Exploring Two Different Feeding Strategies During Dry Period With Regard to Dry Matter Intake, Intermediary Metabolism and Certain Health Aspects of Dairy Cows in Germany.

Dry cow feeding plays an essential role in dairy production. Therefore, the objective of this study was to evaluate two different dry cow feeding strategies regarding dry matter intake (DMI), metabolism and health aspects of dairy cows in the first 50 days after calving. One hundred and six primiparous (n = 35) and multiparous (n = 71) cows (German Holstein) were assigned to one of two different feeding regimes 6-8 weeks before expected parturition. Group one phase (1P) received a single-phase diet with 6.0 MJ NEL/kg DM. Group two phases (2P) received a two-phase diet. During first 4-6 weeks of dry period, cows were fed a diet containing 5.5 MJ NEL/kg DM, while during the 2 weeks before expected parturition, cows received the transition diet (6.6 MJ NEL/kg DM). Post-partum, all cows received the same ration (6.9 MJ NEL/kg DM) ad libitum. Considering the entire dry period, DMI was higher in the 1P multiparous (1P: 14.8 vs. 2P: 12.9 kg/day/animal, p < 0.001) and primiparous (1P: 12.0 vs. 2P: 9.90 kg/day/animal, p < 0.001) compared to 2P. During the whole trial, there were no differences in body weight and body condition score between treatments. No differences were observed in the serum levels of calcium, phosphorus, non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) between 1P and 2P multiparous. However, primiparous fed 1P showed higher serum NEFA levels during lactation period (1P: 611 vs. 2P: 425 µmol/L, p = 0.017) and higher BHB levels during preparation period compared to 2P (1P: 0.382 vs. 2P: 0.320 mmol/L, p = 0.016). The energy-corrected milk yield (ECM) in multiparous showed no significant differences between feeding treatments (38.0 and 37.1 kg for 1P and 2P, respectively), while in the case of primiparous, the ECM yield differed between feeding systems (27.5 and 23.9 kg for 1P and 2P, respectively, p = 0.030). Results indicate that in our conditions, the additional effort associated with two-phase feeding seems to have limited suitability for primiparous.