The first objective of this study was to examine milking-to-milking variations in milk fat, protein and SCC (somatic cell count). The second objective of this study was to examine variations of milk components (fat, protein and SCC) over a period of six months (April-September 2010) at Agricultural Research Development Station Simnic. A total of 128 milk samples (64 morning milking and 64 evening milking ones) from milk bulk tank commingled from 90±4 Holstein cows, were collected and analyzed for fat, protein and SCC. Data suggested that milking period effects milk fat, making the fat percentage lower in the morning compared with the evening milking period, effect which was not similar in protein content. Seasonal differences in milk fat and protein were also investigated. The season of year had influenced SCC, fat and protein: SCC increased, while fat and protein decreased. The period of the day when milking took place and the season influenced fat, protein and SCC, but the composition of milk, as well as its hygienic quality, fell within the aplicabile standards for raw milk.

The adjective of this study was to determine the effect of partial replacement of whole milk with second-and third-milking colostrum on the health status and growth performance of preweaned Holstein dairy calves. A minimum of 110 calves of 2 -3 days old Holstein Friesian calves were enrolled and randomly allocated to two treatment groups 1) CS-colostrum supplement group and 2) UC-unsupplemented control group. The CS group of calves received pooled second and third milking colostrum with Brix reading between 19 and 24% (mean 21.8% ± 1.75%) as colostrum supplement (one liter mixed with 3 L of whole milk), and UC group of calves received 4 L of whole milk in each of the 2 daily meals for 14 days. Serum IgG levels were determined to evaluate passive transfer of immunity. Milk and grain consumption was recorded for 28 days by research personnel. All calves were weighted at entry of the trial, at 28 days and at weaning (65 days). Calves receiving supplemental colostrum had less diarrhea and respiratory disease than control calves. Also, the results indicated that health problems were associated with low serum IgG levels and low-weight calves. Grain consumption and average daily gain (ADG) over 28 days of life were greater in CS group of calves compared with UC group of calves. Colostrum supplementation during the first 14 days of life in calves was effective in reading diarrheal and bovine respiratory diseases and in the use of antimicrobials. Further studies are needed to identify the molecular mechanisms involved in beneficial effects of colostrum supplementation on calf growth and health.

Several claw measurements, horn growth and wear were recorded monthly in a research farm to investigate the effect of solid concrete floor and gradual growth of these traits over 3 month after trimming. Two methods of hoof trimming were used: Standard Dutch (STD) and hollow (HOL). The experimental cows (19 primiparous and 19 multiparous) were selected (8 primiparous and 11 multiparous cows for STD and 9 primiparous and 10 multiparous cows for HOL). Information on claw traits was recorded on right lateral hind claw between November 2021 and April 2022. In addition, lesions development of interdigital dermatitis and heel erosion (IDHE) and digital dermatitis (DD) was studied in both rear feet. No differences were detected in claw traits among the trimming methods. A gradual growth of all claw traits investigated, was detected in each month (1, 2 and 3) after trimming. Lesions of IDHE developed gradually over time in both trimming methods. Development of different stages of DD was investigated 3 months after trimming methods. Classical ulcerative lesions (stage M2). Persisted in each month after trimming and did not cure effectively after caw trimming and frequent use of footbaths.

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The aim of this study was to assess the association of hypocalcemia at calving with health and performance of Holstein cows and their calves. Data were collected January 1st 2017 to December 31st 2020. A total of 431 lactating Holstein Friesian cows (118 primiparous and 313 multiparous) from a research of hypocalcemia was 2 groups (hypo and non-hypo). The overall prevalence of hypocalcemia was 3.4% for first-lactation cows and 18% for multiparous cows. Lactating dairy cows with hypocalcemia had greater proportion of cows with Retained Fetal Membranes (RFM) metritis and culling within 60 days in milk (DIM), compared with non-hypocalcemia respectively. For the first 2 official milk tests milk yield and components (% fat, % protein on SCC) did not differ between hypo and non-hypo cows. The days in milk at first service, mastitis, dystocia and pregnancy at first service were not different between hypo and non-hypo groups. The proportion of stillbirth, survival at 60 days of age in calves did not differ between calves born from hypo or non-hypo cows. Calves born from Hypo cows had greater incidence of diarrhea (38.3%) than calves born (22.3%) from non-hypo cows. The results of this study show that hypocalcemia in calving has significant health implications for both dams and their calves.