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Twenty-six multiparous Italian Holstein cows were used to compare two feeding strategies for the prepartum period. Cowswere allocated to two dietary treatments on the basis of their parity (3.1 ± 1.1) and mature equivalent production (11473± 1449 kg). From 20 ± 7 d precalving to the calving day, one group of 13 cows (parity = 3.1 ± 1.0; mature equivalentproduction = 11473 ± 1606 kg) was fed a Control diet made by mixing a 50:50 as fed combination of the far off dryration and the lactation diet fed postpartum. The remaining cows (parity = 3.1 ± 1.1; mature equivalent production =11473 ± 1338 kg) were fed a prepartum diet (Anionic) obtained by supplementing the far off dry ration with energy andprotein sources plus calcium chloride. This diet had a lower dietary cation-anion difference than the Control diet (7.35 vs26.66 meq/100 g DM; Pfed the Anionic diet had the lowest DM intake during the prepartum (12.0 vs 13.4 kg/d; Pshowed a limited drop in plasma Ca reducing the incidence of subclinical hypocalcaemia in comparison with the Controlgroup (8 vs 62%; Pof hepatic function (aspartate-amino transferase, ϒ-glutamil transferase, creatin-kinase and bilirubine). After calving,all the cows were co-mingled and fed the same lactation ration and those that had received the Anionic diet duringthe prepartum showed a significant increase in milk yield with no changes in milk quality. Average production at the peakof lactation was 43.8 kg/d for Control cows while it raised up to 47.8 kg/d (Pduring the prepartum. This positive result was obtained with a lower loss in cows’ body condition score measured at 30and 60 days in milk and without any effect on the uterine involution process. The use of the Anionic diet has proven tobe an effective alternative to the common practice of feeding close-up diets made by a partial replacement of the far offdry ration with the diet fed to the lactating cows. This strategy should be particularly recommended for dairy herds inwhich there is a great incidence of metabolic and health problems related to clinical or subclinical hypocalcaemia in theearly postpartum.

A simple and rapid method based on the in vitro bovine lymphocyte proliferation was developed to assess the immunomodulatory activity of natural compounds extracted from plant and foods. The proliferation of lymphocytes was measured by the MTT [3-(4, 5- dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide] assay. This test was used to measure the immuno-enhancing activity of 2 plant extracts and 2 samples of fermented milk after 48 h of incubation.To evaluate the effect of the cow physiological phase on the assay response, the tests were repeated using lymphocytes taken from non-pregnant dry, pregnant dry and post partum cows. The assay was not affected by the cow physiological phase and the results obtained were comparable. Both plant extracts enhanced lymphocyte growth, in particular the extract 2 was slightly more potent than extract 1. The fermentation of milk with proteolytic starter cultures, such as FAIR E-63 and LA 2, can generate peptidic compounds from milk protein with potential immunostimulating activity. These samples tested in cell culture inhibited lymphocyte proliferation because they showed an acidic pH of 4.5. However, this bioassay was enough sensitive to detect biological activity of different compounds also at low concentrations.

This study aimed to evaluate the effects of a delay (at 09:30 instead of 07:30 h) in Total Mixed Ration (TMR) delivery on the behaviour, milk yield, and haematological parameters in dairy cows. Twelve healthy Italian Holstein cows, divided into two homogeneous groups of six each, were involved. The TMR delay was applied either for one (on Tuesday; single delay, SD) or for three consecutive days (Tuesday to Thursday; repeated delay, RD) to one group at a time while the other acted as control. A week of pause was interposed between treatments and the order of the treatment was randomised. Behaviour was observed by instantaneous scan sampling every 2 min during seven half-hour periods on Tuesday and Thursday and blood samples were taken at 14:30 h on these days. Milk yield was recorded daily. Data were analysed by a mixed models for repeated measurements. The delay caused a marked increase in activities towards the feeding rack prior to feeding on day 1 when delay was applied both as SD (P

The aim of this study was to investigate the effect of dry period omission on subsequent milk production over a whole lactation and the effect on milk quality around calving. Seventeen Italian Friesian cows, homogeneous for milk yield and parity, were managed either with a traditional dry-off period of 55d (CTR group; n=8) or continuously milked up to parturition (CON group; n=9). Milk yield was recorded daily from 75±7 d before expected calving date to the end of subsequent lactation to fit the lactation curve. Before parturition milk samples were collected at -70 d, -60 d, and -55 d for CTR and CON groups and at -40 d, -30 d, and -7 d for CON cows. After calving, six milk samples were taken from 1d to 90 d from both groups and analyzed for fat, protein, lactose, MUN and somatic cells. Body weight (BW) and body condition (BCS) were obtained 7 times from -55 d before expected calving to 90 d after calving. The omission of the dry period modified the shape of lactation in CON cows that reached the peak 10 d earlier and producing - 5.5 kg/d than CTR. Over a 305 d period, the milk yield reduction was of -2241 kg in CON group. The higher amount of milk produced before calving, i.e., 560 kg of milk in 52 d of mean pre-partum period, did not compensate the milk yield reduction after a continuous lactation. Milk quality was unaffected by the omission of dry period after calving, and animals in both lactation groups showed a similar decreasing trends over time for fat and protein, and increasing trends for lactose and MUN. Somatic cell score remained higher (4.54 vs 3.40) in CON than in CTR cows after calving. No different BW or BCS changes were observed for both groups after calving. We conclude that despite the absence of great differences in milk quality, the complete omission of the dry period in cows reduce significantly the milk yield, suggesting no economical benefit from this management strategy.