The aim of this study was to evaluate the effect of negative energy balance (NEB) on the final growth of the dominant ovarian follicle in Holstein cows. Cows at 14 to 21 d postpartum from an intensive dairy farm were randomly selected and allocated into a positive energy balance group (PEB, with β-hydroxybutyric acid (BHBA) level < 1.2 mmol/L, n = 15) and an NEB group (BHBA > 1.2 mmol/L, n = 15). Plasma samples were collected at 21, 50 and 55 d postpartum to assess the concentrations of energy metabolites, minerals, hormones and cytokines. Ovaries were examined by transrectal ultrasound on days 50 and 55 (120 hours later) to evaluate the diameter of the largest follicle. Compared with PEB cows, there were a more severe body condition loss and a lower milk yield in NEB cows (P < 0.05) and these had greater concentrations of plasma BHBA, non-esterified fatty acids, triglycerides, urea nitrogen, growth hormone, interleukin 6, and fibroblast growth factor 21 and lesser concentrations of plasma glucose, total cholesterol, insulin, insulin-like growth factor 1, insulin-like growth factor binding protein 3, leptin, brain-derived neurotrophic factor and angiopoietin-like protein 8 on d 21 (P < 0.05), while plasma minerals were not affected by energy status (P > 0.05). These changes persisted until the end of the study period (50–55 days postpartum) resulting in a lower follicular growth rate for cows in the NEB than the PEB group. These observations indicate that follicular growth rate is associated with measurable changes in energy metabolite, hormone and cytokine concentrations caused by early postpartum NEB.

The aim of this study was to evaluate the effect of negative energy balance (NEB) on the final growth of the dominant ovarian follicle in Holstein cows.

This study aimed to characterise the effects of ketosis on milk yield and composition and digestive capacity in transition dairy cows.

This study aimed to characterise the effects of ketosis on milk yield and composition and digestive capacity in transition dairy cows. Seven ketotic and seven healthy cows were housed in individual stalls for six days. Samples of plasma, milk, refused total mixed ration, and faeces were collected, and the blood biochemical parameters, milk yield and composition, dry matter intake, and faecal dry matter (FDM) production were determined. Compared with healthy cows, the ketotic cows had significantly higher concentrations of milk fat and citrate, but lower levels of milk protein and lactose. The cows exhibited a need for acid detergent fibre in forage and better digestion of neutral detergent fibre, starch, crude protein, and phosphorus than healthy cows, but more fat and gross energy were excreted in their faeces. Ketotic cows had higher energy-corrected milk yields and lower FDM than healthy cows. Lower feed intake coinciding with the requirement to maintain high milk production is considered to be the cause of ketosis in dairy cows. Ketotic cows exhibited lower dry matter fat digestion.

Lameness is a painful and debilitating condition that affects dairy cows worldwide. The aim of this study was to determine the plasma concentration of norepinephrine, β-endorphin, and substance P in dairy cows with lameness and different mobility scores (MS). A total of 100 Friesian and Jersey cows with lameness (parity range: 1–6; weight: 400–500 kg; milk yield: 22–28 L a day, and lactation stage less than 230 days) were selected. Animals were selected and grouped according to MS (MS 0–3; n = 25), and plasma concentration of norepinephrine, substance P, and β-endorphin was measured using ELISA. Cows with MS 3 had higher plasma concentrations of norepinephrine and substance P and lower plasma concentrations of β-endorphins when compared to MS 0 cows. Variations in plasma concentration of norepinephrine, substance P, and β-endorphin could be associated with intense pain states in dairy cows with lameness, but are insufficient to differentiate these states from the mildest pain states. Further studies are necessary in order to evaluate the potential use of these biomarkers in the detection of chronic bovine painful conditions.

Lameness is a painful and debilitating condition that affects dairy cows worldwide. The aim of this study was to determine the plasma concentration of norepinephrine, β-endorphin, and substance P in dairy cows with lameness and different mobility scores (MS).

Introduction: The aim of this study was to investigate the relationship between body condition score (BCS) determined on the dry-off day, calving day, and in the first month of lactation, its changes during the dry period and early lactation, and periparturient indices and fertility in high-producing dairy cows. Material and Methods: The experiment was conducted in two herds: A and B, located in Western Poland. The studies were conducted on 116 and 108 Polish Holstein-Friesian dairy cows respectively, with an average milk yield of >10 000 kg/305-day lactation. The experiment included the dry period (-56 d to the calving day), the calving day, and early lactation (from +1 to +56 d). The experimental factor was BCS (0 to 5-point scale). The BCS was performed by one person on day -56, on parturition day (in the first 12 h after calving) and on day 30 of lactation. Results: A decrease in BCS (≥-0.25) in herd A during the dry period accelerated the planned calving period by 7.3 d. In the group of cows with BCS <3.25 on the dry-off day, the lowest artificial insemination index (1.80), the shortest period of insemination services (25 d), and days open (87 d) were recorded. Moreover, cows with BCS < 3.25 at calving had the shortest days open (91 d). BCS >3.50 in the first month of lactation (30 d) resulted in the extension of uterine involution period (56 d). Improvement of BCS during the dry period shortened the anoestrus (60 d) in herd A and the period of insemination service (60 d) in herd B. However, in this group (IM BCS ≥ 0.25) of cows the day of the highest artificial insemination index (2.50) in herd B was analysed. Conclusion: The body condition on the dry-off day and at calving, as well as its deterioration in the first month of lactation, have a considerable effect on fertility indices in dairy cows, thus confirming the advisability of its regular monitoring during routine operations connected with the management of a dairy cattle herd.

Introduction: The aim of this study was to investigate the relationship between body condition score (BCS) determined on the dry-off day, calving day, and in the first month of lactation, its changes during the dry period and early lactation, and periparturient indices and fertility in high-producing dairy cows. Material and Methods: The experiment was conducted in two herds: A and B, located in Western Poland. The studies were conducted on 116 and 108 Polish Holstein-Friesian dairy cows respectively, with an average milk yield of >10 000 kg/305-day lactation. The experiment included the dry period (-56 d to the calving day), the calving day, and early lactation (from +1 to +56 d). The experimental factor was BCS (0 to 5-point scale). The BCS was performed by one person on day -56, on parturition day (in the first 12 h after calving) and on day 30 of lactation. Results: A decrease in BCS (≥-0.25) in herd A during the dry period accelerated the planned calving period by 7.3 d. In the group of cows with BCS <3.25 on the dry-off day, the lowest artificial insemination index (1.80), the shortest period of insemination services (25 d), and days open (87 d) were recorded. Moreover, cows with BCS < 3.25 at calving had the shortest days open (91 d). BCS >3.50 in the first month of lactation (30 d) resulted in the extension of uterine involution period (56 d). Improvement of BCS during the dry period shortened the anoestrus (60 d) in herd A and the period of insemination service (60 d) in herd B. However, in this group (IM BCS ≥ 0.25) of cows the day of the highest artificial insemination index (2.50) in herd B was analysed. Conclusion: The body condition on the dry-off day and at calving, as well as its deterioration in the first month of lactation, have a considerable effect on fertility indices in dairy cows, thus confirming the advisability of its regular monitoring during routine operations connected with the management of a dairy cattle herd.