Water Stress Influences Phytoestrogen Levels in Red Clover (Trifolium pratense) but Not Kura Clover (T. ambiguum).

Some forage legumes synthesize phytoestrogens. We conducted a glasshouse study to investigate how water stress (drought and waterlogging) influences phytoestrogen accumulation in red clover and kura clover. Compared to the red clover control, the 20 day drought resulted in an over 100% increase in the phytoestrogens formononetin and biochanin A, which together accounted for 91-96% of the total phytoestrogens measured. Waterlogging resulted in elevated concentrations of daidzein, genistein, and prunetin but not formononetin or biochanin A. Concentrations of phytoestrogens in kura clover were low or undetectable, regardless of water stress treatment. Leaf water potential was the most explanatory single-predictor of the variation in concentrations of formononetin, biochanin A, and total phytoestrogens in red clover. These results suggest that drought-stressed red clover may have higher potential to lead to estrogenic effects in ruminant livestock and that kura clover is a promising alternative low- or no-phytoestrogen perennial forage legume.

Enteric methane emissions in grazing dairy systems.

Approximately 80% of agricultural CH4 comes from livestock systems, with 90% of that derived from enteric CH4 production by ruminants. Grazing systems are used worldwide to feed dairy cattle. Although quantifying enteric CH4 emissions in grazing systems has unique challenges, emerging technologies have made gaseous data collection more feasible and less laborious. Nevertheless, robust data sets on enteric CH4 emissions under various grazing conditions, as well as effective and economic strategies to mitigate CH4 emissions in grazing dairy cows, are still in high demand because data collection, feeding management, and milk market regulations (e.g., organic certification, grassfed) impose more challenges to grazing than confinement dairy systems. This review will cover management strategies to mitigate enteric CH4 emissions and applicability to pastoral dairy systems. The effects of enteric CH4 in the broader context of whole-system assessments will be discussed, which are key to assess the overall environmental impact of grazing dairies.

Maine organic dairy producers' receptiveness to seaweed supplementation and effect of Chondrus crispus on enteric methane emissions in lactating cows.

Introduction: There is a growing interest in utilizing seaweed in ruminant diets for mitigating enteric methane (CH4) emissions while improving animal health. Chondrus crispus is a red seaweed that grows in the Gulf of Maine (United States) and has shown to suppress CH4 production in vitro. Organic dairy producers in Maine are currently feeding seaweed due to herd health promoting benefits. However, large-scale adoption depends on technical and financial factors, as well as validation from pilot studies. Methods: A survey was developed to identify barriers and drivers towards the adoption of CH4-reducing algal-based feeds. Concurrently, a randomized complete block design study was conducted to investigate the effect of C. crispus on enteric CH4 emissions and milk production in a typical Maine organic dairy farm. Twenty-two organically certified Holstein and Jersey cows averaging 29 ± 6.8 kg of milk/d and 150 ± 69 days in milk, were blocked and randomly assigned to a control diet without C. crispus (0CC), or with 6% [dry matter (DM) basis] C. crispus (6CC). Samples were collected on the last week of the 2-wk covariate period, and wk 3, 5, 8, and 10 after initiation of treatments for a total of 12 weeks. Gaseous emissions were measured using a GreenFeed unit. Data were analyzed using the MIXED procedure of SAS with repeated measures over time. Results: All survey respondents (n = 35; 54% response rate) were familiar with seaweeds as feed, and 34% were already users. Producers who were willing to pay 0.64 USD/cow/d on average for a CH4-reducing algal-based feed, also stated the need for co-benefits in terms of cattle health and performance as a requirement for adoption. Feeding 6CC decreased enteric CH4 production by 13.9% compared with 0CC (401 vs. 466 g/d). Further, milk yield (mean = 27.1 kg/d), CH4 intensity (mean = 15.2 g of CH4/kg of energy corrected milk), and concentrations and yields of milk fat and true protein were not affected by treatments. Discussion: Producer receptiveness to CH4-reducing algal-based feeds will not only be dependent on purchase price, but also on co-benefits and simplicity of integration into existing feed practices. Feeding C. crispus at 6% of the diet DM decreased CH4 production in dairy cows by 13.9% without negative effects on milk yield and composition. Identifying the bioactive compounds in C. crispus is critical to understand the effect of this red seaweed on mitigating enteric CH4 emissions in dairy cows.

Feeding incremental amounts of ground flaxseed: effects on diversity and relative abundance of ruminal microbiota and enteric methane emissions in lactating dairy cows.

We evaluated the effects of incremental amounts of ground flaxseed (GFX) on diversity and relative abundance of ruminal microbiota taxa, enteric methane (CH4) emissions, and urinary excretion of purine derivatives (PD) in lactating dairy cows in a replicated 4 × 4 Latin square design. Twenty mid-lactation Jersey cows were used in the study. Of these 20 cows, 12 were used for ruminal sampling, 16 for enteric CH4 measurements, and all for spot urine collection. Each period lasted 21 d with 14 d for diet adaptation and 7 d for data and sample collection. Diets were formulated by replacing corn meal and soybean meal with 0%, 5%, 10%, and 15% of GFX in the diet's dry matter. Ruminal fluid samples obtained via stomach tubing were used for DNA extraction. Enteric CH4 production was measured using the sulfur hexafluoride tracer technique. Diets had no effect on ruminal microbiota diversity. Similarly, the relative abundance of ruminal archaea genera was not affected by diets. In contrast, GFX decreased or increased linearly the relative abundance of Firmicutes (P < 0.01) and Bacteroidetes (P < 0.01), respectively. The relative abundance of the ruminal bacteria Ruminococcus (P < 0.01) and Clostridium (P < 0.01) decreased linearly, and that of Prevotella (P < 0.01) and Pseudobutyrivibrio (P < 0.01) increased linearly with feeding GFX. A tendency for a linear reduction (P = 0.055) in enteric CH4 production (from 304 to 256 g/d) was observed in cows fed increasing amounts of GFX. However, neither CH4 yield nor CH4 intensity was affected by treatments. Diets had no effect on the urinary excretion of uric acid, allantoin, and total PD. Overall, feeding GFX decreased linearly the relative abundance of the ruminal bacterial genera Ruminococcus and Clostridium and enteric CH4 production, but no change was seen for CH4 yield and CH4 intensity, or urinary excretion of total PD, suggesting no detrimental effect of GFX on microbial protein synthesis in the rumen.

Feeding Calcium-Ammonium Nitrate to Lactating Dairy Goats: Milk Quality and Ruminal Fermentation Responses.

We aimed to investigate the effects of calcium-ammonium nitrate (CAN) fed to lactating dairy goats on dry matter (DM) intake, digestibility of nutrients, milk properties (composition, antioxidant capacity, fatty acid profile, and nitrate residues), and ruminal fermentation parameters. Twelve lactating Saanen goats averaging 98.5 ± 13.1 days in milk, 53.5 ± 3.3 kg of body weight, and 2.53 ± 0.34 kg of milk/day were randomly assigned in four 3 × 3 Latin squares to receive the following diets: a control group (without CAN) with 7.3 g/kg DM of urea (URE), 10 g/kg DM of CAN (CAN10), and 20 g/kg DM of CAN (CAN20). Each period lasted 21 days, with 14 days for diet adaptation and seven days for data and sample collection. The DM intake, digestibility of nutrients, yields of milk, 3.5% fat-corrected milk, and energy-corrected milk were not affected by treatments. Similarly, there were no treatment effects on the yields and concentrations of milk fat, true protein, and lactose, along with minor effects on milk fatty acid profile. Total antioxidant capacity in milk was unaffected by treatments; however, concentration of conjugated dienes increased, while thiobarbituric acid reactive substances in milk decreased linearly. Nitrate and nitrite residues in milk were elevated by treatments, while the total of volatile fatty acids and ammonia-N concentration in the rumen were unaffected. Collectively, feeding CAN (up to 20 g/kg of DM) to lactating dairy goats did not affect feed intake, nutrient digestibility, and milk composition; however, it may increase milk lipid oxidation, as evidenced by increased conjugated diene concentration.

Production performance, nutrient use efficiency, and predicted enteric methane emissions in dairy cows under confinement or grazing management system.

There has been an intense debate regarding the economic, social, and environmental sustainability of confinement versus grazing dairy systems. Our goal was to conduct a meta-analysis to compare dry matter intake, milk yield and composition, nutrient use efficiency (i.e., feed efficiency, milk N efficiency), and predicted enteric CH4 emissions using studies that simultaneously evaluated confinement and grazing. We were able to include in the meta-analysis 8 peer-reviewed articles that met the following selection criteria: (1) publication between 1991 and 2021 in English language, (2) report either SEM or SD, (3) inclusion of at least 1 confinement [total mixed ration or fresh cut herbage fed indoors (i.e., zero-grazing)] and 1 grazing treatment in the same study, and (4) use of markers (internal or external) to estimate herbage dry matter intake. Two unpublished experiments were added to the data set resulting in a total of 10 studies for comparing confinement and grazing. The magnitude of the effect (i.e., effect size) was evaluated using weighted raw mean differences between grazing and confinement systems for a random effect model. Enteric CH4 production was predicted as follows: CH4 (g/d) = 33.2 (13.54) + 13.6 (0.33) × dry matter intake + 2.43 (0.245) × neutral detergent fiber. Dry matter intake (-9.5%), milk yield (-9.3%), milk fat yield (-5.8%), milk protein yield (-10%), and energy-corrected milk (-12%) all decreased in grazing versus confined dairy cows. In contrast, concentration of milk fat and feed efficiency (energy-corrected milk/dry matter intake) were not affected by management system. Whereas milk protein concentration increased, milk nitrogen (N) efficiency (milk N/N intake) tended to decrease in grazing compared with confinement. Predicted enteric CH4 production was 6.1% lower in grazing than confined dairy cows. However, CH4 yield (g/kg of dry matter intake) and CH4 intensity (g/kg of energy-corrected milk) did not change between confinement and grazing. In conclusion, while production performance decreased in grazing dairy cows, nutrient use efficiency and predicted enteric CH4 emissions were relatively similar in both management systems. Results of our meta-analysis should be interpreted with caution due to the small number of studies that met our inclusion criteria leading to a limited number of treatment mean comparisons.

Effects of cutting time and maceration on preference and nitrogen balance in beef steers fed mixed birdsfoot trefoil-timothy grass hay cut at sunrise or sundown.

Forages cut at sundown usually contain a greater concentration of nonstructural carbohydrates (NSC) than those cut at sunrise. Maceration can speed up the rate of moisture loss of cut forage during field drying and reduce NSC utilization by plant cells. We aimed to evaluate the effects of cutting time and forage maceration on feed preference, apparent total tract digestibility of nutrients, and N balance in growing steers. A mixed sward of birdsfoot trefoil and timothy grass was divided into two halves, with the first half cut at sundown (1800 h) after a sunny day and the second half at sunrise (0600 h) the next day. Approximately 50% of the sundown- and sunrise-cut herbage were macerated. Forages were harvested as hay resulting in four treatments: 1) sunrise-cut hay (AM); 2) AM plus maceration (AM-M); 3) sundown-cut hay (PM); and 4) PM plus maceration (PM-M). Hays were offered as the sole feed source to four crossbred steers (296.1 ± 7.25 kg) according to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Each period lasted 21 d with 14 d for diet adaptation and 7 d for collection. Hays cut at sundown had 15% greater NSC than those cut at sunrise. A cutting time by maceration interaction was found (P < 0.05) for intake and apparent digestibility of crude protein (CP), indicating that these two variables decreased more when maceration was applied to sundown- versus sunrise-cut hays. Similarly, interaction effects were observed (P < 0.05) for total digestible nutrients and digestible energy, showing that maceration decreased the energetic value of sundown-cut hays but did not change that of sunrise-cut hays. Steers fed hays cut at sundown had decreased urinary N excretion and improved retained N (P < 0.05), whereas N retention was reduced by maceration (P < 0.05). In addition, six crossbred steers were used to assess feed preference, 2 wk before (period 1) and 1 wk after (period 2) the digestibility trial. Animals were randomly assigned to receive a sequence of the four hays combined in pairs. The intake rate was greater for sundown- than sunrise-cut hays, and it was decreased by maceration. Steers showed the greatest preference for PM hay, while AM-M was the most rejected. In conclusion, shifting forage cutting from sunrise to sundown increased hay NSC concentration, which resulted in improved N utilization and preference. Forage maceration during field drying decreased CP concentration and N retention in beef steers under the conditions of our study.

A Review of Lignan Metabolism, Milk Enterolactone Concentration, and Antioxidant Status of Dairy Cows Fed Flaxseed.

Lignans are polyphenolic compounds with a wide spectrum of biological functions including antioxidant, anti-inflammatory, and anticarcinogenic activities, therefore, there is an increasing interest in promoting the inclusion of lignan-rich foods in humans' diets. Flaxseed is the richest source of the lignan secoisolariciresinol diglucoside-a compound found in the outer fibrous-containing layers of flax. The rumen appears to be the major site for the conversion of secoisolariciresinol diglucoside to the enterolignans enterodiol and enterolactone, but only enterolactone has been detected in milk of dairy cows fed flaxseed products (whole seeds, hulls, meal). However, there is limited information regarding the ruminal microbiota species involved in the metabolism of secoisolariciresinol diglucoside. Likewise, little is known about how dietary manipulation such as varying the nonstructural carbohydrate profile of rations affects milk enterolactone in dairy cows. Our review covers the gastrointestinal tract metabolism of lignans in humans and animals and presents an in-depth assessment of research that have investigated the impacts of flaxseed products on milk enterolactone concentration and animal health. It also addresses the pharmacokinetics of enterolactone consumed through milk, which may have implications to ruminants and humans' health.

Prediction of enteric methane production, yield, and intensity in dairy cattle using an intercontinental database.

Enteric methane (CH4 ) production from cattle contributes to global greenhouse gas emissions. Measurement of enteric CH4 is complex, expensive, and impractical at large scales; therefore, models are commonly used to predict CH4 production. However, building robust prediction models requires extensive data from animals under different management systems worldwide. The objectives of this study were to (1) collate a global database of enteric CH4 production from individual lactating dairy cattle; (2) determine the availability of key variables for predicting enteric CH4 production (g/day per cow), yield [g/kg dry matter intake (DMI)], and intensity (g/kg energy corrected milk) and their respective relationships; (3) develop intercontinental and regional models and cross-validate their performance; and (4) assess the trade-off between availability of on-farm inputs and CH4 prediction accuracy. The intercontinental database covered Europe (EU), the United States (US), and Australia (AU). A sequential approach was taken by incrementally adding key variables to develop models with increasing complexity. Methane emissions were predicted by fitting linear mixed models. Within model categories, an intercontinental model with the most available independent variables performed best with root mean square prediction error (RMSPE) as a percentage of mean observed value of 16.6%, 14.7%, and 19.8% for intercontinental, EU, and United States regions, respectively. Less complex models requiring only DMI had predictive ability comparable to complex models. Enteric CH4 production, yield, and intensity prediction models developed on an intercontinental basis had similar performance across regions, however, intercepts and slopes were different with implications for prediction. Revised CH4 emission conversion factors for specific regions are required to improve CH4 production estimates in national inventories. In conclusion, information on DMI is required for good prediction, and other factors such as dietary neutral detergent fiber (NDF) concentration, improve the prediction. For enteric CH4 yield and intensity prediction, information on milk yield and composition is required for better estimation.

Two-Stage Rumen Cannulation Technique in Dairy Cows.

OBJECTIVE: To describe a 2-stage rumen cannulation technique for dairy cows. STUDY DESIGN: Case series. ANIMALS: 172 dairy cows from 2 research institutions. METHODS: The 2-stage rumen cannulation technique first exteriorized a rumen segment within a wooden clamp, fixing the clamp to the skin with 6 mattress sutures. After 1 week, the necrotic rumen segment was removed, leaving a rumen fistula in which a 7.5 cm cannula was inserted. This was replaced by a 10 cm cannula a further 1 week later. The surgery took an average of 30 minutes. At least 1 assistant is required for the technique. RESULTS: The overall complication frequency was 7/172 (4%). One cow and 1 heifer aborted less than 10 days after surgery. Two late-pregnant heifers died from peritonitis after insertion of the 7.5 cm cannula because of incomplete adhesion of the rumen to the abdominal wall. The exteriorized rumen segment slipped back in the abdomen in 3 cows but was successfully re-clamped prior to insertion of the 7.5 cm cannula. CONCLUSION: A high success rate was achieved with this 2-stage cannulation technique. Postoperative complications were attributed to delayed adhesion of the rumen, perhaps because of stress-related factors (e.g., transport, mixing with other animals, transition period).

Hiperplasia neo-intimal intra-stent e progressão de placa aterosclerótica no vaso-alvo em pacientes tratados com stents libertadores de zotarolimus / Intra-stent neointimal hyperplasia and plaque progression inthe target vessel in patients treated with zotarolimus eluting stents

Fundamentos: Após intervenções coronárias percutâneas, tem sido descrita uma reação inflamatória local que está diretamente relacionada à hiperplasia neo-intimal e à reestenose. O quanto esse processo inflamatório pode levar à progressão de placa aterosclerótica no vaso tratado ou nas outras artérias coronárias é ainda motivo de debate. Objetivo: Avaliar se há relação entre o grau de hiperplasia intimal intra-stent e a progressão de placa no vaso tratado. Método: Estudo retrospectivo com 36 pacientes com 40 lesões tratados com stents liberadores de zotarolimus, avaliados com ultra-sonografia intracoronária (USIC) após o procedimento e no reestudo protocolar tardio. Obtidos o porcentual do volume de obstrução intimal intra-stent (%VO) e a mudança de volume da placa aterosclerótica fora do segmento tratado (ΔVAT). Avaliamos a intensidade da relação entre as variáveis %VO e ΔVAT por meio do coeficiente de correlação de Spearman. Resultados: O %VO foi de 14,5% ± 14,9%. Observada progressão de placa nas porções proximais (20,04 mm³/mm ± 58,61 mm³/mm) e distais (7,37 mm³/mm ± 25,86 mm³/mm) ao segmento tratadocom stent. Não houve correlação entre o porcentual de hiperplasia neo-intimal e o grau de progressão de placa proximal (-0,015; p = 0,93), distal (-0,166; p = 0,36) ou em ambos os segmentos (-0,026; p = 0,89). Conclusão: Neste grupo de pacientes tratados com stents liberadores de zotarolimus, a ausência de correlação entre o volume de obstrução intimal intra-stent e a progressão de placa fora do segmento tratado sugere a existência de diferentes mecanismos inflamatórios por trás desses processos.

Background: A local inflammatory response has been described after percutaneous coronary intervention and has been associated with neointimal hyperplasia and restenosis. Whether this inflammatory process might cause atherosclerotic progression in the same coronary artery or in the other coronary arteries is a matter of debate. Objectives: To assess a possible relation between the degree of neointimal hyperplasia and the progression of atherosclerotic plaque in the nearby stented segments. Methods: Retrospective study in which 36 patients with 40 lesions treated with zotarolimus eluting stents were studied with intravascular ultrasound (IVUS) during the index and follow-up procedures. In-stent percent volume obstruction (%VO) and change in atheroma volume in the arterial subsegments outside the stented segment (ΔATV) were obtained. We assessed the strength of the relationship between %VO and ΔATV by the Spearman correlation coefficient. Results: %VO was 14.5% ± 14.9%. Plaque progression was observed in proximal (20.04 mm³/mm ± 58.61 mm³/mm) and distal (7.37 mm³/mm ± 25.86 mm³/mm) arterial subsegments nearby the stented segment. There was no correlation between the degree of neointimal hyperplasia and the degree of plaque progression either in the proximal (-0.015; p = 0.93), distal (-0.166; p = 0.36) or both segments (-0.026, p = 0.89). Conclusion: In this group of patients treated with zotarolimus eluting stents, the lack of correlation between the degree of neointimal hyperplasia and plaque progression suggests different inflammatory reactions behind those phenomena.