Milk Samples Research Articles

Genotypic insights to Panton-Valentine leukocidin positive methicillin-resistant Staphylococcus aureus isolated from cattle mastitis.

In this research communication we investigate the prevalence and antimicrobial susceptibility of S. aureus harboring virulent genes responsible for mastitis in cattle of Punjab, Pakistan. A total of 690 milk samples were collected from commercial dairy farms for analysis of the prevalence of subclinical and clinical mastitis and isolation of S. aureus. Virulence ability and methicillin resistance in S. aureus (MRSA) was determined by targeting the pvl (the gene for Panton-Valentine leukocidin) and mecA genes, respectively. A total of 175 S. aureus isolates exhibiting prevalence of pvl gene (6.28%) and mecA gene (22.28%) were determined. Antimicrobial susceptibility testing of pvl positive and negative MRSA against different classes of antibiotics revealed 100% resistance against β-lactams while 100% sensitivity towards tylosin and linezolid.

Genetic diversity and phylogenetic relationships of Clostridium perfringens strains isolated from mastitis and enteritis in Egyptian dairy farms

BackgroundClostridium perfringens, a common environmental bacterium, is responsible for a variety of serious illnesses including food poisoning, digestive disorders, and soft tissue infections. Mastitis in lactating cattle and sudden death losses in baby calves are major problems for producers raising calves on dairy farms. The pathogenicity of this bacterium is largely mediated by its production of various toxins.ResultsThe study revealed that Among the examined lactating animals with a history of mastitis, diarrheal baby calves, and acute sudden death cases in calves, C. perfringens was isolated in 23.5% (93/395) of the total tested samples. Eighteen isolates were obtained from mastitic milk, 59 from rectal swabs, and 16 from the intestinal contents of dead calves. Most of the recovered C. perfringens isolates (95.6%) were identified as type A by molecular toxinotyping, except for four isolates from sudden death cases (type C). Notably, C. perfringens was recovered in 100% of sudden death cases compared with 32.9% of rectal swabs and 9% of milk samples. This study analyzed the phylogeny of C. perfringens using the plc region and identified the plc region in five Egyptian bovine isolates (milk and fecal origins). Importantly, this finding expands the known data on C. perfringens phospholipase C beyond reference strains in GenBank from various animal and environmental sources.ConclusionPhylogenetic analyses of nucleotide sequence data differentiated between strains of different origins. The plc sequences of Egyptian C. perfringens strains acquired in the present study differed from those reported globally and constituted a distinct genetic ancestor.

Susceptibility to antibiotics and virulence profiling of Proteus mirabilis among foodstuff

Proteus mirabilis is a genus of bacteria that can cause foodborne diseases. We collected 100 canned food samples from local supermarkets in Hillah (Iraq), including juice (23%), milk products (22%), beef (20%), fish (14%), milk (12%), and tomato paste (9%) samples. We subsequently characterized some virulence factors of P. mirabilis found in these foodstuff, including biofilm formation, protease activity, motility, haemolysis, adhesion, urease production, lipase pro¬duction, and antibiotic susceptibility. In a total of 32 foodstuff samples of positive culture, P. mirabilis was isolated in 15 (46.8%), including 3 juice samples, 4 milk product samples, 2 beef samples, 1 fish sample, 3 milk samples, and 2 tomato paste samples. All isolates exhibited swarming motility (100%) and urease production (100%), while none of the isolates was found to produce haemolysin. The results of the antibiotic susceptibility test revealed a higher re¬sistance against ampicillin (86.6%).

PSIV-A-10 Pilot study: Acute changes in mare milk composition in response to concentrate feeding

Abstract Evaluating dietary effects on mare milk composition is important for optimizing nutrition programs for broodmares. Additionally, accurately measuring milk composition is important for many research studies. Different techniques have been used to collect milk samples, however, the effect time of collection after feeding has not been investigated. The objective of this study was to evaluate the short-term changes in mare milk composition after a concentrate meal. We hypothesized that milk composition, specifically lactose, follows a similar pattern as blood glucose after a high starch meal. Milk samples were collected from four mares at 6 to 7 d postpartum. Baseline blood samples and milk samples were collected, then mares were fed a concentrate meal containing 0.697 g starch/kg body weight (BW). Blood samples were collected via jugular venipuncture at 60, 120, 240, 360, and 480 min postprandial. Blood glucose was measured using a glucometer (OneTouch Ultra 2, LifeScan, USA). Milk samples were collected every 60 min for 480 min postprandial. Foals were muzzled for 60 min intervals and allowed to nurse at each time point to induce milk ejection. Milk samples (> 50 mL) were collected by hand while foals nursed. Milk lactose was measured using an infrared-based milk analyzer (MilkoScan FT+, Foss, Denmark). Area under the curve for lactose and glucose were calculated using the trapezoid method. Changes over time in milk lactose and blood glucose were evaluated using mixed model ANOVA with repeated measures. Pearson’s correlation coefficient was used to evaluate relationships between variables (SAS 9.4). Results were considered significant when P < 0.05. There was a change over time in milk lactose after the concentrate meal (P < 0.0001). Milk lactose was the least pre-feeding (59.0 ± 0.50 g/L) and greatest between 240 to 360 min postprandial (61.6 ± 0.47 g/L; P < 0.05). Blood glucose changed over time after the concentrate meal (P = 0.0365). Pre-feeding glucose was 88.25 ± 2.10 mg/dL which increased to 126.75 ± 10.82 mg/dL by 60 min postprandial (P < 0.05). By 240 min blood glucose was similar to pre-feeding (91.25 ± 6.90 mg/dL; P >0.05). Mean blood glucose AUC was 663 and mean milk lactose AUC was 834. Time to peak glucose was 82.5 min whereas time to peak milk lactose was 225 min. There was no relationship between peak blood glucose and peak milk lactose (P = 0.7311) or AUC for blood glucose or milk lactose (P = 0.8256). The lack of significant relationships may be due to the small sample size. The results from this pilot study demonstrated short term changes in milk lactose after a concentrate meal. Collecting milk samples between 240 to 360 min may be suitable to evaluate dietary effects on milk lactose. However, additional research is needed to evaluate other milk components.

204 Detecting subclinical mastitis in meat-breed ewes using infrared thermography

Abstract Mastitis, the inflammation of the mammary gland most commonly due to bacterial infection, is an important welfare concern in meat-breed sheep. The objective of our study was to evaluate udder surface temperature obtained from infrared thermography as a diagnostic tool for subclinical mastitis. We predicted that udder halves with subclinical mastitis would have greater surface temperatures than healthy udder halves. We enrolled 39 meat-breed ewes (10 Hampshire, 24 Polypay, 5 Targhee; 2 to 9 yr of age) at the University of Wisconsin-Madison sheep unit. All procedures were approved by the UW-Madison Institutional Animal Care and Use Committee. Milk samples from each udder half were collected in duplicate weekly beginning 2 to 4 d postpartum until 8 wk postpartum. Immediately before milk sampling, the udder was photographed from the rear using a thermal camera. A sample was considered a true infection if at least 100 CFU/mL of a bacterial species were isolated. From each photo, we obtained values for minimum, maximum, and mean skin surface temperature for the right and left udders. Three linear mixed models were fit using minimum, maximum, and mean temperatures as the response variables. Fixed effects were infection status (infected or not), weeks postpartum (wk 1-8), and ambient temperature, with a random effect of udder half nested within animal ID. Contrary to our predictions, infection status did not predict udder skin surface temperature (P > 0.12). Healthy udder halves had a mean temperature of 35.5 ± 0.1°C (mean ± SE), minimum temperature of 29.9 ± 0.3°C, and maximum temperature of 37.8 ± 0.1°C. Infected udder halves had a mean temperature of 35.4 ± 0.1°C, minimum temperature of 30.5 ± 0.3°C, and maximum temperature of 37.7 ± 0.1°C. Our results contradict findings in dairy cows, and suggest more research is needed to evaluate the relationship between udder surface temperature and subclinical mastitis in sheep.

185 Maternal live yeast supplementation protects newly weaned piglets against lipopolysaccharide challenge by regulating immune-associated milk proteins

Abstract Sow milk serves as a crucial source of nutritional, immunological, and growth-promoting components for the piglets. Our previous studies established that maternal live yeast (LY) supplementation altered the expression of antioxidant and immune-regulatory genes in the intestinal mucosa of suckling piglets. The current study aimed to investigate the effects of maternal LY supplementation during late gestation and lactation on milk proteomic profile in dams and health of offspring under lipopolysaccharide (LPS) challenge. On d 77 of gestation, 40 sows were allocated to 2 dietary treatments: without (CON) or with LY supplementation at 0.05% of diet during gestation and 0.1% during lactation. Milk samples were collected on d 0, 10, and 18 post-partum (n = 6), respectively. Within 24 h postweaning, piglets from the CON and LY groups were intraperitoneally injected with sterile saline or LPS [25 μg/kg body weight (BW)] and divided into four groups (n = 8): 1) saline + CON (CS), 2) saline + LY (YS), 3) LPS + CON (CLPS), and 4) LPS + LY (YLPS). Data were analyzed in a 2 × 2 factorial arrangement with main effects of maternal diet and immunological challenge. Rectal temperature was measured hourly for 4 h post-injection after which piglets were euthanized. Results showed that LPS increased concentrations of serum tumor necrosis factor (TNF) -α and interlekin (IL) -10 (P < 0.05) and tended to increase IL-8 in the ileal mucosa of piglets (P < 0.10). At 3 h post-injection, YLPS piglets tended to have a lower rectal temperature than CLPS piglets (P < 0.10). YLPS piglets also had decreased protein levels of TNF-α in the ileal mucosa (P < 0.05), with a tendency for greater protein abundance of E-cadherin but decreased mRNA abundance of catalase (P < 0.10) in the jejunal mucosa at 4 h post-injection (P < 0.05). In addition, YLPS piglets had less mRNA abundance of TLR2 and TLR4 in the liver than CLPS piglets (P < 0.05). With shotgun proteomics analysis, we found that milk of LY sows had more abundant proteins associated with immunity, including immunoglobulin and complement protein (Ig-like and C1q domain-containing proteins) on d 0 and d 10. Insulin-like growth factor binding protein (IGFBP) 5 was also more abundant in the d 0 milk of LY sows, whereas prostaglandin synthase was greater in d 10 and d 18 milk of CON sows. Additionally, pathway analysis showed that proteins identified in the milk of CON sows have roles in neutrophil degranulation and IL-12 signaling and production, whereas pathways associated with regulation of complement system, IGF and DHCR24 signaling, were enriched in the milk of LY sows. These results suggest that maternal LY supplementation could protect newly weaned piglets from bacteria endotoxin effect by suppressing inflammatory response, improving expression of tight junction proteins in offspring, and altering immune-associated proteins in sow milk.

PSV-17 Glycerol monolaurate improves litter performance and modifies milk composition when fed to lactating sows

Abstract Glycerol monolaurate (GML) has proven antibacterial, antiviral and anti-inflammatory properties, and additionally has been shown to increase milk immunoglobulins and improve gut health. However, limited information is available on how feeding GML to the sow prior and during lactation can influence the performance of the nursing pig. The objective of this study was to determine if feeding GML to sows would help maintain body condition, increase lauric acid in milk and improve litter performance. A total of 50 sows were randomly assigned to either a control feed or to a control feed with 1.5 kgs/mT of GML (LipoVital GL-90) 3 to 5 dbefore farrowing. Sow and litter performance was measured until weaning at 25 d. On d 1, piglets were cross-fostered within treatment and weighed. Creep feed was offered. Milk samples were taken from 5 randomly selected sows per treatment on d 3 and 25. Glycerol monolaurate had no effect on number of pigs born alive, born dead, stillborn, or number weaned (P > 0.20). No treatment differences (P > 0.20) were observed for sow feed intake, loss of backfat thickness or body weight losses during the study. Control piglets tended to consume more creep feed than GML piglets (P < 0.15). Starting body weight was less for GML piglets (P < 0.001). Despite the decreased starting body weight, weaning weight was not different between treatments (P > 0.20). Using starting body weight as a covariate, total body weight gain tended to be greater (P < 0.08) for GML piglets than the control piglets (5.01 kgs vs 4.89 kg, respectively). Glycerol monolaurate-fed pigs in the bottom quartile of starting body weights (< 1.3 kgs) numerically out gained their control counterparts (4.67 kgs vs 4.12 kgs). Milk from GML sows had 57% more lauric acid on d 3 (P < 0.05) and 124% more lauric acid at weaning compared with control sows (P < 0.05). In conclusion, GML maintained sow body condition, increased the content of lauric acid in milk and improved piglet body weight gain, especially in lighter body weight piglets. The results from this study demonstrate the application of GML in commercial sow herds will be beneficial to both sow and litter.

PSIII-10 Impact of late gestation vitamin A and D injection on offspring growth and immune parameters in piglets

Abstract Supranutritional use of vitamins may have an impact on mortality rates of sows and piglets. Specifically, injection of vitamin A, and vitamin A and D (VitAD) has improved subsequent preweaning mortality when given to sows after weaning and improved immune response in offspring when administered to cattle in late gestation. However, little work has been conducted to investigate developmental impacts of gestational vitamin supplementation in piglets that may impact immune development. To investigate the relationship of VitAD supplementation on offspring development, this study evaluated sows (n = 20) injected intramuscularly with VitAD (312,000 IU vitamin A, 52,500 IU vitamin D) or a saline at d 85 of gestation. Effect of VitAD on performance and immune development was assessed from birth through wk 5 post weaning. Starting at birth (n = 95 VitAD, n = 114 control) piglet serum was collected weekly during the 4 wk lactation period, and a subset of piglets were bled weekly through the nursery. Blood was analyzed for retinol concentrations from birth through 5 wk post weaning and immune parameters via complete blood count analysis for 5 wk post weaning. Milk samples were also collected weekly during lactation and assessed for retinol concentrations via liquid chromatography. Data were assessed via a mixed procedure (SAS 9.4) with sow as random and treatment as fixed variables. Covariate of wean age was assessed for post weaning growth and of sampling time for retinol and CBC analysis. At farrowing, differences in birth weights were not observed (P ≥ 0.69). Through the lactation phase, control piglets had a tendency for increased average daily gain (P ≥ 0.07); however, no differences (P ≥ 0.27) were observed in piglet growth performance during the nursery phase. Blood and immune parameters assessed were not different across treatments from birth through 9 wk of age. Circulating retinol concentrations were greater in the control group, (P ≤ 0.05) at 15, 22, and 28 d of age, compared with VitAD. Milk retinol concentrations were increased in the VitAD group on d 8 of life, (P ≤ 0.05), but not at any other time during lactation. These results suggest that supplementation of VitAD on d 85 of gestation in sows impacts the retinol concentrations in milk for a limited period, but not growth or circulating retinol and immune parameters in piglets at any age. Based on these data, efficacy of supranutritional injection of VitAD may be timing specific and limited to benefiting the litter during lactation. Further research is needed to assess specificity of timing and impacts on piglet health and survival.

96 Evaluating the impact of macroenvironment temperature on thermoregulatory and milk quality parameters in lactating sows and their litter

Abstract Farrowing facility macroenvironment temperatures (TMacro) are often maintained at the upper end of the thermoneutral zone (24–25°C) of lactating sows, which may result in heat stress and reduced milk quality and quantity. Therefore, the study objective was to evaluate the impact of TMacro on thermoregulatory and milk quality parameters in lactating sows and their litters. In two repetitions, 37 lactating sows (parity = 3.1 ± 1.7) and their litters (d 1 litter size = 12.0 ± 1.0) were housed within 1 of 3 farrowing rooms set to different TMacro: LOW (n = 12 sows and litters; 15.0 ± 0.4°C), MID (n = 13 sows and litters; 19.3 ± 0.2°C), and HIGH (n = 12 sows and litters; 24.6 ± 0.8°C). Lactating sows and litters were monitored from d 3 of lactation until weaning (19.8 ± 0.9 d of age). All litters were provided with a 0.34 × 1.52 m heating pad. Sow respiration rates (RR, breaths per minute, BPM) were measured daily at 0800, 1200, 1600 and 2000 h by counting the number of flank movements. Vaginal temperature (TV) was measured in all sows at 10-min intervals using implanted data loggers. One sentinel piglet from each litter was implanted with a temperature recording bolus at d 2 of age to monitor core body temperature in 15-min intervals. Milk samples were collected from all sows on d 6, 12, and 18 of lactation and analyzed for true protein %, total solid %, and fat %. Data were analyzed using PROC GLIMMIX. The litter was considered the experimental unit for piglet measures, and the sow was considered the experimental unit for sow measures. Respiration rates were greater (P < 0.01) for HIGH (48 ± 2 bpm) sows versus MID (33 ± 2 BPM) and LOW (27 ± 2 bpm) sows, but no differences were detected between MID and LOW sows. A TMacro treatment by lactation day effect was observed for TV (P = 0.02), where HOT sows had greater TV on lactation d 15 (+0.31°C), 18 (+0.43°C) and 19 (+0.34°C) versus MID and LOW sows. Piglet core body temperature was reduced (P < 0.01) in the HIGH (39.07 ± 0.06 °C) versus the MID (39.31 ± 0.06 °C) and LOW (39.33 ± 0.07 °C) treatment groups, but it was similar for MID and LOW litters. Fat % was reduced for COLD (6.15 ± 0.52%) versus MID (7.35 ± 0.50%) sows on d 12, but no differences were observed when compared with HIGH sows (6.97 ± 0.52%). In conclusion, the HIGH treatment resulted in physiological heat stress for lactating sows and lowered piglet core body temperature, but it had minimal effects on measures of milk quality.

PSVI-13 Formulated botanical preparation improves passive immunity from sows to piglets

Abstract The medicinal plant turmeric increases immunoglobulin production in livestock and rodents. The purpose of this investigation was to determine the effect of a formulated blend of turmeric, capsicum, and black pepper oleoresins (TCB) on colostrum and milk quality of sows and health of piglets. Twenty-four sows (Parity 2+) were assigned to one of the following dietary treatments (n = 8 sows/treatment): 1) unsupplemented control (CON); 2) 100 ppm of TCB (TCB-100), and 3) 150 ppm of TCB (TCB-150). Supplementation was from 87 d of gestation until weaning (d 28). During gestation and lactation, individually housed sows were fed fortified corn and soybean meal diets at 2.5 kg/d and 2.5 + 0.25 * piglet kg/d, respectively, with ad libitum access to water. Blood and colostrum samples were collected from the sow within 24 h of farrowing for IgG and IgA analysis, and milk samples were collected weekly for IgA analysis. Piglet blood samples were collected at weaning (d 28) for IgG and IgA analysis and at 4-wk post weaning for IgA analysis. Data were subjected to a one-way ANOVA (or two-way in the case of repeated measures), with tests for linear trend of the dose response. Serum IgG and IgA in sows at farrowing were linearly increased with TCB supplementation (Table). Similarly, colostrum IgG, and colostrum and milk IgA were linearly increased with TCB, with greatest concentration in TCB-150 relative to CON (Table). Serum IgG in piglets was not affected by sow supplementation, but serum IgA was linearly increased. Interestingly, the increase in serum IgA persisted through 4-wk post-weaning. Diarrhea frequency in piglets 1 to 4 wk post-weaning was linearly decreased with TCB supplementation (Table). A follow-up study with a similar design was conducted with supplementation of TCB-150 starting at 108 d of gestation to represent a commercial application in lactating diets only. Sow serum IgG and IgA at farrowing were measured, and both were significantly increased with TCB-150 (Table). In conclusion, supplementation of TCB at 150 ppm improves colostrum and milk quality, and passive immunity from sows to piglets. Furthermore, enteric health of the piglets was improved. Additional experiments to determine the implications of this response on sow and piglet health and performance in commercial conditions are warranted.

PSI-17 Effect of timing of high dietary zinc supplementation on the microbiome of gestating sows and their piglets

Abstract The objective of this study was to assess if high dietary zinc (Zn) fed to gestating sows modulates the microbiome of the sow and that of their offspring. Sows were fed 1 of 3 dietary treatments: 1) Control: a corn-soybean meal-based diet containing 125 ppm total supplemental zinc, 2) Breed-to-Farrow: as Control + 141 ppm supplemental Zn as ZnSO4 fed from 5 d post-breeding to farrowing; and 3) Day 110-to-Farrow: as Control + 2,715 ppm supplemental Zn as ZnSO4 starting on d 110 of gestation until farrowing. A subset of third parity sows (n = 30; 10 per treatment) were selected to assess the microbiome of colostrum, milk, and rectal and vaginal surfaces of sows. At farrowing, 4 pigs per litter (n = 120) were selected based on birthweight (BiW; 2 average BiW pigs and 2 pigs with BiW below the litter average) were selected to assess the piglet gut microbiome on the day of birth (d 0) and d5 of age. 16S rRNA sequencing was implemented for colostrum and milk samples while all other sample types were sequenced using shotgun metagenomics to determine taxonomic and functional profiles. Measures of alpha and beta diversity were conducted along with determination of differentially abundant taxa and pathways in tandem with generalized linear mixed models. Greater dietary concentrations of Zn fed to gestating sows minimally affected their colostrum, milk, and vaginal microbiome. However, fecal samples of Breed-to-Farrow sows showed decreased abundance of potentially pathogenic bacteria such as Salmonella enterica and Shigella flexneri and greater abundance of bacteria typically involved in fiber fermentation compared with Control sows (Figure 1a). Piglets born to Day 110-to-Farrow sows also showed greater abundance of some taxa typically involved in fiber breakdown and short chain fatty acid (SCFA) generation on d 5 compared with Control pigs (Figure 1b). At d 0, Breed-to-Farrow piglets showed less abundance of methanogenic archaea and differential abundance of taxa with potentially pathogenic roles, compared with Control pigs (Figure 1c). Gene families and pathways playing roles in central metabolic functions (starch, pyruvate, sucrose, amino acid metabolism) were more abundant in Breed-to-Farrow piglets compared with pigs born to Control sows on d 0 and 5 of age. In conclusion, greater Zn fed to gestating sows impacted the abundance of gut taxa with potential roles in SCFA-production and pathogenicity in both sow and piglet, despite overall minor effects. However, the physiological significance of these findings for the sow and piglet remains unclear.

PSV-9 Effects of increasing amounts of high-oleic or conventional soybeans in diets fed to mid-lactation dairy cows on measures of dry matter intake and lactation

Abstract The objective of the study was to determine effects of increasing amounts of conventional (CONV) or high-oleic (HO) soybean in diets fed to mid-lactation dairy cows on dry matter intake (DMI) and performance. Rumen and duodenally cannulated cows (n = 8) were split into two groups and placed in a split-plot design. The whole plot factor was type of soybean (CONV vs. HO) and was provided to cows in a crossover arrangement so that each cow was provided both types of soybeans throughout the experiment. The subplot factor was amount of soybeans (0, 4, 8, 12%). Each group of cows receiving the same type of soybean were placed in a 4 x 4 Latin square with treatment sequences balanced for carryover effects. Diets were formulated to contain 18.5% crude protein and to slightly exceed requirements for ruminally degradable protein. Additions of soybeans replaced soybean meal and soybean hulls so that diets provided similar amounts of soy-based protein and fiber. During the last 4 d of each 14-d period, spot samples of feed, orts, and milk were collected together with measures of milk production and feed intake. Data were analyzed using the MIXED procedure of SAS. There were no interactions of soybean type and amount on lactation or DMI except for measures of milkfat, milk energy concentration and milkfat yield. Increasing amounts of HO resulted in a quadratic response in milkfat and energy concentration together with measures of milkfat yield. Specifically, these measures were greater (P ≤ 0.02) when cows were fed diets containing 4 and 8% HO compared with diets containing 0 or 12% HO; increasing amounts of CONV had no impact (P ≥ 0.32) on milkfat and energy concentration or milkfat yield. Measures of milk yield were not affected by type or amount of soybean (P ≥ 0.54), but measures of energy corrected milk yield (ECM) tended to respond differently to increasing amounts of soybean from either CONV or HO (P = 0.07). Interestingly, ECM responded quadratically (P = 0.02) to increasing amounts of HO but not to increasing amounts of CONV (P ≥ 0.58). Overall, however, ECM tended (P = 0.06) to be slightly greater with HO compared with CONV (42.5 vs. 41.1 kg/d). Yet, DMI was also greater (P ≤ 0.01) with HO compared with CONV (26.6 vs. 24.4 kg/d). Differences in DMI, therefore, resulted in a tendency (P = 0.07) for greater efficiency of ECM production when cows were fed CONV vs. HO. Overall, treatments had no effect on measures of milk protein, urea-nitrogen, solids-not-fat or lactose concentrations or yields. These data seem to indicate that performance responses among lactating cows to increasing amounts of HO are dynamic but that responses to CONV are not.

102 Circadian patterns of behavior, respiration, rectal temperature, saliva melatonin, cytokine concentrations, and milk immune cells are altered by cooling heat-stressed lactating sows

Abstract Lactating sows are particularly vulnerable to heat stress (HS) due to the increased metabolism from milk production. A greater understanding of HS response could assist in mitigating its detrimental effects on animal production. Two core circadian clock genes were pinpointed in a recent genome study as potential mediators of HS response, indicating the possible alteration of circadian clocks by HS exposure. This study aimed to assess how cooling of lactating sows under natural heat stress conditions in the summer influenced circadian patterns of respiration rate (RR), rectal temperature (RT), behaviors, salivary concentration of cortisol and melatonin, milk cell populations and relative abundance of multiple cytokines in saliva. Lactating sows of mixed parities were divided into two treatment groups: treated with electronic cooling pad (C; n=9) and heat-stressed control (H; n=9). Experiments were conducted during two 48 h periods of increased environmental temperatures from summer heatwaves. During the initial 48 h period, rectal temperature (RT) was monitored every 60 min, rectal temperature (RT) every 30 min, and behaviors of eating, standing, sitting, laying, sleeping, drinking, and nursing every 5 min. Morning milk samples were collected following the completion of the first phase and utilized to categorize and count somatic cells. The second trial was approximately 1 wk later, and during this period saliva samples were collected every 4 h over the 48-h period. Results were analyzed for significant effect of treatments and interaction using periodic regression while circadian patterns were further detected by incorporating a Fourier series model utilizing sine-cosine variables that denote a fit and/or shift in circadian pattern. The analysis revealed that cooling decreased RT and RR while also modifying circadian patterns (P < 0.05). Cooling had no impact on the percentage of time spent in any activity over the 48-h period (P > 0.05). Nevertheless, the daily patterns of eating, standing, and sitting were different between the treatments (P < 0.05). A shift in eating time to later in the day in H sows relative to C sows related to a second rise in RT during the dark phase of the light-dark cycle (P < 0.05). Saliva melatonin concentrations were increased in C sows and circadian pattern altered relative to H (P < 0.05), but there was no effect on salivary cortisol concentrations (P > 0.05). Cooling reduced milk lymphocytes (P < 0.05) and influenced diurnal pattern of saliva cytokines including interleukins (IL) IL-1 alpha, IL-1 beta, IL-10, and IL-15 and transforming growth factor-beta 1. In conclusion, the cooling of heat-stressed sows altered the circadian patterns of physiology, behavior and melatonin, suggesting the need for additional research to investigate whether circadian disruption contributes to reduced production efficiency observed in HS animals.

A Ce2MgMoO6 double perovskite decorated on a functionalized carbon nanofiber nanocomposite for quantification of ciprofloxacin in milk and honey samples: Density functional theory interpretation

In this study, a novel Ce2MgMoO6/CNFs (cerium magnesium molybdite double perovskite decorated on carbon nanofibers) nanocomposite was developed for selective and ultra-sensitive detection of ciprofloxacin (CFX). Physical characterization and analytical techniques were used to explore the morphology, structure, and electrocatalytic characteristics of the Ce2MgMoO6/CNFs nanocomposite. The sensor has a wide linear range (0.005–7.71 μM and 9.75–77.71 μM), a low limit of detection (0.012 μM), high sensitivity (0.807 μA μM−1 cm−2 nM), remarkable repeatability, and an appreciable storage stability. Here, we used density functional theory to investigate CFX and oxidized CFX as well as the locations of the energy levels and electron transfer sites. Furthermore, the Ce2MgMoO6/CNFs-modified electrode was successfully tested in food samples (milk and honey), indicating an acceptable response with a recovery percentage and relative standard deviation of less than 4%, which is comparable to that of GC-MS. Finally, the developed sensor exhibited high selectivity and stability for CFX detection.

Lithium acetate mediated paper-based assay for absorbance analysis of E. coli concentrations

Paper-based assays have revolutionized POC diagnostics, offering significant values across diverse sectors due to their simplicity, cost-effectiveness, and portability. Detecting E. coli is critical for public health but faces challenges in traditional methods, prompting ongoing exploration of alternative approaches. To address the need for heightened sensitivity, this study introduces lithium acetate as a novel element in a paper-based E. coli detection assay, accompanying absorbance analysis using microplate readers. Utilization of lithium acetate as a lysis reagent and carrying out absorbance measurements in paper microtiter plates provide a significant stride in improving sensitivity and assay efficiency. The assay substantially reduced the analysis time to 4 hours with a lower quantification limit of 103 cfu/ml for detecting E. coli in pure cultures. The results suggest that the assay could determine 10 cfu/ml of E. coli in a contaminated milk sample with 4 hours of enrichment time. Thus, the study contributes towards improving E. coli detection with lower quantification limits and shorter analysis times. It is anticipated that the diagnostic methodology would circumvent the challenges in conventional E. coli detection methods, placing emphasis on absorbance analysis to achieve a streamlined, accurate, and rapid paper-based detection technique.

Luminescent gold nanoclusters loaded on iron metal–organic framework with enhanced peroxidase-like activity for the colorimetric/fluorescent determination of H2O2

In this work, a composite nanozyme, termed AuNCs/Fe-MIL, was obtained by combining glutathione-stabilized gold nanoclusters (AuNCs) on the surface of the Fe metal–organic framework (Fe-MIL-88B-NH2). The AuNCs/Fe-MIL nanocomposite retains the red emission of AuNCs, exhibiting unique dual-emission fluorescence with remarkable stability. This nanozyme exhibits improved peroxidase-like activity as a result of the heightened rate of electron transfer. As a result, the decomposition of H2O2 is accelerated, leading to the generation of more •OH radicals that oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) into blue ox-TMB. The generated ox-TMB can quench the fluorescence of AuNCs/Fe-MIL in the red-light region. By leveraging the dual function of the catalytic product ox-TMB, a fusion of colorimetric and fluorescence signals enabled H2O2 detection within 10 min. The sensing platform demonstrated wide linear ranges of 5–1000 μM with a detection limit of 2.78 μM in colorimetry mode and 5–500 μM with a detection limit of 0.78 μM in fluorescence mode. This method was successfully utilized for accurate in situ monitoring of H2O2 release from different types of living cells. Additionally, a dual-mode portable sensing platform based on AuNCs/Fe-MIL/TMB hydrogel was constructed for convenient H2O2 detection. Through a smartphone application, precise quantitation of H2O2 added to milk samples was achieved. This work provides a rational design of multifunctional nanozymes for reliable biomimetic catalysis.

ELISA based Monitoring and Quantification of Tetracycline Residues in Fresh and Powdered Cow Milk Commercialized in Constantine Region (Northeast Algeria)

Background: This study aimed to identify tetracycline residues in milk consumed in the region of Constantine (northeast Algeria) using ELISA based tetracyclin kit. Methods: A total of 180 samples were analyzed (fresh cow milk and imported powdered milk). To compare ELISA and HPLC detection values, 22 fresh milk ELISA positive samples were confirmed by HPLC analysis. Result: 92.5% of fresh milk samples contained tetracycline residues at values between 5 and 74 µg/L and 33.3% of the samples showed concentrations between 49 and 74 µg/L, that exceed the MRLs recommended by the FDA. No significant differences (p greater than 0.01) were found between the values obtained by the two methods.

Identification of an Enterococcus faecium strain isolated from raw bovine milk co-harbouring the oxazolidinone resistance genes optrA and poxtA in China

Oxazolidinones are potent antimicrobial agents used to treat human infections caused by multidrug-resistant Gram-positive bacteria. The growing resistance to oxazolidinones poses a significant threat to public health. In August 2021, a linezolid-resistant Enterococcus faecium BN83 was isolated from a raw milk sample of cow in Inner Mongolia, China. This isolate exhibited a multidrug resistance phenotype and was resistant to most of drugs tested including linezolid and tedizolid. PCR detection showed that two mobile oxazolidinones resistance genes, optrA and poxtA, were present in this isolate. Whole genome sequencing analysis revealed that the genes optrA and poxtA were located on two different plasmids, designated as pBN83–1 and pBN83–2, belonging to RepA_N and Inc18 families respectively. Genetic context analysis suggested that optrA gene on plasmid pBN83–1 was located in transposon Tn6261 initially found in E. faecalis. Comprehensive analysis revealed that Tn6261 act as an important horizontal transmission vector for the spread of optrA in E. faecium. Additionally, poxtA-bearing pBN83–2 displayed high similarity to numerous plasmids from Enterococcus of different origin and pBN83–2-like plasmid represented a key mobile genetic element involved in movement of poxtA in enterococcal species. The presence of optrA- and poxtA-carrying E. faecium in raw bovine milk represents a public health concern and active surveillance is urgently warranted to investigate the prevalence of oxazolidinone resistance genes in animal-derived food products.

Magnetic molecularly imprinted polymers are used to selectively extract cephalosporins from milk samples and analyze by LC-MS/MS

Cephalosporins were extracted from milk samples by using magnetic molecularly imprinted polymers (MMIP). To characterize the physical properties of MMIP, an experiment was conducted involving both static and dynamic adsorption. Samples were analyzed with LC-MS/MS to identify cephalosporin residues. The quantitative technique employed was the use of an isotope as an internal standard. Analysis was conducted using an Ascentis C8 column with a mobile phase consisting of a 0.1 % aqueous solution of formic acid and acetonitrile. The determination coefficients varied between 0.9945 and 0.9995, as indicated by the linear equations. Cephalosporins exhibited a diverse spectrum of recovery rates, varying between 80.7 % and 118.3 %, accompanied by a range of relative standard deviations spanning from 3.8 % to 13.5 %. The detection limits for 9 kinds of cephalosporins in milk samples varied from 1 μg kg−1 to 20 μg kg−1, while the quantification limits ranged from 3 μg kg−1 to 60 μg kg−1. The successful implementation of the validated technique has been applied to detect 9 different kinds of cephalosporins in real milk products.

Human Milk Cannabinoid Concentrations and Associations with Maternal Factors: The Lactation and Cannabis (LAC) Study.

Background and Objectives: As cannabis use increases among reproductive-aged women, there is a growing need to better understand the presence of cannabinoids in milk produced by women using cannabis. It is unclear how concentrations of cannabinoids such as delta-9-tetrahydrocannabinol (Δ9-THC) persist in milk after cannabis use and what factors contribute to variation in milk Δ9-THC concentrations. Our objectives were to measure cannabinoids in human milk following cannabis abstention, after single and repeated instances of cannabis use, and identify factors contributing to concentration variation. Methods: The Lactation and Cannabis (LAC) Study prospectively observed 20 breastfeeding participants who frequently used cannabis (≥1/week), had enrolled <6 months postpartum, were feeding their infant their milk ≥5 times/day, and were not using any illicit drugs. Participants collected a baseline milk sample after ≥12 hours of abstaining from cannabis and five milk samples at set intervals over 8-12 hours after initial cannabis use. Participants completed surveys and recorded self-directed cannabis use during the study period. Results: Δ9-THC peaked 120 minutes after a single instance of cannabis use (median, n = 9). More instances of cannabis use during the study period were associated with greater Δ9-THC area-under-the-curve concentrations (ρ = 0.65, p = 0.002), indicating Δ9-THC bioaccumulation in most participants. Baseline Δ9-THC logged concentration was positively associated with self-reported frequency of cannabis use (b = 0.57, p = 0.01). Conclusions: Cannabinoids are measurable in human milk following cannabis use, and concentrations remain elevated with repeated cannabis use over a day. Substantial variation in Δ9-THC milk concentrations reflects individual differences in characteristics and behavior, including average postpartum frequency of cannabis use.