The timing in which supplements are provided in grazing systems can affect dry matter (DM) intake and productive performance. The objective of this study was to evaluate the effect of timing of corn silage supplementation on ingestive behaviour, DM intake, milk yield and composition in grazing dairy cows. In total, 33 Holstein dairy cows in a randomized block design grazed on a second-year mixed grass–legume pasture from 0900 to 1500 h and received 2.7 kg of a commercial supplement at each milking. Paddock sizes were adjusted to provide a daily herbage allowance of 15 kg DM/cow determined at ground level. The three treatments imposed each provided 3.8 kg DM/day of corn silage offered in a single meal at 0800 h (Treatment AM), equally distributed in two meals 0800 and 1700 h (Treatment AM-PM) or a single meal at 1700 h (Treatment PM). The experiment was carried out during the late autumn and early winter period, with 1 week of adaptation and 6 weeks of measurements. There were no differences between treatments in milk yield, but 4% fat-corrected milk yield tended to be greater in AM-PM than in AM cows, which did not differ from PM (23.7, 25.3 and 24.6±0.84 kg/day for AM, AM-PM and PM, respectively). Fat percentage and yield were greater for AM-PM than for AM cows and intermediate for PM cows (3.89 v. 3.66±0.072% and 1.00 v. 0.92±0.035 kg/day, respectively). Offering corn silage in two meals had an effect on herbage DM intake which was greater for AM-PM than AM cows and was intermediate in PM cows (8.5, 11.0 and 10.3±0.68 kg/day for AM, AM-PM and PM, respectively). During the 6-h period at pasture, the overall proportion of observations on which cows were grazing tended to be different between treatments and a clear grazing pattern along the grazing session (1-h observation period) was identified. During the time at pasture, the proportion of observations during which cows ruminated was positively correlated with the DM intake of corn silage immediately before turn out to pasture. The treatment effects on herbage DM intake did not sufficiently explain differences in productive performance. This suggests that the timing of the corn silage supplementation affected rumen kinetics and likewise the appearance of hunger and satiety signals as indicated by observed changes in temporal patterns of grazing and ruminating activities.

In mixed systems (pasture plus TMR), it is essential to provide the cows with good housing conditions at times of supplementation during confinement. However, given that there are different types of confinement for high‐producing cows in pastoral‐based systems, it is necessary to determine how such confinement conditions can affect their welfare. The aim of this study was to determine if the type of confinement (compost barn (CB) versus outdoor soil‐bedded (OD)) used in mixed systems affects the welfare of dairy cows through behavioral and biochemical indicators. Holstein cows ( n = 32) calving in autumn were assigned to two treatments (CB or OD) at calving. During confinement (half a day) in CB, the cows were kept indoors with a compost bed (13.5 m ² /cow), including ventilation, while OD cows were kept in the open space with a dirt floor and shaded area (4.8 m ² /cow). Confinement and grazing behavior (eating, ruminating, drinking, lying, standing, and walking) and the number of agonistic interactions in confinement were recorded every 10 min, on 3 days within a week for 5 months. Blood was collected to determine the concentration of creatine kinase, total proteins, and albumin during lactation. During confinement, cows in CB were found to be more frequently eating ( p = 0.07), drinking ( p < 0.0001), and lying down ( p = 0.003) than those in OD, while OD cows were more time ruminating ( p = 0.0005), standing ( p = 0.02), and walking ( p < 0.0001). During pasture access, cows in CB were more time eating ( p = 0.01) and standing ( p = 0.0003), while they were less lying ( p = 0.01) than cows in the OD and no differences were found in ruminating, drinking, and walking behaviors. CB cows tended to present more agonist interactions than in OD cows ( p = 0.09). Cows in CB had higher total proteins ( p = 0.02) and globulins ( p = 0.006) than cows in OD. In conclusion, the type of confinement differentially affected the different behavioral indicators (lying, standing, walking, rumination, and agonist interactions), as well as blood concentration of total protein and globulins. Although CB did not have all the behavioral indicators of welfare in its favor for autumn‐calving cows (ruminating and agonist interactions), blood indicators (total protein and globulins) highlight advantages of CB in relation to OD.

Phytochemicals are a potential alternative to antibiotic growth promoters. This study evaluated the effects of phytochemicals (curcuminoids, trans-cinnamaldehyde, and piperine) and monensin on performance and ruminal fermentation during the transition period in grazing dairy cows. In a complete randomized design, 60 Holstein cows (36 multiparous, 24 primiparous; 9 fistulated) were assigned to (1) control (CTL), (2) monensin (MON, 0.30 g/cow/day), or (3) phytochemicals (PHY, 50 g/cow/day) treatment from 30 days prepartum to 60 days postpartum. Prepartum, cows received a total mixed ration (TMR); postpartum, they grazed between a.m. and p.m. milking and were supplemented with TMR. Ruminal fermentation was evaluated at −7, 30, and 60 days postpartum. Prepartum dry matter intake was lower in MON primiparous cows than in CTL and PHY. Additives increased milk yield and lactose percentage in primiparous cows. PHY cows had lower acetate, higher propionate, and reduced acetate-to-propionate and ketogenic-to-glucogenic ratios at 60 days postpartum. MON reduced prepartum protozoa, while PHY increased prepartum branched-chain volatile fatty acids (BCVFAs). Both additives decreased BCVFA and protozoa postpartum. Additives reduced ammonia at 30 days, but only PHY persisted at 60 days. MON and PHY improved primiparous performance, enhanced ruminal fermentation, and promoted glucogenic fermentation while reducing ammonia and protozoa.

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.