Journal of Dairy Research最新文献

Dairy cow longevity affects production economy, climate footprint, and cow welfare. Based on data from the Danish Cattle Database, this research paper evaluates the relationship between early-life risk factors associated with the period before first calving and cow longevity, including data from all Danish dairy cows culled in 2019-2023. Explanatory variables for linear mixed models included calf size, twinning, and age at first calving. Information about the length of productive life (LPL) (mean: 1,074 days) and lifetime milk yield (mean: 32,088 kg energy-corrected milk) was available for 767,305 and 716,120 cows, respectively. Milk yield per day of life increased from 7 kg in cows culled during the first lactation to more than 20 kg in cows culled in their fifth or later lactations. For cows born as singletons, LPL was one month longer for cows born as large calves than for medium-sized calves, and 2 months longer than for small calves. Cows born as twins had 2 to 3 months shorter productive lives compared to cows born as singletons. For singletons, lifetime milk yield was 1,200 kg higher for large calves than for medium-sized calves, and 2,100 kg higher than for small calves. Lifetime milk yield was 1,500 to 3,500 kg lower in cows born as twins. Cows being among the third quartile of age at first calving had an estimated productive life 2.5 months longer, and a lifetime milk yield more than 2,600 kg higher than cows calving among the first quartile of age. The results from this study clearly demonstrate the importance of 'a good start'.

A systematic review and meta-analysis was undertaken to predict the effect of prepartum energy level on postpartum energy metabolism and milk production in dairy cows. In this systematic review, the criteria of PRISMA guidelines were followed: in vivo experimental evaluation of diets with different prepartum energy levels; presentation of initial, final, and/or total results; statement of treatment period including the last 21 days of the prepartum of period; and description of dry matter intake (DMI), milk production, blood parameters and feed efficiency data. A descriptive analysis was performed for better visualization of the data, and Pearson's correlation was used between the collected variables and the prepartum energy intake. The acquired data were subsequently analysed, employing a link function in a polynomial regression model. Prepartum energy intake does not influence DMI or energy balance in the postpartum phase. A higher-energy diet prepartum increased feed efficiency postpartum, accompanied by an increase in blood levels of BHB and NEFA. However, it also resulted in a decrease in milk production and blood glucose.

This research paper evaluated the effects of different concentrations of pitanga (Eugenia uniflora L.) bagasse (PB) on the chemical, technological, and sensory properties of Petit Suisse. Petit Suisse cheeses were formulated without PB (control) and with the enrichment of 0.5%, 1.0%, and 1.5% PB, respectively. The cheeses were evaluated over a 21-day storage period. PB significantly increased Petit Suisse cheeses' fibre content and yield. There was also an increase in antioxidant activity. Higher levels of PB resulted in lower hardness and greater syneresis. In rheological measurements, the cheeses showed typical behaviour of a viscoelastic solid; However, the inclusion of PB altered the casein network, making the structure softer than the control. The PB does not affect the viability of Lactococcus and Streptococcus, maintaining the probiotic character of the product. The Petit Suisse with 1% PB resulted in greater sensory acceptance. In conclusion, adding pitanga bagasse to Petit Suisse cheese has been demonstrated to provide attractive, functional characteristics and sensory properties, opening new possibilities for product development in the dairy industry.

Probiotics, defined as live microorganisms that confer health benefits when administrated in adequate amounts, including genera such as Lactobacillus, Bifidobacterium, Bacillus, Enterococcus, Escherichia, Streptococcus and the fungal strain Saccharomyces boulardii. Extensive research has demonstrated their beneficial effects, including vitamin synthesis, inhibition of pathogenic bacterial colonization, antimicrobial activity through bacteriocins and other bioactive compounds, and modulation of immune responses via secretory IgA antibodies. These attributes render probiotics promising candidates for managing antibiotic-associated colitis, post-surgical recovery and various diarrhoeal conditions. However, concerns regarding the safety of probiotics have emerged, with reports of Bacillus clausii sepsis in immunocompromised individuals and neonates, emphasizing the need for rigorous risk assessment. Similarly, postbiotic bioactive metableelites and components derived from probiotics have gained the attention of the scientific community all over the globe as potential alternatives to live probiotics. The International Scientific Association of Probiotics and Prebiotics defines postbiotics as 'a preparation of inanimate microorganisms and/or their components that confers a health benefit on the host'. Unlike probiotics, postbiotics do not require viability to exert their effects and include bioactive compounds such as short-chain fatty acids, peptides and exopolysaccharides. These molecules exhibit immunomodulatory, anti-inflammatory and antimicrobial properties, making them promising candidates for clinical applications, particularly in immunocompromised patients where live probiotics may pose risks. Despite their recognized benefits, both probiotics and postbiotics require further investigation to optimize their therapeutic potential while mitigating associated risks. This review critically evaluates the advantages, limitations and emerging applications of probiotics and postbiotics, emphasizing the necessity of rigorous scientific validation to ensure their safety and efficacy.

The pros and cons of probiotic microorganisms.

This research article aimed to evaluate the effect of a commercial nutraceutical additive in milk replacer on the health and weight gain of dairy calves during the pre-weaning phase. A total of 126 female Holstein calves were randomly assigned to two groups: a treatment group (TRT, n = 63) receiving a commercial nutraceutical additive in the milk replacer, and a control group (CON, n = 63) receiving only the milk replacer. Health assessments included clinical diagnosis, Wisconsin scores and lung ultrasonography to assess the incidence and severity of respiratory and enteric diseases, as well as the average daily gain (ADG). The TRT group showed a reduction in the number of antibiotic treatments for respiratory diseases compared to the CON group. However, calves in the TRT group exhibited greater lung consolidation scores at 75 days of age and lower odds of recovery from pulmonary lesions. No differences were observed between groups in ADG and weaning weight. Additionally, the use of the product did not reduce the incidence or severity of diarrhoea. In fact, calves in the TRT group experienced the first episode of diarrhoea earlier than those in the CON group. These findings indicate that the nutraceutical additive did not contribute to improved enteric or respiratory health. Under real farm conditions, the use of the applied nutraceutical does not consistently lead to beneficial or additive effects across health parameters. These results underscore the importance of context-specific evaluation, as well as the consideration that formulation and environmental factors can significantly influence the outcomes of such interventions.

This study was undertaken to investigate the molecular detection of biofilm-producing Staphylococcus aureus (S. aureus) from goat mastitis. An overall 384 milk samples were initially screened for subclinical mastitis (SCM) followed by molecular characterization of S. aureus isolates. The biofilm formation was assessed using Congo Red agar (CRA), a microtiter plate and the presence of the icaA gene. The results revealed a molecular prevalence of 53.24% (115/216) for pathogenic S. aureus in milk samples of goats. The phenotypic prevalence of biofilm production by CRA and microtitre methods was recorded to be 38.26% (44/115) and 26.96% (31/115) respectively, while the molecularly confirmed biofilm-forming S. aureus through polymerase chain reaction targeting icaA gene was 58.26% (67/115). The phylogenetic analysis of icaA gene revealed high identity between sequences of study isolates and the isolates of other neighbouring countries. The antibiogram profiling of pathogenic S. aureus showed increased resistance to cefoxitin and oxytetracycline followed by gentamicin. Out of 115, 45.22% (52/115) were declared as multiple drug resistant with multiple antibiotic resistance index greater than 0.2. The study concluded that biofilm-producing S. aureus strains are considered to be a common cause of SCM in dairy goats of Pakistan and biofilm formation is associated with multidrug resistance of study isolates.

To achieve more targeted antibiotic use, this research paper addresses the investigation of a quarter-selective dry cow therapy (QSDCT) on 16 commercial dairy farms based solely on the pathogen species detected. Cytobacteriological analysis was performed on quarter milk samples collected 2 weeks prior to drying off and 3 to 5 days after calving. Treatment decisions were based on results before dry-off: Only quarters infected with major bacterial pathogens were treated with antibiotics. To prevent new intramammary infections (IMI), all quarters received an internal teat sealant. A total of 1,155 dry periods were evaluated. Only 8.1% of all quarters (range per farm 2.6% - 28.8%) were treated with antibiotics at dry-off and a high bacteriological cure risk of 97.1% was determined for IMI in these antibiotic-treated quarters. For IMI caused by minor pathogens a self-cure risk of 82.1% was observed. The risk of new IMI after calving was 14.6%. Results of binomial logistic regression models indicated that self-cure of IMI by minor pathogens was not related to the pathogen group, the level of quarter somatic cell count at dry-off, or the presence of at least one other quarter infected with minor pathogens in a cow. Furthermore, the risk for new IMI in uninfected quarters was not increased by the presence of at least one quarter infected with major pathogens within cow. However, 95.4% of all IMI by major pathogens after calving were due to new IMI. In conclusion, a pathogen-based QSDCT can be successfully applied on commercial dairy farms to reduce the antibiotic use, but more attention should be paid to prevent new IMI.

The present study aimed to conduct a meta-analysis using the random-effects model to merge published genetic parameter estimates for metabolic disorders [mastitis (MA), metritis (ME), ketosis (KE), milk fever (MF), retained placenta (RP), displaced abomasum (DA), and lameness (LA)] in dairy cows. A total of 239 heritability and 355 genetic correlation estimates were extracted from 61 peer-reviewed articles published between 1991 and 2024. Heritability estimates for metabolic disorders were generally low, ranging from 0.034 for ME to 0.067 for DA and MF. These estimates were associated with small standard errors and narrow 95% confidence intervals, with all estimates being statistically significant (P < 0.05). The estimates for genetic correlations between metabolic disorders were positive, ranging from 0.038 (MA-DA) to 0.522 (KE-DA). Furthermore, only the genetic correlations for DA-LA (0.147), RP-ME (0.472), MA-LA (0.239), MA-MF (0.365), KE-DA (0.522), KE-RP (0.124), and KE-ME (0.157) were significant (P < 0.05). Positive and low genetic correlations were observed between MA-milk yield (MY), MF-MY, and LA-MY (0.291, 0.135, and 0.263, respectively; P < 0.05). Similarly, positive correlations were found between DA-fat yield (FY), MA-FY, MA-protein yield (PY), LA-FY, and LA-PY (0.121, 0.170, 0.303, 0.176, and 0.236, respectively; P < 0.05). The genetic correlations between KE-fat to protein ratio (FPR) and DA-FPR were positive and ranged from low to moderate (0.520 and 0.196, respectively; P < 0.05). Significant genetic correlations were also noted between MA-days open (DO) (0.416), MA-days from calving to first service (DCFS) (0.207), and LA-calving interval (CI) (0.210; P < 0.05). This meta-analysis provides valuable insights into the genetic contribution to metabolic disorders in dairy cows and highlights the generally low heritability and the variable genetic correlations between these disorders and performance traits. These findings may contribute to more effective breeding strategies aimed at reducing the occurrence of metabolic disorders in dairy herds.

Animal welfare is a growing concern in dairy production, influencing consumer preferences and industry practices. While extensive research has been conducted in Europe and North America, limited data exist on consumers´ attitudes in Latin America, particularly Argentina. This study aimed to assess Argentine consumers' perceptions, knowledge, and preferences regarding dairy cow welfare in grazing and confined systems. An online survey was conducted among Argentine residents (n = 3,051), assessing sociodemographic characteristics, knowledge of animal welfare, perceptions of dairy production systems, and willingness to pay for animal welfare-certified products. Most respondents (99%) believed that cows feel pain, and 85% believed they have emotions. Most respondents (91%) agreed that pasture access improves animal welfare. A significant portion (70%) expressed willingness to pay a premium for animal welfare-certified dairy products, with women (p < 0.001) and younger consumers (p < 0.001) showing higher interest. Women and respondents connected to the agricultural sector considered animal welfare more frequently when buying animal-based products compared with men and those without an agricultural connection (p < 0.001). Consumers without a direct agricultural background were more likely to perceive confined systems negatively. Grazing systems were widely preferred, with respondents associating them with better welfare, healthier products, and environmental sustainability. Our findings indicate a consumer preference for pasture-based dairy systems in Argentina. These insights can help industry stakeholders refine their communication strategies and promote welfare-oriented production practices that better align with consumer expectations.