The influence of time and frequency of feed delivery on the daily patterns of feeding behavior, milk production, and ruminal pH of lactating cows was evaluated by conducting two experiments. Forty lactating Holstein cows that were housed in free-stall barn were divided into two groups. Cows were milked twice daily at 0530 and 1600. To evaluate the effect of time of feeding, two feeding times were used in the first experiment:(A) feed delivery time that was the same as the milking time and (B) feed delivery at 1000 and 1600 (the same as the second milking time). In the second experiment that evaluated the frequency of feeding, two treatments were conducted with once and twice feed deliveries per day. Milk production and composition were not affected by the diet in both the experiments, although milk urea nitrogen tended to be lower when the feeding time was the same as the milking time, i.e., in A than in B, in experiment 1. In experiment 1, daily eating time in B was longer than that in A (P < 0.05). Furthermore, eating activity was found to be high in the morning, at the 1000 feeding time. In experiment 2, the eating time tended to be longer when feed delivery was once per day than twice per day (P < 0.10). Ruminal pH significantly decreased when the cows were fed twice per day (P < 0.05). These results indicated no negative influence in the productivity of lactating cows when the feed delivery was once per day. Further, the feeding activity increased when the feeding time was apart from the milking time.
The current study was undertaken to evaluate the effect of a non-forage fiber source (NFFS) on milk production, chewing activity, and ruminal mat characteristics of lactating cows. Four rumen-cannulated, lactating Holstein cows were assigned to the conventional diet of a commercial dairy farm in Hokkaido, as the control diet (CON), and a diet that substituted domestic by-products for the entire quantity of concentrate and a portion of the forage, as the experimental diet (EXP). The ratio of forage to concentrate in the CON diet and that of forage to by-products in the EXP diet was 60.4:38.9 and 53.3:45.4, respectively, based on the measurement of dry matter (DM). Cows fed EXP had increased NDF intake compared to those fed CON. Eating time and rumination time per NDF intake tended to be shorter for EXP than for CON. Total chewing time per DM intake and NDF intake were shorter for EXP than those for CON. Milk production and composition were not affected by the treatment, although milk urea nitrogen tended to be lower when cows were fed EXP. The ruminal mat consistency tended to be lower for EXP at 2 h after feeding; however, no significant effect was observed on other physical characteristics of ruminal mat at other sampling times.The proportion of small ruminal particles (< 1.18mm) tended to be higher for EXP. Ruminal fermentation parameters were not affected by the treatment, except for the concentration of ruminal NH3-N, which was lower for EXP than that for CON. Thus, normal ruminal function and milk production was maintained when the supply of NFFS was increased, even if the forage feeding ratio was low, because the ruminal mat was stratified and the rumination time was not reduced.
In loose housing, a cow's eating must be guaranteed at all times. The ration’s form was changed in accordance with the cows’ eating and due to human’s pushing up operation. In this experiment, three indices of the ration’s form (LER: the length from the trough wall to the edge of ration, LTR: the length from the trough wall to the top of ration, and HTR: the height of the top of ration) were measured in five loose housings to represent different ration forms. The form of the ration just after feeding was changed by the cows’ eating from a mono-peak type to a twin-peak type. The LER in every free-stall barns increased with the cows’ eating behavior, and decreased with pushing up. The LTR was changed variously (increased and decreased) in each barn with the cow’s eating and with the pushing up operations.
Sixteen lactating Holstein dairy cows were randomly separated into two groups, and two groups were assigned to one of the following dietary treatments (1) C: feeding steam flaked corn (4kg FM/d) + commercial formula feed (4kg FM/d) + soybean meal (2kg FM/d) + grass hay (3kg FM/d) and corn silage (CS) (ad lib); (2) BP: feeding beet pulp (4kg FM/d) and amount of other feed was the same as C. The experiment started immediately after calving. Total DMI of BP was significantly higher than that of C. DM digestibility and GE digestibility tended to be higher for BP than for C. GE and ME intake of BP was significantly higher than that of C. An interaction was detected for energy balance indicating earlier recovery to positive energy balance for BP than for C. Cows for BP attained positive ME balance during 22 to 42 days in milk, whilst those for C attained positive during 43 to 60 days in milk. The molar portion of acetic acid of BP was significantly higher than that of C. The molar portion of propionate of C was significantly higher than that of BP. Plasma glucose of cows fed C tended to be higher than that of cows fed BP. Plasma nonesterified fatty acid concentration decreased with advancing DIM but was not affected by dietary treatments. Six of eight cows for both dietary treatments ovulated until 60 DIM. Although six of eight cows fed C ovulated twice, only one of eight cows fed BP ovulated. Days from calving to first ovulation for BP was significantly longer than for C.