Oral and Poster Abstracts

Objective of study: Currently it is assumed, that the lung of newborn
calves expands and starts gas exchange quite shortly after birth. Up to
now, it was not shown at what time during the first weeks of life,
different lung areas of bovine neonates show a maximum gas exchange
rate. Therefore the lung development of bovine neonates within the first
three weeks post natal was examined using CT.
Material and methods: For the ongoing examinations of the first three
weeks post natum 15 healthy Holstein Frisian calves, born without any
complications, were chosen. Their vitality was checked with the
APGAR-Score (>7.5) and blood-gas-analysis.The lung function was
measured segmental in a spiral CT -PQ 2000- of the brand Picker
International. In order to examine the thorax area, the animals were
slightly sedated (Xylazinhydrochloride, Impfstoffwerke Dessau, 0.09
mg/kg body weight). The Region of interest (ROI) was chosen in a way
that lung tissue without larger supply-structures (such as vessels) was
measured (Roi sqnn 12): dorsal left and right quadrant, ventral left and
right quadrant; from cranial to caudal direction. The CT-measuring
times were: 0.5-1 h, 6 h, 12 h p. n., 1 st , 2 nd and 3 rd week p. n.The
statistical analysis was made with SPSS 14.0 using variance analysis
and Pearson’s correlation coefficient.
Results: 1. Immediately p. n. the two dorsal lung areas are ventilated,
with a delay of about 12 hours also the ventral ones (p < 0.001). 2.The
expansion of the lung-alveoli increases from cranial to caudal. The time
until the cranial lung areas are completely ventilated was two weeks,
for the caudal areas three weeks. 3. In the cranial area, the left half of
the lung is better ventilated than the right. (1 st hour p. n. until 2 nd week
post natum p < 0.02 to 0.001) whereas the right caudal lung area
participates more intensively after the 12 th hour post natum until the
third week post natum in the increasing gas exchange than the left area
(p < 0.05 to 0.001).
Conclusions: A complete gas exchange activity within the bovine lung
is only given with the beginning of the second week post natum. It was
shown that there are significant differences in the development of the
stability of lung alveoli comparing cranial and caudal lung segments as
well as dorsal and ventral lung areas.
Key words: neonatal calves, lung ventilation, lung computer
tomography
440 Effects of Meloxicam Therapy on the Behaviour and Welfare
of Dairy Calves with Neonatal Calf Diarrhea Complex
C. Todd 1 , S. Millman 1,2 , T. Duffield 1 , D. McKnight 3 , K. Leslie 1
1 University of Guelph, Population Medicine, Guelph, Canada
2 Iowa State University, Population Medicine, Ames, United States
3 University of Guelph, Kemptville Campus, Kemptville, Canada
Infectious disease poses a major welfare challenge for neonatal dairy
calves. Opportunities for supportive therapy which may alleviate
animal suffering during disease states need to be identified and
formally evaluated. The objective of this study was to examine
whether meloxicam (Metacam ® 20 mg/mL solution for injection for
cattle, pigs and horses, Boehringer Ingelheim) is an effective
supportive therapy for the alleviation of sickness and pain-related
behaviours in cases of neonatal calf diarrhea complex. For this
double-blind controlled trial, 62 Holstein bull calves were purchased
at birth and transported to a calf research facility. At the naturally
occurring onset of diarrhea, the calves were enrolled in the study and
randomly assigned to receive a single subcutaneous injection of
meloxicam (0.5 mg/kg BW) or an equal volume of placebo solution.
Starter ration and milk intakes were recorded daily for each calf until
56 days of age. Following onset of diarrhea, calf feeding behaviour,
lying posture, standing posture and activity were evaluated over a
five day observation period. During the study, 56 calves presented
with clinical signs of diarrhea and were subsequently treated with
meloxicam (n=28) or placebo (n=28). Meloxicam-treated calves
began consuming starter ration significantly earlier (p1/50 (Pomona 11/24 vs. 23/23, D 54% CI 28-80%, P