Stefano Rapaccini

Sorghum grain in poultry feeding.

The authors review the main studies of the last 30 years concerning the chemical and nutritional features of sorghum grain. They describe the problems related to the tannins which lower to various ...

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.

Evolution of chemical composition, somatic cell count and renneting properties of the milk of Massese ewes

Abstract The experiment was carried out on 52 lactations of 37 multiparous Massese ewes. Because of the mating practice of the breed, three types of lactation were detected: Type 1, a short lactation initiated in autumn; Type 2, a short lactation initiated in spring, following the Type 1 lactation; Type 3, a long lactation initiated in autumn. Milk yield was recorded weekly, starting not before the eighth day from lambing. On a total 984 milk samples, contents of fat, protein, casein and lactose, SCC, pH and clotting parameters (R, K20 and A30) were determined. Data were analysed by a mixed model including lactation order, lactation type, DIM, and individual lactation as random effects. Protein and casein content increased from the second to fifth lactation; the highest fat content was detected in the sixth lactation and over; milk of fourth lactation had higher SCC and worse renneting properties than that of second lactation. The pattern of evolution of parameters within the three types of lactation showed that the increase of nutrients with DIM was particularly noticeable for fat content in the Type 2 lactation (spring/short) which exhibited, at an average of 94 DIM, 1.5 percentage units above the other two types. Evolution of lactodynamographic parameters indicates that generally there was a substantial improvement in cheese-making suitability during the first 2–3 months postpartum, and a worsening thereafter. The Type 2 lactation yielded milk with better renneting properties, particularly with respect to milk obtained during the same season from ewes that had an autumn delivery. This suggested that the newly started milk from the spring lactation could have a corrective effect on the total amount of bulk milk produced, a possible advantage for the Massese breed, which is characterised by a particularly pronounced deseasonalisation of lambings.

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.

Effect of Quebracho tannin extract on soybean and linseed oil biohydrogenation by solid associated bacteria: an in vitro study

An in vitro trial was carried out to study the effects of Quebracho tannins extract (QE) on fatty acid profile of rumen solid adherent bacteria (SAB) during the fermentation of diets supplemented with soybean or linseed oil, as sources of linoleic (LA; 18:2 n-6) and α-linolenic acid (α-LNA; 18:3 n-3), respectively. Two control diets were prepared using a basal mixture of grass hay [760 g/kg on dry matter (DM)], soybean meal (55 g/kg DM), barley meal (130 g/kg DM), vitamin mineral premix (20 g/kg DM) and 35 g/kg DM of soybean (SOC diet) or linseed oil (LOC diet) as lipid supplement. Other two diets (SOCT and LOCT) were obtained by integrating SOC and LOC with QE (49 g/kg DM). The results confirmed that Quebracho tannins may be an effective method for reducing in SAB the biohydrogenation of LA (17.3 vs 34.5 g/100 g of fatty acid in SOC and SOCT, respectively) and LNA (10.7 vs 21.4 g/100 g of fatty acid in LOC and LOCT, respectively), but not for increasing the rumen accumulation of cis9, trans11 18:2 (0.77 vs 0.32 g/100 g of fatty acid in SOC and SOCT, respec tively; 0.51 vs 0.43 g/100 g of fatty acid in LOC and LOCT, respectively) and trans11 18:1 (6.15 vs 3.64 g/100 g of fatty acid in SOC and SOCT, respectively; 5.53 vs 4.47 g/100 g of fatty acid in LOC and LOCT, respectively).

Effect of oleic and conjugated linoleic acid in the diet of broiler chickens on the live growth performances, carcass traits and meat fatty acid profile

Abstract Olive oil and CLA enriched olive oil were compared with each other in a growth trial with broiler chickens, as energy supplements to the diet. A commercial CLA blend was used at the level of 1 kg per 100 kg mixed integrated feed. Two hundred and forty commercial hybrid broilers (Ross 308) were randomly subdivided and allotted to 8 pens of 30 birds each. Four pens of birds were fed the olive oil diet and considered the control group; the other 4 pens were fed the olive oil supplemented with CLA and considered the treated group. The experiment lasted 47 days. The live performance of the treated birds resulted different from the performance of the control ones: the final body weight was slightly lighter (2.544 kg vs 2.639 kg; P≤0.05) with a lower feed intake (4.886 kg feed vs 4.998 kg, P≤0.05) and, of course, an almost perfectly overlapping feed/gain ratio (1.90 vs 1.91). The fatty acid composition of the breast fat of the CLA treated birds resulted enriched by the two major CLA isomers, trans 10 cis 12 and cis 9 trans 11, whereas oleic acid and the linoleic, linolenic and arachidonic polyunsaturated acids showed a decrease (P≤0.05). CLA appears a recommendable ingredient in the diets of broilers as it improves the beneficial characteristics of poultry meat.

Changes in conjugated linoleic acid and C18:1 isomers profile during the ripening of Pecorino Toscano cheese produced with raw milk

The aim of the present study was to investigate the evolution of the fatty acid profile, with particular attention to conjugated linoleic acid (CLA) and to C18:1 isomers, during ripening of sheep cheese (Pecorino Toscano cheese) produced with raw milk. After 60 days of ripening the total concentration of C18:1 isomers and that of CLA pool content decreased. In particular, if isomers profile is considered, the percentage of trans11 C18:1, trans10 C18:1 and cis9, trans11 CLA decreased as consequence of biohydrogenation or of double bonds isomerisation, while the concentration of trans10, cis12 CLA increased.

Effect of three species of herbage (Medicago sativa, Lolium multiflorum, Avena sativa) on in vitro ruminal production of conjugated linoleic and vaccenic acids

Abstract Little information is available about the effect of different forage species on the rumen biohydrogenation process. The aim of the present work is to compare the in vitro production of CLA and C18:1 isomers after incubation of three different herbage species in rumen liquor from sheep. Pasture herbage samples of lucerne (Medicago sativa; MS), ryegrass (Lolium multiflorum; LM) and oats (Avena sativa; AS) were submitted to in vitro fermentation with sheep rumen inoculum. Samples were collected at 2, 4, 6 and 8 hours of fermentation. The fatty acid profile of MS was characterised by 11.62 (g/100 g of lipid extract) of linoleic acid (LA) and 27.08 (g/100 g of lipid extract) of α-linolenic acid (LNA), whereas LA in the other two herbages was 6.60 (g/100 g of lipid extract) and 6.95 (g/100 g of lipid extract) in AS and LM, respectively; LNA was 52.20 (g/100 g of lipid extract) and 54.49 (g/100 g of lipid extract) in AS and LM, respectively. The crude fat content of botanical species was respectively 11.90 (g/100g DM) for AS, and 15.77 (g/100g DM) for LM and 26.17 (g/100g DM) for MS. Rumenic acid (RA, cis-9, trans-11 CLA) was the predominant CLA isomer and the maximum yield was attained with AS after 6 hours of fermentation (0.81 g/100 g of lipid extract); RA concentration remained quite low with the other two herbages. The concentration of the other isomer (trans-10, cis-12 CLA) was always very low; the maximum yield (0.09 g/100 g of lipid extract) was reached after 6 hours with AS. The maximum yield of vaccenic acid (VA, trans-11 C18:1) was reached after 8 hours with MS (2.64 g/100 g of lipid extract). This herbage also produced the highest amount of trans-10 C18:1 at 6 and 8 hours (0.17 g/100 g of lipid extract). AS appeared to have induced the highest amounts of RA relative to the other two forages. The differences in conjugated dienes and C18:1 isomers content during fermentation could be due not only to different amounts of LA or LNA in the herbage, but also to different releasing times of FA from the plant substrate.

Quality of lipid fraction in Tuscan sheep cheese (Pecorino Toscano DOP)

Abstract Bulk milk from dairy ewes of North Tuscany was sampled and analyzed for the fatty acids profile. Cheese was then made out of milk, pasteurized and fortified with Lactobacilli. The same analysis was performed on the lipid fraction of samples of the freshly made cheese and of samples of the same cheese, but ripened for different times: 30, 60, 90, 120 days of ageing. As a result, cheese making did not affect the acidic composition of the lipid fraction of the original milk and, furthermore, ageing up to 120 days had no important effect on the same composition. It is confirmed that Pecorino cheese is a sound, healthy, functional food.