Enteric methane (CH4) emissions of 3 genetic groups (GG) of dairy cows were recorded across the grazing season (early March to late October). The 3 GG were (1) high economic breeding index (EBI) ...Holstein-Friesian (HF) representative of the top 1% of dairy cows in Ireland at the time of the study (elite), (2) national average (NA) EBI, which were representative of the average HF dairy cow in Ireland, and (3) purebred Jersey (JE) cows. Enteric CH4 was recorded using GreenFeed technology. Seasonal variation in CH4 was observed, with the lowest daily CH4 emissions and CH4 expressed per unit of dry matter intake occurring in spring (253 g/d and 15.56 g/kg, respectively), intermediate in summer (303 g/d and 18.26 g/kg, respectively), and greatest in autumn (324 g/d and 19.80 g/kg, respectively). Seasonal variation was also observed in the proportion of gross energy intake converted to CH4 (Ym); in the spring the Ym was lowest at 0.046, increasing to 0.053 and 0.058 in the summer and autumn, respectively. There was no difference in daily CH4 between the elite and NA, whereas JE had lower CH4 emissions compared with the elite. When expressed per unit of milk solids (fat + protein yield; MS), the elite and JE produced 6.8% and 9.7% less CH4 per kilogram of MS, respectively, compared with NA. There was no difference between the GG for CH4 per unit of DMI or the Ym. This research emphasizes the variation in CH4 emissions across the grazing season and among cows of differing genetic merit for CH4 emission intensities but not for CH4 per unit of DMI or the Ym.
Chromium (Cr) has been reported to modulate blood biochemistry in dairy cows. However, there is a discrepancy in the literature regarding the effects of dietary Cr supplementation on various blood ...parameters. This meta-analysis aimed to evaluate the effects of Cr supplementation in dairy cows on blood glucose, insulin, glucagon, nonesterified fatty acid (NEFA), cortisol, and serum total protein (STP) concentrations. Following relevant literature data extraction, a 3-level meta-analytical random effect model was fitted to the data expressed as standardized mean difference (SMD) of outcome measures of control versus Cr-supplemented cows (i.e., difference in mean between control and treatment group or pooled standard deviation). The SMD can be categorized as having a small effect (0.20), a moderate effect (0.50), and a large effect (0.80). The meta-regression identified the potential sources of heterogeneity, including the body weight of cows, experimental duration/duration of Cr supplementation, blood sampling time (3 wk before parturition until 4 wk after parturition categorized as the transition period, else as the nontransition period), and form of Cr complexes. Blood glucose did not differ significantly between control and Cr-supplemented cows with an estimated SMD of μ = 0.0071 (95% confidence interval CI: −0.212 to 0.226). The effect of Cr supplementation on blood insulin was also nonsignificant with an SMD of μ = 0.0007 (95% CI: −0.191 to 0.193). Cows receiving Cr supplements had significantly higher levels of glucagon than controls (95% CI: 0.116 to 0.489), with an estimated SMD = 0.303. Combined transition and nontransition data suggest Cr supplementation did not affect the concentration of NEFA. However, in transition cows, Cr supplementation significantly decreased blood NEFA levels as compared with controls (95% CI: −0.522 to −0.0039), with estimated SMD = −0.263. The estimated SMD was μ = −0.1983 (95% CI: −0.734 to 0.337) for cortisol and −0.0923 (95% CI: −0.316 to 0.131) for total protein. In summary, Cr supplementation in the transition cows decreased NEFA concentration. Blood glucose, insulin, cortisol, and STP concentrations were unaffected. However, Cr supplementation increased glucagon concentration.
An analyze of the teats of cows from four farms with milking parlor was carried out to see the environment impact on mastitis The major causes of the mastitis were the low preoccupation for the ...maintenance of the normal function of the milking machine, the lack to keep the waiting time in a standing position, after the milking, the lack of instruction of the milking personnel.
Our research sets out to quantify the way in which the nutritional value of the food ratios influences the milk production in Fleckvieh cows which were imported in Agriland ranch in the summer of ...2008, from Germany. The different types of fodder existent at the ranch and their supply in the animals’ ratios according to the season has been taking into consideration when calculating the nutritional value which has been afterwards compared with the expected values. The main objective was estimating the potential production and then comparing it with the real one obtained in the ranch, under the specific conditions of shelter and feeding. The health of the animals has also been observed. The evolution of the real graphic of lactation is very different from the potential one, in the sense that in the first two or three months of lactation the production decreases, and its peak is somewhere between the fourth month and the fifth month. This proves a feeding which is not proper, because it is not differentiated by production. The ratios should be made proper and this is done relatively easy by including phosphates into the ratio. The energy level can be corrected by individually administering the concentrated fodder which has to be correlated with the milk production.
The purpose of this research was to establish the manner in which the flooring type may influence the welfare levels in dairy cows by assessment of laminitis incidence and animals’ behaviour. 42 ...dairy cows were grouped based on the shelter floor surface: concrete with straw bedding, asphalted concrete with straw bedding and concrete plus shavings. The behaviour was assessed through direct observation and laminitis incidence was established by numerical assessment of locomotion prior or following milking. The results have indicated an increase of laminitis incidence by 15-25 % in B and C lot and was absent in A lot. The large number of diseases was recorded on concrete floors with shavings bedding (53%). The behavioural displays of the cows suffering from laminitis were different from the healthy ones, as their resting behaviour outside the stalls was more prevalent (17.6% compared to 8.8%) while the feeding behaviour was less present (10.1% compared to 14.7%). Likewise, the socializing behaviour was more active in these animals, compared to the healthy cows.
The aim of the work was to obtain data and formulate knowledge about the behavioural manifestations of dairy cows in relation to the management system of feeding regime on the farm, where Holstein ...cows are bred. The observations took place on the 13 and 14 August, 2014, when the cows were observed for 24 hours continuously. The ethogram records were recorded after 1 minute and physical activity of cows, periods of rest, ruminating, eating, drinking, defecation, urination and comfort and social behaviour. Cows are herded for milking 3 times a day. It was found that within 24 hours dairy cows spend on average 10 hours by lying, 8 hours by ruminating, 20 minutes by drinking, 6 hours by eating, they defecate 14 times, urinate 6 times and walk about 430 meters. They are also scratching, licking each other and tail swiping (comfort behaviour) within 24 hours. The observations of the responses to serving food indicate that cows actively react to the passage of the food vehicle, not the passage of a piling-up tractor.
High-yield dairy cows typically undergo intense cellular metabolism, leading to oxidative stress in their mammary tissues. Our study found that these high-yield cows had significantly elevated levels ...of hydrogen peroxide (H2O2), lipoperoxidase, and total antioxidant capacity in their blood, compared with ordinary cows. This increased oxidative stress is associated with heightened expression of genes such as GCLC, GCLM and SIRT1 and proteins such as SIRT1 in the mammary tissue of high-yield cows. MAC-T cells were stimulated with H2O2 at a concentration equal to the average H2O2 level in the serum of ethically high-yielding cows, as detected by an assay kit. Our observations revealed that short-term exposure (12 h) to H2O2 upregulated the expression of SIRT1 gene and protein. It also increased gene expression for SOD2, CAT, GCLC, GCLM, PGC-1α, and NQO1, elevated the phosphorylation of AMPK, and enhanced protein expression of PGC-1α, NQO1, Nrf2, and HO-1, while reducing the phosphorylation of NF-κB. Additionally, short-term H2O2 stimulation resulted in increased total antioxidant capacity, SOD, GSH, and CAT levels in the mammary epithelial cells of dairy cows. In contrast, prolonged exposure to H2O2 (24 h) yielded opposite results, indicating reduced antioxidant capacity. Further investigation showed that SIRT1 inhibitor (EX 527) could reverse the enhanced cellular antioxidant capacity triggered by short-term oxidative stress. However, it is crucial to note that while 12 h H2O2 stimulation improved antioxidant capacity, reactive oxygen species (ROS) and malondialdehyde (MDA) levels inside the cell gradually increased over time, suggesting greater damage under long-term stimulation. Conversely, the SIRT1 activator (SRT 2104) could reverse the reduced cellular antioxidant capacity caused by long-term oxidative stress and significantly inhibit the accumulation of ROS and MDA. Notably, SRT 2104 demonstrated similar effects in MAC-T cells during lactation. In summary, SIRT1 plays a crucial role in regulating the antioxidant capacity of mammary epithelial cells in dairy cows. This discovery provides valuable insights into the antioxidant mechanisms of mammary cells, which can serve as a theoretical foundation for future mammary health strategies.
The CellCheck Dry Cow Consult (DCC) was developed by the CellCheck Technical Working Group to enable farmers to engage with their nominated vet to develop farm-specific selective dry cow therapy ...(SDCT) plans, where appropriate. This study evaluated the effect of the DCC on farmer decision-making around dry cow therapy, and the udder health impact of implementing SDCT, in study herds over the 2019 and 2020 dry periods.
The DCC was a 3-h consult, delivered and funded as part of the Targeted Advisory Service on Animal Health (TASAH). Herds that completed a DCC were invited to register for a Dry Cow Review the following year. The combined data set for analysis across both years comprised of 439 herds and 25,357 cows. Available herd size ranged from 25 to 800. The median SCC of cows dried off with teat sealant only was 47,000 cells/ml before drying off in 2019 and 48,000 cells/ml at first milk recording in 2020, and 43,000 cells/ml before drying off in 2020 and 39,000 cells/ml at first milking recording in 2021. Following both the 2019 and 2020 dry periods, cows tended to converge toward a similar median SCC early in the following lactation, irrespective of prior dry cow treatment strategy. The uptake of SDCT was greater in Review herds, with 21% of cows receiving teat sealant only in 2020, compared with 16.3% of cows in herds participating in a Consult for the first time in 2020.
At an individual cow level, in both years dry period new infection rate (NIR) was approximately 2.7% higher for cows treated with teat sealant only, than for those treated with both dry cow antibiotic tubes and teat sealant, and 1.2% higher than cows treated with antibiotic only. Regardless of treatment, there was a significant association between increasing parity and the risk of a dry period new infection. Increasing herd size had a statistically significant effect on the risk of dry period new infection rates. At a herd level, there was no statistically significant increase in NIR when SDCT was used compared with herds where blanket dry cow therapy was used.
While not without risk, SDCT can be successfully implemented in Irish herds; however, constant attention to hygiene and management is essential. Though there are challenges to face, facilitating continued farmer education and engagement with professional guidance will be important.
In modern breeding systems, cows are subjected to many stress factors. Animals fed with a high-grain diet may have a decreased rumen pH, which would lead to subacute ruminal acidosis syndrome. The ...aim of this study was to investigate the evolution of microbial community composition in cows undergoing a dietary stress challenge. Twelve cows were subjected to a challenge period consisted in a rapid change of ration, from a normal (45.4:54.6 forage: concentrate) to a high-grain content diet (24.8:75.2 forage: concentrate) to induce sub-acute ruminal acidosis. Individual rumen fluid content samples were collected before (T0), and during the challenge (T3, T14, T28). DNA from rumen contents was extracted, purified, and sequenced to evaluate Bacterial populations and sequencing was performed on Illumina MiSeq. The effect of animal conditions on rumen microbial community was quantified through a linear mixed model. The acidogenic diet created 2 main clusters: ruminal hypomotility (RH) and milk fat depression (MFD). The microbial composition did not differ in T0 between the 2 groups, while during the challenge Ruminococcus spp., Treponema spp., Methanobrevibacter spp., and Methanosphaera spp. concentrations increased in RH cows; Succinivibrio spp. and Butyrivibrio spp. concentrations increased in MFD cows. Prevotella spp. and Ruminococcus spp., were negatively correlated, while Christenellaceae family were positively correlated with both Methanobrevibacter spp. and Methanosphaera spp. Moreover, the same diet affected differently cows' microbiota composition, underlying the impact of the host effect. Other studies are necessary to deepen the relationship between microbiota composition and host.
Antimicrobial use (AMU) in Switzerland is above target and requires reduction especially in dairy cattle. Measuring AMU is pivotal to identify starting points for AMU reduction and so are studies ...investigating its potential drivers in dairy farms worldwide. However, although AMU in dairy farms is high, studies estimating AMU specifically in tie stall farms are scarce. Tie stalls are a common housing system and their prevalence among dairy farms accounts to approximatively 73%, 41% and 40% in Canada, the US and Switzerland, respectively. The objectives of this cross-sectional, retrospective observational study were to estimate AMU using the newly established Swiss national reporting system for AMU in livestock and to identify associated factors on Swiss tie stall dairy farms. We calculated the treatment incidence (TI) by using the European Medicines Agency's methodology and their Defined Daily and Defined Course Dose (DDD/DCD) standards. Data on factors potentially associated with AMU were obtained through personal interviews with farm managers on 221 farms. Retrospectively, during a 1-year period, data on a total of 7,619 treatments were extracted from the national database. Associations between management factors and TI were analyzed using a generalized linear model with gamma distribution. The mean overall TI was 5.46 DDD/cow-year (±standard deviation: 4.10 DDD/cow-year). Intramammary treatment during lactation accounted for highest TI (3.24; ± 3.16 DDD/cow-year), whereas dry-cow therapy accounted for lowest TI (0.44; ± 0.49 DCD/cow-year). Five of the investigated management factors were significantly associated with TI. Organic production (estimate −2.16; 95% confidence interval 95 CI −3.62, −0.70) and herd size (estimate −0.81; 95 CI −1.23, −0.39) were negatively associated with TI. Specific cow breeds (Brown Swiss and Holstein Friesian: estimate 1.56; 95 CI 0.45, 2.68; estimate 1.42; 95 CI 0.03, 2.82, respectively; reference: other breeds) and the use of hygienic powders on the lying area (estimate 1.10; 95 CI 0.04, 2.17) were positively associated with TI. In conclusion, the Swiss national reporting system is a valuable tool for AMU estimation. Several herd characteristics and management factors were associated with AMU in tie stall farms. Further studies focusing on factors associated with AMU and which are amenable to intervention will help improve stewardship programs and subsequently reduce AMU in dairy cows.
