Transition Cows Research Articles

Effects of supplementing rumen-protected arginine on performance of transition cows

An experiment was conducted to determine the effects of supplementing rumen-protected arginine (RPA) on productive performance in dairy cows. One-hundred and 2 cows were blocked by parity and then by energy-corrected milk (ECM) yield. Within block, cows were randomly assigned to control (CON) that received 200 g/d of a mixture of hydrogenated soybean oil and heat-treated soybean meal to supply 30 g of metabolizable protein (MP), or 200 g/d of a product containing 30 g of metabolizable arginine (RPA), which increased the dietary arginine from 5.7 to 7.5% of the MP from 250 d of gestation to 21 d postpartum. After 21 d postpartum, cows were fed the same diet and data were collected until 84 d postpartum. Cows fed RPA produced an additional 2.5 kg of colostrum (5.3 vs. 7.8 ± 1.0 kg) and 220 g more immunoglobulin G (526 vs. 746 ± 93 g) than CON cows. Supplementing RPA increased the yields of milk (32.8 vs. 34.9 ± 1.0 kg/d), ECM (37.8 vs. 40.9 ± 1.2 kg/d), and milk total solids (4.48 vs. 4.86 ± 0.14 kg/d) in the first 21 DIM. The benefits of RPA extended beyond the period of supplementation, with a 6.4% increase in yield of ECM per kg of dry matter consumed in all cows (1.88 vs. 2.00 ± 0.05 kg/kg) and an increase in ECM yield, but only in parous cows (44.2 vs. 48.5 ± 1.5 kg/d). Feeding RPA increased the concentrations of urea N in plasma pre- (12.5 vs. 13.9 ± 0.4 mg/dL) and postpartum (11.6 vs. 13.2 ± 0.4 mg/dL), and in milk during the first 21 d postpartum (11.0 vs. 12.0 ± 0.3 mg/dL). Treatment did not affect the concentrations of AA in plasma prepartum, but feeding RPA tended to increase citrulline (72.5 vs. 77.5 ± 2.7 μM), whereas RPA either tended to decrease isoleucine (129.5 vs. 120.9 ± 5.7 μM) or decreased the concentrations of leucine (181.3 vs. 170.2 ± 6.4 μM) and valine (293.2 vs. 276.7 ± 10.4 μM) postpartum. Feeding RPA increased the relative expression of transcripts involved in AA transport (SLC38A4), urea cycle (ARG1), and gluconeogenesis (PC, PEPCK, and G6PC) in hepatic tissue. Feeding diets to supply additional arginine as RPA during the transition period benefited productive performance in dairy cows that extended beyond the period of supplementation despite minor changes in plasma AA concentrations.

Assessing Transition Cow Management in Dairy Cows for Improved Health, Milk Production, Pregnancy and Culling Outcomes

Understanding of the social environment has the potential to benefit dairy cow welfare and production. Our aim was to evaluate the associations of stocking density, calving density, days spent in a pre-partum group before calving (days spent in close-up, DCU) and the number of days from a pen filling event (addition of new cows to the pre-partum pen) on early-lactation health, production, pregnancy and culling outcomes in dairy cows. Data were gathered from 2780 cows in 2 herds. Herd management and reproductive records were analyzed for cows receiving treatment in the first 30 d of lactation (days in milk, DIM) for clinical mastitis, reproductive tract disease, ketosis, milk fever and displaced abomasum. Principal component analysis was used to account for the relationship between gestation length (GL) and DCU and their association with early lactation disease, milk production, pregnancy and culling outcomes. The effect of stocking density, the number of days from a pen filling event to calving and the calving density experienced by a cow in her week of calving was also evaluated. Causal inference was used to correct for confounding bias due to farm identity. The odds of disease in the first 30 DIM increased with stocking density before calving. A quadratic association was found between the first principal component (PC1), representing the combined effect of GL and DCU, and the odds of disease in multiparous cows only. Early lactation milk production and 305 d milk production in multiparous cows increased with PC1 score. Quadratic relationships were found between stocking density at d 8 to 2 before calving with both early lactation and 305 d milk production in multiparous cows but no associations were found in primiparous cows. Calving density showed a quadratic association with 305 d milk production in primiparous cows. The number of days from the last pen filling event to calving was not associated with changes in milk production. Disease occurrence was negatively associated with both early lactation and 305 d milk yield in multiparous cows but only with early lactation milk production in primiparous cows. The occurrence of disease was associated with a delayed time to pregnancy only in primiparous cows while both disease and being in lactation group ≥ 3 were negatively associated with time to pregnancy in multiparous cows. Week 4 milk (W4MK) was positively associated with reduced time to pregnancy in multiparous cows. For primiparous cows, increasing age at calving was associated with increased culling risk, while being in lactation group ≥ 3 was associated with increased culling risk in multiparous cows. Culling risk decreased with increasing W4MK in all cows. These results suggest that gestation length, time spent in close-up and stocking density are important factors influencing disease incidence in early lactation and subsequent lactation performance but had differing effects on primiparous versus multiparous cows. A better understanding of how pre-partum management factors influence postpartum health and milk production can help farms to plan facilities and organize the day-to-day management of cows and will assist in improving cow welfare and productivity.

Association of uterine health in the first lactation with transition cow health and reproductive performance in the second lactation of Holstein dairy cows

The objective of this study was to evaluate the effects of puerperal metritis (PM) diagnosed and treated during the early postpartum period of the first lactation on transition cow health, milk production, reproduction, and culling of dairy cows in their second lactation. Diagnosis of PM was based on fetid watery red-brown uterine discharge and rectal temperature above 39.5°C. Two farms were enrolled in this retrospective observational cohort study (farms A and B). In both farms, the following diseases were recorded during the first 30 DIM in lactation 1 and 2: clinical hypocalcemia (CH), retained fetal membrane (RFM), PM, hyperketonemia (KET), left displaced abomasum (LDA), and clinical mastitis (MAST). Statistical analyses were performed using SPSS for Windows separately for each farm. Linear and logistic regression models were used for continuous (e.g., milk yield) and binary (e.g., disease, pregnancy per AI, pregnancy loss) outcomes, respectively. Cox proportional hazard regression models were calculated to model the time to event outcomes for culling or death during the first 60 DIM and for pregnancy within 250 d of the second lactation. The initial models contained the following variables: year of calving, month of calving, calving ease, stillbirth, twins, days open in lactation 1, 305-d milk yield in lactation 1, PM in lactation 1, and PM in lactation 2 as explanatory variables. A total of 4,834 cows (farm A) and 4,238 cows (farm B) in the second lactation were considered for statistical analyses. On farm A, the incidence of PM in lactations 1 and 2 were 20.1% and 11.2%, respectively. On farm B, the incidence of PM in lactations 1 and 2 were 14.4% and 8.5%, respectively. On both farms, cows with PM in their first lactation had greater odds for RFM and PM in their second lactation, whereas there was no association of PM in the first lactation with any other nonuterine diseases (i.e., CH, KET, LDA, and MAST) in the second lactation. Cows with PM in lactation 2 had reduced milk yield. The reduction in milk yield in second lactation was greater for cows that already experienced PM in lactation 1. On farm A, cows with PM in their first lactation had a greater hazard for culling within 60 DIM of the second lactation; however, the same association was not present on farm B. Cows with PM in lactation 1 had reduced pregnancy per AI at first service in the second lactation only on farm B. Cows with PM in lactation 2 had reduced pregnancy per AI at first service in the second lactation on both farms. Pregnancy loss in lactation 2 was only associated with PM in lactation 2 but not with PM in lactation 1. On both farms, cows had a reduced hazard for pregnancy in their second lactation within 250 DIM when they experienced PM in either lactation. In conclusion, PM in the first lactation had long-lasting negative consequences (i.e., risk of uterine disease and lower reproductive performance) for cows in their next lactation.

Dietary Anion Cation Difference in Ration of Transition Cows Kept under KPSBU and KPBS Cooperative Administration

Dietary Anion Cation Difference in Ration of Transition Cows Kept under KPSBU and KPBS Cooperative Administration

Use of rumination time in health risk assessment of prepartum dairy cows

The objectives of this observational cohort study were to evaluate the associations of rumination time (RT) in the last week of pregnancy with transition cow metabolism, inflammation, health, and subsequent milk production, reproduction, and culling. Pregnant nulliparous (n = 199) and parous (n = 337) cows were enrolled 21 d before the expected calving. RT and physical activity were monitored automatically by sensors from d -21 to 15 relative to calving. Blood samples were collected on d -14, -5, 4, 8, and 12 ± 1 relative to calving. Diagnoses of clinical health problems were performed by researchers from calving to 15 d in milk (DIM). In classification 1, cows were ranked based on average daily RT in the last week of pregnancy and classified into terciles as short RT (SRT), moderate RT (MRT), or long RT (LRT) for association analyses. In classification 2, RT deviation from the parity average was used in a receiver operating characteristic curve to identify the best threshold to predict postpartum clinical disease. Cows were then classified as above the threshold (AT) or below the threshold (BT). Compared with cows with LRT, cows with SRT had greater serum concentrations of NEFA (0.47 vs 0.40 ± 0.01 mmol/L), BHB (0.58 vs 0.52 ± 0.01 mmol/L), and haptoglobin (0.22 vs 0.18 ± 0.008 g/L) throughout the transition period, and reduced concentrations of glucose, cholesterol, albumin, and magnesium in a time-dependent manner. Parous cows with SRT had higher odds of postpartum clinical disease (adjusted odds ratio [AOR]: 3.7; 95% confidence interval [CI]: 2.1-6.4), lower odds of pregnancy by 210 DIM (AOR: 0.34; CI: 0.15-0.75), and lower milk production (46.9 vs 48.6 ± 0.5 kg/d) than parous cows with LRT. Deviation in prepartum RT had good predictive value for clinical disease in parous cows (area under the curve [AUC]: 0.65; CI: 0.60-0.71) but not in nulliparous (AUC: 0.51; CI: 0.42-0.59). Separation of parous cows according to the identified threshold (≤-53 min from the parity average) resulted in differences in serum concentrations of NEFA (AT = 0.31 ± 0.006, BT = 0.38 ± 0.014 mmol/L), BHB (AT = 0.49 ± 0.008, BT = 0.53 ± 0.015 mmol/L), and globulin (AT = 32.3 ± 0.3, BT = 34.8 ± 0.5 g/L) throughout the transition period, as well as in serum cholesterol, urea, magnesium, albumin, and haptoglobin in a time-dependent manner. BT parous cows had higher odds of clinical disease (AOR: 3.7; CI: 2.1-6.4), reduced hazard of pregnancy (AHR: 0.64, CI: 0.47-0.89), greater hazard of culling (AHR: 2.1, CI: 1.2-3.6), and lower milk production (46.3 ± 0.7 vs 48.5 ± 0.3 kg/d). External validation using data from 153 parous cows from a different herd and the established threshold in RT deviation (≤-53 min) resulted in similar predictive value, with the odds of postpartum disease 2.4 times greater in BT than AT (37.5 vs 20.1%). In conclusion, RT in the wk preceding calving was a reasonable predictor of postpartum health and future milk production, reproduction, and culling in parous cows but not in nulliparous cows.

UFL1 regulates cellular homeostasis by targeting endoplasmic reticulum and mitochondria in NEFA-stimulated bovine mammary epithelial cells via the IRE1α/XBP1 pathway

Elevated levels of NEFA caused by negative energy balance in transition cows induce cellular dyshomeostasis. Ubiquitin-like modifier 1 ligating enzyme 1 (UFL1) can maintain cellular homeostasis and act as a critical regulator of stress responses besides functioning in the ubiquitin-like system. The objective of this study was to elucidate the UFL1 working mechanism on promoting cellular adaptations in bovine mammary epithelial cells (BMECs) in response to NEFA challenge, with an emphasis on the ER and mitochondrial function. The results showed that exogenous NEFA and UFL1 depletion resulted in the disorder of ER and mitochondrial homeostasis and the damage of BMEC integrity, overexpression of UFL1 effectively alleviated the NEFA-induced cellular dyshomeostasis. Mechanistically, our study found that UFL1 had a strong interaction with IRE1α and could modulate the IRE1α/XBP1 pathway of unfolded protein response in NEFA-stimulated BMECs, thereby contributing to the modulation of cellular homeostasis. These findings imply that targeting UFL1 may be a therapeutic alternative to relieve NEB-induced metabolic changes in perinatal dairy cows.

Dietary Supplementation with Naringin Improves Systemic Metabolic Status and Alleviates Oxidative Stress in Transition Cows via Modulating Adipose Tissue Function: A Lipid Perspective.

Dairy cows face metabolic challenges around the time of calving, leading to a negative energy balance and various postpartum health issues. Adipose tissue is crucial for cows during this period, as it regulates energy metabolism and supports immune function. Naringin, one of the main flavonoids in citrus fruit and their byproducts, is a potent antioxidant and anti-inflammatory phytoconstituent. The study aimed to evaluate the effects of supplemental naringin on performance, systemic inflammation, oxidative status, and adipose tissue metabolic status. A total of 36 multiparous Holstein cows (from ~21 d prepartum through 35 d postpartum) were provided a basal control (CON) diet or a CON diet containing naringin (NAR) at 30 g/d per cow. Supplemental NAR increased the yield of raw milk and milk protein, without affecting dry matter intake. Cows fed NAR showed significantly lower levels (p < 0.05) of serum non-esterified fatty acid (NEFA), C-reactive protein, IL-1β, IL-6, malonaldehyde, lipopolysaccharide (LPS), aspartate aminotransferase, and alanine aminotransferase, but increased (p < 0.05) glutathione peroxidase activity relative to those fed CON. Supplemental NAR increased (p < 0.05) adipose tissue adiponectin abundance, decreased inflammatory responses, and reduced oxidative stress. Lipidomic analysis showed that cows fed NAR had lower concentrations of ceramide species (p < 0.05) in the serum and adipose tissue than did the CON-fed cows. Adipose tissue proteomics showed that proteins related to lipolysis, ceramide biosynthesis, inflammation, and heat stress were downregulated (p < 0.05), while those related to glycerophospholipid biosynthesis and the extracellular matrix were upregulated (p < 0.05). Feeding NAR to cows may reduce the accumulation of ceramide by lowering serum levels of NEFA and LPS and increasing adiponectin expression, thereby decreasing inflammation and oxidative stress in adipose tissue, ultimately improving their systemic metabolic status. Including NAR in periparturient cows' diets improves lactational performance, reduces excessive lipolysis in adipose tissue, and decreases systemic and adipose tissue inflammation and oxidative stress. Integrating lipidomic and proteomic data revealed that reduced ceramide and increased glycerophospholipids may alleviate metabolic dysregulations in adipose tissue, which in turn benefits systemic metabolic status.

Effects of feeding difructose anhydride on the mineral status and milking performance of transition cows

The objective of this study was to assess the potential effect of difructose anhydride III (DFAIII) on calcemia, magnesemia, and milking performance of dairy cows. Sixty-six multiparous Holstein cows in late pregnancy (gestation days = 253.8 ± 2.13 d) were blocked according to their expected calving date and randomly assigned to either receiving no supplementation (Control) or receiving 40 g/d of DFAIII (DFA) between -14 and +7 d relative to calving following a complete randomized block design. Cows on Control received 640 g/d of a pellet containing no DFAIII, whereas DFA cows received the same pellet but containing 6.25%DFAIII. Pellets of each treatment were top-dressed on a daily basis while cows were dry, and were fed via an automatic feeding system twice daily (320 g each feeding) during milking. Dry cows were fed once a day, whereas lactating cows were fed twice daily. Dry matter intake was individually monitored on a daily basis. Cows were milked twice daily and milk production and milk protein and fat contents recorded at every milking. Cows were kept on the study until they reached 21 d postpartum. Cows were weighed at dry-off (about 45 d before study enrolment) and twice daily after calving at the exit of the milking parlor. Three days before the expected calving date and 6, 12, 24, 48 h and 7 and 14 d after calving cows were blood sampled for subsequent determination of serum Ca and Mg concentrations. There were no differences in DMI before calving, but DFA cows consumed more feed than Control cows about 15 DIM. All cows lost BW after calving but DFA cows lost slightly less BW during the first 5 DIM than Control cows. Cows on DFAIII produced more milk around 10 DIM compared with Control cows, and DFAIII cows produced more milk protein than Control cows after 3 d post-calving. Serum Ca concentrations were not affected by DFAIII supplementation; however, serum Mg concentrations at 6, 12, and 24 h after calving were greater in DFA than in Control cows. In conclusion, DFAIII did not affect postpartum calcemia but improved magnesemia between 6 and 24 h post-calving. Milk production in DFA cows was improved around 10 d post-calving and milk protein yield after 3 d postpartum compared with Control cows. The mechanism leading to increased Mg availability is not clear and warrants further research.

SYMPOSIUM REVIEW: EXPLORING SUSTAINABILITY IN DAIRY CATTLE BREEDING FOCUSING ON FEED EFFICINCY AND METHANE EMISSIONS

Reducing emissions is vital to improve sustainability and industry leaders have set emission goals to either reduce gross emissions, lower emissions intensity, or reach net-zero. However, additional traits should also be measured and compared in terms of their impact on the broader definition of sustainability. In addition to environmental impact, a sustainable breeding objective must consider profit, animal welfare, farmer well-being, and social responsibility. Traits to be considered include direct emissions (e.g., nitrogen and methane), production efficiency (e.g., feed efficiency), health (e.g., calf and transition cow health) and welfare traits (e.g., polled). Many of these novel traits require labor- and/or cost-intensive phenotyping procedures. Consequently, this results in relatively modest data sets and estimated breeding values with limited reliability. Opportunities exist to overcome this limitation by developing cost-effective and easily quantifiable proxy traits and utilizing international collaboration to expand novel phenotype reference populations. Furthermore, non-economic values can be estimated to quantify the impact a trait has on societal perspective (e.g., farmer preference) or environmental impact (methane emissions), and combined with economic weights to calculate aggregate weights for each trait. While validation techniques are still uncertain, the United Nations Sustainable Development Goals may be applied to determine the improvement in sustainability due to genetic selection. This approach provides the flexibility to accommodate diverse sustainability perspectives, encompassing the disparities between developed and developing countries. Currently, the number and quality of relevant phenotypes are the main limiting factor. However, as confidence grows in the opportunity to improve sustainability through genetic selection, substantial new investment will be required both in refining phenotyping methodologies and conceptualizing novel breeding designs.

Predictive modelling of deviation from expected milk yield in transition cows on automatic milking systems

The transition period is a pivotal time in the production cycle of the dairy cow. It is estimated that between 30% and 50% of all cows experience metabolic or infectious disease during this time. One of the most common and economically consequential effects of disease during the transition period is a reduction in early lactation milk production. This has led to the utilisation of deviation from expected milk yield in early lactation as a proxy measure for transition health. However, to date, this analysis has been used exclusively for the retrospective assessment of transition cow health. Statistical models capable of predicting deviations from expected milk yield may allow producers to proactively manage animals predicted to suffer negative deviations in early lactation milk production. The objective of this retrospective cohort study was first, to explore the accuracy with which cow-level production and behaviour data collected on automatic milking systems (AMS) from 1–3 days in milk (DIM) can predict deviation from expected 30-day cumulative milk yield in multiparous cows. And second, to assess the accuracy with which predicted yield deviations can classify cows into groups which may facilitate improved transition management. Production, rumination, and physical activity data from 31 commercial AMS were accessed. A 3-step analytical procedure was then conducted. In Step 1, expected cumulative yield for 1–30 DIM for each individual cow-lactation was calculated using a mixed effect linear model. In Step 2, 30-Day Yield Deviation (YD) was calculated as the difference between observed and expected cumulative yield. Lactations were then assigned to one of three groups based on their YD, RED Group (</= −15% YD), AMBER Group (−14% ̶ 0% YD), GREEN Group (>0% YD). In Step 3, yield, rumination, and physical activity data from days 1–3 in lactation were used to predict YD using machine learning models. Following external validation, YD was predicted across the test data set with a mean absolute error of 9%. Categorisation of animals suffering large negative deviations (RED group) was achieved with a specificity of 99%, sensitivity of 35%, and balanced accuracy of 67%. Our results suggest that milk yield, rumination and physical activity patterns expressed by dairy cows from 1–3 DIM have utility in the prediction of deviation from expected 30-day cumulative yield. However, these predictions currently lack the sensitivity required to classify cows reliably and completely into groups which may facilitate improved transition cow management.

Successful clinical management of chronic mastitis cum udder abscess in a transition cow

Based on ultrasonographic findings and ABST results, a Holstein Friesian cross-bred cow, which had previously experienced udder swelling accompanied by thick yellowish milk discharge from all quarters except the left fore quarter, characterized by curdy yellowish discharge, was diagnosed and subsequently treated for chronic mastitis cum udder abscess.

Differences of serum glucose and lipid metabolism and immune parameters and blood metabolomics regarding the transition cows in the antepartum and postpartum period.

This study aims to investigate differences in metabolism regarding the transition cows. Eight cows were selected for the test. Serum was collected on antepartum days 14th (ap14) and 7th (ap7) and postpartum days 1st (pp1), 7th (pp7), and 14th (pp14) to detect biochemical parameters. The experiment screened out differential metabolites in the antepartum (ap) and postpartum (pp) periods and combined with metabolic pathway analysis to study the relationship and role between metabolites and metabolic abnormalities. Results: (1) The glucose (Glu) levels in ap7 were significantly higher than the other groups (p < 0.01). The insulin (Ins) levels of ap7 were significantly higher than pp7 (p = 0.028) and pp14 (p < 0.01), and pp1 was also significantly higher than pp14 (p = 0.016). The insulin resistance (HOMA-IR) levels of ap7 were significantly higher than ap14, pp7, and pp14 (p < 0.01). The cholestenone (CHO) levels of ap14 and pp14 were significantly higher than pp1 (p < 0.01). The CHO levels of pp14 were significantly higher than pp7 (p < 0.01). The high density lipoprotein cholesterol (DHDL) levels of pp1 were significantly lower than ap14 (p = 0.04), pp7 (p < 0.01), and pp14 (p < 0.01), and pp14 was also significantly higher than ap14 and ap7 (p < 0.01). (2) The interferon-gamma (IFN-γ) and tumor necrosis factor α (TNF-α) levels of ap7 were significantly higher than pp1 and pp7 (p < 0.01); the immunoglobulin A (IgA) levels of pp1 were significantly higher than ap7 and pp7 (p < 0.01); the interleukin-4 (IL-4) levels of pp7 were significantly higher than ap7 and pp1 (p < 0.01), the interleukin-6 (IL-6) levels of ap7 and pp1 were significantly higher than pp7 (p < 0.01). (3) Metabolomics identified differential metabolites mainly involved in metabolic pathways, such as tryptophan metabolism, alpha-linolenic acid metabolism, tyrosine metabolism, and lysine degradation. The main relevant metabolism was concentrated in lipid and lipid-like molecules, organic heterocyclic compounds, organic acids, and their derivatives. The results displayed the metabolic changes in the transition period, which laid a foundation for further exploring the mechanism of metabolic abnormalities in dairy cows in the transition period.

Retracted: Nutrigenomic Interventions to Address Metabolic Stress and Related Disorders in Transition Cows.

[This retracts the article DOI: 10.1155/2022/2295017.].

Automated extraction of domain knowledge in the dairy industry

Three weeks prior to calving to three weeks after calving, the transition period poses challenges for dairy cattle and farmers. Vast changes in housing, feeding, and reproduction might result in milk drop, metabolic and reproductive diseases. Moreover, most of the metabolic processes are intricately linked as many conditions can coexist. This challenge means that dairy producers and their advisors have difficulty drawing concise conclusions because of all aspects and relationships in transition cow management. Herein, machine-learning techniques and knowledge-graph theory were explored with a view to creating a decision-support system that could provide producers and their advisors with knowledge from domain literature. Specifically, knowledge is modelled as entities and relationships in knowledge graph theory, and natural language models were developed to extract information as knowledge graphs. A dataset comprising 1152 sentences from 20 papers was created and split into 922 sentences for training and 230 sentences for testing. Sequentially, two deep learning models were trained to extract entities and relationships respectively. For training results, a Bi-directional Long-Short-Term Memory model was applied for the entity extraction task and obtained an F1 score of 80 %. As for relationship extraction, a Transformer-based model was deployed but yielded a low F1 of 23 %, thus another pre-trained Transformer model with 89 % accuracy was deployed into the system. After feeding the domain literature into the deep-learning models, a knowledge graph of 1,576 nodes and 3,456 edges was constructed and stored in the graph database Neo4j. Afterward, a semantic parsing method was used to allow users to conduct question answering through the knowledge graph in natural language. In addition, to determine the quality of answers that the knowledge built from the papers, answers were sampled and evaluated based on human judgment. On average, answers scored 7.5 out of 10 and proved informative with respect to the original literature. Although the final interactive results demonstrated a high degree of visualization and scalability, this study primarily sought to demonstrate its feasibility. For tailored commercial applications, further improvements could be implemented in knowledge graph expansion and reasoning.

Predicted essential fatty acid intakes for a group of dairy cows also apply at individual animal level

The ruminant requirements for essential fatty acids (EFAs), particularly linoleic acid (LA) and alpha-linolenic acid (ALA), have not been fully determined, although evidence suggests that an adequate supply of polyunsaturated fatty acids (FAs) could improve immunity and reproduction in transition cows. In previous studies, we predicted EFA intake for a group of cows based on animal characteristics and milk EFA secretions. However, to support precision livestock feeding, we need to match the nutrient requirements and intakes of each cow as closely as possible. Our group-level predictions may not be accurate enough to estimate the EFA intake of an individual cow, due to inter-individual variations in EFA digestion and metabolism related to differences in feed intake, intake patterns, and the composition and functioning of the rumen microbiota. To address this issue, here we set out to establish specific equations that predict EFA intake for an individual cow based on the difference (i.e. the residuals) between observed EFA intake and the predicted EFA intake based on our group-level equations. We studied a database of individual dairy cows (26 experiments; 503 datapoints from three research teams) and we predicted the residuals from (1) dietary and animal-related factors (i.e. full predictions) and (2) animal-related factors only (i.e. field predictions), which are considered more field-amenable. The variance of predicted LA and log ALA intake was explained to 68% by observed LA intake and 66% by observed log ALA intake, respectively. The residuals of LA intake were predicted by dietary ALA content, total FA intake, BW, milk yield and fat content in full predictions, and by BW, feeding level, milk yield and fat content, and sum of milk C4:0 to C14:0 FA in field predictions. The log residuals of ALA intake were predicted by dietary NDF and total FA contents, NDF intake, BW, milk protein, LA and ALA contents, and fat yield in full predictions, and by BW, DM intake, milk LA and ALA contents, and fat yield in field predictions. The field predictions showed a moderate loss of accuracy compared to full predictions based on RMSE of prediction (from 38 to 54 g/d for LA and from 0.090 to 0.12 log (g/d) for ALA). This work is the first to predict the EFA intake of an individual cow based on previously established group-level predictions of EFA intake adjusted for dietary and animal-related factors.

Comparison of two different anionic supplements and a low calcium diet fed to transition cows prepartum on DM intake, mineral homoeostasis and performance.

This study evaluates the effects of two rations with a positive dietary cation-anion difference (DCAD) and varying Ca content and two anionic diets on mineral homoeostasis and performance in early lactation cows. For this purpose, 48 pregnant dairy cows stratified for mature equivalent milk production, parity, body condition score (BCS), and BW were randomly assigned to four treatment groups and fed the following rations during the last 3weeks of gestation: LC: low Ca (0.24% Ca, 1.14% K, DCAD: +86mEq/kg DM), HC: high Ca (1.23% Ca, 1.17% K, DCAD: +95mEq/kg DM), AS: Anionic salt (1.21% Ca, 1.21% K, DCAD: -112mEq/kg DM, and SC: SoyChlor (1.28% Ca, 1.16% K, DCAD: -115mEq/kg DM). After parturition, all animals were fed a common postpartum diet. Data were collected until 21days in milk. Urinary pH was significantly decreased with the AS and SC treatment in comparison to the LC and HC groups. The highest prepartum DM intake (DMI) was found in the LC group, while DMI in AS cows was lowest. Postpartum, DMI was significantly greater in LC and SC cows than in animals fed the HC and AS rations. Prepartum serum concentrations of Ca, P, and Mg as well as postpartum serum concentrations of P and Mg did not differ, while postpartum Ca was lower in the HC group, especially 24 and 48h after parturition. The greatest energy-corrected milk (ECM) yield was observed in cows fed the LC ration prepartum. Interestingly, milk protein production was lower in SC cows compared to LC, HC and AS. This study indicates that a ration containing a restricted Ca content fed prepartum is as suitable as a low DCAD diet to improve Ca balance without compromising DMI and performance.

Association of transition cow health with pregnancy per artificial insemination and pregnancy loss in Holstein cows submitted to a Double-Ovsynch protocol for first service

This observational study was conducted to evaluate the effect of transition cow health on pregnancy per artificial insemination (P/AI) and pregnancy loss (PL) in cows submitted to a Double-Ovsynch protocol (DO) for first service. Lactating Holstein cows (n = 15,041) from one commercial dairy farm in northern Germany between January 2015 to December 2021 were enrolled into a modified Double-Ovsynch protocol (GnRH, 7 d later PGF2α, 3 d later GnRH, 7 d later GnRH, 7 d later PGF2α, 24 h later PGF2α, 32 h later GnRH, and 16 to 18 h later timed artificial insemination) for first service at 72 ± 3 d in milk. Pregnancy was diagnosed at 32 and 60 d post-AI via transrectal ultrasonography. Pregnancy loss was defined as the proportion of cows diagnosed pregnant 32 d post-artificial insemination that were diagnosed nonpregnant 60 d post-artificial insemination. Health-related events (i.e., milk fever [MF], hyperketonemia [KET], retained fetal membranes [RFM], metritis, mastitis, left displaced abomasum [LDA]) were assessed by farm personnel using standard operating procedures. Multivariable logistic regression was used for testing potential associations between transition cow health event occurrence and outcome variables, including P/AI and PL. Three separate models were built for cows in first lactation, second lactation, and ≥third lactation. Overall, 20.0% (885/4,430), 34.9% (1,391/3,989), and 53.9% (3,570/6,622) of cows had at least one transition cow health event for first, second, and ≥third lactations, respectively. The most prevalent transition cow health event for first-lactation cows was metritis (10.7%; [473/4,430]), whereas second-lactation cows suffered mostly from mastitis (16.6%; [664/3,989] and KET (16.6%; [661/3,989]), and cows with ≥third lactations were mostly affected by KET (33.2%; [2,198/6,622]). We observed a negative association between inflammatory disorders (i.e., RFM, metritis, mastitis) and P/AI in all cows irrespective of parity. Metabolic disorders (i.e., MF, KET, LDA) were negatively associated with P/AI only in multiparous cows. Irrespective of parity, only uterine diseases (i.e., RFM, metritis) were significantly associated with PL. These results show that enrolling cows into a fertility protocol, such as DO, cannot overcome the carryover effects of inflammatory and metabolic disorders on P/AI and PL and highlight the importance of optimizing transition cow health as a prerequisite for achieving high fertility in a DO protocol.

Effects of dietary chromium supplementation on blood biochemical parameters in dairy cows: A multilevel meta-analytical approach

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.

Transition Cow Nutrition and Management Strategies of Dairy Herds in the Northeastern United States: Associations of Nutritional Strategies with Analytes, Health, Milk Yield, and Reproduction.

The objective was to identify relationships between transition cow nutritional strategies and the prevalence of elevated analytes (nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), and haptoglobin (Hp)), disorder incidence (DI), milk yield, and reproductive performance. Multiparous and primiparous cows from 72 farms in the northeastern US were enrolled in a herd-level cohort study. Farms were dichotomized within parity into a nutritional strategy within each period; far-off: controlled energy (CE; <16.5% starch and ≥40% forage neutral detergent fiber (FNDF)) or not CE (NCE; ≥16.5% starch or <40% FNDF or both), close-up: high FNDF (HF; ≥40% FNDF) or low FNDF (LF; <40% FNDF), and fresh: low starch (LS; <25.5% starch) or high starch (HS; ≥25.5% starch). No evidence existed that transition cow nutritional strategies were associated with milk yield outcomes (p ≥ 0.20). In general, our results support feeding multiparous cows HF close-up and HS fresh to minimize excessive BHB and DI; however, multiparous cows fed LF close-up had a higher pregnancy rate, and lower prepartum NEFA and Hp. Similarly, our results support feeding primiparous cows CE far-off, HF close-up, and HS fresh to maximize reproductive performance, and minimize BHB and DI; however, herds fed HF close-up or HS fresh had higher Hp.

Effect of Parenteral Supplementation of Minerals and Vitamins on Oxidative Stress Biomarkers and Hepatic Fatty Acid Metabolism in Dairy Cows During the Transition Period.

In the present work we aimed to study the effects of parenteral vitamin and mineral supplementation on hepatic fatty acid metabolism as well as on the oxidative stress biomarkers in biological samples of transition cows. The supplemented group (SG, n = 11) received a subcutaneous injection of 5mL of vitamin A palmitate 35mg/mL, vitamin E acetate 50mg/mL plus other injection of 5mL of copper edetate 10mg/mL, zinc edetate 40mg/mL, manganese edetate 10mg/mL, and sodium selenite 5mg/mL on days - 60, - 30, and 7 (± 3) relative to calving. The control group (CG, n = 11) received two subcutaneous injections of 5mL of 9mg/mL sodium chloride at the same times of the SG. Blood, urine, and liver biopsies were sampled 21 (± 3) days before the expected calving date and 7 and 21 (± 3) days after calving. Results revealed that supplemented animals had higher glutation peroxidase (GSH-Px) activity, lower and higher concentration of 3-nitrotyrosine (3-NT) in the liver and plasma, respectively, higher expression of the mitochondrial beta-oxidation enzyme carnitine palmitoyltransferase 1 in the liver, and lower content of hepatic triacylglycerol, mirroring plasma liver function parameters. No differences between groups were found in the superoxide dismutase activity, MDA concentrations, the protein abundance of peroxisomal acyl-CoA oxidase 1, diacylglycerol O-acyltransferase 1, and peroxisome proliferator-activated receptor alpha. These results suggest that the vitamin and mineral supplementation provided to dairy cows had a beneficial effect on GSH-Px activity, hepatic 3-NT concentration, and on the metabolic adaptation during the peripartum period.