Afro Quarantelli

Dry matter and nutritional losses during aerobic deterioration of corn and sorghum silages as influenced by different lactic acid bacteria inocula

The economic damage that results from aerobic deterioration of silage is a significant problem for farm profitability and feed quality. This paper quantifies the dry matter (DM) and nutritional losses that occur during the exposure of corn and sorghum silages to air over 14 d and assesses the possibility of enhancing the aerobic stability of silages through inoculation with lactic acid bacteria (LAB). The trial was carried out in Northern Italy on corn (50% milk line) and grain sorghum (early dough stage) silages. The crops were ensiled in 30-L jars, without a LAB inoculant (C), with a Lactobacillus plantarum inoculum (LP), and with a Lactobacillus buchneri inoculum (LB; theoretical rate of 1 × 10(6) cfu/g of fresh forage). The pre-ensiled material, the silage at silo opening, and the aerobically exposed silage were analyzed for DM content, fermentative profiles, yeast and mold count, starch, crude protein, ash, fiber components, 24-h and 48-h DM digestibility and neutral detergent fiber (NDF) degradability. The yield and nutrient analysis data of the corn and sorghum silages were used as input for Milk2006 to estimate the total digestible nutrients, net energy of lactation, and milk production per Mg of DM. The DM fermentation and respiration losses were also calculated. The inocula influenced the in vitro NDF digestibility at 24h, the net energy for lactation (NE(L)), and the predicted milk yield per megagram of DM, whereas the length of time of air exposure influenced DM digestibility at 24 and 48 h, the NE(L), and the predicted milk yield per megagram of DM in the corn silages. The inocula only influenced the milk yield per megagram of DM and the air exposure affected the DM digestibility at 24h, the NE(L), and the milk yield per megagram of DM in the sorghum silages. The milk yield, after 14 d of air exposure, decreased to 1,442, 1,418, and 1,277 kg/Mg of DM for C, LB, and LP corn silages, respectively, compared with an average value of 1,568 kg of silage at opening. In the sorghum silages, the milk yield, after 14 d of air exposure, decreased to 1,226, 1,278, and 1,250 kg/Mg of DM for C, LB, and LP, respectively. When the estimated milk yield per megagram of harvested DM of corn and sorghum silage were related to mold count, it was shown that the loss of potential milk production occurred when the mold count exceeded 4 log cfu/g of silage, and it was almost halved when the mold count reached values greater than 8 log cfu/g of silage. Inoculation with L. buchneri, at a rate of 1 × 10(6) cfu/g of fresh forage, enhanced the stability of the silage after exposure to air, and, consequently, contributed to maintaining the nutritional value of the harvested forage over time, for air exposure up to 7 d.

Cyclopropyl and ω-cyclohexyl fatty acids as quality markers of cow milk and cheese.

Content of cyclopropyl and ω-cyclohexyl fatty acids of microbial origin, respectively, from silage and rumen, was determined by GC-MS and confirmed by (1)H NMR in more than 200 milk samples from dairy cows fed with different forages. Cyclopropyl fatty acids (about 0.1% of milk fat) were detected for the first time in milk and they were present only in milk samples from cows fed with forages containing maize silage, which is not allowed to produce milk for some PDO cheeses as Parmigiano-Reggiano. Their determination can be proposed as a quality parameter of milk or feed and it can be useful especially to distinguish cheeses sold as Parmigiano Reggiano from others cheeses. The content of ω-cyclohexyl tridecanoic acid varied from 0.0% to 0.15% of milk fat, and it was higher in milk samples from cows fed with diets richer in cereal meals.

Relationships Among Early Lactation Milk Fat Depression, Cattle Productivity and Fatty Acid Composition on Intensive Dairy Farms in Northern Italy

An observational study was conducted on three northern Italy Holstein dairy herds to evaluate the impact of milk fat depression (MFD, defined as milk fat lower than 3.2) on milk production and fatty acids (FA) composition in order to investigate the practical consequences and the possible origin of this phenomenon. The diet composition and the individual milk production and composition, were monitored during the first six months of lactation. Two virtual groups were created in each farm on the basis of the milk fat levels observed during the first two months of lactation (higher or lower than 3.2). Individual milk samples were taken from 16 animals/group/farm for composition and fatty acid analysis. The diet of Farm A, characterized by the highest average prevalence of MFD (33.1%), showed the highest acidogenic attitude (high NFC, low NDF, low peNDF8). The milk fat level differed significantly per group over time in all farms. Cattle with MFD showed tendentially lower energy corrected milk output and greater concentrations of C12:0÷C15:0, C18:1trans 10, total polyunsaturated, total odd chain (OCFA), total n-6 as well as OCFA/branched chain fatty acids, and C18:1trans 10/C18:1trans 11 ratios. Farm A milk fat showed higher values of C12:0, C13:0, C14:0 and C15:0. It appears that MFD cattle are characterized by lower mammary energy output and a milk FA profile similar to cattle fed acidogenic diets, thus suggesting an alteration in the rumen fermentation patterns, as occurs in acidotic cattle.

Use of Penn State Particle Separator for the evaluation of total mixed rations typical of Parmigiano Reggiano cheese production area

Abstract An observational study was conducted on 18 dairy farms located in the area of Parmigiano Reggiano cheese production with the aim to supply some recommendations regarding the more efficient TMR physical form. The effects of TMR particle size distributions on digestion process and on dairy productivity were investigated. Lower particle size appeared to improve digestion process and resulted in increased DMI, milk yield, and milk casein level without affecting milk fat. Routinary TMR particle size measurement with PSPS could be a good practice to standardize TMR particle size distribution and to maximize DMI and dairy productivity.

Simplified HPLC-UV method for the determination of α-tocopherol in plasma

Abstract Vitamin E, known for its great nutritional importance, is normally included in animal diets as DL-α-tocopherol acetate. The authors propose a method that makes it possible to determine the concentration of vitamin E in plasma without saponification. This method enable to avoid aggressive treatments on the analyte and complex procedures; it detects vitamin E only in form of DL-α-tocopherol. Lipoproteins of analysed plasma were denaturised by methanol. Vitamin E was extracted by petroleum ether in presence of NaCl. The extract was dried by rotavapor at 45 °C, solubilized by methanol and injected in HPLC (C18 column, reversed phase). The quantitative determination was carried out by UV detector settled on 294 nm. Tests of repeatability inter-analysis and intra-analysis gave coefficient of variability (CV%) respectively of 1.64 and 2.41%. The mean recovery was 100%.

“In vivo” and “in vitro” degradability of diets for Parmigiano Reggiano cheese production

Abstract In vitro” Dry Matter (IVDMD) and fiber degradability (IVNDFD) dynamics were determined for Total Mixed Rations (TMR) typical of Parmigiano Reggiano cheese area. The same parameters were estimated on some of these ration also “in vivo” on a group of fresh cows. “In vivo” trial showed values of 62.21 and 44.82% for DMD and NDFD respectively, while average IVDMD was 67.48 and 74.33% at 24 and 48 hours respectively. At the same intervals IVNDFD was of 49.32 and 62.61%, indicating an high fiber digestibility of fresh cow. Based on the “in vitro” equations and the “in vivo” values, the ruminal retention time was estimated to be of about 21 hours for DMD and of 19 hours for NDFD.

Influence of Oregano Essential Oil (Oeo) on Prevalence and Oocyst Shedding Dynamics of Naturally Acquired Eimeria Spp. Infection in Replacement Dairy Heifers

Abstract The administration of oregano essential oil (OEO) was tested in a dairy farm (Piacenza, Italy) with a history of sporadic cases of clinical coccidiosis in order to evaluate its influence on infection prevalence and oocyst excretion pattern in calves and replacement dairy heifers. Animals were recruited at 1 month of age and allocated to two groups of 25 animals, experimental (E) and control (C). OEO was added at a concentration of 100 ppm to the feedstuff administered to group E. Prevalence of infection and the number of oocysts per gram of feces (OPG) was evaluated monthly from 30 days of life (d30) till d150, with one extra sampling at d45, for a total of 6 time points. No significant differences were observed regarding the prevalence of infection between the two groups (83% general prevalence, 93% in group E, 72% in group C) although slightly higher prevalence was seen for Eimeria bovis and Eimeria alabamensis in group C, while the opposite was seen for Eimeria zuernii. OEO addition to the diet did not have any effect on the course of coccidial infections in calves and replacement dairy heifers. Other variables, in particular data on growth and production, should likely be tested before ruling out the potential role of OEO, alone or in combination with other control measures, to reduce infection pressure and therefore to improve animal welfare and performance.

The effects of Silymarin on ovarian activity and productivity of laying hens

Abstract In a previous work we evaluated the effects of Silymarin, a natural antioxidant and hepatoprotective polyphenolic compound, on laying hens performances and health status. The aim of the present work was to further confirm the previous results and to investigate the effects of Silymarin on ovarian endocrine activity and productivity of laying hens as well as on egg traits. Eighteen laying hens were randomly allotted into 3 groups and observed for 20 weeks: control hens were fed control diet, while treated groups received supplementations of 200 (S200) and 400 (S400) ppm of Silymarin. S200 group showed improved eggs laying rate (+2.91%), feed conversion rate (-4.52%) and a significant (P<0.05) increase of dry matter content (+0.54%), total lipids (+0.72%) and total sterols (0.02%) of the eggs. Any significant difference was shown for Silymarin at the highest dose (400 mg/kg of feed). At the end of the trial the hens were sacrificed and hierarchical follicles were removed and cultured for 48h. Media were assayed for progesterone (P4) and estradiol-17 beta (E2). Average E2 production increased (P<0.05) from F5 (follicles with initial development) to F3 (follicles with intermediate development), then decreased (P<0.05) from F3 to F1 (pre-ovulatory follicles). Basal P4 production augmented (P<0.05) throughout all follicle growth. Both Silymarin treatment inhibited (P<0.05) steroidogenesis. Silymarin may act as an endocrine-modulating chemical affecting hen performances.

Effects of different levels of dietary biotin on the performance and bone structure of broilers

Abstract We evaluated the effects of different levels of biotin on broilers performances and bone growth. Biotin was added at concentrations of 100, 200, 300, 400, 500 μg/Kg to a corn and soybean diet for yellow skin broiler production during the whole production cycle. Biotin at dosages of 200, 300, 400 μg/Kg increased growth rate, and, regardless of dosage, feed conversion rate in the second and third period of growth. Femur and tibiotarsus volume was slightly reduced while the bone mineral content of the same bones showed an increase as a result of biotin supplementation. Any particular dose-response effect was recorded with regard to plasma mineral content and ALP activity.