ABSTRACT
The objectives of this study were to investigate how milk replacer (MR) allowance and differing concentrations of starch and neutral detergent fiber in starter alters visceral tissue and overall growth of the calf. Calves were randomly assigned to 1 of 4 dietary treatments (n = 12 per treatment) arranged in a 2 × 2 factorial based on daily MR allowance (MRA) and amount of starch in pelleted starter (SPS) as follows: 0.691 kg of MR/d [dry matter (DM) basis] with starter containing low or high starch (12.0% and 35.6% starch, respectively) and 1.382 kg of MR/day (DM) with starter containing low or high starch. All calves were housed in individual pens with straw bedding until wk 5 when bedding was covered to minimize intake. Calves were fed MR twice daily (0700 and 1700 h) containing 24.5% crude protein (DM) and 19.8% fat (DM), and had access to pelleted starter (increased by 50 g/d if there were no refusals before weaning, and then 200 g/d during and after weaning) and water starting on d 1. Calves arrived between 1 and 3 d of age and were enrolled into an 8-wk study, with calves undergoing step-down weaning during wk 7. Intakes were measured daily, and body weight (BW) and blood samples were recorded and collected weekly. Calves were dissected in wk 8 for visceral tissue measurements. Overall, there was increased MR DM intake for the high- (0.90 ± 0.01 kg/d; ± SE) compared with the low-MRA (0.54 ± 0.01 kg/d) calves, whereas starter DM intake increased in low- (0.47 ± 0.05 kg/d) compared with high-MRA (0.20 ± 0.05 kg/d) calves, which was driven by increases in wk 6, 7, and 8. High-MRA calves had increased BW during wk 2, 3, 4, 5, 6, and 7. The difference in BW disappeared by wk 8, with overall average daily gain having a tendency to be increased in high (0.57 ± 0.04 kg/d) compared with low-MRA (0.50 ± 0.04 kg/d) calves, whereas average daily gain was increased in high-MRA calves during wk 2 and 3 and increased in low-MRA calves during wk 7 and 8. There were several differences throughout visceral tissue measurements, but most notably, an increase in rumen mass (i.e., full, empty, and digesta weights) in low- compared with high-MRA calves, as well as in low- compared with high-SPS calves was observed. The length, width, and 2-dimensional area of rumen papillae were also increased in low- (area: 0.88 ± 0.03 mm2) compared with high-MRA (0.46 ± 0.03 mm2) calves. The majority of differences were attributed to increased MR allowance, which contributed to reduced pelleted starter intake by more than 50% and reduced rumen development, whereas differences in starch intake from the completely pelleted starter had minimal effects on overall growth and tissue measurements.
Subject(s)
Milk , Starch , Animal Feed , Animals , Body Weight , Cattle , Diet/veterinary , Rumen , WeaningABSTRACT
Coating of high-aspect-ratio nanostructures has previously been achieved using batch processes poorly suited for high-throughput manufacturing. It is demonstrated that uniform, nanoscale coatings can be rapidly deposited on zinc oxide nanorod arrays in open-air using an atmospheric pressure spatial deposition system. The morphology of the metal oxide coatings is examined and good electrical contact with the underlying nanorods is observed. The functionality of the coatings is demonstrated in colloidal quantum dot and hybrid solar cells.
ABSTRACT
A number of active prediction planning and execution (APPE) systems have recently been proposed for robotic interception of moving objects. The cornerstone of such systems is the selection of a robot-object rendezvous-point on the predicted object trajectory. Unlike tracking-based systems, which minimize the state difference between the object and the robot at each control period, in this methodology the robot is sent directly to the selected rendezvous-point. A fine-motion tracking strategy would then be employed for grasping the moving object. Herein, a novel strategy for selecting the optimal (earliest) rendezvous-point is presented. For objects with predictable trajectories, this is a significant improvement over previous APPE strategies which select the rendezvous-point from a limited number of non-optimally chosen candidates.
ABSTRACT
Two experiments investigated discrimination learning with preweanling rats (Rattus norvegicus) following different experimental deprivation treatments. In Experiment 1, 10- to 11-day-old Sprague-Dawley rats were deprived for 24 h of either nutrients and maternal contact through placement in an incubator or only nutrients by placement in the nest of a bromocryptine mesylate-treated dam. Bromocryptine mesylate inhibits prolactin release and thereby prevents lactation with only minimal effect on maternal behaviors. After the deprivation period, pups were trained to perform a spatial discrimination for milk infusion into the oral cavity or for the opportunity to suckle the dry nipples of an anesthetized dam. The results revealed, irrespective of deprivation treatment, that pups failed to acquire a simple T-maze spatial discrimination for milk reward although they rapidly learned to approach and locate an anesthetized dam to suckle. Experiment 2 followed up with a different procedure. Results indicated that during bouts of suckling rat pups preferred an active, lactating dam letting down milk to an identical dam not letting down milk due to her pretreatment with bromocryptine mesylate. These results illustrate a constraint on learning which affects immature rats. The capability to learn on appetitively motivated spatial discrimination appears intricately tied to the context in which training occurs. Results are discussed according to how the organism's expectancy can mediate performance.
