Search Results (1,134)

Digital technologies that continuously quantify animal behavior, physiology, and production offer significant potential for the early identification of health and welfare disorders of dairy cows. In this study, a multimodal artificial intelligence (AI) framework is proposed for real-time health monitoring of dairy cows through the integration of physiological, behavioral, production, and thermal imaging data, targeting veterinarian-confirmed udder, leg, and hoof infections. Predictions are generated at the cow-day level by aggregating multimodal measurements collected during daily milking events. The dataset comprised 88 lactating cows, including veterinarian-confirmed udder, leg, and hoof infections grouped under a single ‘sick’ label. To prevent information leakage, model evaluation was performed using a cow-level data split, ensuring that data from the same animal did not appear in both training and testing sets. The system is designed to detect early deviations from normal health trajectories prior to the appearance of overt clinical symptoms. All measurements, with the exception of the intra-ruminal bolus sensor, were obtained non-invasively within a commercial dairy farm equipped with automated milking and monitoring infrastructure. A key novelty of this work is the simultaneous integration of data from three independent sources: an automated milking system, a thermal imaging camera, and an intra-ruminal bolus sensor. A hybrid deep learning architecture is introduced that combines the core components of established models, including U-Net, O-Net, and ResNet, to exploit their complementary strengths for the analysis of dairy cow health states. The proposed multimodal approach achieved an overall accuracy of 91.62% and an AUC of 0.94 and improved classification performance by up to 3% compared with single-modality models, demonstrating enhanced robustness and sensitivity to early-stage disease. Full article

The aim of this study was to evaluate the effect of the linoleic–α-linolenic acid ratio (LA:ALA) on cyclicity, oocyte quality, early pregnancy parameters, milk yield, and composition. Holstein cows were randomized to a 6:1-LA:ALA diet (Low-OMG3: n = 3 pens; 11 primiparous, 14 multiparous) or a 2:1-LA:ALA diet (High-OMG3: n = 3 pens; 10 primiparous, 14 multiparous). Diets were isocaloric and isonitrogenous and fed between 15 and 140 days in milk (DIM). Data were compared using linear mixed models. As expected, omega-3 concentrations in milk and blood increased in the High- compared to Low-OMG3 cows. No effect of diet was observed on cyclicity by 45DIM or oocyte quality at 50DIM. High-OMG3 cows had larger corpus luteum size (11–32 d post-timed artificial insemination [TAI]) and greater blood flow (32–60 d post-TAI) than Low-OMG3 cows. However, there was no effect of diet on progesterone, pregnancy-associated glycoproteins, or conceptus size. High-OMG3 cows produced more milk throughout the study, had greater lactose, and tended to have greater protein yield at 50DIM. In conclusion, decreasing the LA:ALA dietary ratio in lactating dairy cows did not provide evidence of effects on cyclicity, oocyte quality, or other early pregnancy-related parameters, but affected corpus luteum size and blood flow, enhanced milk production, and partially increased protein and lactose yields. Full article

Reduced winter hair shedding in beef cows through the spring and summer months may contribute to heat stress and reduced performance in spring-calving herds. This study evaluated the relationship of hair shedding with the fertility and maternal performance of 72 Dexter cows. Hair shedding data for 20 May, 3 June, 17 June, and 1 July in 2019 were used to classify cows as high or low hair shedders. Hair shedding levels were lower (p < 0.05) for 2-year-old cows than for cows 7+ years of age for the first three dates and lower (p ≤ 0.05) for lactating cows than for dry cows on the first two dates. Concurrent and four years of historical performance records were used to assess the associations between hair shedding and cow–calf performance. Data from 230 natural matings in July and August from 2015 to 2019 were analyzed. Birth to weaning weight data were recorded from 2016 to 2019 on 124 spring-born calves. Cow fertility was higher (p < 0.05) for high-shed cows than for low-shed cows for the 1 July classification. When the records from cows that were dry in 2019 were excluded from testing, fertility was higher (p < 0.05) for high-shed cows than for low-shed cows at all four scoring dates. The associations of cow hair shedding levels with preweaning calf performance were minimal. Dexter cows exhibiting higher hair shedding levels in the spring and summer expressed higher summer fertility. Full article

The aim of the present study was to evaluate the association between seasonal variation, the temperature–humidity index (THI), and lipid indices related to human health in the milk of Simmental and Montbéliarde cows. The investigation was conducted on a dairy farm located in Central Southern Bulgaria over a 12-month period and included 100 lactating cows, with equal numbers from each breed, housed in semi-open free-stall barns and fed an unchanged total mixed ration. Monthly measurements of microclimatic parameters (temperature, relative humidity, THI, and air velocity) were conducted throughout the study, and composite milk samples were analyzed for fatty acid composition by gas chromatography. The atherogenic index (AI), thrombogenic index (TI), health-promoting index (HPI), hypo-/hypercholesterolemic index (h/H), desaturase indices (DI16 and DI18), and the UFA/SFA, PUFA/SFA, and MUFA/SFA ratios were calculated based on the fatty acid profile. The results indicate that season has a statistically significant effect on all studied lipid indices (p < 0.001). The Kruskal–Wallis H values ranged from 16.68 for AI to 27.82 for DI18, indicating that seasonal variations in microclimatic conditions significantly influence the lipid metabolism of the cows. The data for the studied lipid indices indicate that the most favorable fat profile for human health was observed in autumn, characterized by lower AI (2.24) and TI (1.26) values and higher HPI (0.45) and h/H (0.76) values. Seasonal variation also affected DI 16 and DI 18, with the most favorable values for humans observed in autumn (DI 16: 4.38; DI 18: 74.39). The ratios of unsaturated to saturated fatty acids (UFA/SFA, PUFA/SFA, and MUFA/SFA) indicate that the milk from the studied farm exhibits the most favorable functional properties in autumn. Full article

Cow efficiency is vitally important to beef sustainability, and computer simulation models may be useful tools to identify characteristics of the most efficient cow genotypes for a given production environment. The objective of this analysis was to determine whether the Beef Cattle Systems Model could replicate empirical research demonstrating a genotype–nutritional environment interaction for efficiency of feed conversion to calves weaned. Combinations of cow genotypes for lactation potential (8, 10, and 12 kg/d at peak milk) and growth potential (450, 505, and 650 kg mature weight) were simulated across four dry matter intake levels (58, 76, 93, and 111 g/kg BW^0.75). At lower dry matter intakes, cows had lesser body condition scores and weight and longer postpartum intervals, but dry matter intake had minimal influence on pregnancy percentage or calf-weaning weight. These trends match empirical research except for pregnancy percentage, where decreasing dry matter intake had a dramatic effect on pregnancy percentage in high-milking, high-growth-potential genotypes. Efficiency of feed conversion was greatest at low dry matter intake for the model simulation with no evidence of a genotype–dry matter intake interaction, which is in contrast to empirical research demonstrating a genotype–dry matter intake interaction. In conclusion, standard nutrition equations do not replicate the genotype–nutritional environment interaction observed in empirical research studies. Full article

Sawdust represents a locally available lignocellulosic resource that may complement ruminant diets during periods of forage shortage. This study evaluated the feeding value of birch (Betula pendula) sawdust subjected to physical and chemical processing using a stepwise experimental approach. Steam-exploded and fresh sawdust were treated with 0, 4% ammonia, or 4% sodium hydroxide in a 2 × 3 factorial design and initially evaluated by in vitro gas production, dry matter digestibility, and fermentation pH. Based on these results, selected materials were further assessed for rumen dry matter and fiber degradation using the in sacco technique in cannulated dairy cows, with untreated and ammonia-treated wheat straw included for comparison. In addition, steam-exploded sawdust was compared with wheat straw and grass silage for in vivo digestibility in sheep. A pilot study also tested aspen (Populus tremula) sawdust in lactating cow diets. Steam explosion substantially reduced fiber fractions, particularly hemicellulose, and increased residual carbohydrates, resulting in higher gas production and in vitro digestibility compared with fresh sawdust (p < 0.05). Ammonia treatment markedly increased crude protein content, whereas sodium hydroxide primarily increased ash concentration. In sacco, steam-exploded birch showed similar or higher ruminal dry matter and neutral detergent fiber degradation compared with ammonia-treated wheat straw, while untreated fresh birch remained largely undegraded. In vivo, steam-exploded sawdust exhibited greater organic matter digestibility and net energy than untreated wheat straw but remained less digestible than grass silage (p < 0.0001). A pilot feeding test with lactating dairy cows demonstrated good acceptance of untreated aspen sawdust as a partial roughage substitute under non-standardized conditions. Overall, the results indicate that steam-exploded sawdust has potential as a complementary roughage source for ruminants when conventional forages are limited. Full article

Milk production and quality are increasingly affected worldwide by rising ambient temperatures associated with climate change, with heat stress (HS) representing one of the major environmental challenges for dairy cattle. HS alters physiological and metabolic processes, leading to significant changes in milk composition, particularly in regions exposed to prolonged summer heat. The Temperature–Humidity Index (THI) is widely used to assess the degree of thermal discomfort and its impact on dairy performance. This study investigated the effects of heat stress on milk quality parameters in a dairy herd managed under identical conditions, comprising Romanian Black Spotted (RBS, Holstein strain) and Romanian Spotted (RS, Simmental strain) cows. Descriptive statistics were performed using the SAVC for Windows program, while differences between means were evaluated using the t-test in GraphPad Prism 9. Milk quality traits were significantly affected when THI values exceeded 73, with a consistent decline observed from early summer onwards. In the RBS breed, milk protein content decreased significantly compared with spring values, reaching 3.25% (p < 0.0001) in 2023 and 3.35% (p < 0.01) in 2024. Similar trends were recorded in the RS breed, with minimum protein values of 3.10% (p < 0.0001) and 3.19% (p < 0.0001). Fat content, casein concentration, and milk urea levels also showed highly significant HS-related changes (p < 0.0001). Overall, heat stress negatively affected milk quality, while the RS breed appears less affected under the studied conditions than the RBS breed. Full article

Lactoferrin (LF) is an iron-binding immunoprotein of the mammary gland whose levels increase during mastitis and may be influenced by the metabolic status of the cow. During early lactation, dairy cows are exposed to a negative energy balance (NEB) and the associated increase in susceptibility to mastitis. However, the extent to which the metabolic profile influences LF secretion in milk during the postpartum period remains unclear. The objective of this study was to assess the associations between metabolic status and milk LF contents in Holstein cows (n = 122) in the first twenty days of lactation. Based on the milk LF contents, the cows were categorized into two groups: LF-LOW (≤123 mg/L; n = 81) and LF-HIGH (>123 mg/L; n = 41). Serum indicators of energy and nitrogen metabolism, hepatic function, and selected macro-/microelements were measured; urine electrolytes and net acid–base excretion (U-ABB) were assessed; and milk composition, including somatic cell count (SCC), was determined. LF-HIGH cows showed higher SCC (p = 0.0516) and serum glucose (p < 0.001), together with lower serum triglycerides (p = 0.0101) versus LF-LOW cows. Milk beta-hydroxybutyric acid (BHB) content was lower in the LF-HIGH group (trend, p ≈ 0.062). LF-HIGH also exhibited significantly greater natriuresis (p = 0.0078) and a more negative U-ABB (p < 0.001), indicating higher acid–base load. In conclusion, elevated LF contents during the postpartum period were associated with the activation of local mammary gland immune defence and concurrent compensatory metabolic processes related to NEB, rather than with pronounced alterations in basic milk composition. Milk LF content may therefore be considered as a specific indicator of immunometabolic compensation during the early postpartum period, rather than as a general marker of overall cow health. Full article

Prevalence of LPS in Gram-negative bacterial udder infections determines mastitis severity and disease prognosis. This pilot study explores the notion that milk-soluble (s) LPS/IgG complex levels in dairy cows link mastitis severity to intramammary Gram-negative infections during early lactation. Milk, within a single herd, was analysed from (i) 34 early lactating cows with acute mastitis and (ii) milk selected from peak lactation cows displaying either healthy (SCC < 100 × 10³ cells/mL, n = 146) or subclinical mastitis (SCC > 150 × 10³ cells/mL, n = 135) characteristics. Milk was assessed for (i) sLPS/IgG using an “in-house” ELISA, (ii) udder inflammation using LDH activity, and (iii) bacterial presence applying on-farm and standard microbiological laboratory techniques. Mean milk sLPS/IgG absorbances in acute mastitis cows were higher than those detected in healthy and subclinical mastitis cows, with mean differences of 0.35 (95% CI, 0.28 to 0.42) and 0.36 (95% CI, 0.28 to 0.44), respectively. On day 1 of acute mastitis, sLPS/IgG levels in milk containing only Gram-positive bacteria ranged from OD 0.04 to 0.14 (median = 0.1). In contrast, sLPS/IgG levels ranging from OD 0.27 to 1.42 (median = 0.58) and from 0.02 to 1.67 (median = 0.21) were detected in milk containing only Gram-negative bacteria or both Gram-negative and Gram-positive bacteria (i.e., polymicrobial), respectively. Furthermore, differential milk sLPS/IgG absorbance profiles (observed during the testing period days 1–3) were observed in cows with acute mastitis caused by Gram-positive, Gram-negative or polymicrobial infections. Our preliminary findings support the notion that milk sLPS/IgG complexes provide a link between mastitis severity and intramammary Gram-negative infections in dairy cows during early lactation. Full article

The aim of this study was to evaluate different doses of bacterial inoculants and the inclusion of 8% ground corn grain (GCG) on fermentative characteristics, chemical composition, and in situ ruminal degradability of low-DM elephant grass (cv. BRS Capiaçu) silage. The experiment followed a completely randomized design in a 6 × 3 factorial arrangement (six treatments × three fermentation periods). Treatments were a control without additive (CTR); 0.5 or 1 g/ton of Lentilactobacillus buchneri (LBU0.5 and LBU1); 1 or 2 g/ton of a Lactiplantibacillus plantarum + Pediococcus acidilactici inoculant (LPP1 and LPP2); and 8% GCG. After 60 d of fermentation, in situ ruminal degradability was evaluated using rumen-fistulated lactating cows with incubation times from 0 to 240 h. The GCG treatment increased DM, CP, and ether extract concentrations and reduced NDF, ADF, and lignin contents. Additionally, GCG silage exhibited lower pH, butyric acid, and ammonia nitrogen concentrations, along with higher lactic acid levels. No treatment effects were observed for water-soluble carbohydrates or total DM losses. The effective NDF degradability, degradation rate of the slowly degradable fraction, and undigested NDF after 240 h were not affected by treatments. In conclusion, the inclusion of GCG improved the fermentative profile of low-DM elephant grass silage, whereas bacterial inoculants did not significantly enhance the silage quality under the conditions evaluated. Full article

This study aimed to evaluate in situ ruminal nutrient degradation, fractional disappearance rate, and effective ruminal degradation of hydroponically sprouted barley, wheat, and triticale. Two ruminally canulated lactating cows were used in a complete randomized block design with four treatments and nine incubation times (0, 2, 4, 8, 12, 24, 48, 72, and 240 h). Treatments were corn silage (control), and sprouted barley, triticale, and wheat. Quadruplicate samples (5 g each) were placed in Dacron bags and incubated in the rumen. Then, bags were rinsed and spun, dried (48 h × 55 °C; 3 h × 105 °C), and weighed to determine residual dry matter (DM). Data were analyzed using mixed models (MIXED, SAS 9.4) with treatment, time, and their interaction as fixed effects, and cow and replicate (cow) as random effects. Denominator degrees of freedom were adjusted using the Kenward–Roger method, and means were separated by Tukey–Kramer. Significance was declared at p ≤ 0.05 and tendencies at 0.05 < p ≤ 0.10. Sprouted triticale and wheat treatments had a greater rapidly soluble fraction for DM (p < 0.01), the greatest fractional disappearance rate for DM (p < 0.01) and neutral detergent fiber (NDF; p < 0.01), and greater effective ruminal degradability (ERD) for DM (p < 0.01) and crude protein (CP; p < 0.01). Sprouted wheat also had the greatest ERD for NDF (p < 0.01). In contrast, sprouted barley had the lowest rapidly soluble fractions for DM (p < 0.01), NDF (p < 0.01), and CP (p < 0.01), lower fractional disappearance rate for DM (p < 0.01) and NDF (p < 0.01) than sprouted triticale and wheat, and the lowest ERD for DM (p < 0.01) and CP (p < 0.01). Overall, sprouted triticale and wheat had greater in situ ruminal nutrient degradation, effective ruminal degradation, and nutrient degradation kinetics, indicating their potential for inclusion in dairy cattle diets to improve nutrient degradability. Full article

Effective nitrogen management in dairy cow diets is essential for optimising milk production and minimising environmental nitrogen emissions. This study develops a simplified model to estimate nitrogen excretion in dairy farms, distinguishing excretion by animal category (lactating cows, heifers, calves) and organic matrix (faeces, urine), with nitrogen intake as a key input. A comprehensive literature review guided the selection of equations for estimating nitrogen excretion based on dietary nitrogen content, dry matter intake and milk yield. The model was specifically calibrated for Holstein dairy herd in the Po Valley (Italy) context using data collected from ten Lombardy dairy farms over 30 months, focusing on diet composition and nitrogen excretion via faeces, urine, and milk. Validation against established the literature and the Nitrates Directive (91/676/EEC) excretion factors demonstrated the model’s alignment in estimating nitrogen excretion. Within this context, the proposed framework may support nitrogen management at farm level by providing a practical, descriptive tool to explore nitrogen flows and to identify potential areas for improving nutrient efficiency and reducing environmental impacts. Full article

This study was conducted to evaluate the effect of rumen-protected γ-aminobutyric acid (GABA) supplementation on milk productivity of lactating Holstein cows. Eighteen Holstein dairy cows (mean parity, 2.2 ± 1.0 year; mean milk yield, 34.3 ± 5.5 kg) were selected in a commercial dairy farm for the experiment. The experiment was conducted from 17 July 2024 to 11 September 2024 (56 days). Generally, THI 72 is set as a threshold since the productivity of Holstein cows starts to decrease. Animals were exposed to heat stress conditions (THI ≥ 72) during the experimental period. The basal diet was fed as a total mixed ration (TMR), and GABA was top-dressed onto the TMR. The treatments were basal diet (Control), basal diet supplemented with rumen-protected GABA 3 g/d (Treatment 1), and basal diet supplemented with rumen-protected GABA 6 g/d (Treatment 2) as a completely randomized design. Statistical significance was compared between the control and GABA treatment groups using the method of repeated measurement. Increased levels of rumen-protected GABA supplementation tended to mitigate the decline in milk yield associated with heat stress (p = 0.083). Milk fat content in the GABA supplementation groups was significantly greater than that in the control group (p = 0.036). Milk lactose content was significantly increased by GABA supplementation (p = 0.017). Blood metabolic profiles and cortisol did not differ significantly between the control and GABA supplementation groups. Activities in the GABA supplementation groups were significantly greater than those in the control group (p < 0.05). Rest and rumination times in the GABA supplementation group were significantly lower than those in the control group (p < 0.05). These results suggest that rumen-protected GABA can be a practical nutritional intervention for minimizing productivity losses in Holstein cows during periods of elevated ambient temperature. Full article

Milk fat globule membrane (MFGM) phospholipids could promote the development of infants’ brain, nervous system and digestive system. This research conducted a comparative analysis of phospholipid composition in MFGM of colostrum from different bovine species (Holstein cattle, yak, and Buffalo), with a particular focus on analyzing phospholipid variations in yak MFGM across different lactation stages. Chromatographic quantification revealed phosphatidylcholine (PC) as the predominant phospholipid class (34.7–47.44%) in all examined species. Notably, Holstein cow milk contains significantly higher levels of phosphatidylethanolamine (PE). Distinct phospholipid profiles emerged between species: yak milk demonstrated significantly higher concentrations of sphingomyelin (SM), lysophosphatidylethanolamine (LPE), dimethylphosphatidylethanolamine (dMePE), and bis-methylphosphatidic acid (BisMePA), whereas buffalo milk showed preferential accumulation of phosphatidylinositol (PI), phosphatidylserine (PS), phosphatidylglycerol (PG), and lysophosphatidylcholine (LPC). Longitudinal analysis revealed dynamic changes in yak milk phospholipids during lactation: as the lactation period in-creases, PC, PS, LPC, LPE, methylphosphatidylcholine (MePC), BisMePA, and dMePE exhibited progressive decline, while PE, SM, PI and PG showed incremental increases. Analysis of phospholipid metabolism pathways indicates that yak colostrum supports early calf development by enriching phospholipids associated with immune and neuroprotection, while mature milk shifts toward maintaining membrane stability. These compositional characteristics position yak milk as a promising phospholipid-fortified alternative to human breast milk. Full article

Sward structure and post-grazing heights (SH) significantly influence plant growth and animal intake, crucial for dairy grazing systems. However, these interactions are dynamic and vary with season, resource heterogeneity, and defoliation patterns. Seasonal effects of control (TC), medium (TM), and lax (TL) post-grazing SH of grazed Lolium arundinaceum-based pasture on forage production and utilization, herbage mass, green cover, and chemical composition were tested during autumn-winter and spring seasons and among tall (TP), medium (MP), and short (SP) patches in spring. Thirty-six lactating Holstein cows were randomized evenly to TC, TM, and TL grazing treatments to achieve 6, 9, and 12 cm of post-grazing SH during autumn-winter, and 9, 12, and 15 cm in spring. Forage production was higher on TL than TM and TC, yet utilization was similar across all treatments. The TP relative to MP on SP increased for TL compared to TC and TM. The TP-TC presented higher leaf-density and leaf-proportion, than TP-TL, without modifying leaf canopy distribution of superior-medium horizons among treatments. Grazing management modulated forage production and structural heterogeneity across SH treatments. Critically, monitoring patch-level dynamics—rather than mean height—is essential for optimizing production and harvest efficiency in temperate systems by improving grazing horizon accessibility. Full article