana ewes at 122±6 d in milking were allotted into 3 experimental groups. Diets were characterized by chopped grass hay administered ad libitum and by 800 g/head and day of 3 experimental concentrates containing 84.5 g of soybean oil/kg of dry matter (DM) and 52.8 g/kg of DM of bentonite (control diet), chestnut tannin extract (CHT diet), or quebracho tannin extract (QUE diet). The trial lasted 4 wk. Milk yield was recorded daily, and milk composition and blood parameters were analyzed weekly. At the end of the experiment, samples of rumen fluid were collected to analyze pH, volatile fatty acid profile, and the relative proportions of Butyrivibrio fibrisolvens and Butyrivibrio proteoclasticus in the rumen microbial population. Hepatic functionality, milk yield, and gross composition were not affected by tannin extracts, whereas milk FA composition was characterized by significant changes in the concentration of linoleic acid (CHT +2.77% and QUE +9.23%), vaccenic acid (CHT +7.07% and QUE +13.88%), rumenic acid (CHT -1.88% and QUE +24.24%), stearic acid (CHT + 8.71% and QUE -11.45%), and saturated fatty acids (CHT -0.47% and QUE -3.38%). These differences were probably due to the ability of condensed versus hydrolyzable tannins to interfere with rumen microbial metabolism, as indirectly confirmed by changes in the relative proportions of B. fibrisolvens and B. proteoclasticus populations and by changes in the molar proportions of volatile fatty acids. The effect of the CHT diet on the milk FA profile and microbial species considered in this trial was intermediate between that of QUE and the control diet, suggesting a differential effect of condensed and hydrolyzable tannins on rumen microbes. Compared with control animals, the presence of B. fibrisolvens increased about 3 times in ewes fed CHT and about 5 times in animals fed QUE. In contrast, the abundance of B. proteoclasticus decreased about 5- and 15-fold in rumen liquor of ewes fed CHT and QUE diets, respectively. The use of soybean oil and a practical dose of QUE or CHT extract in the diet of dairy ewes can be an efficient strategy to improve the nutritional quality of milk.

Upgrading the lipid fraction of foods of animal origin by dietary means: rumen activity and presence of trans fatty acids and CLA in milk and meat

Abstract The recent literature dealing with the effect of the diet on the quality of milk and meat fat is reviewed. Some aspects of the rumen metabolism of lipids are dealt with: lipolysis, bio-hydrogenation, synthesis of microbial fatty acids and inhibition mechanisms on fermentation. Firstly, the influence of forage is considered. Pasture is the best forage, better if high hill pasture, as compared to hay and silage: short chain fatty acids (SCFA) (shorter than C10) are increased, medium chain fatty acids (MCFA) (C12 through C16) are decreased, oleic (OA), linoleic (LA) and linolenic (LNA) acids are increased and so are the conjugated linoleic acid pool of isomers (CLA) and n-3 polyunsaturated fatty acids (n-3 PUFA). Secondly, the energy supplementation of diets with fats is looked at. Animal fats depress milk yield and SCFA, while OA is increased because of the enhanced activity of mammary ∆9 desaturase. Fish oil depresses milk yield as well, but promotes CLA and n-3 PUFA. If animal fats are protected against rumen bacteria, milk yield and milk fat depression are avoided. Vegetable fats are richer in unsaturated fatty acids (UFA), thus more susceptible to the rumen bio-hydrogenation. As calcium soaps or inside whole seeds, plant fats are protected and CLA is increased. CLA is an important component of fat. In ruminants it comes from the desaturation of vaccenic acid (VA) both in rumen and udder; and the yield of VA depends on the diet quality. In conclusion, simple directions are given on how to improve the quality of animal fat by dietary means, without affecting yield.

Production of bio-fuels (hydrogen and lipids) through a photofermentation process.

The purple non-sulfur photosynthetic bacteria Rhodopseudomonas palustris (strain 42OL) was investigated for a co-production of both bio-H(2) and biodiesel (lipids). The investigation was carried out using malic and glutamic acids in a fed-batch cultivation system under continuous irradiances of 36, 56, 75, 151, 320, 500, and 803 W m(-2). Boltzmanns sigmoidal regression model was used to determine growth kinetic parameters during hydrogen photoevolution. The upper limit of volumetric hydrogen photoevolution was 15.5 + or - 0.9 ml l(-1) h(-1). During the entire cultivation period (408 h), the highest average hydrogen production rate (HPR(av)) of 11.1 + or - 3.1 ml l(-1) h(-1) was achieved at an irradiance of 320 W m(-2). Biomasses stored at the end of each experimental set were analyzed in order to determine lipid content, which ranged from a minimum of 22 + or - 1% to a maximum of 39 + or - 2% of biomass dry weight.

Olive oil calcium soaps and rumen protected methionine in the diet of lactating ewes: effect on milk quality

Abstract Eight Massese ewes were fed 4 diets with alfalfa hay as the forage (73% on the DM basis): 1) control diet (C); 2) diet C supplemented with olive oil calcium soaps, 50 g/d (L); 3) diet C supplemented with protected methionine, 5 g/d (M) or 4) plus both soaps and methionine (ML); the experimenthal design was a 4x4 Latin square with 2 replicates per diet. During the experimental periods, lasting one week each, the ewes were milked twice daily (8:00 a.m. and 7:00 p.m.). Milk yield was not affected by diet quality, but milk fat percentage and 6.5% fat corrected milk yield were higher in diets L, M and ML with respect to diet C (P<0.05). Milk protein content was depressed and blood urea increased following the Ca soap diet alone or with protected methionine. Diet M worsened (P<0.05) Rennet clotting time (r) and curd firmness after 30 minutes (A30). Saturated fatty acids C10:0, C12:0, C14:0 and C16:0 were depressed in milk fat with the Ca soap supplemented diet, some of them significantly. C18:1 increased (P<0.05) with diet L only, whereas the association of Ca salts and methionine in diet ML significantly affected the linoleic acid and CLA content. It is concluded that the use of olive oil fatty acids as a protected fat source seems to improve the milk fatty acid characteristics towards a safer pattern, but the presence of this type of Ca salts in the diet appears to worsen the metabolic utilisation of amino acids.

Effect of chestnut and quebracho tannins on fatty acid profile in rumen liquid- and solid-associated bacteria: an in vitro study

Tannins are phenolic compounds that interfere with biohydrogenation (BH) of polyunsaturated fatty acids (FAs). The aim of the present in vitro study was to investigate the effects of two different sources of tannins on FA profiles of rumen bacteria, with particular reference to rumenic and vaccenic acid. A control diet (C; composed of 300 g/kg of wheat straw, 132 g/kg of soyabean meal, 96 g/kg of barley meal, 152 g/kg of maize meal, 300 g/kg of maize gluten and 20 g/kg of mineral vitamin premix, all expressed on dry matter (DM)) and four diets, obtained by adding to C two different types of tannins from chestnut (TC) and from quebracho (TQ) at two concentration levels (49 and 82 g/kg DM), were compared. The content of the main unsaturated FAs (C18:1 cis9, C18:1 trans11, C18:2 cis9, cis12 and C18:3 cis9, cis12, cis15) from solid-associated bacteria (SAB) and liquid-associated bacteria (LAB) was affected by the presence of tannins in the diets. In particular, C18:1 trans11 content was significantly increased, especially with TC1, whereas the decreasing of C18:1 cis9 was unaffected, regardless of the presence or the kind of tannins added to feeds. SAB contained higher amounts of intermediates of polyunsaturated FA BH (as C18:1 trans11 and C18:2 cis9, trans11) than LAB that were characterized by a higher amount of C18:0. In the concentration range adopted in this study, the effect of TC and TQ on changes of bacterial FA profile was comparable. Tannins seem to be a good means to modulate the FA profile of rumen bacteria, favouring the accumulation of C18:1 trans11 during in vitro rumen fermentation.