B.F. Rossi, E.C.R. Bonsaglia, L.B.B. Da Silva
et al.
ABSTRACT: Staphylococcus aureus is a major pathogen responsible for both clinical and subclinical bovine mastitis. Its ability to persist within the mammary gland and evade host immune responses makes it particularly significant for herd health and dairy production. So, this study aimed to evaluate whether the presence and diversity of S. aureus virulence genes mastitis-causing are associated with the onset and severity of mastitis in dairy cows. We analyzed 50 S. aureus isolates obtained from milk samples of cows with subclinical mastitis (SM) and 101 isolates from clinical mastitis (CM), including 28 from mild and 73 from moderate cases. These isolates were screened for genes encoding enterotoxins (sea, seb, sec, sed, see, seg, seh, sei, and sej), biofilm production (bap, icaA, and icaD), toxic shock syndrome toxin (tsst-1), Panton–Valentine leukocidin (pvl), and microbial surface components recognizing adhesive matrix molecules (fnbA, fnbB, fib, clfA, clfB, cna, eno, and ebpS). In addition, pulsed-field gel electrophoresis (PFGE) was used to differentiate the genetic profiles associated with the various disease presentations. The CM isolates presented 16 out of 22 (72.7%) virulence genes compared with 14 (63.6%) in SM isolates. Regardless of mastitis severity, icaD (99.3%), eno (98%), and clfA (78.8%) were the most frequently observed, and seb and sej were not found. Our results also revealed that the virulence genes significantly associated with CM were fnbA, fib, clfA, clfB, cna, ebpS, seg, seh, sei, bap, and icaA. The PFGE revealed that no single cluster included isolates causing both CM and SM. However, CM clusters contained isolates from both mild and moderate mastitis cases. Although the host is a significant variable in the development of mastitis, our findings demonstrate that the virulence profile can play a crucial role in disease progression, as further supported by PFGE results, which showed a distinct separation between CM and SM clusters.
Marialetizia Ponte, Marianna Pipi, Gabriele Busetta
et al.
ABSTRACT: Sulla is a forage legume species exploited mainly by grazing ruminants, greatly appreciated for its high protein content and moderate levels of condensed tannins with antioxidant activity. This study was aimed to explore the potential of sulla in relation to its seasonal utilization, as fresh or stored forage, and to improve the quality traits of sulla forage stocks, proposing dehydration as alternative to haymaking. Two experiments were carried out in different seasons, spring and autumn, both involving Valle del Belìce ewes fed different diets evaluated in terms of dairy production. In the spring experiment, diets consisting of fresh sulla forage (SUL) or fresh barley forage (BAR) provided ad libitum were compared using 12 ewes at 70 DIM divided into 2 groups and fed the 2 diets in a 2 × 2 Latin square design. In the autumn experiment, pellets of dehydrated sulla forage (DSF) obtained from an early (April) or a late (May) cutting time were compared with sulla hay (SH) using 9 ewes at 60 DIM divided into 3 groups and fed the following 3 diets in a 3 × 3 Latin square design: 2 kg/d per ewe of April pellets and SH ad libitum (A-DSF); 2 kg/d of May pellets and SH ad libitum (M-DSF); and SH ad libitum (SHL). Concentrate feed was supplied to all ewes (600 or 800 g/d in spring and autumn, respectively). In both experiments, cheeses manufactured from bulk milk of the different groups were sampled at 15 and 30 d of storage. In spring, compared with BAR, SUL improved the milk casein content, and in cheeses increased the level of PUFA, especially rumenic and α-linolenic acids, reduced redness index (a*) and fat content. In autumn cheese, DSF diets enhanced total PUFA, especially due to linoleic and α-linolenic acids, and polyphenol contents, whereas the A-DSF diet tended to improve the cheese antioxidant capacity, regardless of storage time. The microbiological profile of spring and autumn cheeses was almost similar among diets, indicating no negative effect of stored forages on fermentation process. In triangle tests, the panel was able to distinguish cheese from different diets for both seasons and storage times, without recording differences in their acceptance degree. These results highlight the advantages of dehydration as an alternative to haymaking, and confirm the promising potential of DSF in ensuring adequate dairy production during periods of limited fresh forage availability.
ABSTRACT: Obesity driven by high-fat diets is associated with metabolic dysregulation and gut microbiota disruption. Traditional fermented dairy products, such as Qula from Qinghai Province, China, are valuable sources for isolating novel probiotics with potential therapeutic applications against obesity. This study explored the appetite-regulating mechanisms and gut microbiota modulation by Lacticaseibacillus rhamnosus HF01, a strain isolated from traditional Qula, in mice with high-fat diet–induced obesity. The L. rhamnosus HF01 improved lipid profiles, reduced BW and lipid accumulation, and modulated the hypothalamic expression of appetite-related genes (NPY, POMC), with a particular focus on PYY in appetite regulation. The L. rhamnosus HF01 stimulated PYY secretion through activation of intestinal L cells, which then activated the NPY-Y2 receptor, modulating NPY and POMC expression to regulate appetite. Additionally, L. rhamnosus HF01 reshaped the gut microbiota by increasing the abundance of key short-chain fatty acid (SCFA)-producing genera (Akkermansia, unclassified_f__Muribaculaceae, unclassified_f__Lachnospiraceae, Allobaculum, Candidatus_Saccharimonas). Elevated levels of SCFA, including butyric, isobutyric, and isovaleric acids, correlate with specific microbial taxa and activate GPR41/43 receptors, further promoting PYY secretion. These findings suggest that L. rhamnosus HF01 exerts its antiobesity effects through gut microbiota modulation, SCFA production, and GPR receptor activation, leading to PYY secretion, appetite suppression, and improved metabolic health via the gut-brain axis. The L .rhamnosus HF01 provides a promising therapeutic approach for obesity by targeting the gut-brain axis, regulating appetite through microbiota-driven SCFA production.
Stan Jourquin, Florian Debruyne, Laurens Chantillon
et al.
ABSTRACT: Purchase dependent calf rearing systems, such as the white veal industry, systematically rely on antimicrobial mass medication (metaphylaxis) to counter respiratory tract infections. Despite mounting criticism, the industry fears that without metaphylaxis, mortality would drastically increase. This randomized clinical trial aimed to compare the efficacy of a quick thoracic ultrasonography (qTUS) individualized treatment length between oxytetracycline (OTC) and florfenicol (FF). Regression of maximum consolidation depth <1 cm was used as a criterion for cure and to stop antimicrobial treatment. Additionally, the study assessed the associations of consolidation depth at treatment initiation with cure and treatment duration. The trial involved 320 veal calves, randomly assigned into one of 2 groups: one receiving OTC (n = 160) and the other FF (n = 160) on d 1 (2-d metaphylaxis). Clinical scoring and qTUS were done on d 1 and every 48 h for a 10-d period. After d 1, only calves with consolidations ≥1cm were given further treatment. On each time point, maximum consolidation depth was used to categorize calves into 4 qTUS categories: healthy (no consolidation), mild pneumonia (consolidation <1 cm), moderate pneumonia (consolidation 1–3 cm) and severe pneumonia (consolidation ≥3 cm). Cure, treatment duration and the number of antimicrobial dosages (NAD) were compared between treatment groups. In addition, pathogen identification and antimicrobial susceptibility testing was performed on isolates from nonendoscopic broncho-alveolar lavage fluid. On d 1, 30.0% (96/320) of the calves had consolidation ≥1cm, which increased to 50.9% (162/318) by d 9. After single metaphylactic treatment, cure was 20.9% (9/43) and 20.9% (9/43) in the OTC and FF group, respectively. Calves with severe pneumonia had lower odds to be cured after first treatment than calves with moderate pneumonia (odds ratio = 0.17; 95% CI: 0.04–0.63). By d 9, final cure of the initial cases was 27.9% in both the OTC and FF groups. In both groups, cure was similar at all observation points. Overall, final cure of all calves with either moderate or severe pneumonia during the trial was 41.2% (52/102) and 19.0% (12/63), respectively. Median (Med) treatment duration was 4 d (interquartile range [IQR] = 2–6; minimum [Min] = 2; maximum [Max] = 8) and was similar in both treatment groups. Treatment duration for calves with moderate pneumonia (Med = 6; IQR = 4–6; Min = 2; Max = 8) was lower than the median treatment duration of calves with severe pneumonia (Med = 8; IQR = 4–8; Min = 2; Max = 8). When compared with calves with mild pneumonia on d 1, calves with moderate and severe pneumonia had significantly longer treatment durations. In this study, cure was low and not different between both antimicrobials. Categorizing calves based on consolidation depth appears useful as both cure and treatment duration were different for the mild, moderate, and severe groups.
John B. Cole, Christine F. Baes, Sophie A.E. Eaglen
et al.
ABSTRACT: When related animals are mated to one another, genetic defects may become apparent if recessive mutations are inherited from both sides of the pedigree. The widespread availability of high-density DNA genotypes for millions of animals has made it possible to identify and track known defects as well as to identify and track previously unknown defects that cause early embryonic losses. Although the number of known defects has increased over time, the availability of carrier information has been used to dramatically reduce the frequency of many disorders. The economic impact of known genetic defects in the US dairy cattle population has decreased by ∼2/3 since 2016, due largely to the avoidance of carrier-to-carrier matings. Effective population management requires robust systems for reporting new defects, identification of causal mechanisms, and development of commercially available tests. The United States and Canada depend on informal cooperation among many groups, including farmers, purebred cattle associations, genetics companies, and researchers, to identify emerging and causal defects. The structure of a collaborative system including all key sectors of the dairy cattle industry to support long-term population management is described. This review provides a comprehensive overview of the landscape surrounding genetic defects in dairy cattle. Topics covered include current defects of relevance to commercial dairy producers, trends in carrier frequencies over time, how best to manage these defects, strategies for detecting emerging diseases, and marketing and trade considerations.
ABSTRACT: The Lacticaseibacillus paracasei ProSci-92 (ProSci-92) strain was isolated from traditional fermented yak milk in the Shangri-La Tibetan region, China. Initial screening revealed its promising potential for lactose and protein hydrolysis. This study monitored the growth and metabolic dynamics of ProSci-92 and during a 60-h milk fermentation process using nontargeted metabolomics. Fermented milk samples were collected every 12 h, enabling comparative metabolomic profiling at adjacent time points. By the end of fermentation, the viable cell count reached 4.59 × 109 cfu/mL, accompanied by significant changes in acidity (both pH and titratable acidity). ProSci-92 exhibited active growth, particularly within the first 24 h of fermentation. Notably, the metabolic profiles of fermented milk at different fermentation stages were closely correlated with key fermentation characteristics, including pH, titratable acidity, and the viable cell count in Procrustes analysis (M2 = 0.4085). Our findings revealed significant enrichment of metabolites and pathways associated with AA metabolism and ABC transporters throughout fermentation. Substantial differences in metabolomic profiles were noted between the start (0 h) and end (60 h) of fermentation, marked by an increase in health-promoting metabolites and nutrients, including essential AA, short-chain fatty acids, organic acids, and purines (variable importance in projection score >1). This study elucidates the dynamic changes in the metabolome during ProSci-92 milk fermentation, providing valuable insights into metabolomic transformations over extended fermentation periods. The findings underscore the potential of ProSci-92 as a beneficial starter culture for enhancing the nutritional and health-promoting attributes of fermented milk beverages.
Tony C. Bruinjé, Lucio Campora, Bryn Van Winters
et al.
ABSTRACT: Our objective was to investigate the effects of intravenous (IV) or intrauterine (IU) lipopolysaccharide (LPS) challenge at 5 or 40 d postpartum (DPP) on clinical signs, systemic and uterine inflammation, dry matter intake (DMI), and milk yield (MY). Holstein cows at 5 DPP (n = 23) or at 40 DPP (n = 24) were blocked by parity and randomly assigned to 1 of 3 treatments: (1) IV-LPS (0.0625 μg/kg BW [5 DPP] or 0.1 μg/kg BW [40 DPP] over 1h), (2) IU-LPS (100 μg [5 DPP] or 300 μg [40 DPP] in 20 mL of saline), or (3) 20 mL of saline IU (IU-SAL; same for 5 and 40 DPP). The proportion of polymorphonuclear (PMN) cells was measured by endometrial cytology at d −1, 1, 4, and 7 relative to treatment. Blood haptoglobin (Hp), serum amyloid A (SAA), and LPS-binding protein (LBP), DMI, and MY were measured from d −1 through d 7. Data were analyzed separately for each DPP group in multivariable linear regression models accounting for repeated measures. Both DPP groups showed increases in rectal temperature and heart and respiratory rates, and decrease in rumination rate following IV-LPS, but not following IU-LPS. At 5 DPP, endometrial PMN proportion was similar in IU-LPS and IU-SAL. Serum Hp was unaffected by LPS challenge, SAA was greater in IV-LPS from 12 h to 24 h after challenge, and LBP was greater in IV-LPS from 8 h to 24 h. At 40 DPP, PMN was greater in IU-LPS (37 ± 4%) than in IU-SAL (15 ± 4%) 1 d after LPS challenge. Serum Hp was greater from 24 h to 72 h after challenge in IV-LPS than in the other groups, SAA was greater in IV-LPS from 6 h to 48 h, and LBP was greater in IV-LPS from 8 h to 24 h. At both 5 and 40 DPP, treatment did not affect DMI, but MY was lesser in IV-LPS cows at 12 h and 24 h than in IU-SAL or IU-LPS. The IV-LPS challenge resulted in more pronounced changes in clinical signs and acute phase protein (APP) concentrations than IU-LPS or IU-SAL at 40 DPP, but more subtle or inconsistent changes at 5 DPP. These may be due to the different doses of LPS used at 5 and 40 DPP or possibly due to the high variation in baseline clinical signs and APP observed in all groups at 5 DPP. The IU-LPS increased uterine PMN 1 d after challenge at 40 DPP but not at 5 DPP. At each time, IU-LPS did not produce changes in clinical signs or markers of systemic inflammation.
Camélia Marchand, Isabelle Royer, Rachel Gervais
et al.
ABSTRACT: Most trace minerals (TM) are fed above dairy cow requirements in commercial herds but their fate and effects on dairy cows have not been well documented. In this study, we evaluated the effects of feeding short-term sulfate TM above recommendations on apparent total-tract digestibility of nutrients, rumen fermentation characteristics, serum concentrations, and milk yield and composition, as well as milk, fecal, and urinary TM excretion in midlactation dairy cows. Eight multiparous Holstein cows with an average body weight (± SD) of 684 ± 29 kg at 82 ± 10 DIM in a quadruple 2 × 2 crossover design were fed a basal diet, differing in sulfate TM supplement concentrations, to provide either 0.11, 17, and 63 (control; CON) or 0.95, 114, and 123 (high trace minerals; HTM) mg of dietary Co, Mn, and Zn per kilogram of DM, respectively. Each experimental period had a 21-d adaptation to the diet, followed by a 10-d sample collection period. Feed ingredients and total feces and urine were collected during 4 consecutive d and rumen fluid was collected 0, 1, 2, 4, and 6 h relative to feeding. Milk yield was recorded daily, and milk samples were collected on 4 consecutive milkings. Ingestion of Co, Mn, and Zn was higher for the HTM group compared with the CON group by 216%, 233%, and 93%, respectively. Dry matter intake averaged 25.0 (SE = 0.6) kg/d, and apparent total-tract digestibility of major nutrients was similar between treatments. High trace minerals had no measurable effect on ruminal pH, major volatile fatty acids, and protozoa counts. Isovalerate molar proportion was 9.4% greater for the HTM group compared with the CON group. Neither milk yield (43.5 kg/d; SE = 0.8) nor milk fat and protein concentrations differed between treatments. Milk urea nitrogen concentration was significantly higher for HTM (11.7 mg/dL) compared with CON (9.7 mg/dL; SE = 0.7). Fecal excretion of Co, Mn, and Zn increased by 223%, 198%, and 75%, respectively, for the HTM group compared with the CON group. Urinary excretions of TM were marginal compared with feces, and only urinary Co and Mn were significantly higher for HTM cows than CON cows, as was similarly obtained for serum Co and Mn concentrations. Milk TM yields were not modified by treatments. In summary, short-term dietary sulfate TM supply over the recommendation did not improve cow performance but significantly increased fecal TM excretion, which could affect TM accumulation in soils where manure is applied and could potentially result in leaching into nearby watersheds. Further studies are needed to evaluate the impact of high fecal TM excretion on the environment using the One Health approach. Moreover, the effects of TM oversupply on milk production and cow health should be evaluated by long-term experiments.
ABSTRACT: The use of the immunomodulator OmniGen-AF (OMN) feed supplement, where the response in milk yield, health, and reproduction is uncertain, allows for an application of type I (use the product when it is not profitable) and type II (do not use the product when it is profitable) analysis to aid decision-making regarding its profitability. This study applies a type I and II error analysis to quantify the economic risk of investing in OMN feed supplementation using data from a controlled study and a field dataset collected on dairy farms. Four prediction models were applied considering the expected value and SD of the response in milk yield; milk and health; milk and reproduction; and milk, health, and reproduction. Uncertainty in the milk response was modeled following a normal distribution with mean 0.15 kg/cow per day and SD 0.81 kg/cow per day. This distribution was left-truncated at 0 kg, which resulted in a mean (expected) response of 0.7 kg/cow per day. Based on the field dataset, the reduction in health costs and reproduction were estimated at $0.086 and $0.33/cow per day. All 3 responses were assumed to be present or not in the first 90 DIM. The increase in milk yields necessary to pay for the OMN supplementation considering a response in milk yield only; milk and health; milk and reproduction; and milk, health, and reproduction were 0.45, 0.19, −0.56, and −0.82 kg/cow per day, respectively. The break-even OMN cost per cow per day when considering the increases in milk yield; milk and health; milk and reproduction; and milk, health, and reproduction were $0.23, $0.31, $0.56, and $0.65, respectively. Production responses resulted in costs exceeding revenue with a type I error cost of $2.62 for milk and $0.47 for milk and health response for the broke even. There was no type I error cost associated when considering the responses in milk and reproduction, and the combination of milk, health, and reproduction, which implies that there is no risk of using OMN when it is not profitable (= the product is profitable for certain). Type II costs were associated with returns that are unrealized because of failing to use OMN when it is profitable with an opportunity cost of $9.92, $15.53, $37.23, and $45.08 per cow per day for the responses in milk yield; milk and health; milk and reproduction; and milk, health, and reproduction, respectively. We concluded that a type I and II error analysis applied to the use of the OMN feed additive provided additional insights beyond a break-even analysis to support economic decision-making when the response on dairy farms is uncertain. The type I and II error analysis can aid in decision-making process to evaluate the adoption of a new technology.
Martina Piazza, Stefano Schiavon, Sudeb Saha
et al.
ABSTRACT: This study aimed to compare rotational 3-breed crossbred cows of Viking Red, Montbéliarde, and Holstein breeds with purebred Holstein cows for a range of body measurements, as well as different metrics of the cows' productivity and production efficiency. The study involved 791 cows (440 crossbreds and 351 purebreds), that were managed across 2 herds. Within each herd, crossbreds and purebreds were reared and milked together, fed the same diets, and managed as one group. The heart girth, height at withers, and body length were measured, and body condition score (BCS) was determined on all the cows on a single test day. The body weight (BW) of 225 cows were used to develop an equation to predict BW from body size traits, parity, and days in milk, which was then used to estimate the BW of all the cows. Equations from the literature were used to estimate body protein and lipid contents using the predicted BW and BCS. Evidence suggests that maintenance energy requirements may be closely related to body protein mass, and Holstein and crossbred cows may be different in body composition. Therefore, we computed the requirements of net energy for maintenance (NEM) on the basis either of the metabolic weight (NEM-MW: 0.418 MJ/kg of metabolic BW) or of the estimated body protein mass according to a coefficient (NEM-PM: 0.631 MJ/kg body protein mass) computed on the subset comprising the purebred Holstein. On the same day when body measurements were collected, individual test-day milk yield and fat and protein contents were retrieved once from the official Italian milk recording system, and milk was sampled to determine fresh cheese yield. Measures of NEM were used to scale the production traits. Statistical analyses of all variables included the fixed effects of herd, days in milk, parity, and genetic group (purebred Holstein and crossbred), and the herd × genetic group interaction. External validation of the equation predicting BW yielded a correlation coefficient of 0.94 and an average bias of −4.95 ± 36.81 kg. The crossbreds had similar predicted BW and NEM-MW compared with the Holsteins. However, NEM-PM of crossbreds was 3.8% lower than that of the Holsteins, due to their 11% greater BCS and different estimated body composition. The crossbred cows yielded 4.8% less milk and 3.4% less milk energy than the purebred Holsteins. However, the differences between genetic groups were no longer significant when the production traits were scaled on NEM-PM, suggesting that the crossbreds and purebreds have the same productive ability and efficiency per unit of body protein mass. In conclusion, measures of productivity and efficiency that combine the cows' production capability with traits related to body composition and the energy cost of production seem to be more effective criteria for comparing crossbred and purebred Holstein cows than just milk, fat, and protein yields.
ABSTRACT: Colostrum yield and quality are influenced by prepartum nutrition and the metabolic status of the cow; however, data considering these associations on multiple dairy farms are limited. Our objective was to identify cow-level prepartum metabolic indicators, as well as farm-level nutritional strategies associated with colostrum yield and the indicator of colostrum quality, Brix %. A convenience sample of 19 New York Holstein dairies (median: 1,325 cows; range: 620 to 4,600 cows) were enrolled in this observational study. Records for individual colostrum yield and Brix % were collected by farm personnel between October 2019 and February 2021. Farms were visited 4 times, approximately 3 mo apart, to obtain feed samples of the prepartum diets, collect blood samples from 24 pre- and postpartum cows, respectively, and determine prepartum body condition score. Feed samples were submitted for analysis of chemical composition, and particle size was determined on-farm using a particle separator. Prepartum serum samples (n = 762) were analyzed for glucose and nonesterified fatty acid concentrations. Whole blood from postpartum cows was analyzed for herd prevalence of hyperketonemia (proportion of samples with β-hydroxybutyrate ≥1.2 mmol/L). A cohort of primiparous (PP; n = 1,337) and multiparous (MPS; n = 3,059) cows calving ± 14 d of each farm visit were included in the statistical analysis. Animals calving in this period were assigned results for the close-up diet composition and herd prevalence of hyperketonemia collected from the respective farm visit. Greatest colostrum yield from PP and MPS cows was associated with moderate starch [18.6–22.5% of dry matter (DM)] and a moderate herd prevalence of hyperketonemia (10.1–15.0%). Greatest colostrum yield from MPS cows was associated with moderate crude protein (13.6–15.5% of DM) and a less severe negative dietary cation-anion difference (DCAD; >−8 mEq/100 g), whereas greatest colostrum yield from PP cows was associated with low crude protein (≤13.5% of DM). In addition, a moderate proportion of the diet with particle length ≥19 mm (15.3–19.1%) was associated with lowest colostrum yield from PP and MPS cows. Highest colostrum Brix % was associated with prepartum dietary factors of low neutral detergent fiber (≤39.0% of DM) and high proportion of the diet with particle length ≥19 mm (>19.1%). In addition, low starch (≤18.5% of DM) and low and moderate DCAD level (≥−15.9 mEq/100 g) were associated with greatest Brix % from PP cows, whereas moderate DCAD (−15.9 to −8.0 mEq/100 g) was associated with greatest Brix % from MPS cows. Prepartum serum nonesterified fatty acid concentration ≥290 µEq/L was associated with increased colostrum yield, but prepartum serum glucose concentration and body condition score were not associated with colostrum yield or Brix %. These data provide nutritional and metabolic variables to consider when troubleshooting colostrum production on farms.
Ricardo S. Aleman, Roberto Cedillos, Ryan Page
et al.
ABSTRACT: l-Glutamine, quercetin, slippery elm bark, marshmallow root, N-acetyl-d-glucosamine, licorice root, maitake mushrooms, and zinc orotate have been reported to help treat leaky gut. The purpose of this research was to explore the impact of these functional ingredients on the physico-chemical, microbiological, and sensory properties of yogurt. The milk from same source was equally divided into 9 pails and the 8 ingredients were randomly assigned to the 8 pails. The control had no ingredient. Milk was fermented to yogurt. The pH, titratable acidity, syneresis, viscosity, color (L*, a*, b*, C*, and h*), Streptococcus thermophilus counts, and Lactobacillus delbrueckii spp. bulgaricus counts of yogurts were determined on d 1, 7, 14, 21, 28, 35, and 42, whereas coliform counts, yeast and mold counts, and rheological characteristics were determined on d 1 and 42. The sensory study was performed on d 3 and particle size of the functional ingredients (powder form) was also determined. When compared with control, the incorporation of slippery elm bark into yogurts led to less syneresis. l-Glutamine increased pH and n′ values (relaxation exponent derived from G′) and lowered titratable acidity values. N-Acetyl-d-glucosamine incorporation resulted in higher n′ and lower titratable acidity values, whereas maitake mushroom led to lower n′ values. Incorporating quercetin increased the growth of L. bulgaricus. Adding maitake mushrooms increased the growth of S. thermophilus but lowered apparent viscosity values, whereas quercetin decreased its S. thermophilus counts. Quercetin decreased L* and a* values but increased b* values, and maitake mushroom increased a* values. Thixotropic behavior increased with the addition of licorice root and quercetin. Adding slippery elm bark, N-acetyl-d-glucosamine, licorice root, maitake mushrooms, and zinc orotate into yogurt did not affect the sensory properties, whereas yogurts with quercetin had the lowest sensory scores. Overall, most of these ingredients did not cause major changes to yogurt properties.
ABSTRACT: Process cheese products (PCP) are dairy foods prepared by blending dairy ingredients (such as natural cheese, protein concentrates, butter, nonfat dry milk, whey powder, and permeate) with nondairy ingredients [such as sodium chloride, water, emulsifying salts (ES), color, and flavors] and then heating the mixture to obtain a homogeneous product with an extended shelf life. The ES, such as sodium citrate and disodium phosphate, are critical for the unique microstructure and functional properties of PCP because they improve the emulsification characteristics of casein by displacing the calcium phosphate complexes that are present in the insoluble calcium-paracaseinate-phosphate network in natural cheese. The objectives of this study were to determine the optimum protein content (3, 6, and 9% protein) in micellar casein concentrate (MCC) to produce acid curd and to manufacture PCP using a combination of acid curd cheese and MCC that would provide the desired improvement in the emulsification capacity of caseins without the use of ES. To produce acid curd, MCC was acidified using lactic acid to get a pH of 4.6. In the experimental formulation, the acid curd was blended with MCC to have a 2:1 ratio of protein from acid curd relative to MCC. The PCP was manufactured by blending all ingredients in a KitchenAid blender (Professional 5 Plus, KitchenAid) to produce a homogeneous paste. A 25-g sample of the paste was cooked in the rapid visco analyzer (RVA) for 3 min at 95°C at 1,000 rpm stirring speed during the first 2 min and 160 rpm for the last min. The cooked PCP was then transferred into molds and refrigerated until further analysis. This trial was repeated 3 times using different batches of acid curd. MCC with 9% protein resulted in acid curd with more adjusted yield. The end apparent viscosity (402.0–483.0 cP), hardness (354.0–384.0 g), melting temperature (48.0–51.0°C), and melting diameter (30.0–31.4 mm) of PCP made from different acid curds were slightly different from the characteristics of typical PCP produced with conventional ingredients and ES (576.6 cP end apparent viscosity, 119.0 g hardness, 59.8°C melting temperature, and 41.2 mm melting diameter) due to the differences in pH of final PCP (5.8 in ES PCP compared with 5.4 in no ES PCP). We concluded that acid curd can be produced from MCC with different protein content. Also, we found that PCP can be made with no ES when the formulation uses a 2:1 ratio of acid curd relative to MCC (on a protein basis).
ABSTRACT: The triglyceride composition of milk fat largely determines the manufacturing characteristics of products containing milk fat. Increasing oleic acid content of milk fat might be desirable for human nutrition and also for butter and whipping cream, among other product applications. The objective of this research was to determine the effects of increasing intestinally available oleic acid (provided via abomasal infusion) on the profile of milk triglycerides. A control and 4 increasing doses of free fatty acids from high oleic sunflower oil (HOSFA) were infused into the abomasum of 4 lactating dairy cows in a changeover experimental design with periods of 7 d. Treatments were (1) control (no fatty acids infused), (2) HOSFA (250 g/d), (3) HOSFA (500 g/d), (4) HOSFA (750 g/d), and (5) HOSFA (1,000 g/d). All treatments included meat solubles and Tween 80 as emulsifiers. Infusion of HOSFA increased oleic acid and decreased short- and medium-chain fatty acids in milk fat. Statistical analysis of results showed linear changes in most of the milk triglycerides analyzed. The most significant changes as the result of increasing HOSFA infusion were a decrease in triglycerides with saturated fatty acids (butyrin-caprylin-palmitin, butyrin-laurin-olein, butyrin-myristin-palmitin, butyrin-palmitin-palmitin, caproin-myristin-palmitin, butyrin-palmitin-stearin, caproin-palmitin-palmitin) and an increase in dioleyl triglycerides (with butyric, lauric, myristic and palmitic acids) and triolein. The synthesis of triglyceride is position-specific and does not follow a random distribution model.
ABSTRACT: Effects of corn silage supplementation on milk production of grazing dairy cows depend in part on the substitution rate between the 2 forages, which may be influenced by grazing management. The aim of this study was to compare 2 grazing management strategies for measuring substitution rate between herbage and corn silage, in interaction with grazing intensity. Six treatments were compared, with 2 grazing intensities and 3 supplementation strategies investigated at both grazing intensities. The 2 grazing intensities were severe and light grazing, defined by either (1) herbage allowance (HA) of 15 (severe) or 30 (light) kg dry matter (DM)/cow per d at 3 cm above ground level or (2) postgrazing sward height, depending on the supplementation strategy. The 3 supplementation strategies were as follows: (U) an unsupplemented treatment, (A) 5 kg DM/d of corn silage offered at a similar HA as in U, and (H) 5 kg DM/d of corn silage offered at a similar postgrazing sward height as in U. Thirty-six multiparous Holstein cows were used in a randomized complete block design and divided in 2 groups for the entire experiment, one for each grazing intensity. Within each grazing intensity group, the corn silage supplementation strategy was studied using a 3 × 3 Greco-Latin square design, with 3 periods of 14 d. Supplementing cows with corn silage increased total DM intake only for severe grazing by 1.7 kg DM/d. The substitution rate between corn silage and grazed herbage was lower for severe than for light grazing, averaging 0.63 and 1.23, respectively. Herbage dry matter intake was lower by 1.2 kg/d for strategy H than A, leading to lower substitution rates (0.81 vs. 0.99, respectively), irrespective of grazing intensity. Milk production increased with silage supplementation for severe grazing (+1.0 kg/d milk) and was unaffected by silage supplementation for light grazing (−0.4 kg/d milk). The milk production response to corn silage supplementation averaged +0.23 and −0.08 kg of milk per kg DM of silage for severe and light grazing, respectively. Fat-corrected milk production tended to be lower by 0.4 kg/d for strategy H than A, leading to lower milk production response (+0.00 vs. +0.12 kg of milk per kg DM of silage, respectively). Milk protein concentration increased with silage supplementation for severe grazing (+1.0 g/kg) but decreased with silage supplementation for light grazing (−0.6 g/kg). Milk fat concentration did not differ among treatments. On average, daily grazing time (−47 min/d, i.e., −9%) and herbage intake rate (−4.9 g of DM/min, i.e., −14%) decreased when cows were supplemented, with greater grazing time reduction at severe than light grazing, and greater herbage intake rate reduction at light than severe grazing. In conclusion, the greater substitution rate and the lower 4% fat-corrected milk production when corn silage was provided at a similar postgrazing sward height rather than at a similar HA to those of unsupplemented cows explain why supplementing grazing dairy cows with conserved forages has no strong effect in practice from a production point of view.
Marina Loch, Tarmo Niine, Elisabeth Dorbek-Kolin
et al.
ABSTRACT: During the first 3 wk of life, the immune system of newborn ruminants starts to work, as indicated by fluctuations in the concentrations of proinflammatory cytokines and acute phase proteins (APP). They have been shown to be markers for short and long-term weight gain in ruminants. This observational study investigated these proteins as possible indicators of first lactation performance of dairy cows. A total of 117 dairy calves from a single farm were enrolled in the study. Serum and fecal samples were taken once a week for the first 3 wk of life. Cryptosporidium spp. infection and its treatment were monitored and accounted for in statistical analysis. The concentrations of the APP serum amyloid A (SAA) and haptoglobin (Hp), and the proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) were analyzed in serum. After the first lactation, health and performance data of the cows were retrieved, and associations between APP and cytokine concentrations with first lactation outcomes were investigated through linear and logistic regression. This study found a negative association between the concentration of Hp in the second week of life and average daily weight gain at one year. The SAA concentration measured during the second and third weeks of life was positively associated with age at first calving. IL-6, SAA, and Hp measured in the second week of life were positively associated with calving to conception interval. The concentrations of IL-6 and TNF-α during the first week of life were associated with higher odds of reproductive issues during the first lactation period. These markers can be used to help understand underlying processes that influence animal health and production. In conclusion, inflammatory responses during the first week of life are related to reproductive success, whereas the second and third weeks of life seem to influence the future productive performance in dairy cows.
ABSTRACT: We fit the Wood's lactation model to an extensive database of test-day milk production records of US Holstein cows to obtain lactation-specific parameter estimates and investigated the effects of temporal, spatial, and management factors on lactation curve parameters and 305-d milk yield. Our approach included 2 steps as follows: (1) individual animal-parity parameter estimation with nonlinear least-squares optimization of the Wood's lactation curve parameters, and (2) mixed-effects model analysis of 8,595,413 sets of parameter estimates from individual lactation curves. Further, we conducted an analysis that included all parities and a separate analysis for first lactation heifers. Results showed that parity had the most significant effect on the scale (parameter a), the rate of decay (parameter c), and the 305-d milk yield. The month of calving had the largest effect on the rate of increase (parameter b) for models fit with data from all lactations. The calving month had the most significant effect on all lactation curve parameters for first lactation models. However, age at first calving, year, and milking frequency accounted for a higher proportion of the variance than month for first lactation 305-d milk yield. All parameter estimates and 305-d milk yield increased as parity increased; parameter a and 305-d milk yield rose, and parameters b and c decreased as year and milking frequency increased. Calving month estimates parameters a, b, c, and 305-d milk yield were the lowest values for September, May, June, and July, respectively. The results also indicated the random effects of herd and cow improved model fit. Lactation curve parameter estimates from the mixed-model analysis of individual lactation curve fits describe well US Holstein lactation curves according to temporal, spatial, and management factors.
Enyew Negussie, Oscar González-Recio, Mara Battagin
et al.
ABSTRACT: Direct measurements of methane (CH4) from individual animals are difficult and expensive. Predictions based on proxies for CH4 are a viable alternative. Most prediction models are based on multiple linear regressions (MLR) and predictor variables that are not routinely available in commercial farms, such as dry matter intake (DMI) and diet composition. The use of machine learning (ML) algorithms to predict CH4 emissions from across-country heterogeneous data sets has not been reported. The objectives were to compare performances of ML ensemble algorithm random forest (RF) and MLR models in predicting CH4 emissions from proxies in dairy cows, and assess effects of imputing missing data points on prediction accuracy. Data on CH4 emissions and proxies for CH4 from 20 herds were provided by 10 countries. The integrated data set contained 43,519 records from 3,483 cows, with 18.7% missing data points imputed using k-nearest neighbor imputation. Three data sets were created, 3k (no missing records), 21k (missing DMI imputed from milk, fat, protein, body weight), and 41k (missing DMI, milk fat, and protein records imputed). These data sets were used to test scenarios (with or without DMI, imputed vs. nonimputed DMI, milk fat, and protein), and prediction models (RF vs. MLR). Model predictive ability was evaluated within and between herds through 10-fold cross-validation. Prediction accuracy was measured as correlation between observed and predicted CH4, root mean squared error (RMSE) and mean normalized discounted cumulative gain (NDCG). Inclusion of DMI in the model improved within and between-herd prediction accuracy to 0.77 (RMSE = 23.3%) and 0.58 (RMSE = 31.9%) in RF and to 0.50 (RMSE = 0.327) and 0.13 (RMSE = 42.71) in MLR, respectively than when DMI was not included in the predictive model. When missing DMI records were imputed, within and between-herd accuracy increased to 0.84 (RMSE = 18.5%) and 0.63 (RMSE = 29.9%), respectively. In all scenarios, RF models out-performed MLR models. Results suggest routinely measured variables from dairy farms can be used in developing globally robust prediction models for CH4 if coupled with state-of-the-art techniques for imputation and advanced ML algorithms for predictive modeling.