Milking system and diet's forage type impact on milk quality of Italian Holstein-Friesian.

Moving from conventional (CMS) to automatic (AMS) milking systems could impact milk quality. Moreover, the type and preservation methods of the forages used in the total mixed ration (TMR) (such as alfalfa hay -HTMR- or corn silage -STMR-) have been demonstrated to modify milk composition. Thus, this study investigated the effect of implementing AMS and different diet forage types on the quality of Italian Holstein-Friesian bulk milk. Milk samples (n = 168) were collected monthly from 21 commercial farms in northern Italy during a period of 8 mo. Farms were categorized into 4 groups according to their milking system (CMS vs AMS) and diet's forage type (HTMR vs STMR). Milk quality data were analyzed through the mixed procedure for repeated measurement of SAS with the milking system, diet's forage type, and sampling day as fixed effects. Milking through the AMS led to lower milk fat, freezing point and ß-lactoglobulin A, longer coagulation time, and higher K content, pH and ß-lactoglobulin B than CMS. Cows fed STMR produced milk with greater fat, protein, casein, Mg content, titratable acidity and ß-lactoglobulin A, while reduced curd firming time, freezing point and ß-lactoglobulin B than those fed with HTMR. In conclusion, milk quality is not only altered by the diet's forage type and characteristics but also by the milking system.

The Meat Standards Australia carcass grading site affects assessment of marbling and prediction of meat-eating quality in growing European beef cattle.

The lack of consumer feedback on beef eating quality contributes to reduced beef consumption in Europe. The Meat Standards Australia (MSA) grading scheme can assess the palatability of beef carcasses usually graded at the 10th thoracic vertebrae. However, the European beef industry relies on late-maturing breeds usually cut at the 5th vertebrae due to commercial reasons. Data from 55 young bulls and heifers of late-maturing breeds were collected in an Italian slaughterhouse following the MSA guidelines at both carcass grading sites and sides. Intramuscular fat levels were assessed through two scores and used with other variables to feed the MSA model, which predicts the MSA index, the meat-eating quality scores (MQ4) for 5 muscles and for each carcass grading site × side combination. The scores were analyzed using a mixed linear model. A correlation analysis was conducted to predict the variables measured at the 10th site using their correspondent at the 5th carcass grading site. A stepwise regression was conducted to understand the weight of each measured variable on marbling and MQ4 scores measured both at 5th and 10th carcass grading sites. Results showed significantly higher value for the studied traits at the 5th carcass grading site, while carcass side had no significant impact. The equations had high predictive capability and MSA marbling score played a key role in explaining the variability across carcass grading sites. The differences in marbling and MQ4 scores between the carcass grading sites suggest considering this factor if the MSA grading system will be applied to Europe.

The ability of a handheld near-infrared spectrometer for a rapid quality assessment of bovine colostrum including the Ig G concentration.

Portable infrared-based instruments have made significant contributions in different research fields. Within the dairy supply chain, for example, most of portable devices are based on near-infrared spectroscopy (NIRS) and are nowadays an important support for farmers and operators of the dairy sector, allowing fast decision-making, particularly for feed and milk quality evaluation and animal health and welfare monitoring. The affordability, portability, and ease of use of these innovative devices have been pivotal factors for the implementation in dairy farms. In fact, pocket-sized devices enable non-expert users to perform quick, low cost and non-destructive analysis on various samples without complex preparation. As bovine colostrum (BC) quality is mostly given by the Ig G (IgG) level, evaluating the ability of portable NIRS tools to measure antibodies concentration is advisable. In this study we used the wireless device SCiO manufactured by Consumer Physics Inc. (Tel Aviv, Israel) to collect BC spectra and then attempt to predict IgG concentration and gross and fine composition in individual samples collected as soon as possible after calving (<6 h) in primiparous and pluriparous Holstein cows farmed in 9 Italian farms. Chemometric analyses revealed that SCiO has promising predictive performance for colostral IgG concentration, total Ig concentration, fat, and AA (R2CV ≥ 0.75). Excellent accuracy was observed for dry matter, protein, and S prediction in cross-validation and good prediction ability in external validation (R2CV ≥ 0.93; R2V ≥ 0.82). Nonetheless, SCiO's ability to discriminate between good- and low-quality samples was satisfactory. The affordable cost, the accurate predictions, and the user-friendly design coupled with the increased interest in colostrum quality within the dairy sector may boost the collection of extensive BC data for management and genetic purposes in the near future.

Effects of vaccination timing and target pathogens on performances and antimicrobial use in long-transported Charolais beef cattle from France to Italy - A retrospective study.

Antimicrobial use (AMU) in the livestock sector is a major driver of antimicrobial resistance. Italian beef industry strongly relies on the import of young cattle from France, which are commingled in sorting facilities before transportation to Italy. Both commingling and transportation are stressors for animals and lead to higher risk of bovine respiratory disease (BRD), which in turn increases the risk of AMU. This study aimed to investigate how the timing of first BRD vaccination and the different vaccination target pathogens affect AMU and performance of young Charolais beef cattle imported from France to Italy. Information on animal performance, antimicrobial treatments, and vaccinations was available for 60,726 Charolais cattle belonging to 1449 batches in 33 Italian specialised fattening farms between January 2016 and December 2021. Antimicrobial use was estimated using the treatment incidence 100 adapted for Italy (TI100it). A mixed linear model was used to quantify the effects of the vaccination and the time of first administration on slaughter age, carcase weight, and average daily carcase gain. Similarly, a generalised linear mixed model was used to analyse the TI100it. The vaccination programme was usually applied the first day after the animals' arrival to the Italian fattening farms. Most animals were vaccinated with a polyvalent vaccine against infectious bovine rhinotracheitis (IBR), bovine parainfluenza type 3 virus (PI-3), bovine viral diarrhoea virus type 1 and 2 (BVDV), and bovine respiratory syncytial virus (BRSV). The most used class of antimicrobials to treat BRD were the macrolides, followed by aminoglycosides, amphenicols, tetracyclines, aminopenicillins, and fluoroquinolones. Animals that got vaccinated against any of the considered BRD pathogens upon arrival had significantly lower TI100it, greater average daily carcase gain, and reached slaughter age earlier than animals that got vaccinated later. Animals that received the vaccination against BVDV had lower TI100it and greater average daily carcase gain, and animals that received the vaccination against BRSV were younger at slaughter than unvaccinated animals. The vaccination against Mannheimia haemolytica significantly decreased the slaughter age and increased the carcase weight and average daily carcase gain, and the vaccination against PI-3 and Histophilus somni significantly increased the slaughter age. Thus, even if the vaccination programme is essential to tackle BRD, this practice is questionable if applied at arrival to the Italian fattening farms and it is advisable that the vaccination programme is planned before the commingling procedure in France.

Application of a short-wave pocket-sized near-infrared spectrophotometer to predict milk quality traits.

Portable handheld devices based on near-infrared (NIR) technology have improved and are gaining popularity, even if their implementation in milk has been barely evaluated. Thus, the aim of the present study was to assess the feasibility of using short-wave pocket-sized NIR devices to predict milk quality. A total of 331 individual milk samples from different cow breeds and herds were collected in 2 consecutive days for chemical determination and spectral collection by using 2 pocket-sized NIR spectrophotometers working in the range of 740 to 1,070 nm. The reference data were matched with the corresponding spectrum and modified partial least squares regression models were developed. A 5-fold cross-validation was applied to evaluate individual device performance and an external validation with 25% of the dataset as the validation set was applied for the final models. Results revealed that both devices' absorbance was highly correlated but greater for instrument A than B. Thus, the final models were built by averaging the spectra from both devices for each sample. The fat content prediction model was adequate for quality control with a coefficient of determination (R2ExV) and a residual predictive deviation (RPDExV) in external validation of 0.93 and 3.73, respectively. Protein and casein content as well as fat-to-protein ratio prediction models might be used for a rough screening (R2ExV >0.70; RPDExV >1.73). However, poor prediction models were obtained for all the other traits with an R2ExV between 0.43 (urea) and 0.03 (SCC), and a RPDExV between 1.18 (urea) and 0.22 (SCC). In conclusion, short-wave portable handheld NIR devices accurately predicted milk fat content, and protein, casein, and fat-to-protein ratio might be applied for rough screening. It seems that there is not enough information in this NIR region to develop adequate prediction models for lactose, SCC, urea, and freezing point.

Teat morphology across five buffalo breeds: a multi-country collaborative study.

The buffalo (Bubalus bubalis) is a species of worldwide importance, raised to produce milk, meat, and hides, and often used as a working animal in rural contexts with low access to hi-tech solutions. In the present study, 100 lactating buffaloes (50 primiparous and 50 pluriparous) of five popular breeds were recruited to characterize and compare teat morphology. In particular, the focus was put on the Nili Ravi, Mediterranean, Egyptian, Bulgarian Murrah, and Azeri buffaloes raised in Pakistan, Italy, Egypt, Bulgaria, and Iran, respectively. In all countries, a longitudinal cross-section ultrasound was obtained before the milking to measure teat parameters at individual level: overall, teat canal length (TCL) averaged 24.13 mm, teat diameter (TD) 30.46 mm, cisternal diameter (CD) 17.80 mm, and teat wall (TW) 7.12 mm. The most variable trait across breeds was TCL which was positively correlated with CD and TD and negatively with TW, regardless of the teat position (front/rear or left/right). A strong negative correlation was found between TW and CD (- 0.43). The analysis of variance revealed that the fixed effect of breed significantly affected all the traits except TD. In fact, Bulgarian Murrah, Azeri, and Egyptian buffaloes presented the greatest estimate of TCL, whereas NR the smallest (14.70 mm). The TW was maximum in Nili Ravi, Egyptian, and Mediterranean buffaloes, with estimates equal to 8.19, 7.59, and 8.74 mm, respectively. Nili Ravi also showed the greatest TL (82.39 mm). In terms of CD, the lowest least square mean was that of Mediterranean buffaloes (12.14 mm). Primiparous and pluriparous buffaloes differed in terms of TD, TW, and TL, with older animals presenting the highest least square mean. In terms of position, instead, significant differences were observed for TD, CD, and TL when comparing front and rear teats, as left and right teats did not differ. Teat anatomy includes a set of heritable morphological features and is therefore breed-dependent. Differences presented in this study could be attributed to the divergent breeding objective and selective pressure across the five breeds; e.g., in some cases such as Mediterranean buffalo, selection for decades was oriented to improve milk production and milkability and achieve optimal conformation for mechanical milking. A better understanding of the mammary gland anatomical descriptors can be informative of the history of a breed and could provide useful insights to guide possible selection.

The effects of dietary iodine content, milking system, and farming practices on milk iodine concentration and quality traits.

Various management practices can influence milk quality traits in dairy cattle. As an example, an increasing investment in automatic milking system to substitute milking parlors has been observed in the last 2 decades in dairy farms which could have affected certain bulk milk quality traits. What is more, milking practices can also affect certain milk parameters; as an example, teat disinfectants containing I are used in commercial farms where pre- or postdipping is performed, leading to presence of some I in the bulk milk. However, this trace mineral is also supplied in cows' diet to fulfill their nutritional requirements, partly contributing to the milk I final concentration. Therefore, the aim of this study was to evaluate the sources of variation of milk I along with other traditional milk quality traits. A total of 91 dairy farms in northeastern Italy were enrolled in the study. In each farm, diet and bulk milk samples were collected on the same day for chemical analysis. Concentration of I, in particular, was determined in both milk and feed with gold standard. Pearson correlations were calculated among the traits available for milk and diet, and a general linear model was used to test significance of fixed effects (feeding system, milking system, farming system, herd size, herd stage of lactation, and sampling month) on milk quality traits including the I concentration. In the case of milk I, diet I and presence of I-based predipping and postdipping teat disinfect application were also tested as fixed effects. Results showed a positive linear correlation between milk and diet I content (correlation coefficient [r] = 0.78). Although milk I was also positively correlated with lactose content (r = 0.25), dietary I was not correlated with other milk traits. Milk I content was significantly affected by dietary I, I-based predipping teat disinfectant application, and herd composition. Compared with conventional farms, organic farms showed lower protein content and greater somatic cell score (SCS) but similar milk I. Milking system significantly affected only lactose content and SCS of milk. Sampling month was only significant for milk urea nitrogen and herd composition, feeding system, herd size, and herd average days in milk did not modify milk gross composition and SCS. In conclusion, dietary supply of I is the main factor affecting milk I concentration and findings suggest that I level in milk can be naturally improved in dairy cows by modulating the I content in the diet administered. However, further research is needed to evaluate the effect of I-based sanitizers on milk I.

Comparative analysis of microbial succession and proteolysis focusing on amino acid pathways in Asiago-PDO cheese from two dairies.

In this study, a comprehensive and comparative analysis was conducted on Italian Asiago-PDO cheese obtained from two different dairies named Dairy I and Dairy II using industrial and natural fermented milk, respectively. The analysis encompassed the evaluation of chemical composition, the succession of the microbiota during manufacture and ripening, and proteolysis mainly focusing on free individual amino acid (FAA) profiles. A metagenomic approach was used to investigate the cheese microbiome functionality. Differences in gross chemical composition were more evident during ripening, with Dairy II showing higher variability within batches. The microbiota varied significantly between the two dairies and ripening stages. The choice of starter culture shaped the microbiota during production and affected the microbial diversity of non-starter lactic acid bacteria (NSLAB) originated from the raw milk during ripening. Peptide chromatographic profiles and FAA concentrations increased as ripening progressed, with Dairy I showing higher production of FAA. Functional analysis of the metagenomes linked species to specific amino acid metabolism/catabolism pathways. The amino acid metabolism pathways, particularly those related to aromatic amino acids, lysine, and branched-chain amino acids, were affected by the presence of specific NSLAB species, which differed between the two dairies. The results obtained in this study reveal the impact of starter culture on peculiar cheese microbiota assemblies, which selectively targets amino acid pathways, providing insights into the potential flavor and aroma characteristics of Asiago-PDO cheese.

Pathogen Detection via Quantitative PCR in Milk of Healthy Cows Collected Using Different Sampling Protocols.

In this study we evaluated the prevalence of pathogens detected via quantitative PCR (qPCR) in milk from apparently healthy cows to identify the most common etiological agents present in Italian dairy farms. Milk samples were collected using a sterile protocol at quarter-level (3239 samples, 822 cows) and a conventional protocol at udder level as composite milk from the functional quarters of each cow (5464 samples, 5464 cows). The qPCR commercial kit detected Mycoplasma bovis, Mycoplasma spp., Staphylococcus aureus, coagulase-negative staphylococci (CNS), Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Prototheca spp., Escherichia coli, Klebsiella spp., Enterococcus spp. and Lactococcus lactis ssp. lactis as well as DNA from the penicillin resistance ß-lactamase gene from staphylococci. The prevalence of specific DNA was calculated based on its presence or absence in the samples, factoring in both the sampling protocols and herds. Regardless of the sampling protocol used, the most frequently detected pathogens were CNS (26.6% in sterile and 13.9% in conventional protocol) and Streptococcus uberis (9.6% and 16.5%, respectively). These results underscore the necessity for pathogen-specific interventions at the farm level to enhance the udder health of dairy cows via management recommendations.

ß-Casein A1 and A2: Effects of polymorphism on the cheese-making process.

Of late, "A2 milk" has gained prominence in the dairy sector due to its potential implications in human health. Consequently, the frequency of A2 homozygous animals has considerably increased in many countries. To elucidate the potential implications that beta casein (ß-CN) A1 and A2 may have on cheese-making traits, it is fundamental to investigate the relationships between the genetic polymorphisms and cheese-making traits at the dairy plant level. Thus, the aim of the present study was to evaluate the relevance of the ß-CN A1/A2 polymorphism on detailed protein profile and cheese-making process in bulk milk. Based on the ß-CN genotype of individual cows, 5 milk pools diverging for presence of the 2 ß-CN variants were obtained: (1) 100% A1; (2) 75% A1 and 25% A2; (3) 50% A1 and 50% A2; (4) 25% A1 and 75% A2; and (5) 100% A2. For each cheese-making day (n = 6), 25 L of milk (divided into 5 pools, 5 L each) were processed, for a total of 30 cheese-making processes. Cheese yield, curd nutrient recovery, whey composition, and cheese composition were assessed. For every cheese-making process, detailed milk protein fractions were determined through reversed-phase HPLC. Data were analyzed by fitting a mixed model, which included the fixed effects of the 5 different pools, the protein and fat content as a covariate, and the random effect of the cheese-making sessions. Results showed that the percentage of κ-CN significantly decreased up to 2% when the proportion of ß-CN A2 in the pool was ≥25%. An increase in the relative content of ß-CN A2 (≥50% of total milk processed) was also associated with a significantly lower cheese yield both 1 and 48 h after cheese production, whereas no effects were observed after 7 d of ripening. Concordantly, recovery of nutrients reflected a more efficient process when the inclusion of ß-CN A2 was ≤75%. Finally, no differences in the final cheese composition obtained by the different ß-CN pools were observed.

Total and Differential Somatic Cell Count in Italian Local Cattle Breeds: Phenotypic Variability and Effect on Milk Yield and Composition.

Milk differential somatic cell count (DSCC) represents the percentage of polymorphonuclear neutrophils and lymphocytes out of the total somatic cell count (SCC) and has been proposed in recent years as a proxy for udder health in dairy cows. We investigated phenotypic factors affecting SCC and DSCC using 3978 records of 212 Alpine Grey and 426 Burlina cows farmed in Northern Italy. The linear mixed model accounted for the fixed effects of breed, parity, lactation stage, sampling season, and first-order interactions of breed with the other effects. Cow, herd-test-date nested within breed were random. Subsequently, four udder health status groups (UHS) were created by combining SCC and DSCC to assess the UHS impact on milk yield and quality. DSCC was greater in Alpine Grey (66.2 ± 0.8%) than Burlina cows (63.2 ± 0.6%) and, similarly to SCC, it increased with days in milk and parity regardless of breed. Milk yield and composition were affected by UHS in both breeds. These results suggest that also udder health of local breeds can be monitored on a large scale through SCC and DSCC for reduction in biodiversity loss and increased farm profitability. However, in addition to milk data, the introduction of mastitis recording and monitoring plans is advisable.

Across countries implementation of handheld near-infrared spectrometer for the on-line prediction of beef marbling in slaughterhouse.

Only few studies have used Near-Infrared (NIR) spectroscopy to assess meat quality traits directly in the chiller. The aim of this study was therefore to investigate the ability of a handheld NIR spectrometer to predict marbling scores on intact meat muscles in the chiller. A total of 829 animals from 2 slaughterhouses in France and Italy were involved. Marbling was assessed according to the 3G (Global Grading Guaranteed) protocol using 2 different scores. NIR measurements were collected by performing 5 scans at different points of the Longissimus thoracis. An average MSA marbling score of 330-340 was obtained in the two countries. The prediction models provided a R2 in external validation between 0.46 and 0.59 and a standard error of prediction between 83.1 and 105.5. Results did provide a moderate prediction of the marbling scores but can be useful in the European industry context to predict classes of MSA marbling.

Genetic characteristics of colostrum refractive index and its use as a proxy for the concentration of immunoglobulins in Holstein cattle.

BACKGROUND: Colostral concentration of immunoglobulins (Ig) is crucial for the passive transfer of antibodies from the cow to the new-born calf. Direct determination of Ig by the gold standard radial immunodiffusion method is demanding in terms of time and costs. For this reason, a refractometer is commonly used at the farm level for an indirect estimation of colostrum quality, which is given as the Ig concentration. In this study, colostrum samples were collected from 548 Italian Holstein cows within 6 h of calving. The refractive index (BRIX, %) of these samples was assessed using a portable optical refractometer, as well as the concentration of total protein, IgG, IgA, and IgM by radial immunodiffusion. A four-trait animal model was used to estimate genetic parameters for BRIX and the different immunoglobulin isotypes. A receiver operating characteristic analysis was carried out to evaluate the BRIX diagnostic accuracy. RESULTS: Colostral BRIX was moderately heritable (0.26) and its genetic and phenotypic correlations with IgG (0.91, 0.78), IgA (0.57, 0.57), and IgM (0.71, 0.61) were all positive and of similar order, although the genetic correlations were generally higher than the phenotypic correlations. Low-quality colostrum samples, defined as those with an IgG concentration lower than 50 g/L, were accurately identified by the refractive index on the BRIX scale, with an area under the curve of 0.90. CONCLUSIONS: The use of a refractometer is recommended on dairy farms to produce a proxy for colostral Ig concentration. BRIX is a useful phenotyping tool that can be used in cattle to improve the quality of colostrum for first feeding of calves through both traditional genetic and genomic strategies. Improving colostrum quality will reduce the incidence of failure of passive transfer of immunity in young stock.

Long-term administration of a commercial supplement enriched with bioactive compounds does not affect feed intake, health status, and growth performances in beef cattle.

Feed additives including natural bioactive compounds (BCs) in combination with vitamin E (VitE) and organic Se could mitigate animal stress associated with intensive livestock farming due to their anti-inflammatory and antioxidant properties. Yeast and yeast derivate are included in feed additives as probiotic products and digestion promoters. Scutellaria baicalensis is a source of bioactive compounds and has been tested in monogastrics, exhibiting many immunostimulating and hepato-protective activities. However, the literature lacks information regarding S. baicalensis effects on beef cattle performance and health status. The aim of the present study was to evaluate the impact on beef cattle's feed intake, health and oxidative status, and growth performances of the inclusion of a commercial supplement (CS) containing VitE, organic Se, yeast derivate, and S. baicalensis extract during the fattening and finishing period. A total of 143 Charolaise male cattle were allotted into 12 pens of 11-12 animals each and assigned to a control ( 463.9 ± 21.48 body weight - BW) or a treated ( 469.8 ± 17.91  BW) group. Each group included two replicates of three pens. The treated groups were supplemented with 20  g CS animal - 1 d - 1 . Feed intake was measured monthly on a pen base during two consecutive days. Total mixed ration and fecal samples were collected at three time points (monthly, from November to February) and pooled by replicate for the analyses to monitor digestibility. Blood samples were individually collected at the beginning and at the end of the trial for oxidative status and metabolic profile determination. Final BW and carcass weight were individually recorded to calculate average daily gain, feed conversion ratio, and carcass yield. Similar feed digestibility between groups were observed during the whole experiment. Feed intake, growth performances, final body weight, average daily gain, feed conversion rate, oxidative status, and metabolic profile were not affected by the dietary inclusion of the tested CS indicating no detrimental effect of the treatment. Different doses of this product should be tested in the future in order to provide a more complete report on the product efficacy.

Breeding for improved protein fractions and free amino acids concentration in bovine milk.

Considerable resources are required to routinely measure detailed milk compositional traits. Hence, an insufficient volume of phenotypic data can hinder genetic progress in these traits within dairy cow breeding programmes. The objective of the present study was to quantify the opportunities for breeding for improved milk protein and free amino acid (FAA) composition by exploiting mid-infrared spectroscopy (MIRS) predictions routinely recorded from milk samples. Genetic parameters for protein fractions and FAA composition were estimated using 134,546 test-day records from 16,166 lactations on 9,572 cows using linear mixed models. Heritability of MIRS-predicted protein fractions ranged from 0.19 (α-lactalbumin) to 0.55 (ß-lactoglobulin A), while heritability of MIRS-predicted FAA ranged from 0.08 for glycine to 0.29 for glutamic acid. Genetic correlations among the MIRS-predicted FAA were moderate to strong ranging from -0.44 (aspartic acid and lysine) to 0.97 (glutamic acid and total FAA). Adjustment of the genetic correlations for the genetic merit of 24-h milk yield did not greatly affect the correlations. Results from the current study highlight the presence of exploitable genetic variation for both protein fractions and FAA in dairy cow milk. Besides, the direction of genetic correlations reveals that breeding programmes directly selecting for greater milk protein concentration carry with them favourable improvement in casein and whey fractions.

The Role of Quarantine on Post-Mortem Performances of Charolaise Young Bulls.

Biosecurity is essential to prevent the spread of diseases in livestock animals such as the bovine respiratory disease which can lead to negative effects on growth performance, and carcass and meat quality, as well as to an increase of antimicrobial use. The aim of this study was to investigate the effects of the quarantine on post-mortem performances (hot carcass weight, dressing percentage, pH 60 min after slaughtering, carcass SEUROP conformation, and fat cover) of 576 Charolaise young bulls imported from France and fattened in specialized Italian farms. Approximately half of the animals followed a standard fattening procedure without initial quarantine upon arrival to Italy (NO-QUA) and the other half underwent a 30-day period of quarantine (QUA) since their arrival to the farm. Post-mortem performances and parenteral administration of antimicrobial use were recorded. NO-QUA animals had lower average daily gain and slaughter weight but scored higher for carcass SEUROP evaluation and pH than QUA animals (p < 0.05). NO-QUA received more than double the number of parenteral antimicrobial treatments than QUA animals for respiratory diseases (139 vs. 56). Overall, quarantine applied on-farm contributes to improve post-mortem performances while reducing antimicrobial use in beef production.

Promoting Judicious Antimicrobial Use in Beef Production: The Role of Quarantine.

Judicious antimicrobial stewardship in livestock industry is needed to reduce the use of antimicrobials (AMU) and the associated risk of antimicrobial resistance. Biosecurity measures are acknowledged for their role against the spread of diseases and the importance in reducing AMU in different species. However, their effectiveness in beef production has been scarcely considered. The aim of this study was to investigate the effect of the quarantine strategy on AMU in beef cattle. A total of 1206 Charolaise animals in five farms were included in the trial. Roughly half of the animals followed the standard procedure of the fattening cycle (no-quarantine; NO-QUA group) and half followed a 30-day period of quarantine (QUA group) since their arrival. Performance and antimicrobial data were recorded and a treatment incidence 100 (TI100it) per animal was calculated. Penicillins was the most used class of antimicrobials. Differences between groups were significant for males only, with NO-QUA group having greater TI100it (3.76 vs. 3.24; p < 0.05) and lower body weight at slaughter (713.4 vs. 723.7 kg; p < 0.05) than QUA group. Results suggest that quarantine strategy can reduce AMU in males without compromising their performance, whereas further investigation is needed for females.

Handheld near-infrared spectrometer allows on-line prediction of beef quality traits.

The aim of this study was to evaluate the ability of a miniaturized near-infrared spectrometer to predict chemical parameters, technological and quality traits, fatty acids and minerals in intact Longissimus thoracis and Trapezius obtained from the ribs of 40 Charolais cattle. Modified partial least squares regression analysis to correlate spectra information to reference values, and several scatter correction and mathematical treatments have been tested. Leave-one-out cross-validation results showed that the handheld instrument could be used to obtain a good prediction of moisture and an approximate quantitative prediction of fat or protein contents, a*, b*, shear force and purge loss with coefficients of determination above 0.66. Moreover, prediction models were satisfactory for proportions of MUFA, PUFA, oleic and palmitic acids, for Fe and Cu contents. Overall, results exhibited the usefulness of the on-line miniaturized tool to predict some beef quality traits and the possibility to use it with commercial cuts without sampling, carcass deterioration nor grinding and consequent meat products' loss.

Milk Somatic Cell Count and Polymorphonuclear Cells in Healthy Quarters of Cows That Underwent Blanket and Selective Dry Therapy: An Italian Case Study.

The incidence of mastitis increases with parity in dairy cattle and multiparous cows are often treated at drying off to limit the risk of udder health issues and support mammary gland tissues recovery. Milk somatic cells count (SCC, cells/mL) comprises different white blood cells fractions and is worldwide used to monitor and genetically improve udder health. Nevertheless, only certain SCC fractions increase when an udder inflammation occurs. Considering that antibiotic use for preventive purposes will be forbidden in 2022, we compared two different dry therapy protocols, blanket (BDCT) and selective (SDCT), on different SCC fractions in healthy quarters milk. Multiparous Holstein cows were enrolled in a randomized controlled trial and SCC, neutrophils, macrophages, lymphocytes, polymorphonuclear cells (PMN) and differential somatic cell count (DSCC) recorded after the experimental drying off were available. Significant differences were observed between the two protocols, with more favorable parameters in BDCT than SDCT cows. Results showed that moving from BDCT to SDCT is expected to significantly increase some SCC fractions, such as PMN, in healthy quarters. The baseline SCC level at the onset of lactation was greater in cows under SDCT than BDCT. Although not significant, clinical mastitis prevalence was numerically lower in BDCT (7.32%) than SDCT (8.62%). In this study we referred to a limited number of cows, but still findings will be useful to improve the knowledge on the impact of SDCT on milk SCC fractions in healthy quarters.

The concentrations of immunoglobulins in bovine colostrum determined by the gold standard method are genetically correlated with their near-infrared prediction.

BACKGROUND: The quality of colostrum administered to calves is based on its concentration in immunoglobulins G (IgG, g/L). Immunoglobulins A (IgA) and M (IgM) are also present but at a lower level. The gold standard reference analysis for these traits, radial immunodiffusion, is time-consuming and expensive. In order to define breeding strategies that are aimed at improving colostrum quality in dairy cattle, a large amount of data is needed, and the use of indicator traits would be beneficial. In the study presented here, we explored the heritabilities of reference (radial immunodiffusion) and near infrared-predicted IgG, IgA, and IgM concentrations and estimated their genetic correlations. First, the colostrum of 765 Holstein cows from nine herds was sampled to perform a reference analysis and the near-infrared spectra (400-2500 nm) were stored. We used a calibration set (28% of the initial samples) that was representative of the herds and cow parity orders to develop prediction equations for IgG, IgA, and IgM concentrations. Finally, these traits were predicted in the validation set (72% of the initial samples) to estimate genetic parameters for the predictions. Genetic correlations between reference and predicted values of each trait were estimated through bivariate linear animal models. RESULTS: The three near-infrared-predicted immunoglobulin fractions were genetically correlated with their reference value. In particular, the reference and predicted IgG concentrations were strongly correlated at both the genetic (0.854 ± 0.314) and phenotypic level (0.767 ± 0.019). Weaker associations were observed for IgA and IgM concentrations, which were predicted with lower accuracy compared to IgG. Simulation analyses suggested that improving colostrum quality by selective breeding in Holstein cattle based on near-infrared predicted colostrum immunoglobulins concentrations is feasible. In addition, less than 10 mL of colostrum are needed for spectra acquisition and thus implementation of such analyses is possible in the near future. CONCLUSIONS: The concentrations of colostrum immunoglobulins can be predicted from near-infrared spectra and the genetic correlation between the reference and the predicted traits is positive and favourable, in spite of the large standard errors of the estimates. Near-infrared spectroscopy can be exploited in selective breeding of dairy cattle to improve colostral immunoglobulins concentration.