Journal: Journal of Dairy Science

Abbreviation

J. Dairy Sci.

Publisher

Elsevier

Journal Volumes

ISSN

0022-0302
1525-3198

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Publications1 - 10 of 99
  • Invited review: Nitrogen in ruminant nutrition: A review of measurement techniques
    Item type: Journal Article
    Hristov, Aleksander N.; Bannink, André; Crompton, Leslie A.; et al. (2019)
    Journal of Dairy Science
  • Milk Cortisol Concentration in Automatic Milking Systems Compared with Auto-Tandem Milking Parlors
    Item type: Journal Article
    Gygax, L.; Neuffer, I.; Kaufmann, C.; et al. (2006)
    Journal of Dairy Science
  • Effects of forage and grain legume-based silages supplemented with faba bean meal or rapeseed expeller on lactational performance, nitrogen utilization, and plasma amino acids in dairy cows
    Item type: Journal Article
    Räisänen, Susanna; Kuoppala, Kaisa; Rissanen, Paula; et al. (2023)
    Journal of Dairy Science
    The objective of this experiment was to investigate the effect of forage type [red clover (51%)-grass silage, i.e., RCG; vs. faba bean (66%)-grass silage, i.e., FBG] and concentrate type (faba bean, FB; vs. rapeseed expeller, RE) on lactational performance, milk composition and nitrogen (N) utilization in lactating dairy cows. Eight lactating multiparous Nordic Red cows were used in a replicated 4 × 4 Latin Square experiment, with 21-d periods, in a 2 × 2 factorial arrangement of treatments. The experimental treatments were as follows: (1) RCG with RE, (2) RCG with FB, (3) FBG with RE, and (4) FBG with FB. Inclusion rates of RE and FB were isonitrogenous. Crude protein contents of the experimental diets were 16.3, 15.9, 18.1, and 17.9% of dry matter, respectively. All diets included oats and barley and were fed ad libitum as total mixed rations with forage-to-concentrate ratio of 55:45. Dry matter intake and milk yield were recorded daily, and spot samples of urine, feces, and blood were collected at the end of each experimental period. Dry matter intake did not differ across diets, averaging 26.7 kg/d. Milk yield averaged 35.6 kg/d and was 1.1 kg/d greater for RCG versus FBG, and milk urea N concentration was lower for RCG compared with FBG. Milk yield was 2.2 kg/d and milk protein yield 66 g/d lower for FB versus RE. Nitrogen intake, urinary N, and urinary urea N excretions were lower, and milk N excretion tended to be lower for RCG compared with FBG. The proportion of the dietary N excreted as fecal N was larger in cows fed RCG than for those fed FBG, and the opposite was true for urinary N. We detected an interaction for milk N as percentage of N intake: it increased with RE compared with FB for RCG-based diet, but only a marginal increase was observed for FBG-based diet. Plasma concentration of His and Lys were lower for RCG than for FBG, whereas His tended to be greater and Lys lower for FB compared with RE. Further, plasma Met concentration was around 26% lower for FB than for RE. Of milk fatty acids, saturated fatty acids were decreased by RCG and increased by FB compared with FBG and RE, respectively, whereas monounsaturated fatty acids were increased by RCG versus FBG, and were lower for FB than for RE. In particular, 18:1n-9 concentration was lower for FB compared with RE. Polyunsaturated fatty acids, such as 18:2n-6 and 18:3n-3, were greater for RCG than for FBG, and 18:2n-6 was greater and 18:3n-3 was lower for FB versus RE. In addition, cis-9,trans-11 conjugated linoleic acid was lower for FB compared with RE. Faba bean whole-crop silage and faba bean meal have potential to be used as a part of dairy cow rations, but further research is needed to improve their N efficiency. Red clover-grass silage from a mixed sward, without inorganic N fertilizer input, combined with RE, resulted in the greatest N efficiency in the conditions of this experiment.
  • Flowering catch crops used as forage plants for dairy cows: Influence on fatty acids and tocopherols in milk
    Item type: Journal Article
    Kälber, Tasja; Meier, Janina S.; Kreuzer, Michael; et al. (2011)
    Journal of Dairy Science
  • Predicting CO2 production of lactating dairy cows from animal, dietary, and production traits using an international dataset
    Item type: Journal Article
    Kjeldsen, Maria H.; Johansen, Marianne; Weisbjerg, Martin R.; et al. (2024)
    Journal of Dairy Science
    Automated measurements of the ratio of concentrations of methane and carbon dioxide, [CH4]:[CO2], in breath from individual animals (the so-called “sniffer technique”) and estimated CO2 production can be used to estimate CH4 production, provided that CO2 production can be reliably calculated. This would allow CH4 production from individual cows to be estimated in large cohorts of cows, whereby ranking of cows according to their CH4 production might become possible and their values could be used for breeding of low CH4-emitting animals. Estimates of CO2 production are typically based on predictions of heat production, which can be calculated from body weight (BW), energy-corrected milk yield, and days of pregnancy. The objectives of the present study were to develop predictions of CO2 production directly from milk production, dietary, and animal variables, and furthermore to develop different models to be used for different scenarios, depending on available data. An international dataset with 2,244 records from individual lactating cows including CO2 production and associated traits, as dry matter intake (DMI), diet composition, BW, milk production and composition, days in milk, and days pregnant, was compiled to constitute the training dataset. Research location and experiment nested within research location were included as random intercepts. The method of CO2 production measurement (respiration chamber [RC] or GreenFeed [GF]) was confounded with research location, and therefore excluded from the model. In total, 3 models were developed based on the current training dataset: model 1 (“best model”), where all significant traits were included; model 2 (“on-farm model”), where DMI was excluded; and model 3 (“reduced on-farm model”), where both DMI and BW were excluded. Evaluation on test dat sets with either RC data (n = 103), GF data without additives (n = 478), or GF data only including observations where nitrate, 3-nitrooxypropanol (3-NOP), or a combination of nitrate and 3-NOP were fed to the cows (GF+: n = 295), showed good precision of the 3 models, illustrated by low slope bias both in absolute values (−0.22 to 0.097) and in percentage (0.049 to 4.89) of mean square error (MSE). However, the mean bias (MB) indicated systematic overprediction and underprediction of CO2 production when the models were evaluated on the GF and the RC test datasets, respectively. To address this bias, the 3 models were evaluated on a modified test dataset, where the CO2 production (g/d) was adjusted by subtracting (where measurements were obtained by RC) or adding absolute MB (where measurements were obtained by GF) from evaluation of the specific model on RC, GF, and GF+ test datasets. With this modification, the absolute values of MB and MB as percentage of MSE became negligible. In conclusion, the 3 models were precise in predicting CO2 production from lactating dairy cows.
  • Nutritive quality of a species-rich, extensively managed pasture exposed to elevated ozone in a free-air fumigation system
    Item type: Other Conference Item
    Lin, J.C.; Nadarajah, K.; Volk, M.; et al. (2007)
    Journal of Dairy Science
  • One-week storage of refrigerated bovine milk does not affect the size, concentration, or molecular properties of extracellular vesicles
    Item type: Journal Article
    Saenz-de-Juano, Mara D.; Silvestrelli, Giulia; Ulbrich, Susanne E. (2024)
    Journal of Dairy Science
    Milk extracellular vesicles (EV) have gained extensive attention as promising diagnostic and therapeutic tools. Pre-analytical raw milk storage at low temperatures is an ordinary and usually necessary step after sample collection. It is known that direct freezing of unprocessed whole milk contaminates the native pool of milk EV with other cell structures. However, less evidence is available regarding prolonged cooling at 4°C. The current study assessed whether pre-analytical storage of bovine raw milk for several days affected EV isolation and further analysis. To confirm the independence from the health status of the mammary gland, we analyzed milk samples stored at 4°C for 1, 2, 3, and 7 d past collection, respectively, from 2 quarters of the same cow with different somatic cell counts (SCC). Seven days of refrigeration did not change the milk EV size, concentration, or morphology. We did not detect any changes in the EV cargo regarding the amount of protein and RNA, nor in the specific EV markers TSG101, CD9, and CD81 in milk from quarters with high and low SCC. Overall, we observed fewer CD81 and CD9 markers in quarters with high SCC. Moreover, we found no reduction in the mastitis-related miRNA bta-miR-223-3p, suggesting that refrigeration for several days up to 1 wk is a possible storage option compatible with further EV analyses. The findings of this study enhance the confidence that milk EV are highly stable in the raw milk matrix.
  • Effect of exchanging Onobrychis viciifolia and Lotus corniculatus for Medicago sativa on ruminal fermentation and nitrogen turnover in dairy cows
    Item type: Journal Article
    Brinkhaus, Anja Grosse; Bee, Giuseppe; Silacci, Paolo; et al. (2016)
    Journal of Dairy Science
    The objective of the study was to determine the effect of feeding sainfoin (SF; Onobrychis viciifolia) and birdsfoot trefoil (BT; Lotus corniculatus), 2 temperate climate forage legumes that contain condensed tannins (CT), on ruminal fermentation and N turnover in dairy cows. Six ruminally cannulated multiparous dairy cows (milk yield = 40 kg/d; 36 d in milk) were used in a replicated 3 × 3 Latin square design. All animals were fed basal diets containing 20% pelleted SF (223 g of CT/kg of dry matter), BT (30.3 g of CT/kg of dry matter), or alfalfa (AL) and concentrate to meet their predicted nutrient requirements. Each experimental period consisted of a 21-d adaptation period in a tiestall, followed by a 7-d collection period in metabolic crates, where feces and urine were collected quantitatively. During the 7-d period, milk yield was recorded daily and milk samples were taken at each milking. Blood, ruminal fluid, and papillae were sampled on d 2 and 5. The relative abundance of selected bacterial strains in ruminal fluid and the gene expression of transporter genes in the papillae were determined with quantitative PCR. Total volatile fatty acids and the abundance of the cellulolytic bacteria Prevotella spp. and Ruminococcus flavefaciens decreased with SF compared with AL. The relative gene expression of the monocarboxylate transporter 1 was increased with BT compared with AL and SF. Total yields of milk, milk fat, and milk protein were similar among treatments. The proportion of 18:3n-3 in milk fat was greater and those of 22:5n-3 and 22:6n-3 were lower with SF than with BT. The contents of urea N in blood (2.71, 3.45, and 3.90 mmol/L for SF, AL, and BT, respectively), milk (79.8, 100.1, and 110.9 mg/kg for SF, AL, and BT, respectively), and urine were lower with SF than with AL and BT, and a trend toward a lower ruminal ammonia content occurred with SF compared with BT. Intake and excretion of N with milk were similar among treatments, but urine N was lower with SF than with AL. The N excretion to N intake relation showed a shift in a part of urine N (17.5, 20.8, and 19.5% for SF, AL, and BT, respectively) to fecal N (45.2, 41.3, and 38.5% for SF, AL, and BT respectively) with SF compared with AL and BT. In conclusion, SF and BT differed in their effects on fermentation and milk fatty acid profile and SF also showed potential to decrease metabolic and environmental loads. The main reason for the different efficiency was likely a higher CT content of SF compared with BT.
  • Development of a new real-time quantitative PCR assay for the detection of Staphylococcus aureus genotype B in cow milk, targeting the new gene adlb
    Item type: Journal Article
    Sartori, Carlotta; Boss, R.; Ivanovic, I.; et al. (2017)
    Journal of Dairy Science
    The specific and reliable diagnosis of mastitis pathogens is essential for successful sanitation programs. The aim of the present study was to develop and evaluate a new real-time quantitative PCR (qPCR) assay for the very sensitive and specific detection of Staphylococcus aureus genotype B in cow milk samples. This mastitis pathogen is contagious and particularly prevalent in Switzerland and other central European countries. The new test is based on a rapid preparation of bacteria, followed by DNA isolation and qPCR for a unique target gene coding for the adhesion-like bovine protein (adlb). The inclusivity of the new target gene was 97% and the exclusivity 98%, meaning that other genotypes and bacterial species could be excluded with high reliability. The limit of detection of the new assay was 235 staphylococcal cell equivalents/mL of culture. The new test shows high intra- and interassay repeatability. Results are available within 2 d after sampling, allowing farmers and veterinarians to apply sanitation measures immediately. Based on the results of a preliminary field study, the diagnostic sensitivity and specificity of the new qPCR assay are 99 and 100%, respectively. The new analytical procedure is straightforward and can be applied for routine diagnostics.
Publications1 - 10 of 99