Survey on conjugated linoleic acid (CLA) content and fatty acid composition of Grana Padano cheese produced in different seasons and areas

A study was carried out to determine the content of conjugated linoleic acid (CLA) and fatty acid composition of Grana Padano P.D.O. (Protected Designation of Origin) Italian cheese. Samples were obtained from spring and summer cow’s milk in different areas of Grana Padano production district and from all present dairies. In particular, 253 samples of lowland-hill Grana Padano (LH-GP) were analysed: 137 produced from spring milk, and 116 from summer milk. Forty-three mountain Grana Padano (M-GP) samples were also analysed: 25 obtained from spring milk, and 18 from summer milk. The results were subjected to statistical analysis; a factorial arrangement was used, and the fixed effects in the model included season, the manufacturing area of the Grana Padano cheese, and the first order interaction (season x area). Further, cheese β-carotene concentration was measured in a representative number of summer samples (32), selected according to the CLA level (9 with CLA concentration 7 mg/g total fat), in order to investigate the correlation between CLA content and β-carotene concentration. M-GP had higher levels of CLA, vaccenic (TVA) and α-linolenic (LNA) acid than LH-GP. CLA concentrations increased from spring to summer both in M-GP and LH-GP. This rise was greater in M-GP showing an effect of interaction between season and production area (P<0.001). An effect of first order interaction (P<0.001) was also seen for TVA with values increasing from spring to summer in M-GP, whereas there only was an effect of the manufacturing area on LNA. During summer, M-GP had the highest polyunsaturated fatty acids (PUFA) percentage. An increase in PUFA from spring to summer was observed only in M-GP (first order interaction, P<0.001). The saturated fatty acids (SFA) decreased from spring to summer both in LH-GP and M-GP and with major entity in M-GP (first order interaction, P<0.001). The β-carotene concentration resulted positively correlated with CLA level (r=0.92; P<0.01) in summer cheese. The present results underline the role of mountain cheese obtained from summer milk as a natural source of CLA and beneficial fatty acids for human health

Reduction of Carryover of Aflatoxin from Cow Feed to Milk by Addition of Activated Carbons.

According to a double-reversal experimental design on 12 late-lactation Friesian cows the effect of two activated carbons (ACs) (CAC1 and CAC2) and a hydrated sodium calcium aluminosilicate (HSCAS) on carryover of aflatoxin B1 (AFB1) from feed to aflatoxin M1 (AFM1) in milk was determined. Cows were fed a basal diet containing AFB1 naturally contaminated corn meal and copra, During week 1 cows were fed diets containing AFB1 alone (11.28 μg of AFB1/kg of feed); in week 2 the diets contained AFB1 plus 2.0% sorbent; and in week 3 the diets again contained AFB1 alone (13.43 μg of AFB1/kg of feed). ACs reduced the analytical content of AFB1 in the pelleted feed by from 40.6% to 73.6%, whereas reduction by HSCAS was 59.2%, The AFM1 concentrations in milk in weeks 1 and 3 were higher than that in week 2, Decreases in the AFM1 excreted in the milk by addition to feed of 2% of the sorbents ranged from 22% to 45%. CAC1 and HSCAS were significantly different from each other in reducing the AFM1concentration in milk (45.3% versus 32.5%); these reductions were significantly higher than that of CAC2 (22.0%). Carryover reduction by addition of CAC1 (50%) was significantly higher than that of HSCAS (36%). Addition of 2% CAC2 did not allow pelleting of feed because of the caking action of this carbon, The lower performance of CAC2 could be related to the unsuccessful pelleting. The addition of ACs did not influence feed intake, milk production, milk composition, or body weight. Our results suggest that ACs, high-affinity sorbents for AFB1 in vitro, are efficacious in reducing AFB1 carryover from cow feed to milk. Further in vivo investigations should establish lower amounts of ACs which can be efficacious

Effect of insertion of Bt gene in corn and different fumonisin content on growth performance of weaned piglets

The objective of this study was to compare the effect of Bt corn and isogenic corn on the growth of weaned piglets. One hundred twenty-eight weaned piglets weighing 8.8 ±1.27 kg live weight were randomly assigned to 4 groups of 32 animals each (16 castrated males and 16 females). Bt corn (line MON810) and isogenic corn were produced at two farms located in the Lodi and Venezia provinces (northern Italy). Bt corn had the same chemical composition as the isogenic corn but a lower content of fumonisin B1 (FB1). The experimental period (35 days) was divided into two phases: 0-14 d and 15-35 d. There was no significant difference in average daily gain (ADG) among groups during the first feeding phase. Compared to animals fed isogenic corn, the piglets fed Bt maize gained more weight during the second feeding phase (Bt: 464.1 g/d, isogenic: 429.1 g/d; P < 0.05). Also, the ADG over the entire trial was higher in piglets fed Bt corn versus piglets fed isogenic corn (Bt: 396.4 g/d, isogenic: 374.1 g/d; P < 0.05). The ADG of the whole period decreased linearly (P<0.05) with respect to FB1 content of diet. Final weight was higher in piglets fed the diet containing Bt corn (Bt: 22.68 kg, isogenic: 21.83 kg; P < 0.05). No differences in feed intake and in the feed:gain ratio were observed, however a linear response between FB1 and feed:gain ratio in first 14 days of the experiment was detected

Iodine carry over in dairy cows: effects of levels of diet fortification and milk yield

Thirty multiparous lactating cows were divided in three groups based on milk yield: high (H), average (A) and low (L). Within each group, cows were randomly allotted to two levels of iodine inclusions into the diet and respectively: level 1 (1): base diet containing 1.55 mg/kg dry matter, level 2 (2): base diet plus 47.2 mg/d. Potassium iodide was used. Feeds, orts, drinking water and individual milk samples were collected and analysed for the iodine content. The iodine concentration and total excretion in milk were affected by the level of iodine supplementation (P<0.05). No effect on milk iodine concentration could be addressed either to the level of milk yield or to the milk yield x treatment interaction. The total amount of iodine excretion and carry over were affected (P<0.05) by the level of milk yield

Effects of a glucooligosaccharide supplement on the morphological characteristics of the gastro-intestinal tract and growth performance in weaned piglets

This study was designed to evaluate the effects of a gluco-oligosaccharide (GOS), as an alternative to growth promoters in piglets, on: growth performance, blood parameters and morphological characteristics of the intestinal tract. Four week old weaned piglets (n=128) (7.2 ± 1.04 kg l.w.) were divided into four groups and fed for 77 days on different diets as follows: 1.- Basal diet (CTR); 2.- Basal diet supplemented with a 2% GOS; 3.- Basal diet supplemented with chlortetracycline and spiramicine at 1000 and 400 mg/ kg, respectively, for 14 days and then fed the CTR basal diet (CTRM); or 4.-a GOS diet supplemented and administered as in group 3 (GOSM). Animals were individually weighed 5 times, on days 0, 14, 35, 56 and 77. At the same time, the feed intake and average daily gains (ADG) were recorded and the feed conversion ratio (FCR) was calculated. On days 0 and 77, plasma was sampled from 6 piglets/treatment group, whereas on 77th day, 4 piglets/treatment were slaughtered to assess the morphological characteristics of parts of their gastro-intestinal tracts (ileum and caecum). The results showed no effects of the medications on the ADG in all the experimental periods. However, from days 57 to 77 of the trial period, the ADG was found to be higher in the GOS-fed animals (P=0.0747). During the first 14 days of the trial, the piglets on the medicated diets showed a higher intake than the animals in the normal diet groups, but no differences were detectable in the FCR. The globulin concentration and the albumin/globulin ratio was found to be reduced by GOS treatment (P <0.01). The urea concentration in the blood was decreased (P<0.05), whereas the plasma concentration of phosphorous was increased (P<0.01), by GOS supplementation. We found that the heights of the villi in the ileum was higher in the piglets on the GOSM diet compared to CTRM diet: (188.66 mm vs 255.74 mm; P<0.01). We also observed that supplementing these diets with GOS lead to a higher caecum epithelial cell height (11.7 μm vs 14.7 μm; P 0.068) compared with animals on the non-supplemented diets. Our current data indicate that the growth performance did not differ between piglets fed on control, antibiotic- supplemented or GOS-supplemented diets. A dietary supplementation of GOS does increase the villus length, but only in animals previously fed with medicated feeds. The use of GOS seems to exert anti-inflammatory effects upon these animals

Monitoring of the declining trend of Polychlorobifenyls concentration in milk of contaminated dairy cows

Six pregnant heifers, coming from a herd with a history of high concentration of polychlorobifenyls (PCB) into the milk, were fed with a very low-PCB diet starting from the 6th month of pregnancy. After parturition cows were milked for at least 190 d with a maximum of 270 d. Diet was made of: corn silage (31.7% of DMI), dehydrated alfalfa (13.3% of DMI), grass hay (3.7% of DMI) and concentrate (51.3% of DMI). The average DMI was 23.12 kg/d. Milk production was recorded and samples of milk and blood were taken and analyzed for PCB (18, 28, 31, 52, 44, 101, 149, 118, 153, 138, 180 and 194 congeners) content using a GC-MS technique. The average milk yield (kg/d) of the 6 cows was 26.0, 22.5, 23.2, 24.5, 28.9, 29.3. The maximum PCB concentration of 100 ng/g of fat allowed by the Italian law was reached after 144-209 d of lactation. One animal after 204 days had a PCB concentration of 102 ng/g fat. If log10 of PCB concentration (ppb) in milk fat is regressed against days in milking (DIM) the following significant equation was obtained: log10 PCB (ng/g of milk fat)= 2.796 -0.00474 DIM; r2 0.72; P<0.01 The initial level of contamination is not the main factor affecting the time required in order for PCB to return to below the legal threshold of 100 ng/g fat, while daily milk yield significantly affects PCB excretion. Body condition and energy balance could be important factors affecting PCB excretion. In the presence of high contamination, about 6 months of lactation are required in order to obtain milk with a sufficiently low PCB content. Among the seven congeners considered by Italian legislation, PCB 101, PCB 118, PCB 138, PCB 153 constitute almost all the PCBs found in tissues and milk, with a much smaller presence of PCB 180, and the numbers of the congeners PCB 28 and PCB 52 are almost insignificant, probably because they accumulate little in the body. The congeners PCB 138 and PCB 153 are those most frequently found. For PCB 138 the liver is the principal organ of accumulation, while for PCB 153 we found equal accumulations in the liver, kidneys and tail, but a low presence in milk. The PCBs 118 and 138 are those most abundant in milks

Clinical mastitis in cows treated with sometribove (recombinant bovine somatotropin) and its relationship to milk yield.

Effect of sometribove (methionyl bovine somatotropin) on mastitis in 15 full lactation trials (914 cows) in Europe and the US and 70 short-term studies (2697 cows) in eight countries was investigated. In full lactation studies, sometribove (500 mg/2 wk) was given for 252 d, commencing 60 d postpartum. Although herds varied considerably, incidence of clinical mastitis within a herd was similar for cows receiving control and sometribove treatments. Relative risk analyses indicated no treatment effect, and percentage of mastitis during treatment was similar for control and sometribove groups. A positive linear relationship existed between peak milk yield and mastitis incidence (percentage of cows contracting mastitis or cases per 100 cow days); sometribove treatment did not alter this relationship. Increases in mastitis related to milk yield increase from sometribove or related to genetic selection were similar. When expressed per unit of milk, mastitis incidence declined slightly as milk yield increased; this relationship was not altered by sometribove. No effect on clinical mastitis was observed in 70 commercial herds utilizing sometribove for 84 d. However, effects were significant for stage of lactation and milk yield. Overall, studies represented a wide range of research and commercial situations demonstrating that sometribove had no effect on incidence of clinical mastitis during the lactation of treatment. Furthermore, sometribove did not alter typical relationships between milk yield or herd factors and incidence of clinical mastitis

Effects of yeast on dairy cow performance, ruminal fermentation, blood components, and milk manufacturing properties.

Effect of dietary yeast culture on milk production and composition, ruminal fermentation, blood parameters, and milk manufacturing properties of 24 midlactation Holstein-Friesian cows was determined in a 6-wk experiment. The control diet (DM) consisted of 30% corn silage, 22% alfalfa hay, and 48% concentrate. After a 2-wk preliminary period, cows were assigned in equal numbers to either 0 or 10 g/d of yeast culture for the remainder of the 4-wk study on the basis of age, DIM, and pretrial milk production. Production of milk (26.2 vs. 25.4 kg/d), FCM (23.6 vs. 21.6 kg/d), and milk fat (.90 vs. .78 kg/d) was increased significantly by dietary yeast culture. No differences were significant for milk composition. Molar proportion of acetate and acetate:propionate ratio in ruminal liquor tended to be higher in cows fed yeast culture. Total VFA concentration in ruminal fluid was not different between treatments. Manufacturing properties of milk and blood plasma components were not affected adversely by added dietary yeast culture

Antioxidant Responses Induced by PFAS Exposure in Freshwater Fish in the Veneto Region

In recent decades, the interest in PFAS has grown exponentially around the world, due to the toxic effects induced by these chemical compounds in humans, as well as in other animals and plants. However, current knowledge related to the antistress responses that organisms can express when exposed to these substances is still insufficient and, therefore, requires further investigation. The present study focuses on antioxidant responses in Squalius cephalus and Padogobius bonelli, exposed to significant levels of PFAS in an area of the Veneto Region subjected to a recent relevant pollution case. These two ubiquitous freshwater species were sampled in three rivers characterised by different concentrations of PFAS. Several biomarkers of oxidative stress were evaluated, and the results suggest that PFAS chronic exposure induces some physiological responses in the target species, at both cellular and tissue scales. The risk of oxidative stress seems to be kept under control by the antioxidant system by means of gene activation at the mitochondrial level. Moreover, the histological analysis suggests an interesting protective mechanism against damage to the protein component based on lipid vacuolisation

A comparative study of fatty acid composition and CLA concentration in commercial cheese

A total of 52 Italian and French commercial cheeses were analysed for fatty acid composition and conjugated linoleic acid (CLA) concentration. The cheeses were first grouped according to the ruminant species of the milk used inmanufacturing, then according to the following criteria: (1) cheeses obtained from milk of the same ruminant species but using different production technologies; (2) cheeses produced from milk of different ruminant species but through similar cheesemaking processes. Comparative studies of fatty acid composition and CLA levels in the different cheese classes were carried out. In our study, the arrangement of the ruminant species according to the increasing CLA concentration in cheese was: goat = cow < sheep. Sheep cheeses had the highest levels of CLA (9.86 mg/g fat), a-linolenic acid (0.75%) and trans-vaccenic acid (1.63%), and the lowest contents of linoleic acid (1.80%) and oleic acid (16.83%). The comparison of cheeses obtained from milk of the same ruminant species but through different production technologies reported statistically significant differences in the fatty acid profiles that could be due to a different degree of lipolysis in the cheeses compared. Nevertheless, statistically significant differences in CLA concentration were not found; this suggests that the factors involved in the cheesemaking process generally do not affect the CLA content in milk fat