Luigi Calamari

Effect of selenium source and dose on selenium status of mature horses.

This study was conducted to determine the effects of either dietary Se source or dose on the Se status of horses. Twenty-five mature horses were blocked by BW and randomly allocated to 1 of 5 dietary treatments that comprised the same basal diet that differed only in Se source or dose. Treatments were as follows: negative control (0.085 mg of Se/kg of DM), 3 different dietary concentrations of supplemental organic Se (Se yeast; 0.2, 0.3, and 0.4 mg of total Se/kg of DM), and positive control (0.3 mg of total Se/kg of DM) supplemented with Na selenite. Horses initially received the control diet (6 kg of grass hay and 3 kg of concentrate per horse daily) for 56 d to allow diet adaptation. After the period of diet adaptation, horses were offered their respective treatments for a continuous period of 112 d. Jugular venous blood samples were collected before the morning feed on d 0, 28, 56, 84, and 112. Whole blood and plasma were analyzed for total Se, glutathione peroxidase activity in whole blood (GPX-1) and plasma, and thyroid hormones (thyroxine and triiodothyronine) in plasma. The proportion of total Se as selenomethionine (SeMet) or selenocysteine in pooled whole blood and plasma samples was determined on d 0, 56, and 112. Data were analyzed as repeated measures. Total Se in blood and plasma and GPX-1 activity were greater in all supplemented horses (P < 0.001, except P < 0.01 for GPX-1 in horses supplemented with the least dose of Se yeast) with a linear dose effect of Se yeast for whole blood and plasma Se (P < 0.001) and a quadratic dose effect (P < 0.05) for whole blood GPX-1 activity. A plateau for total Se in plasma was achieved within 75 to 90 d, although this was not observed in blood total Se or GPX-1 activity. On d 84 and 112, horses supplemented with Se yeast showed greater total Se in blood (P < 0.05) compared with horses supplemented with Na selenite, and a source effect (P < 0.05) was observed in the relationship between total blood Se and GPX-1 activity. Selenocysteine (the predominant form of Se in whole blood and plasma) increased in all horses supplemented with Se. The SeMet content of whole blood and plasma increased in horses supplemented with Se yeast, but it was not observed in those supplemented with selenite. The rate of increase in SeMet over time was greater in whole blood (P < 0.05) and plasma (P = 0.10) with the Se yeast product. In conclusion, Se yeast was more effective than Na selenite in increasing total Se in blood, mainly as consequence of a greater increase of the proportion of Se comprised as SeMet, but it did not modify GPX-1 activity.

Rumination time around calving: An early signal to detect cows at greater risk of disease

The main objective of this experiment was to evaluate the use of rumination time (RT) during the peripartum period as a tool for early disease detection. The study was carried out in an experimental freestall barn and involved 23 Italian Friesian cows (9 primiparous and 14 multiparous). The RT was continuously recorded by using an automatic system (Hr-Tag, SCR Engineers Ltd., Netanya, Israel), and data were summarized in 2-h intervals. Blood samples were collected from 30 d before calving to 42 d in milk (DIM) to assess biochemical indicators related to energy, protein, and mineral metabolism, as well as markers of inflammation and some enzyme activities. The liver functionality index, which includes some negative acute-phase proteins and related parameters (albumin, cholesterol, and bilirubin), was used to evaluate the severity of inflammatory conditions occurring around calving. The cows were retrospectively categorized according to RT observed between 3 and 6 DIM into those with the lowest (L) and highest (H) RT. The average RT before calving (-20 to -2d) was 479 min/d (range 264 to 599), reached a minimum value at calving (30% of RT before calving), and was nearly stable after 15 DIM (on average 452 min/d). Milk yield in early lactation (on average 26.8 kg/d) was positively correlated with RT (r = 0.33). After calving, compared with H cows, the L cows had higher values of haptoglobin (0.61 and 0.34 g/L at 10 DIM in L and H, respectively) for a longer time, had a greater increase in total bilirubin (9.5 and 5.7 μmol/L at 5 DIM in L and H), had greater reductions of albumin (31.2 and 33.5 g/L at 10 DIM in L and H) and paraoxonase (54 and 76 U/ml at 10 DIM in L and H), and had a slower increase of total cholesterol (2.7 and 3.2 mmol/L at 20 DIM in L and H). Furthermore, a lower average value of liver functionality index was observed in L (-6.97) compared with H (-1.91) cows. These results suggest that severe inflammation around parturition is associated with a slower increase of RT after calving. Furthermore, more than 90% of the cows in the L group had clinical diseases in early lactation compared with 42% of the H cows. Overall, our results demonstrate the utility of monitoring RT around calving, and in particular during the first week of lactation, as a way to identify in a timely fashion those cows at a greater risk of developing a disease in early lactation.

Effect of summer season on milk protein fractions in Holstein cows

Milk characteristics are affected by heat stress, but very little information is available on changes of milk protein fractions and their relationship with cheesemaking properties of milk. The main objective of the study was to evaluate the effect of hot season on milk protein fractions and cheesemaking properties of milk for Grana Padano cheese production. The study was carried out in a dairy farm with a cheese factory for transforming the milk to Grana Padano cheese. The study was carried out from June 2012 to May 2013. Temperature and relative humidity of the inside barn were recorded daily during the study period using 8 electronic data loggers programmed to record every 30 min. Constant managerial conditions were maintained during the experimental periods. During the experimental period, feed and diet characteristics, milk yield, and milk characteristics were recorded in summer (from June 29 to July 27, 2012), winter (from January 25 to March 8, 2013), and spring (from May 17 to May 31, 2013). Milk yield was recorded and individual milk samples were taken from 25 cows selected in each season during the p.m. milking. Content of fat, proteins, caseins (CN), lactose and somatic cell count (SCC), titratable acidity, and milk rennet coagulation properties were determined on fresh samples. Milk protein fraction concentrations were determined by the sodium dodecyl sulfate-PAGE. Data were tested for nonnormality by the Shapiro-Wilk test. In case of nonnormality, parameters were normalized by log or exponential transformation. The data were analyzed with repeated measures ANOVA using a mixed model procedure. For all the main milk components (fat, protein, total solids, and solids-not-fat), the lowest values were observed in the summer and the greatest values were observed in the winter. Casein fractions, with the exception of γ-CN, showed the lowest values in the summer and the greatest values in the winter. The content of IgG and serum albumin was greater in summer than in the winter and spring. A mild effect of season was observed for milk SCC, with greater values in summer than in the winter and spring. A worsening of milk coagulation properties was observed in summer season. The alteration of cheesemaking properties during hot season seems strictly linked with changes of milk protein fractions mainly with the decrease of αS-CN and β-CN and the increase of undefined proteins.

Metabolic and hematological profiles in mature horses supplemented with different selenium sources and doses.

This study was conducted to determine the effects of dietary Se source and dose on metabolic and hematological profiles, and their relationships with oxidative status in horses. Twenty-five mature horses were blocked by BW and randomly allocated to 1 of 5 dietary treatments: negative control (CTRL: 0.085 mg of Se/kg of DM), 3 different dietary concentrations of organic Se provided by Se yeast (SY02, SY03, and SY04 containing 0.2, 0.3, and 0.4 mg of total Se/kg of DM, respectively), and 1 positive control provided by sodium selenite (SS03 containing 0.3 mg of total Se/kg of DM). Horses were fed the same basal diet (6 kg of grass hay and 3 kg of concentrate per horse daily) and received their respective treatments for a continuous period of 112 d. Jugular venous blood samples were collected before the morning feed on d 0, 28, 56, 84, and 112. Whole blood was analyzed for hematological profile, and plasma was analyzed for metabolites of energy, protein, and mineral metabolism; enzymatic activities and metabolites related to liver and muscle damage; and markers of inflammatory and oxidative status. Plasma metabolites related to energy, protein, and mineral metabolism, acute phase proteins, and enzyme activities related to hepatocellular, hepatobiliary, and muscle damage were not affected by Se source or dose. There were no differences among treatments in either reactive oxygen metabolites or thiol group concentrations in plasma. However, a linear decrease (P < 0. 01) in plasma total antioxidants was observed with increasing Se yeast supplementation. Furthermore, total antioxidant concentrations were less in SY03 than SS03 horses (P < 0.05), and were less in SY03 and SY04 than CTRL horses (P < 0.05). These results could be interpreted as an improvement in the preventive antioxidant systems of horses fed Se yeast. Total white blood cell count was not affected by treatment. There was a tendency for horses receiving greater concentrations of Se yeast to have greater lymphocyte counts (P = 0.09), with greater lymphocyte counts in blood of SY03 vs. SS03 horses (P < 0.05). Despite the lack of effect of Se source and dose on markers of inflammatory and liver status, the hematological profile seems to indicate an immunomodulatory action, as shown by mild changes in the white blood cell populations in response to Se yeast inclusion.

Milk skimming, heating, acidification, lysozyme, and rennet affect the pattern, repeatability, and predictability of milk coagulation properties and of curd-firming model parameters: A case study of Grana Padano.

Milk coagulation properties are used to evaluate the cheesemaking aptitude of milk samples. No international standard procedure exists, although laboratories often mimic the production of a full-fat fresh cheese for milk coagulation properties. Questions have arisen about the predictability of such a procedure for different types of cheese production. The aim of this study was to establish a procedure mimicking the production conditions of a long-ripened hard cheese, taking Protected Designation of Origin Grana Padano as a case study. With respect to the traditional conditions (standard procedure; SP), the Grana Padano procedure (GP) modifications were the use of standardized milk, coagulation lower temperature, previous milk acidification, lysozyme addition, and rennet type. Each modification was tested in turn versus the SP and also all together in the GP. Another 3 tests were carried out: SP on naturally creamed milk, SP with double the quantity of rennet, and a simplified GP on a full-fat milk sample. The 10 procedures were tested on 2 subsamples with 2 replicates each and were repeated using individual milk samples from 15 dual-purpose Simmental cows in 4 sessions for a total of 600 tests. Two Formagraph instruments (Foss Electric A/S, Hillerød, Denmark) measuring curd firmness every 15 s were used, prolonging test duration to 60min to obtain 5 traditional single-point milk coagulation properties and 3 parameters of the curd firming model using all 240 points recorded for each replicate. The 8 traits of each replicate were analyzed according to a mixed model with fixed effects of 4 sessions, 10 treatments, 2 instruments, and 16microvats, and random effects of 15 animals and 300 subsamples. Compared with the SP, the coagulation and curd firming was slowed by low temperature and was accelerated by acidification and by adding a double amount of rennet; natural creaming, fat standardization, and rennet with 5% pepsin affected only some traits, whereas lysozyme addition affected none. Combination of all modifications tended to compensate for each of their effects, resulting in similar average patterns between GP and SP. Modifications to repeatability were found for all traits with the exception of 2. The ability of the SP to predict GP, tested through correlations between procedures, was not very high. Whereas SP is used for both research and in the dairy industry, better results for Grana Padano cheesemaking can only be achieved by adopting specific, more complex, and labor-intensive procedures at the research level or, possibly, by specific calibrations through Fourier-transform infrared spectroscopy at the industry level.

Selection for milk coagulation properties predicted by Fourier transform infrared spectroscopy in the Italian Holstein-Friesian breed

Milk coagulation is based on a series of physicochemical changes at the casein micelle level, resulting in formation of a gel. Milk coagulation properties (MCP) are relevant for cheese quality and yield, important factors for the dairy industry. They are also evaluated in herd bulk milk to reward or penalize producers of Protected Designation of Origin cheeses. The economic importance of improving MCP justifies the need to account for this trait in the selection process. A pilot study was carried out to determine the feasibility of including MCP in the selection schemes of the Italian Holstein. The MCP were predicted in 1,055 individual milk samples collected in 16 herds (66 ± 24 cows per herd) located in Brescia province (northeastern Italy) by means of Fourier transform infrared (FTIR) spectroscopy. The coefficient of determination of prediction models indicated moderate predictions for milk rennet coagulation time (RCT=0.65) and curd firmness (a₃₀=0.68), and poor predictions for curd-firming time (k₂₀=0.49), whereas the range error ratio (8.9, 6.9, and 9.5 for RCT, k₂₀, and a₃₀, respectively) indicated good practical utility of the predictive models for all parameters. Milk proteins were genotyped and casein haplotypes (αS₁-, β-, αS₂-, and κ-casein) were reconstructed. Data from 51 half-sib families (19.9 ± 16.4 daughters per sire) were analyzed by an animal model to estimate (1) the genetic parameters of predicted RCT, k₂₀, and a₃₀; (2) the breeding values for these predicted clotting variables; and (3) the effect of milk protein genotypes and casein haplotypes on predicted MCP (pMCP). This is the first study to estimate both genetic parameters and breeding values of pMCP, together with the effects of milk protein genotypes and casein haplotypes, that also considered k₂₀, probably the most important parameter for the dairy industry (because it indicates the time for the beginning of curd-cutting). Heritability of predicted RCT (0.26) and k₂₀ (0.31) were close to the average heritability described in literature, whereas the heritability of a₃₀ was higher (0.52 vs. 0.27). The effects of milk proteins were statistically significant and similar to those obtained on measured MCP. In particular, haplotypes including uncommon variants showed positive (B-I-A-B) or negative (B-A(1)-A-E) effects. Based on these findings, FTIR spectroscopy-pMCP is proposed as a potential selection criterion for the Italian Holstein.

Model to evaluate welfare in dairy cow farms.

Abstract The assessment of herd welfare is a scientific discipline that is rapidly developing. The scientific community plays an important role in delivering appropriate, repeatable, valid and feasible models for this assessment. Unfortunately, there are different feelings regarding the welfare of animals and it is imperative for its assessment that certain agreement on the meaning of animal welfare is accepted. Then it is necessary to look at the goals of the models of welfare assessment because different goals require a different combination of welfare indicators. The different models for welfare assessment can be categorized broadly into research, legislative requirements, certification systems, and advisory/management tools. These models may have various goals: quantification of welfare, provision of welfare assurance or welfare management. However, it is widely accepted that welfare is best assessed with multiple different measures; therefore, a welfare assessment model for a livestock herd can include two types of measure: a description of the housing system and management (indirect indicators) and data recording on how the animals react to the system (direct indicators). The first type provides information on risk factors for welfare problems. Direct measures on the animals provide information on their response to the environment and are more direct measures of welfare than their counterparts, but direct welfare indicators alone do not point out the causes of impaired welfare. Because welfare is a complex construct, different approaches for the aggregation of the different aspects of welfare have been proposed, although the aggregation in an overall welfare value is not sufficient. The thresholds between acceptable and unacceptable welfare levels have to be included in the model of welfare assessment but it seems useful to set certain minimum standards for each single welfare aspect. Afterward, judging the validity of a common welfare assessment model is important. In addition to considering its aim and the fact that a gold standard for animal welfare does not exist, it aids in identifying some widely accepted reference parameters which cannot be utilized in the field (i.e. ACTH challenge, immune system parameters, etc.), but which can be utilized to validate the field models. A new model has been recently set up in our Institute, which is based on many environmental factors included into two clusters: life conditions and feeding. A further cluster considers the animal responses in general and to the previous factors; specific indicators of behavioural, physiological, performance and health type have been included in this last cluster.

Assessment of the main plasma parameters included in a metabolic profile of dairy cow based on Fourier Transform mid-infrared spectroscopy: preliminary results

BackgroundAlthough a metabolic profile represents a valid tool utilized in dairy herds to determine abnormalities in blood chemistry related to an increased risk of production diseases, there are no studies on application of Fourier Transform mid-infrared (FT-MIR) spectroscopy. This study assesses the potential application of FT-MIR to analyze the main blood biochemical parameters included in the metabolic profile of dairy cows. Infrared transmission spectra were acquired for 35 plasma samples (two replicates on each sample) of Italian Friesian dairy cows (14 primiparous and 21 pluriparous), all without clinical events, and at different stages of lactation, although mainly in the transition phase. Each sample was also analyzed independently using accepted reference clinical chemical methods and these results were used as calibrating values to perform predictive models by PLS method using cross validation.ResultsMeasured blood parameters concentrations were all within the reference ranges reported for healthy dairy cows. The number of extracted factors with the PLS procedure for each prediction model ranged between 3 and 7. The coefficient of determination (R2) of the prediction models ranged between 0.1 to values close to 1. R2 values greater than 0.9 were observed for the prediction models of total cholesterol, total protein, globulin, and albumin; values between 0.75 and 0.9 were observed for urea, NEFA, and total bilirubin, while values of R2 lower than 0.6 were observed for all minerals and for enzyme activity. The range error ratio (RER) and prediction to deviation (RPD) ranged from 5.1 to 43.8 and from 1 to 13.8 for RER and RPD, respectively. Values of RPD greater than 5 were observed for total cholesterol, total protein, albumin, and globulin. RPD ranged between 2 and 5 for the prediction models of urea, NEFA, and total bilirubin, while RPD and RER were low for minerals and enzyme activities.ConclusionsAlthough the results of this study require further validation, the use of FT-MIR spectroscopy was possible and provides fairly accurate measurement of various parameters of great importance in the evaluation of the metabolic and inflammatory status in dairy cows.

Improving the prediction ability of FT-MIR spectroscopy to assess titratable acidity in cow's milk.

This study investigated the potential application of Fourier transform mid-infrared spectroscopy (FT-MIR) for the determination of titratable acidity (TA) in cows milk. The prediction model was developed on 201 samples collected from cows in early and late lactation, and was successively used to predict TA on samples collected from cows in early lactation and in samples with high somatic cell count. The root mean square error of cross-validation of the model by using external validation dataset was 0.09 °Soxhlet-Henkel/50 mL. Applying the model on milk samples from cows in early lactation or with high somatic cell count, the root mean square error of prediction was 0.163 °Soxhlet-Henkel/50 mL, with a RER and RPD of 23.9 and 5.1, respectively. Our results seem to indicate that FT-MIR can be used in individual milk samples to accurately predict TA, and has the potential to be adopted to measure routinely the TA of milk.

Sustainable ruminant production to help feed the planet

Abstract Ruminant production has been an essential part of human activities worldwide since ancient times. The expected increase in world population and per capita income, with an increase in the amount and prevalence of animal products in human diet, urbanisation, with a concentration of population in urban areas and an increase in losses in the supply chain, and the growing concern over the environmental impact of animal farming require a long-term global strategy for a more intensive and sustainable ruminant production. Therefore, solutions to increase the supply of high-quality products of ruminant origin, without harming human health, animal welfare, and environment, should consider the following interconnected issues discussed in this review: (a) effects of meat, milk and dairy products consumption on human health, focussing on the imbalance caused by their insufficient consumption, and the alleged increased incidence of certain diseases due to their consumption; (b) importance of the sustainable intensification of ruminant production systems (e.g. better feed conversion and higher production output per unit of input introduced into the farming system); (c) environmental impact of ruminant production; (d) improvement of animal performance by improving animal welfare; (e) adaptation of ruminants to climate change; (f) sustainable ruminant feeding (e.g. precision feeding techniques, optimisation of grazing systems, and use of unconventional feeds); (g) challenges posed by production intensification to animal breeding and conservation of animal biodiversity; and (h) strategies to increase ruminant production in developing countries, thus achieving food security in vast areas of the planet affected by fast growth of human population.