G. Battelli

Effect of maize, rumen-protected fat and whey permeate on energy utilisation and milk fat composition in lactating goats

Abstract The efficiency of utilisation of diets with different proportions of energy sources (starch, fat, lactose) was studied with three pairs of lactating Saanen goats; the animals were fed, in a Latin square design, 3 silage-based diets containing (on DM basis) the following energy sources: 32% maize meal (diet M); 4.7% rumen-protected fat (Megalac®) and 23.5% maize meal (diet F); 9.8% milk whey permeate powder and 22.3% maize meal (diet W). During each of the three experimental periods, 8 days of total collection balance trials were conducted during which goats were allocated for 72 h (three 24 h cycles) in open circuit respiration chambers to determine methane and heat production and, hence, the energy balance. Diet F, in comparison with diets M and W, significantly increased the milk fat content (4.13 vs 3.11 and 3.14%, P<0.001) and the 4%-FCM yield (3367 vs 2927 and 3055 g/d, P<0.01 and P<0.05, respectively), while no relevant changes were observed for milk protein content and yield. Energy digestibility was equal in diets F and W. Megalac® did not decrease fibre digestibility. The partition of the gross energy intake (EI) differed significantly between diets: diet M had lower DE (72.4 vs 74.3 and 74.3%; P<0.01) and ME (62.1 vs 64.7 and 63.5%; P<0.05) in comparison with diets F and W, respectively. Energy lost as methane was not significantly decreased by the inclusion of rumenprotected fat in the diet, although a trend for a reduction of methanogenesis was observed. Heat production determined by treatment F was lower in comparison with the other treatments. This difference was almost significant (P=0.056) when expressed as a percentage of the ME. Milk energy output increased significantly (+12%, P<0.001) by including fat in the diet, as compared with treatments M and W: 21.4 vs 19.1 and 19.0% of the EI. The net energy content of the protected fat was 27.94 MJ NEl/kg DM (+340% vs maize meal); its kl value resulted 0.77. The corresponding values for whey permeate were 7.76 MJ NEl/kg DM (-5% vs maize meal) and 0.50, respectively. Summarizing, the efficiency of energy utilization in diet M was significantly lower in comparison with the other two diets in terms of digestibility and metabolisability, while its NEl content was similar to that of diet W. On the other hand, diet F had a significantly higher ME (P<0.01) and NEl (P<0.05) as compared to the other two diets. Diet F greatly influenced the fatty acid composition of the milk fat with less short (-30%) and medium (-33%) chain fatty acids and more (+18%) long chain fatty acids. In conclusion, whey permeate and even more Megalac® can be successfully used as feed ingredients in the diet of highly productive lactating goats, but the economical convenience of their utilisation must be evaluated based on the market values of feedstuffs.

The evolution of chemical and microbiological properties of fresh goat milk cheese during its shelf life

This study investigated the changes in chemical and microbiological properties of fresh goat milk cheese stored in an open deck refrigerated display cabinet (6 ± 2°C) or in a dark cold room (4 ± 1°C). The effects of partial-vacuum packaging and fluorescent lighting were studied during the cheese shelf life (45 d) and 15 d after. Storage conditions did not affect the pH values (4.3), whereas a slight decrease in moisture (ca. 1%) and in water activity (<0.01 units) was recorded. Proteolysis monitored by Kjeldahl determination increased significantly during storage of all samples. The highest increase from 8.5 to 13.0% of soluble nitrogen (expressed as percentage of total nitrogen) was measured in cheese packaged in the presence of air and stored in a lighted cabinet. The proteolytic trend was also studied through capillary zone electrophoresis by monitoring the degradation of the main casein fractions and the formation of new peptides. In particular, 2 indices, based on peak area ratio of new-formed peptides and casein fractions were related to cheese age. Lipolysis, measured by solid-phase microextraction gas chromatography coupled to mass spectrometry of volatile fatty acids, was unaffected by air or light and did not proceed through storage. As expected, hexanal formed mainly in cheeses stored under light and packaged in air. Evaluation of sensorial quality, performed using a hedonic scale, showed significantly lower scores of cheeses kept under light compared with those kept in the dark, both at 45 and 60 d storage. Overall, the microbiological and chemical results suggested that the shelf life of soft goat milk cheese would be extended from 45 to 60 d. Such conclusion was supported also by the sensory quality evaluation.

Competition assays revealed Paenibacillus pasadenensis strain R16 as a novel antifungal agent

The development of new sustainable containment strategies of plant diseases is very important to guarantee food security while reducing the environmental impact of agriculture. Research of new biocontrol agents is a long and difficult process that involves several steps that start from the identification of possible candidates which, for example, show antibiotic activities, and ends with in field, large scale trials. In this study, the plant growth promoting potential and antifungal effect exerted by a novel, putative candidate biocontrol agent, strain R16, identified as Paenibacillus pasadenensis by sequence analysis of 16S rRNA and rpoB genes, against three important plant pathogenic fungi (Botrytis cinerea, Fusarium verticillioides, and Phomopsis viticola), were assessed. Biochemical assays to determine plant growth promoting potential gave negative results for siderophore production and phosphate solubilization, and positive results for ACC-deamination and IAA production. Further biochemical assays for endophytic lifestyle and antifungal activity gave positive results for catalase and chitinase activity, respectively. In vitro antagonism assays showed that strain R16 is effective against B. cinerea, reducing mycelial growth both in dual-culture and through volatile substances, characterized to be mostly composed by farnesol, and inhibiting conidia germination. Good antagonistic potential was also observed in vitro towards P. viticola, but not towards F. verticillioides. Moreover, in vivo assays confirmed the strain R16 activity reduced the infection rate on B. cinerea-inoculated berries. The obtained results firstly proved that P. pasadenesis strain R16 is a putative plant growth promoter and effective against phytopathogenic fungi. Further studies will be needed to investigate the possible application of this strain as a biocontrol agent.

Composition, proteolysis, and volatile profile of Strachitunt cheese.

Strachitunt, a blue-veined Italian cheese, received the Protected Designation of Origin (PDO) label in 2014. Its unique technological feature is represented by the dual-curd method of production. Strachitunt is produced from raw bovine milk with or without the inoculation of natural starter cultures of lactic acid bacteria, and the addition of secondary cultures of mold spores is not permitted by the product specification. Physico-chemical properties, proteolysis, and volatile profile of Strachitunt were investigated in 10 cheese samples (ripened for 75 d) made throughout spring 2015 and provided by the main cheese maker. Overall, composition parameters showed a large variability among samples. Cheese was characterized by an acid paste (pH 5.46) and a lower extent of proteolysis compared with other blue-veined varieties. The main chemical groups of volatile organic compounds were alcohols and esters, whereas ketones represented only a minor component. The erratic adventitious contamination by mold spores of the cheese milk, the unique dual-curd method of cheese-making, and the large time variability between the piercing time and the end of ripening could be highlighted as the main causes of both the distinctive analytical fingerprint and the scarce standardization of this blue-veined cheese.

Characterization of Alpine highland pastures located at different altitudes: forage evaluation, chemical composition, in vitro digestibility, fatty acid, and terpene contents

A survey was conducted over the summer of 2013 on two alpine pastures (P1 and P5), and three mountain pastures (P2, P3, and P4). The aim was to determine the botanical composition, pastoral value (PV), variation in chemical composition, gross energy, in vitro true digestibility (IVTD), in vitro indigestible neutral detergent fiber, fatty acid (FA), and terpene contents of pastures located at different altitudes. PV is highest in alpine pastures (25.7 and 26.9, for P1 and P5, respectively). Exploitation of pastures is intensive only for P1 and P2. Pastures differ in dry matter (DM), ash, crude protein, lipid, and gross energy content. Lignin content was significantly higher in P3 (125 g/kg DM), while in other pastures the variation in its average content (from 73 to 94 g/kg DM) was limited. All pastures had IVTD higher than 725 g/kg with the exception of P3 (659 g/kg). As far as FA content is concerned, in all pastures the most abundant were α-linolenic acid (from 495 to 583 g/kg of total FA) and linoleic acid (from 150 to 222 g/kg of total FA), while palmitic acid and oleic acid significantly differ among pastures. α-Pinene, β-pinene, and p-cymene were the most abundant terpenoids.

Multi-dimensional assessment and scoring system for dairy farms

Abstract The aim of the study is to develop a scoring system for dairy farms in order to give specific information about the product and production process of milk. The scoring system, based on a multi-dimensional approach, was developed on the basis of data collected in 29 Italian dairy farms and included different aspects. For the evaluation of animal welfare, a selection of indicators set up in the European Project® assessment protocol for cattle 2009 was used. Environmental sustainability of milk production was assessed by a cradle-to-farm-gate Life Cycle Assessment. Laboratory analyses were carried out on bulk tank milk to evaluate microbiological, nutritional and nutraceutical quality. Nineteen variables were selected and retained to define six quality aspects: animal welfare, environmental and economic sustainability of farms, microbiological, nutritional and nutraceutical quality of milk. Each farm was visited twice; each visit received, for each variable, a score between 1 and 3 based on the frequency distribution of that variable in the farm sample. The relation among farm characteristics and quality aspects showed the importance to maximise dairy efficiency to improve environmental and economic sustainability of the farms and the inclusion of hay in dairy cows’ ration to enhance the nutraceutical and nutritional quality of milk. The proposed multi-dimensional scoring system is a practical tool: for the farmer, to support decisions for improving the quality of the product and the productive process; for the dairy company, as a value-added opportunity; for the consumer, who receives detailed information about nutritional characteristics and production system of dairy products.