Reconstituted versus dry alfalfa hay in starter feed diets of Holstein dairy calves: Effects on feed intake, feeding and chewing behavior, feed preference, and health criteria

摘要

We investigated the effect of reconstitution of alfalfahay on feeding and chewing behavior, sorting activity,and health status using 20 neonate Holstein male calves(3 d of age; 40.3 ± 1.30 kg of body weight) that wereassigned randomly to 2 treatments, a starter feed containingeither 10% dry (AH) or reconstituted alfalfahay (RAH), each consisting of 10 calves. Alfalfa haywas reconstituted with water 24 h before feeding toachieve a theoretical dry mater (DM) content of 20%.Both starter diets had the same ingredients and nutrientcompositions but differed in their DM content (90.9vs. 66.6% DM for AH vs. RAH, respectively). Calveswere weaned on d 50 and remained in the study untild 70. Reconstitution of alfalfa hay increased the percentageof particles retained on 8- and 1.18-mm sieves,but reduced feed materials retained on the bottompan. Feeding RAH tended to increase meal frequency(preweaning) and increased meal duration (pre- andpostweaning), and thereby increased time devoted toeating without affecting nutrient intake. Calves fedRAH tended to have lower eating rate during thepre- and postweaning periods. Tendencies to concurrentincrease in rumination frequency and ruminationduration in calves fed RAH increased time devoted toruminating during the preweaning period; however, atendency to longer rumination duration did not affectruminating time during the postweaning period. Calvesfed RAH spent less time resting and standing and moretime drinking during the postweaning period. Nonnutritiveoral behaviors were not affected by treatmentduring the pre- and postweaning period. Feeding RAHdecreased sorting of particles retained on 8-mm sievecompared with AH; however, calves in both treatmentgroups sorted for particles retained on 8- and 1.18-mmsieves and against the feed materials retained on thebottom pan. Crude protein and neutral detergent fiberintakes of particles retained on the both 8- and 1.18-mmsieves increased in calves fed RAH versus AH, with nochanges in intake of nutrients retained on the bottompan. Calves fed AH were more susceptible to developdiarrhea (odds ratio = 2.02) and pneumonia (odds ratio= 4.74) and thereby had lower chances of being treated.We found no difference between treatment groups forfrequency and medication days of diarrhea; however,calves fed RAH experienced fewer days with diarrhea.Furthermore, frequency and number of days with pneumoniaand administration of medication were greaterfor calves fed AH compared with calves fed RAH. Bloodconcentrations of total protein and globulin tended tobe higher in calves fed RAH compared with calves fedAH. Overall, feeding RAH increased time devoted toeating by increasing meal frequency and meal durationbut did not affect feed intake due to lower eatingrate. Calves in both treatment groups exhibited feedsorting at the extent to which they balanced intakeof nutrients and met their nutritional needs. Calves,in general, were healthy, but it seems that feeding adiet containing reconstituted alfalfa hay has a potentialhealth-promoting effect, possibly through reducing dietdustiness and improving immune status.