Hasil untuk "Dairying"

M.A. Killerby, G.M. de Souza, K.E. Ruh-Etteldorf et al.

ABSTRACT: Increasing AA sequestration in milk is essential for improving N efficiency in dairy cows and to reduce the environmental impacts of dairy production. Isoleucine, Leu, and Met are promising AA to improve milk protein yield and N efficiency due to their signaling roles in mammary epithelial cells. Glucogenic diets can also stimulate milk protein synthesis and, through their effect on insulin, potentiate the signaling effects of AA. Our objective was to evaluate the effects of Ile, Leu, and Met on production performance and N metabolism, and the role of energy source (ES; glucose or acetate) on lactating cows' responses to AA. The experiment consisted of a 4 × 4 Latin square design replicated 4 times with 4 periods of 21 d and 4 treatments arranged as a 2 × 2 factorial. Sixteen ruminally cannulated, multiparous, Holstein cows were housed in tiestalls and fed the same experimental diet with 4% energy and 15% MP deficiency. The 4 treatments were continuously infused into the abomasum and consisted of isoenergetic amounts (2.86 Mcal/d) of glucose (GLC) or acetate (ACE), without AA as negative control, or with a mix of 12 g/d of Ile, 50 g/d of Leu, and 20 g/d of Met (ILM). Experimental periods consisted of 2 wk of adaptation and 1 wk of sampling, in which feed, urine, milk, and blood samples were collected. Data were analyzed with a mixed model in R, containing the fixed effects of period, square, AA infusion, ES, and ES × AA interaction, and the random effects of cow within square. Overall, ES did not alter the response to AA on production or N metabolism (i.e., no significant interactions). Infusion of ILM, regardless of ES, increased circulating insulin concentration, milk protein and fat contents, and yields of de novo and mixed fatty acids, as predicted by Fourier-transform mid-infrared spectroscopy, but decreased lactose yield and concentration and tended to decrease milk yield. Meanwhile, ILM did not alter ECM or N efficiency for milk production. Compared with ACE, GLC increased DMI, circulating concentrations of glucose and insulin in plasma, and yields of milk and milk protein, but decreased circulating levels of acetate, BHB, and nonesterified fatty acids, as well as yields of presynthesized fatty acids, total milk fat, and fat-corrected milk. Similar to AA infusion, ES did not affect ECM yield nor N efficiency for milk production. In summary, compared with ACE, GLC did not alter the performance response to ILM but independently affected production and metabolism, consistent with its insulinemic potential. Cows responded mildly to AA infusion, most remarkably increasing de novo milk fatty acid production and milk protein content without impairing N efficiency, while also decreasing milk lactose concentration and yield.

Benjamin Robinson, Lang Sun, Nicholas Eddy et al.

ABSTRACT: Cornerstone is a semihard farmstead cheese with a natural rind that was developed as an “American original.” The production of Cornerstone cheese relies on the use of unpasteurized (raw) milk, natural milk starters, and the colonization and activity of adventitious microbes native to each farmstead operation. This study describes and compares the microbial community dynamics as well as the metabolites, volatile compounds, and sensory attributes of Cornerstone cheese produced at 3 different facilities. The microbial composition of samples (n = 96) collected along the cheesemaking continuum was determined via amplicon sequencing of the bacterial 16S rRNA and fungal internal transcribed spacer genes. Despite the high bacterial diversity observed within raw milk samples, the natural milk starters produced on-site at 3 different facilities were primarily Streptococcus thermophilus and Lactobacillus delbrueckii. Microbial communities in the pastes of the resulting cheeses were similar, and ultimately attributed, to their respective natural milk starters throughout aging. The cheese rind microbiota established early and persisted throughout aging. Differential abundance analysis identified microbes uniquely abundant in cheeses produced at each facility. Beta diversity metrics indicated that bacterial communities clustered by production facility, not by aging location, whereas fungi were likely influenced by some combination of both. Aging shelves, fans, and cheese forms were identified as primary environmental sources of microbes. Descriptive sensory analysis revealed significant differences in textural attributes between cheeses but only minor differences in flavor. Volatile compounds clustered by aging day more than production location whereas there was no clear clustering by metabolites. These observations demonstrate the critical importance of natural milk starters and environmental microbes at the site of production on the structure of cheese microbial communities and the complex interplay between microbial communities, metabolic processes, and the development of sensory characteristics in cheese.

Yuichi Yoshizawa, Naruomi Yamada, Akika Nagira et al.

ABSTRACT: We investigated the effects of Lactobacillus paragasseri OLL2716 on sleep under psychological stress. In this randomized, double-blind, placebo-controlled trial, 78 healthy Japanese students in the fourth year of medical school were exposed to 2 consecutive academic exam stressors. They were randomly assigned to the OLL2716 or placebo group, and each group consumed 85 g of yogurt containing L. paragasseri OLL2716 or placebo yogurt daily for 8 wk. Two examinations were performed after 4 and 7 wk of intake. The State-Trait Anxiety Inventory (STAI) was used to assess anxiety level. As the primary endpoint, subjective sleep was evaluated using the Ogri-Shirakawa-Azumi sleep inventory MA version (OSA-MA) and the Pittsburgh Sleep Quality Index. Objective sleep was assessed using Fitbit sleep-monitoring devices. Saliva was collected for 2 min between 1600 and 1800 h. Salivary cortisol and chromogranin A levels were measured to assess physiological stress response. These data were obtained at baseline (0 wk) and during the intake periods (2, 4, 5, 7, and 8 wk after intake). The STAI data showed that anxiety levels were similar in both groups. The OSA-MA data showed that the changes in “sleepiness on rising” score at 2 and 4 wk and “dreaming” score at 8 wk were significantly improved, and the changes in objective sleep length at 2, 4, and 7 wk were significantly increased in the OLL2716 group compared with those in the placebo group. Additionally, the salivary chromogranin A secretion rate at 4 wk and salivary cortisol secretion rate at 5 wk were significantly decreased in the OLL2716 group compared with those in the placebo group. These results suggest that the intake of L. paragasseri OLL2716 improves stress-induced sleep deprivation, maintains sleep homeostasis, and moderates the stress response. Therefore, L. paragasseri OLL2716 is a potential strategy for reduced daytime performance associated with sleep dissatisfaction among individuals living in the modern stressful society.

Rosa I. Vázquez, Devon Charlier, Carol Peterson et al.

ABSTRACT: This project implemented Seguridad en las Lecherías, an award-winning, bilingual (Spanish and English), 5-module curriculum approved by the Occupational Safety and Health Administration. The intervention aimed to increase safety knowledge among immigrant dairy workers, encourage a safety culture, and identify challenges faced by the dairy farming community in Minnesota and South Dakota. A total of 360 Hispanic immigrant workers from 19 participating dairies were trained. Pre- and post-assessments revealed a statistically significant increase in knowledge after each training. Producers and managers provided positive feedback noting improved awareness of safety and positive behavior changes to reduce farm incidents. A flexible approach to implementation was essential to the intervention's success, including synchronizing training with workers' shifts. Overall, this application of the Seguridad en las Lecherías curriculum suggests that comprehensive, culturally responsive safety training delivered in the language spoken by workers can have a positive effect on workers' safety knowledge, practices, and behavior on dairy farms. Continued efforts to prioritize and reinforce worker safety are vital to the sustainability and well-being of the dairy farming community in the region and beyond.

A. Lavery, A. Craig, A.W. Gordon et al.

ABSTRACT: A total of 90 Holstein dairy cows (24 primiparous, 66 multiparous, mean parity = 3.0) were fed diets containing either 150, 160, or 170 g CP/kg DM from 8 to 180 DIM, with all diets designed to supply at least 100% MP requirements. On d 181, half of the cows in each treatment changed to a diet containing 140 g CP/kg DM (supplying 100% MP requirements), with the remaining cows continuing to be offered their original treatment diets. This resulted in 6 treatments in the mid-late lactation period (181–280 DIM): 150, 150/140, 160, 160/140, 170, and 170/140 g CP/kg DM. Decreasing dietary CP concentration from 170 to 150 g CP/kg DM did not affect DMI, milk yield, milk fat or protein yield in early lactation (8–181 DIM), but reduced MUN and the ratio of n-6 to n-3 fatty acids in milk, as well as serum albumin, globulin, total protein, and urea concentrations. In addition, reducing dietary CP content from 170 to 160 g CP/kg DM improved N use efficiency (NUE; milk N/N intake), with no further improvement with 150 g CP/kg DM. Treatment had no effect on apparent total-tract ration digestibility in early lactation. Urinary N output decreased with decreasing dietary CP content in early lactation, whereas manure N (fecal N plus urinary N) output increased. Urinary N/manure N decreased from 170 to 160 g CP/kg DM diet, whereas no further reduction was observed with the 150 g CP/kg DM diet. Cows that remained on the 150 g CP/kg DM treatment in mid-late lactation (181–280 DIM) had a lower DMI than those which remained on the diet containing 170 g CP/kg DM. Reducing the dietary CP concentration to 140 g CP/kg DM in mid-late lactation reduced DMI, milk yield, and milk fat and protein yields, compared with offering the 170 or 160 g CP/kg DM diet throughout lactation, possibly reflecting a response to oversupply of MP with the latter treatments, rather than an undersupply of MP with the former, although this is uncertain. Concentrations of C18:2 cis-9,trans-11 and the ratio of n-6 to n-3 fatty acids in milk were lower for cows offered diets containing 140 or 150 g CP/kg DM in mid-late lactation compared with 160 or 170 g CP/kg DM. Reducing dietary CP concentration from 170 to 140 g CP/kg DM improved NUE from 0.28 to 0.34 in mid-late lactation. Nitrogen digestibility was reduced when cows were offered the 140 g CP/kg DM diet compared with the 150 or 160 g CP/kg DM diet. Lowering the dietary CP concentration from 170 to 140 g CP/kg DM in mid-late lactation decreased N output in milk, feces, urine, and manure. These results indicate that a dietary CP content of 160 g CP/kg DM, which met the MP requirement of cows, may be optimal to support performance over a whole lactation, improve NUE, and reduce N excretion, thus contributing to a more sustainable approach to dairy cow production.

Daniel Talmón, Alejandra Jasinsky, Federica Marin et al.

ABSTRACT: Grazing dairy production systems have gained interest due to the increasing consumer preferences associated with environmental care and animal welfare perception. Nonetheless, grazing dairy cows have lower feed conversion than those fed indoors with a TMR, partly because of increased maintenance energy costs associated with grazing and walking activity. However, to our knowledge, the energy cost of grazing has not been quantified for dairy cows. The objectives of the present work were to evaluate the effects of grazing on the oxygen pulse (O2P; mL O2 consumed per heartbeat; experiment 1) and to quantify the energy cost of grazing in dairy cows using the oxygen pulse–heart rate (O2P-HR) technique (experiments 1 and 2). In both experiments, heat production (HP) was measured using the O2P-HR technique and synchronized with animal activity records. In experiment 1, 15 dairy cows were used to measure the O2P when resting and then immediately after the first grazing session to assess the effect of grazing on O2P. Grazing activity increased HR and oxygen consumption compared with when the cows were resting. However, the increase in both variables was proportional; therefore, O2P was similar, indicating that the change in HR was the main component in the response to an increased O2 demand due to grazing. Hence, it is possible to use the O2P-HR method to measure HP during grazing in dairy cows. The energy cost of grazing was estimated by the difference in HP between when the cow was grazing and when it was not grazing (i.e., idling or ruminating) and ranged from 6.63 ± 1.12 to 7.85 ± 0.68 kJ/kg0.75 per hour and 1.31 ± 0.28 to 1.59 ± 0.14 kJ/kg per hour, respectively. In addition, the energy cost of walking was calculated as the difference in HP when the cow was walking to and from the pasture and the milking parlor versus when it was idling or ruminating. The energy cost of walking was 24.03 ± 1.12 kJ/kg0.75 per hour or 4.72 ± 0.28 kJ/kg per hour. Hourly energy expenditure (kJ/h) was similar between grazing and consuming TMR at the feed bunk, indicating that the extra energy required by dairy cows when fed in a grazing system is mostly explained by the longer time spent to harvest the pasture and the energy cost of walking between the pasture and the milking parlor compared with confined cows fed TMR. Finally, the results of this study suggest that O2P is not affected by grazing and therefore that the O2P-HR technique is a promising methodology to estimate the energy cost of grazing animals without substantially affecting their behavior within the production system.

Caitlin E. Jeffrey, Tucker Andrews, Sandra M. Godden et al.

ABSTRACT: The primary objective of this cross-sectional observational study was to determine whether bulk tank milk quality, udder health, udder hygiene, and milk production outcomes were associated with facility type on organic dairies. A secondary objective was to identify other management-related risk factors associated with bulk tank milk quality, udder health, udder hygiene, and milk production on organic dairy herds in Vermont. We aimed to enroll 40 farms, to compare herds using the 2 most common systems (freestalls, tiestalls) for housing organic dairy cattle in the state with those using a bedded pack during the nongrazing season (typically November–May). Two general styles of bedded packs were observed: cultivated bedded packs and untilled deep-bedded packs. Due to the limited number of herds using bedded packs to house lactating dairy cattle in Vermont, we combined untilled and cultivated bedded packs to describe udder hygiene, milk quality, and udder health on these loose-housing systems deeply bedded with organic material. The study was completed on 21 farms (5 bedded packs, 6 freestalls, 10 tiestalls) before interruption due to the COVID-19 pandemic. Data captured from DHIA records from the test closest to the date of the farm visit included average SCS, standardized 150-d milk (pounds), percentage of cows with current high SCS (SCS ≥4.0), percentage of cows with newly elevated SCS (previous SCS <4.0 to current ≥4.0), and percentage of cows with chronically elevated SCS (SCS ≥4.0 last 2 tests). Multivariable linear regression models were used to describe outcomes by facility type, but suffered from limited statistical power due to small group sample sizes. Unconditional comparisons failed to find statistically significant differences between farms grouped by facility type in metrics captured from DHIA test data, bulk tank milk somatic cell count (BTSCC) and aerobic culture data, or udder hygiene scores. A secondary analysis was conducted using univariate linear regression to identify associations between herd-management factors and outcomes for all 21 farms combined. Although not all differences found were statistically significant in this secondary analysis combining all farms, numeric differences that may be biologically important are reported showing farms with deeper bedding had a lower BTSCC, lower newly elevated SCS, lower chronically elevated SCS, lower elevated current SCS, lower average SCS, and better udder hygiene metrics. Farms with lower mean udder hygiene scores had numerically lower chronically elevated SCS, lower elevated current SCS, and lower average SCS. We could not reject the null hypothesis that milk quality and udder health outcomes did not differ by facility type, and this does not preclude the existence of biological differences in these outcomes between facility types. The current study provides insight on factors affecting bulk tank milk quality, udder health and hygiene measures on organic dairy farms in Vermont. Bedded packs may be a viable option for confinement housing during the winter nongrazing season for pasture-based herds interested in a loose-housing system in the northeastern United States, but more research, such as longitudinal studies with a larger sample size, is needed to test this hypothesis.

S.A. Mulhall, R.D. Sleator, R.D. Evans et al.

ABSTRACT: As the proportion of prime carcasses originating from dairy herds increases, the focus is shifting to the beef merit of the progeny from dairy herds. Several dairy cow total merit indexes include a negative weight on measures of cow size. However, there is a lack of knowledge on the effect of genetic selection, solely for lighter or smaller-sized dairy cows, on the beef performance of their progeny. Therefore, the objective of this study was to quantify the genetic correlations among cow size traits (i.e., cow BW, cow carcass weight [CW]), cow BCS, cow carcass conformation (CC), and cow carcass fat cover (CF), as well as the correlations between these cow traits and a series of beef performance slaughter-related traits (i.e., CW, CC, CF, and age at slaughter [AS]) in their progeny. After data editing, there were 52,950 cow BW and BCS records, along with 57,509 cow carcass traits (i.e., CW, CC, and CF); carcass records from 346,350 prime animals along with AS records from 316,073 prime animals were also used. Heritability estimates ranged from moderate to high (0.18–0.62) for all cow and prime animal traits. The same carcass trait in cows and prime animals were strongly genetically correlated with each other (0.76–0.85), implying that they are influenced by very similar genomic variants. Selecting exclusively for cows with higher BCS (i.e., fatter) will, on average, produce more conformed prime animal carcasses, owing to a moderate genetic correlation (0.30) between both traits. Genetic correlations revealed that selecting exclusively for lighter BW or CW cows will, on average, result in lighter prime animal carcasses of poor CC, while also delaying slaughter age. Nonetheless, selective breeding through total merit indexes should be successful in breeding for smaller dairy cows and desirable prime animal carcass traits concurrently, because of the nonunity genetic correlations between the cow and prime animal traits; this will help to achieve a more ethical, environmentally sustainable, and economically viable dairy-beef industry.

R. W. McDowell, K. Macintosh, C. Depree

Intensive land use, such as dairying, can impair water quality. Although many guidelines exist on how to mitigate the loss of dairy-associated contaminants from land to water through best management practices (BMPs), few datasets exist on the success of implementation on-farm. Five dairy-dominated catchments (from 598 to 2480 ha) in New Zealand were studied from 2001 to 2020. The first period, from 2001 to 2010, involved comprehensive "extension" advice to farmers consisting of workshops, stream water quality and flow monitoring, farm practice surveys, and identified solutions to address site-specific contaminant losses. In the second period (2011-2020), termed "post-extension", only water quality monitoring and farm practice surveys were continued. Of the water quality contaminants (including dissolved reactive phosphorus (DRP), total phosphorus (TP), ammoniacal-nitrogen, nitrate-nitrite-nitrogen [NNN], suspended sediment and E. coli), 83 % of water quality trend directions were either improving (n = 16) or showed no change (n = 9) during the extension period. Over the 20-year dataset, which included the post-extension period, 20 out of 30 contaminant-catchment combinations (67 %) were improving, but nine were degrading, dominated by NNN (n = 4), DRP (n = 2) and E. coli (n = 2). Abrupt decreases in contaminant concentrations, were correlated with on-farm practice changes mainly associated with transition from direct discharge of farm dairy shed effluent to waterways to land application, and the capture of effluent from off-paddock facilities (like stand off or feed pads). Best management practices reduced phosphorus (P) forms, E. coli and sediment concentrations. Increase in NNN concentrations was caused by transitioning from flood to spray irrigation and a commensurate increase in cow numbers and NNN leaching. These data indicate that extension advice and on-farm practice change have helped to improve overall water quality over time. Nevertheless, recent regulatory threshold values for some contaminant concentrations are not being met, meaning that more actions are required, over and above the BMPs implemented.

Ted J. Lawrence, J. Vilbig, G. Kangogo et al.

Productive global agriculture is under a convergence of pressures, and particularly climate change and population growth. The impact is especially stark in East Africa where crop production is mostly rain-fed and population growth rates are among the highest in the world. Our objective for this study was to understand how climate change and population growth have impacted the size of agropastoral areas across Kenya over 40 years. Climate-suitable areas for all primary crops decreased 28% over the study period. Climate-suitable areas for primary crops increased 3% in highly productive counties, decreased 25% in moderately productive counties, and decreased 62% in low productive counties. Climate-suitable areas over the study period decreased 13% for ranching areas, 21% for dairying areas, 24% for mixed crop and ranching areas, and 28% for mixed crop and dairying areas, while climate-suitable areas for pastoralism increased 12%. Population across Kenya more than tripled over the study period, while population relative to climate-suitable areas for crops increased nearly fourfold, and population relative to climate-suitable areas for pastoralism nearly tripled. Population relative to available climate-suitable areas for crops more than doubled in highly productive counties, increased more than four-fold in moderately productive counties, and was nearly 15 times higher in low productive counties. Examining the cumulative effects of climate change and population growth on agricultural sectors across Kenya can help to develop policies and strategies to reach the UN Sustainable Development Goals.

Nina Boberg-Fazlić, P. S. Jensen, M. Lampe et al.

We explore the role of elites for development and the spread of industrialized dairying in Denmark in the 1880s. We demonstrate that the location of early proto-modern dairies, introduced by landowning elites from northern Germany in the eighteenth century, explains the location of industrialized dairying in 1890: an increase of one standard deviation in elite influence increases industrialized dairying by 56 percent of the mean exposure in one specification. We interpret this as evidence for a spread of ideas from the elites to the peasantry, which we capture through measures of specialization in dairying and demand for education and identify a causal relationship using an instrument based on distance to the influential first mover. Finally, we demonstrate that areas with cooperatives enjoyed greater wealth by the twentieth century, and that they are today associated with other Danish cultural attributes: a belief in democracy and individualism.

Wei Hu, J. Drewry, M. Beare et al.

Abstract Agricultural intensification has enhanced productivity, but has also negatively affected soil structure and environmental outcomes. Agriculture is among New Zealand (NZ)'s largest industries. Like other countries, significant land use intensification over the last 20–30 years has occurred in NZ, resulting in undesirable side-effect of soil structural degradation (SSD) (e.g., soil compaction, aggregate fragmentation). Using NZ as a case study, we reviewed and, where possible, quantified the extent of SSD in NZ and its impacts and implications on production, contaminant losses via drainage and runoff, and N2O emissions. Knowledge gaps were identified that will help guide future research both in NZ and internationally. Our review revealed that SSD is common in many regions and under different land uses in NZ. At the national scale, 44% of sites monitored between 2014 and 2017 were below the national target for macroporosity (pore diameter > 30 μm). The occurrence of SSD was greater under more intensive land uses such as dairying and continuous cropping. Soil structural degradation from compaction is typically associated with reduced pasture and crop production. In NZ, pasture production was estimated to decrease by an average of 2.5% for every 1.0% (0.01 cm3 cm−3) decrease in macroporosity (0–10 cm soil). Compaction from livestock treading and wheel traffic has been shown to increase N2O emissions by 51–814% and 19–1300%, respectively, with no significant evidence that this increase is related to N loading. Effects of compaction on contaminant losses via runoff and drainage, and in particular via preferential flow, are less well researched and findings were less consistent and dependent on many factors including the degree of compaction. Important knowledge gaps include a lack of quantitative relationships between degree of SSD and soil hydraulic properties and processes (e.g., water movement and contaminant losses), and poor knowledge of critical thresholds or optimum ranges of soil physical indicators in relation to critical ecosystem services (e.g., pasture yield, gas and water regulation in soils). We also found few estimates of SSD-induced costs related to production and environmental outcomes (e.g., contaminant losses and N2O emissions) at either farm system, regional or national scales. More data are needed to better determine the true costs and implications for farm production and environmental effects associated with SSD.

P. Gerbault, A. Liebert, Y. Itan et al.

Niche construction is the process by which organisms construct important components of their local environment in ways that introduce novel selection pressures. Lactase persistence is one of the clearest examples of niche construction in humans. Lactase is the enzyme responsible for the digestion of the milk sugar lactose and its production decreases after the weaning phase in most mammals, including most humans. Some humans, however, continue to produce lactase throughout adulthood, a trait known as lactase persistence. In European populations, a single mutation (−13910*T) explains the distribution of the phenotype, whereas several mutations are associated with it in Africa and the Middle East. Current estimates for the age of lactase persistence-associated alleles bracket those for the origins of animal domestication and the culturally transmitted practice of dairying. We report new data on the distribution of −13910*T and summarize genetic studies on the diversity of lactase persistence worldwide. We review relevant archaeological data and describe three simulation studies that have shed light on the evolution of this trait in Europe. These studies illustrate how genetic and archaeological information can be integrated to bring new insights to the origins and spread of lactase persistence. Finally, we discuss possible improvements to these models.

Madeleine Bleasdale, K. Richter, Anneke Janzen et al.

Consuming the milk of other species is a unique adaptation of Homo sapiens, with implications for health, birth spacing and evolution. Key questions nonetheless remain regarding the origins of dairying and its relationship to the genetically-determined ability to drink milk into adulthood through lactase persistence (LP). As a major centre of LP diversity, Africa is of significant interest to the evolution of dairying. Here we report proteomic evidence for milk consumption in ancient Africa. Using liquid chromatography tandem mass spectrometry (LC-MS/MS) we identify dairy proteins in human dental calculus from northeastern Africa, directly demonstrating milk consumption at least six millennia ago. Our findings indicate that pastoralist groups were drinking milk as soon as herding spread into eastern Africa, at a time when the genetic adaptation for milk digestion was absent or rare. Our study links LP status in specific ancient individuals with direct evidence for their consumption of dairy products. Consuming the milk of other species is a unique adaptation of Homo sapiens. Here, the authors carry out proteomic analysis of dental calculus of 41 ancient individuals from Sudan and Kenya, indicating milk consumption occurred as soon as herding spread into eastern Africa.

Marion Rambault, Florence B. Gilbert, Philippe Roussel et al.

ABSTRACT: Bovine mastitis is mainly caused by bacterial infection and is responsible for important economic losses as well as alterations of the health and welfare of animals. The increase in somatic cell count (SCC) in milk during mastitis is mainly due to the influx of neutrophils, which have a crucial role in the elimination of pathogens. For a long time, these first-line defenders have been viewed as microbe killers, with a limited role in the orchestration of the immune response. However, their role is more complex: we recently characterized a bovine neutrophil subset expressing major histocompatibility complex class II (MHC-II) molecules (MHC-IIpos), usually distributed on antigen-presenting cells, as having regulatory capacities in cattle. In this study, our objective was to evaluate the implication of different neutrophils subsets in the mammary gland immunity during clinical and subclinical mastitis. Using flow cytometry, we analyzed the presence of MHC-IIpos neutrophils in blood and in milk during clinical mastitis at different time points of inflammation (n = 10 infected quarters) and during subclinical mastitis, defined as the presence of bacteria and an SCC >150,000 cells/mL (n = 27 infected quarters). Our results show, for the first time, that in blood and milk, neutrophils are a heterogeneous population and encompass at least 2 subsets distinguishable by their expression of MHC-II. In milk without mastitis, we observed higher production of reactive oxygen species and higher phagocytosis capacity of MHC-IIpos neutrophils compared with their MHC-IIneg counterparts, indicating the high bactericidal capacities of MHC-IIpos neutrophils. MHC-IIpos neutrophils are enriched in milk compared with blood during subclinical mastitis but not during clinical mastitis. Moreover, we observed a positive and highly significant correlation between MHC-IIpos neutrophils and T lymphocytes present in milk during subclinical mastitis. Our experiments involved a total of 47 cows (40 Holstein and 7 Normande cows). To conclude, our study opens the way to the discovery of new biomarkers of mastitis inflammation.

Abigail Ramsøe, Mia Crispin, M. Mackie et al.

The origins, prevalence and nature of dairying have been long debated by archaeologists. Within the last decade, new advances in high-resolution mass spectrometry have allowed for the direct detection of milk proteins from archaeological remains, including ceramic residues, dental calculus, and preserved dairy products. Proteins recovered from archaeological remains are susceptible to post-excavation and laboratory contamination, a particular concern for ancient dairying studies as milk proteins such as beta-lactoglobulin (BLG) and caseins are potential laboratory contaminants. Here, we examine how site-specific rates of deamidation (i.e., deamidation occurring in specific positions in the protein chain) can be used to elucidate patterns of peptide degradation, and authenticate ancient milk proteins. First, we characterize site-specific deamidation patterns in modern milk products and experimental samples, confirming that deamidation occurs primarily at low half-time sites. We then compare this to previously published palaeoproteomic data from six studies reporting ancient milk peptides. We confirm that site-specific deamidation rates, on average, are more advanced in BLG recovered from ancient dental calculus and pottery residues. Nevertheless, deamidation rates displayed a high degree of variability, making it challenging to authenticate samples with relatively few milk peptides. We demonstrate that site-specific deamidation is a useful tool for identifying modern contamination but highlight the need for multiple lines of evidence to authenticate ancient protein data.

Xiaoyan Feng, Donggen Zhou, Guoyang Xie et al.

ABSTRACT: In addition to Cronobacter spp., Klebsiella pneumoniae is another opportunistic bacterial pathogen present in powdered infant formula (PIF) that can cause pneumonia, septicemia, and other diseases. In this study, a rapid and specific method based on a fluorescence probe was developed for detecting viable K. pneumoniae in PIF samples via the combination of recombinase-aided amplification (RAA) with thiazole orange monoazide (TOMA) dye (the TOMA–RAA assay hereafter). As a novel photosensitive DNA-intercalating dye, TOMA was used to penetrate bacterial cells, including both dead and viable cells, as verified by confocal laser scanning microscopy and fluorescent emission spectrometry. Importantly, the RAA assay exhibited good performance in detecting K. pneumoniae within 40 min at 39°C. Under optimal conditions, the TOMA–RAA assay can detect as low as 2.6 × 103 cfu/mL of K. pneumoniae in pure culture and 2.3 × 104 cfu/g of K. pneumoniae in spiked PIF sample. After 3 h of pre-enrichment, 3 × 100 cfu/g of K. pneumoniae can be detected. Furthermore, the TOMA–RAA assay displayed an excellent anti-interference ability to nontarget bacteria. In short, the proposed method has great potential application for the rapid and accurate detection of viable K. pneumoniae in PIF.

H. Reydams, A. Wuytack, S. Piepers et al.

ABSTRACT: Staphylococcus hominis, a member of the non-aureus staphylococci (NAS) group, is part of the human and animal microbiota. Although it has been isolated from multiple bovine-associated habitats, its relevance as a cause of bovine mastitis is currently not well described. To successfully colonize and proliferate in the bovine mammary gland, a bacterial species must be able to acquire iron from host iron-binding proteins. The aims of this study were (1) to assess the genetic diversity of S. hominis isolated from bovine quarter milk, rectal feces, and teat apices, and (2) to investigate the capacity of bovine S. hominis isolates belonging to these different habitats to utilize ferritin and lactoferrin as iron sources. To expand on an available collection of bovine S. hominis isolates (2 from quarter milk, 8 from rectal feces, and 19 from teat apices) from one commercial dairy herd, a subsequent single cross-sectional quarter milk sampling (n = 360) was performed on all lactating cows (n = 90) of the same herd. In total, 514 NAS isolates were recovered and identified by MALDI-TOF mass spectrometry; the 6 most prevalent NAS species were S. cohnii (33.9%), S. sciuri (16.7%), S. haemolyticus (16.3%), S. xylosus (9.6%), S. equorum (9.4%), and S. hominis (3.5%). A random amplified polymorphic DNA (RAPD) analysis was performed on 46 S. hominis isolates (19 from quarter milk, 8 from rectal feces, and 19 from teat apices). Eighteen distinct RAPD fingerprint groups were distinguished although we were unable to detect the presence of the same RAPD type in all 3 habitats. One S. hominis isolate of a distinct RAPD type unique to a specific habitat (8 from quarter milk, 3 from rectal feces, and 4 from teat apices) along with the quality control strain Staphylococcus aureus ATCC 25923 and 2 well-studied Staphylococcus chromogenes isolates (“IM” and “TA”) were included in the phenotypical iron test. All isolates were grown in 4 types of media: iron-rich tryptic soy broth, iron-rich tryptic soy broth deferrated by 2,2'-bipyridyl, and deferrated tryptic soy broth supplemented with human recombinant lactoferrin or equine spleen–derived ferritin. The growth of the different strains was modified by the medium in which they were grown. Staphylococcus chromogenes TA showed significantly lower growth under iron-deprived conditions, and adding an iron supplement (lactoferrin or ferritin) resulted in no improvement in growth; in contrast, growth of S. chromogenes IM was significantly recovered with iron supplementation. Staphylococcus hominis strains from all 3 habitats were able to significantly utilize ferritin but not lactoferrin as an iron source to reverse the growth inhibition, in varying degrees, caused by the chelating agent 2,2'-bipyridyl.

L. Pisoni, M. Devant, M. Blanch et al.

ABSTRACT: Feed restriction and fasting experienced during commercial production negatively affect unweaned calves' behavior and health status. Transportation and stays at assembly centers are the main factors generating these disorders. For this study, 20 unweaned Angus-Holstein bull calves [44.1 ± 2.04 kg of body weight (BW) and 14.7 ± 0.63 d of age (± standard error)] were used to evaluate the effects of feed restriction and fasting on performance, energy status [serum concentration of glucose, β-hydroxybutyrate (BHB), and nonesterified fatty acids], and gastrointestinal permeability [serum concentration of citrulline, chromium (Cr)-EDTA, lactulose, and d-mannitol]. Calves were randomly assigned to 1 of 4 treatments that simulated the feed restrictions of an assembly center situation on one hand, and the fasting hours during transportation on the other. Treatments were as follows. Control (CT): from d −4 to −1, calves were fed 2.5 L of milk replacer (MR) twice daily; concentrate and straw were offered ad libitum. Mild (MD): calves were fed only MR (d −4 to −1) as described for CT, and on d −1 calves were subjected to a 9-h feed withdrawal. Moderate (MO): calves were fed only MR (d −4 to −1) as described for CT and on d −1 subjected to a 19-h feed withdrawal. Severe (SV): calves were fed only 2.5 L of a rehydrating solution twice daily (d −4 to −1) and on d −1 subjected to a 19-h feed withdrawal. From d 0 to d 42 (weaning) all calves were fed the same feeding program (MR, concentrate, and straw ad libitum). Results showed that BW was greater for the CT treatment compared with the others from d 0 to d 7, whereas BW of SV was lesser compared with the others from d −1 to d 7. No differences among treatments were observed at weaning. At d 2 concentrate intakes of MD, MO, and SV were lesser compared with CT. By d 4, concentrate intake of SV was similar to that for CT and greater than MD and MO. Similarly to BW, no differences in concentrate intake among treatments were observed at weaning on d 42 of the study. At d −1 for SV and d 0 in all restricted calves, serum glucose concentration was lesser compared with CT. At d −1 and 0, nonesterified fatty acids and BHB serum concentrations were greater in the SV calves compared with the other treatments. By d 2, serum concentrations of nonesterified fatty acids, BHB, and glucose were restored to CT levels. At d −1 serum citrulline concentration was lesser in SV and greater in MD calves. The CT calves had lower serum concentrations of Cr-EDTA (d −1 and d 0), lactulose (d 0), and d-mannitol (d 0) compared with the other restricted calves. Results showed that degree of dietary restriction, type of liquid diet (MR or rehydrating solution), and fasting hours (9 vs. 19 h) affected calves' BW, concentrate intake, and serum concentration of markers indicative of energy status and gastrointestinal permeability.