Maurizio Moschini

Carryover of aflatoxin from feed to milk in dairy cows with low or high somatic cell counts

Aflatoxin M1 (AFM1) residues in milk are regulated in many parts of the world and can cost dairy farmers significantly due to lost milk sales. Additionally, due to the carcinogenicity of this compound contaminated milk can be a major public health concern. Thirty-four lactating dairy cows were utilised to investigate the relationship between somatic cell counts (SCC), milk yield and conversion of dietary aflatoxin B1 (AFB1) into milk AFM1 (carryover (CO)). The AFM1 in milk increased as soon as the first milking after animal ingestion with a pattern of increment up to the observed plateau (between 7th and 12th days of AFB1 ingestion). There was a significant (P < 0.01) effect of the milk yield whereas no effect could be attributed to the SCC levels or to the milk yield × SCC interaction. Similarly, the main effect of milk yield was also observed (P < 0.01) on the total amount of AFM1 excreted during the ingestion period. Although the plasma concentration of gamma-glutamyl transferase was significantly affected by aflatoxin administration, levels of this liver enzyme were within the normal range for lactating dairy cows. The current data suggest that milk yield is the major factor affecting the total excretion of AFM1 and that SCC as an indicator of mammary gland permeability was not related to an increase in AFM1 CO.

Pea seeds (Pisum sativum), faba beans (Vicia faba var. minor) and lupin seeds (Lupinus albus var. multitalia) as protein sources in broiler diets: effect of extrusion on growth performance

Abstract The effect of extrusion of pea seeds (Pisum sativum) (PS), faba bean (Vicia faba, variety minor) (FB) and lupin seeds (Lupinus albus, variety multitalia) (LS) on broiler performance were evaluated. Four hundred sixty two 1d-old Ross male chicks, Marek vaccinated, were randomly assigned to seven dietary treatments (3 pens per treatment/22 birds per pen). Chicks were floor housed, ad libitum fed isocaloric and isonitrogenous diets and had free access to water. Artificial light was provided 10 h/d. The bulk of the base diet (control diet) was corn (48.8%, 53.7% and 57%), solvent-extracted soybean meal (42.8%, 37.3% and 33.4%), corn oil (4.4%, 5.2% and 6.3%), plus synthetic amino acids, minerals, trace minerals and vitamins, respectively for the 1-10d-old, 11-28d-old and 29 to 42d-old growing periods. The amounts of PS, FB and LS used on an as fed basis were: PS and extruded PS (EPS): 353 (1-10d-old), 356 (11-28d-old) and 350 (29-42d-old) g/kg; FB and extruded FB (EFB): 479 (1-10d-old), 497 (11-28d-old) and 500 (29-42d old) g/kg; LS and extruded LS (ELS): 360 (1-10d-old) and 300 (11-42d-old) g/kg. High levels of pea (350 g/kg) and faba bean (500 g/kg) did not show negative effects on body weight gain (BWG) and bird feed intake compared to control. Lupin at the 300 g/kg level reduced (P < 0.05) the BWG during the finishing period (22 to 42 d), however the effect disappeared over the whole experimental period (1-42 d) compared to the control group. The ELS group had a lower (P < 0.01) feed intake compared to the control group and to the LS group. The feed conversion rate (FCR) was similar among groups for the whole experimental period; however during the grower period the FCR was higher (P < 0.05) for the PS, FB and EFB groups compared to the control group. Birds consuming the PS diet had a reduced (P < 0.05) eviscerated carcass yield compared to the control group. The breast meat percent yield was higher (P < 0.01) for birds consuming the FB and EFB diets compared to the control group. There were no statistical differences in percent yield of the leg quarters and in blood parameters.

Aflatoxins absorption in the gastro-intestinal tract and in the vaginal mucosa in lactating dairy cows

Abstract The objective of the experiment was to monitor plasma levels of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2) and M1 (AFM1) in lactating dairy cows fed a single oral bolus with aflatoxin naturally contaminated corn meal (Trial 1). The possible aflatoxins (AFs) absorption through mucous membranes was also investigated using the vaginal mucosa (Trial 2). In trial 1, seven lactating Holstein dairy cows were given a single oral bolus of a naturally contaminated corn meal assuring an intake of 4.89 mg AFB1, 1.01 mg AFB2, 10.63 mg AFG1 and 0.89 mg AFG2. Blood samples were collected at 0 and 5, 10, 15, 20, 25, 30 minutes after treatment. In trial 2 an aflatoxin dosage similar to that of trial 1 was provided through vaginal implant to eight lactating Holstein dairy cows. Blood samples were collected at 0 and 15, 30, 60, 180, 360 minutes after treatment. Individual milk samples of six milkings, one before and five after treatment, were also collected. Plasma and milk samples were analysed by HPLC for AFB1, AFB2, AFG1, AFG2 and AFM1 contents. In trial 1 AFB1 in plasma peaked (33.6 ng/L) as soon as 20 minutes after treatment. The plasma AFM1 was already detectable at 5 minutes (10.4 ng/L) and peaked at 25 minutes (136.3 ng/L). In trial 2 only AFB1 and AFM1 were detectable in plasma, starting from the first sampling time (15 minutes), with values of 10.7 and 0.5 ng/L, respectively. The AFB1 peaked at 30 minutes (23.9 ng/L). The AFB1 excreted in milk as AFM1 had the highest concentration (203.0 ng/L) in the first milking after treatment and decreased close to the starting values after 36 hours from treatment. The prompt appearance of studied aflatoxins, and their metabolites, in plasma suggests absorption might also take place in mouth or oesophageal mucous membranes, before the rumen compartment. Results support the hypothesis that the cytochrome P450 oxidative system, which is present in these tissues and in leukocytes, could be involved in the conversion of the AFB1 in AFM1. The absorption of AFB1 through the vaginal mucosa confirms the passive diffusion as a probable mechanism for AFB1 absorption.

Raw Pea (Pisum sativum), raw Faba bean (Vicia faba var. minor) and raw Lupin (Lupinus albus var. multitalia) as alternative protein sources in broiler diets

Abstract The ban of the meat and bone meal for entering animal diets and the concern of transgenic feeds poses a challenge to animal nutritionists in Europe. The challenge is to find homegrown protein-rich feedstuffs, making sure no antinutritional factors are present which could interfere in the animals’ performance. The raw Pea (Pisum sativum) (RP), raw Faba bean (Vicia faba, variety minor) (RFb) and raw Lupin (Lupinus albus, variety multitalia) (RL) were evaluated as alternative protein sources into broiler diets. Six hundred thirty 1d-old Ross male chicks, Marek vaccinated, were randomly assigned to seven dietary treatments (5 pens per treatment/18 birds per pen). Chicks were floor housed, ad libitum fed isocaloric and isonitrogenous diets and had free access to water. Artificial light was provided 10 h/d. The bulk of the base diet (control diet) was corn (48.7%, 56.6% and 57%), solvent-extracted soybean meal (42.8%, 37.3% and 33.4%), corn oil (4.4%, 5.2% and 6.3%), plus synthetic amino acids, minerals, trace minerals and vitamins, respectively for the 1-10d-old, 11-28d-old and 29 to 42d-old growing periods. The RP, RFb and RL entered diets in substitution of the soybean and corn according to the cost optimization (P100, Fb100 and L100, respectively for RP, RFb and RL) and at half of the optimized quantity (RP50, RFb50 and RL50, respectively for RP, RFb and RL). The amount used as fed basis for the higher level of inclusion were: P100: 350 g/kg for all diets; Fb100: 480 g/kg (1-10d-old) and 500 g/kg (11-42d-old); L100: 360 g/kg (1-10d-old) and 300 g/kg (11-42d-old). The average daily gain (ADG) were lower (P < 0.05) in the RP group compared to the control group. Over the whole period of growth, the RFb group had similar ADG compared to the control group and for both levels of inclusion, whereas reduced (P < 0.05) ADG were observed in the RL100 group. Reduced (P < 0.05) ADG were also observed for the RFb100 and the RL100 groups when calculated over the first three weeks of growth. Birds performance was improved (P < 0.05) in the RL50 group. No effects were observed on dressing percentage and breast and leg quarter cuts. The RFb and RL could represent valuable protein feeds in broilers diet formulation.

Iodine and selenium carry over in milk and cheese in dairy cows: effect of diet supplementation and milk yield.

Iodine and selenium are essential trace elements involved in the regulation of thyroid metabolism and antioxidant status. Two experiments were undertaken on lactating cows to determine the milk concentrations of iodine and selenium, carry over (CO) in milk, the fraction in curdle portion and how milk yield affects the milk iodine and selenium concentrations and CO. Sources of elements were potassium iodide and sodium selenite. In Experiment 1, 12 cows were randomly allotted to three diet groups in a completely randomized design: control group (CTR) - total mixed ration (TMR) containing 1.71 and 0.08 mg/kg dry matter (DM); Group 1 (T1) - TMR plus 23.8 and 2.2 mg; Group 2 (T2) - TMR plus 45.5 and 4.3 mg, respectively, for iodine and selenium. In Experiment 2, 30 cows were allotted to three groups according to milk yield: high (H), average (A) and low (L). Within each group, cows were randomly assigned two levels of iodine and selenium: Level 1: TMR containing 1.55 and 0.15 mg/kg DM; Level 2: TMR plus 47.2 mg and 8.0 mg, respectively, iodine and selenium. In both experiments, individual milk samples were collected and analyzed for iodine and selenium contents. In Experiment 1, Grana Padano cheese was obtained at lab scale and the iodine and selenium fractions in the curd were measured. In Experiment 1, the iodine intake increased (P < 0.001) the concentration and total excretion in milk. The CO increased (P < 0.05) from 16 (CTR) to 27 (T1) and 26% (T2); the sampling time was significant (P < 0.05) with no interaction with treatments. Concentration of selenium in milk was increased (P < 0.05) by treatment and CO decreased (P < 0.01) from 26 (CTR) to 12 (T1) and 9% (T2). The iodine showed a mild enrichment factor in the curdle (about 1.7-fold), whereas selenium enriched five- to sevenfold. In Experiment 2, the level of iodine supplementation affected (P < 0.05) the concentration and total excretion in milk. No effects on milk iodine concentration were related to milk yield or milk yield × treatment interaction; however, the iodine excretion in milk was major (P < 0.05) in higher yielding groups. The iodine CO was affected (P < 0.05) by the milk yield in supplemented groups. The selenium milk concentration and excretion were affected (P < 0.01) by the milk yield, whereas the CO was affected (P < 0.05) by the milk yield and selenium supplementation. Results highlight the possibility of fortification with iodine in milk and selenium in cheese through animal feeding.

In vitro production of short-chain fatty acids from resistant starch by pig faecal inoculum

The need to improve the knowledge of fermentation processes within the digestive tract in pigs is growing, particularly for ingredients that may act as potential prebiotic sources, such as resistant starch (RS). A study (based on enzymatic digestion followed by in vitro fermentation) was conducted to investigate whether various sources of RS, obtained from eight native starches characterized by inherent heterogeneous starch chemistry and structure, can influence short-chain fatty acid (SCFA) concentrations and relative production kinetics. Total and individual SCFA productions were evaluated over time and up to 72 h of incubation. The in vitro hydrolysis of native starches allowed a classification from very high [≥ 650 g/kg dry matter (DM)] to low (<50 g/kg DM) RS amount. The total SCFA production was similar between ingredients, whereas acetate and butyrate molar ratios in the SCFA profile differed (from 0.48 to 0.56 and from 0.17 to 0.25, respectively; P < 0.05). Differences in fermentation kinetic parameters for total and individual SCFA productions were observed (P < 0.05). Considering the total SCFA production after 72 h of incubation, the time at which half of the maximum production has been reached (T 1/2), the maximum rate of production (R max) and its time of occurrence (T max) differed between ingredients (P < 0.05), with values ranging from 6.1 to 11.9 h, from 0.459 to 1.300 mmol/g DM incubated per hour and from 5.1 to 9.8 h, respectively. Overall, a similar trend was observed considering individual SCFA productions. In particular, T 1/2 ranged from 6.4 to 12.5 h, from 5.5 to 12.5 h and from 6.7 to 11.3 h for acetate, propionate and butyrate, respectively (P < 0.05). For R max, differences were obtained for propionate and butyrate productions (P < 0.05), whereas no difference was recorded for acetate. In summary, our findings indicated that both quantitative and qualitative production of SCFA and related kinetics were influenced by fermentation of RS obtained from native starches characterized by heterogeneous starch characteristics. Current findings are based on an in vitro approach, and thus require further in vivo validations.

Raw, extruded and expanded pea (Pisum sativum) in dairy cows diets

Abstract The objective of the study was to evaluate the nutritive value of raw, extruded or expanded peas relative to soybean meal in lactating dairy cows feeding. Twenty four Italian Holstein cows (8 primiparous and 16 pluriparous), 604 ± 109 kg body weight, 34.5 ± 2.5 kg/d milk yield, were randomly assigned to four dietary treatments in a 4x4 Latin square arrangement with periods of four weeks and washout period of seven days. Diets were fed ad libitum (5% orts). The bulk of the base diet on a dry matter basis was corn silage (31.2%), alfalfa hay (16.7%), grass hay (4.1%), protein supplement (10.3%), whole cotton seed (8.5%), corn and barley mix (24.9%), soybean meal (3.4%) and calcium soap (0.9%). The pea (2.5 kg/cow/day) partially replaced the soybean meal and totally replaced the barley meal of the base diet. The unprocessed or differently processed pea did not affect the dry matter intake. The extruded pea group had a 3.2% increase (P< 0.05) of the milk yield compared to the control group. When estimated as contrast analysis, the technological treatment (extruded or expanded) on peas did not modify the milk yield and composition. Among pea diets, animal fed the extruded pea had the higher (P< 0.05) milk protein content, although not different than that of the control group. The rumen acetate was reduced (P< 0.05) and the butyrate and valerate were increased (P< 0.05) in animals fed extruded pea compared to the control. No differences were observed among feeding groups on blood parameters except for the cholesterol level higher (P< 0.05) in animals fed the expanded pea diet. There were no effects of diets on milk rennet coagulation characteristics. Results support the partial substitution of soybean meal and the total substitution of barley meal with peas in diets for lactating cows with no negative effects on milk yield and composition.

Transfer of melamine from feed to milk and from milk to cheese and whey in lactating dairy cows fed single oral doses

A study was conducted to evaluate the excretion pattern, after a single oral dose, of melamine from feed into milk, and the subsequent transfer to cheese and whey. The transfer of cyanuric acid was also investigated. Twenty-four lactating Holstein cows were randomly allocated to 4 treatments and received single doses of melamine as follows: 0.05, 0.50, 5.00, and 50.00 g/cow for groups D1, D2, D3, and D4, respectively. Individual milk samples were collected for melamine and cyanuric acid analyses on d 1, 2, 3, 4, 5, and 7. Milk collected individually from the second milking after melamine ingestion was used to make cheese on a laboratory scale. Melamine and cyanuric acid were extracted using a solid-phase extraction cartridge, and analyses were carried out by liquid chromatography-mass spectrometry/mass spectrometry. Maximal melamine concentrations occurred between 6 and 18 h after treatment and increased with log dose (linear and quadratic), ranging from 0.019 to 35.105 mg/kg. More than 60% of the melamine that was transferred to the milk was observed within 30 h after melamine ingestion. Melamine was not detected (limit of detection was 0.002 mg/kg) in milk 5 d after treatment in group D1, and 7 d after treatment in groups D2, D3, and D4. Blood urea nitrogen was not influenced by melamine ingestion. During cheese making, melamine was transferred mainly to the whey fraction. Cyanuric acid was not detected in any of the samples (milk, cheese, or whey). The excretion pattern of melamine in milk and whey may represent a health concern when cows ingest more than 0.50 g of melamine/d. However, only at intake levels of 5 and 50 g/d did cheese exceed the limits as set forth by the European Union. The results confirmed that melamine contamination of milk and milk products may be related not only to direct contamination, but also to adulteration of animal feeds.

New assessment based on the use of principal factor analysis to investigate corn silage quality from nutritional traits, fermentation end products and mycotoxins

BACKGROUND A survey on 68 dairy farms was carried out to evaluate the ensiling procedures adopted to store corn silage. Samples from core, lateral and apical zones of the feed-out face of silos were analysed. A principal factor analysis (PFA) was carried out on the entire database (196 silage samples and 36 variables) and 11 principal factor components (PCs) were retained and interpreted. RESULTS Ensiling procedures influenced the area exposed to risk of air penetration. Cores had higher dry matter, starch and lactic acid content or lower pH, fibre, propionate and butyrate concentrations than peripheral samples (P < 0.05). The highest (P < 0.05) mycophenolic acid and roquefortina C concentrations were detected in lateral samples. Chemical and digestibility variables loaded on two PCs; four PCs were characterized by end-products associated with clostridia, heterolactic, homolactic and aerobic fermentations; two PCs were associated with mycotoxins, whereas three PCs explained ensiling procedures. CONCLUSION The main quality traits of corn silages differed throughout the entire silo face. Minimization of the area exposed to risk of air penetration represents the best strategy to preserve the nutritional value and safety of corn silages. PFA allowed a clusterization of original variables into 11 PCs, appearing able to discriminate well and poorly preserved corn silages.

Raw and extruded pea (Pisum sativum) and lupin (Lupinus albus var. Multitalia) seeds as protein sources in weaned piglets' diets: effect on growth rate and blood parameters

Abstract The 42 days trial was carried out using 140 piglets weaned at 28 days of age. The piglets were allocated according to weight and sex to the 5 dietary treatments with 7 replicates for each treatments (4 pens x 4 castrated males and 3 pens x 4 females). The piglets were fed according to the following experimental design: 1) control diet (CTR) with soybean meal (SBM) 44% c.p. as protein source; 2) CRT diets with 200 g/kg of raw pea (Pisum sativum) (RP); 3) CTR diet with 200 g/kg extruded pea (EP); 4) CRT diet with 170 g/kg raw lupin (Lupinus albus var. Multitalia) (RL); 5) CTR diet with 170 g/kg of extruded lupin (EL). During the trial, animals were weighed at 0 - 21 and 42 days from the start of the trial. Feed intake was monitored and feed conversion ratio was calculated for the periods 0-21 d and 22-42 d. At the end of the trial, blood samples were taken for 14 animals for each dietary treatment (2 animals per replicate) and analysed for total protein, urea and liver activity (ALT, AST and ALP parameters). Average daily weight gain and feed intake did not differ according to dietary treatments whereas during the total experimental period (0-42 d), feed conversion ratio was higher for EP vs CTR diet (2.35 vs 2.09, respectively; P <0.05). The growth rate for diets with extruded protein sources compared with diets containing the raw ingredients did not differ. Feed conversion ratio for the RP was numerically higher than for the EP (2.35 vs 2.16 and 2.76 vs 2.32, respectively during 22-42 d and 0-42 d periods). Blood parameters did not show significant difference among dietary treatments except for higher total protein for CTR diet vs RL diet, EL and RP (67.3 vs 62.2, 62.8 and 63.6 g/l, respectively; P<0.05) and urea that resulted the highest with CTR diet vs RL and RL (4.7 vs 3.7 and 3.8 mmol/l respectively; P<0.05).