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Using Acceleration Data to Automatically Detect the Onset of Farrowing in Sows
No full textThe aim of the present study was to automatically predict the onset of farrowing in crate-confined sows. (1) Background: Automatic tools are appropriate to support animal surveillance under practical farming conditions. (2) Methods: In three batches, sows in one farrowing compartment of the Futterkamp research farm were equipped with an ear sensor to sample acceleration. As a reference video, recordings of the sows were used. A classical CUSUM chart using different acceleration indices of various distribution characteristics with several scenarios were compared. (3) Results: The increase of activity mainly due to nest building behavior before the onset of farrowing could be detected with the sow individual CUSUM chart. The best performance required a statistical distribution characteristic that represented fluctuations in the signal (for example, 1st variation) combined with a transformation of this parameter by cumulating differences in the signal within certain time periods from one day to another. With this transformed signal, farrowing sows could reliably be detected. For 100% or 85% of the sows, an alarm was given within 48 or 12 h before the onset of farrowing. (4) Conclusions: Acceleration measurements in the ear of a sow are suitable for detecting the onset of farrowing in individually housed sows in commercial farrowing crates
Tail Lesions and Losses of Docked and Undocked Pigs in Different Farrowing and Rearing Systems
No full textThis study aimed to investigate the effects of farrowing and rearing systems on tail lesions and losses of docked and undocked pigs. Pigs from three farrowing systems: Conventional farrowing crate (FC), free farrowing (FF) and group housing of lactating sows (GH) were randomly allocated to different rearing systems: A conventional system (CONV), where the pigs were regrouped and transferred to conventional finishing pens at ten weeks of age or a wean-to-finish (W-F) system, where the pigs remained in their pens until slaughter with higher space allowance during rearing. Weekly, tail lesions and losses were assessed individually. The incidence of tail lesions was higher in undocked CONV pigs compared to undocked W-F pigs (maximum: CONV 58.01%, W-F 41.16%). The rearing system had a significant effect on tail losses at the end of finishing (CONV 67.63%, W-F 38.2%). The significant effect of the rearing system might be explained by higher space allowance during rearing and reduced regrouping stress for W-F pigs. In conclusion, farrowing systems showed no effects, but the W-F rearing system reduces the frequency of tail lesions and losses; the curves of tail lesions increased slower and stayed on a lower level, which resulted in lower losses as well
Effects of Different Farrowing and Rearing Systems on Post-Weaning Stress in Piglets
No full textThis study aimed to investigate how farrowing and rearing systems affect skin lesions, serum cortisol, and aggressive behavior as indicators for weaning stress of piglets. Between May 2016 and March 2018, in total 3144 weaning piglets from three different farrowing systems were examined: farrowing crates (FC), single-housing free-farrowing pens (FF), and group-housing of lactating sows and litters (GH). After weaning and regrouping, piglets were relocated to conventional rearing pens (conv; 5.7 m2) or to wean-to-finish pens (w-f; 12.4 m2). Skin lesions were scored 24 h after weaning. Blood samples were taken one week before and 24 h after weaning to analyze the individual difference in serum cortisol. Behavior was observed for 24 h after relocation. Animals raised in FC and FF had significantly more skin lesions than that of GH animals. Piglets born in GH showed lower cortisol differences and fought less and for shorter periods compared to FC and FF piglets. Piglets weaned to w-f pens showed greater cortisol changes and fought significantly longer than piglets in conv pens. Group housing during the suckling period reduced weaning stress for piglets in terms of skin lesions, serum cortisol, and aggressive behavior. Greater space allowance (w-f vs. conv) was not beneficial with regard to the investigated parameters
Validierung möglicher Parameter zur frühzeitigen Krankheitserkennung bei Milchrindern
No full textAn early detection of signs of sickness and consequently an early start of a
therapy is beneficial for a successful treatment of diseases in dairy cattle.
Due to a continuous increase in herd size there is less labour potential per
cow and calf, respectively. Thus, the systematic evaluation of clinical
parameters of animals at risk of disease on a regular basis might help to
select animals for a clinical examination. The overall objective of this study
was to validate cow-side parameters that might help to detect diseases in
dairy cows and calves at an early stage. In the first study the variability of
rectal temperatures in dairy cows considering different factors (intra- and
inter-investigator repeatability, different thermometers, penetration depth
into the cows´ rectum, and defecation) was validated. In a first experiment
rectal temperature was measured multiple times per cow (n = 33) to determine
intra-investigator repeatability. Repeated measures by a single investigator
were consistent (39.5 ± 0.1ºC, coefficient of variance = 0.2%). Within the 10
measurements on the same cow, the maximum difference varied between 0.1 and
0.5ºC. In the second experiment rectal temperature was measured by 2 different
observers in 38 cows to determine inter-investigator repeatability.
Correlation between measures taken by 2 investigators was high (r = 0.98; P <
0.001) and mean difference was 0.1 ± 0.2ºC (P < 0.01). Data from these
experiments demonstrate a high repeatability of rectal temperature
measurements within and between investigator(s). However, for some cows, the
difference between lowest and highest temperature was considerable (0.5ºC in 2
cows and 0.4ºC in 5 cows). In Experiment 3 the variation among different
thermometers was tested in an in vitro and an in vivo phase. During the in
vitro phase a water bath was adjusted in 1.0ºC increments from 35.0 to 42.0ºC
and temperature measured with a validated thermometer and the 4 thermometers
to be tested. During the in vitro phase correlation was high between all 4
thermometers and the validated thermometer (r = 0.99; P < 0.001) and mean
differences were minor (0.0 to 0.1 ± 0.1ºC). During the in vivo phase rectal
temperature was measured with all 4 thermometers in 37 cows by a single
investigator. The measures from the 4 different thermometers were highly
correlated (r = 0.94 to 0.96; P < 0.001). The mean difference between
thermometers varied from 0.1 to 0.3ºC. Agreement was high when both
thermometers compared had either a short or a long probe. Experiment 4 tested
the influence of insertion depth. A single investigator measured rectal
temperature in 33 cows, inserting the probe either 11.5 or 6.0 cm. Measures at
the 2 penetration depths were highly correlated (r = 0.95; P < 0.001), but the
result was 0.4 ± 0.2ºC higher when the probe was inserted deeper into the
rectum (P < 0.001). Experiment 5 tested the effect of defecation on rectal
temperature, measuring rectal temperature before and after defecation in 20
cows. Differences in temperature before and after defecation were minor. In 2
cows the measured temperature was 0.3ºC or higher before defecation, whereas
in 3 cows it was 0.3ºC or higher after defecation. In the remaining 15 cows
the difference before and after defecation was less than 0.3ºC. Overall, the
results of this study indicate that some care is required in generalizing
rectal measures of body temperature in dairy cows. To develop individual-
standard fresh-cow monitoring programs at the herd level, rectal temperature
should be measured with the same thermometer on the same penetration depth.
The objectives of the second study were: 1) to determine repeatability (i.e.
interobserver and intra-observer) of rumen fill scoring, 2) to study variation
of rumen fill scores throughout the day in ad libitum fed cows, 3) to evaluate
relationships between visual rumen fill scores and DMI and 4) to compare
visually estimated rumen fill scores with exact measurements of the depth of
the paralumbar fossa. Experiment 1 was conducted to determine inter-observer
repeatability of rumen fill scoring and to study variation of rumen fill
scores throughout the day in ad libitum fed cows. Three investigator
independently scored rumen fill of 42 cows 3 times a day (0800, 1400, 1900 h).
Experiment 2 consisted of 3 replicates (67, 70, 71 cows) employing 3
observers. Cows in each replicate were scored twice by the same observer to
determine intra-observer repeatability. The intra-observer reliability for the
2 rumen fill scoring sessions showed moderate agreement (κw = 0.69; rS = 0.66,
P < 0.001). Similarly, the inter-observer reliability for 2 independent
observers showed reasonable agreement in rumen fill scores (κw = 0.68; rS =
0.71, P < 0.001). All 3 observers recorded higher rumen fill scores at 1900 h
compared to 0800 h and 1400 h (Observer A: 0800 h: 3.1 ± 0.7, 1400 h: 3.4 ±
0.7, 1900 h: 3.6 ± 0.7; Observer B: 0800 h: 3.2 ± 0.8, 1400 h: 3.5 ± 0.8, 1900
h: 3.7 ± 0.7; Observer C: 0800 h: 2.8 ± 0.7, 1400 h: 3.1 ± 0.8, 1900 h: 3.2 ±
0.7; n = 210). Experiment 3 was conducted to evaluate relationships between
within-cow changes in visual rumen fill score and changes in DMI in
multiparous cows. Within-cow changes in visual rumen fill scores were compared
to changes in DMI calculated for a 24-h interval. Additionally, data collected
during Experiment 1 was used to assess the relationship between within-cow
changes in visual rumen fill score and changes in DMI comparing differences
between daylight hours and the night. I did observe a relationship between
changes in visual rumen fill scores and DMI within cow on a 24-h basis (rS =
0.1, P = 0.09; n = 288) and comparing differences between day and night (rS =
0.68, P < 0.01; n = 257). In Experiment 4, variation in the objectively
measured depth of the left paralumbar fossa within cow (intra-cow variation)
was evaluated and the relationship between the depth of the left paralumbar
fossa and rumen fill score determined. The variation in depth within the 5
classes of rumen fill scores (intra-score variation) was also determined. The
average intracow variation in the depth of the paralumbar fossa was moderate
(5.59 ± 0.9 cm; CV = 16%). On the same cow the range varied between 1.2 and
4.8 cm, measuring 10 times over a period of 70 ± 5 min. Variation in depth
within each of the different rumen fill scores (intrascore variation) was also
high. Spearman´s rank correlation (rS) between the depth of the paralumbar
fossa and the rumen fill score was moderate (Observer A: rS = -0.64, P <
0.001; Observer B: rS = -0.60, P < 0.001). These data illustrate that rumen
fill scores show moderate intra- and inter-observer repeatability. Moreover,
these scores are moderately correlated with an objective measures of the depth
of the left paralumbar fossa; a measure that changes considerably over a 70
min period. We did observe a reasonable relationship between changes in DMI
and rumen fill scores within cow comparing differences between day and night,
two periods with a significant difference in DMI, suggesting that future use
of this measure on farms should be done across time within cow. Further
research is needed to identify more accurate cow-side estimates of DMI, and to
determine if changes in rumen fill scores can be used to identify cows at risk
for disease. The objectives of the third study were: 1) to determine inter-
investigator repeatability of rumination data collected via direct human
observation in heifers and calves, 2) to determine the accuracy of the Hi-Tag
rumination monitoring system in comparison to direct visual observation in
heifers and calves considering different ages and, 3) to study whether sound
of milk suckling in bottle fed pre-weaned calves interferes with the
rumination monitoring system. In Experiment 1, 2 observers independently
recorded rumination behavior from 20 animals via direct human observation for
an observation period of 2 h each to determine the inter-investigator
reliability. The rumination times were highly correlated (r = 0.99, P < 0.001,
n = 20) and differences were minor (0 ± 2 min, P = 0.91). In Experiment 2, 6
groups consisting of 5 animals (Group 4 = 10 animals) of different ages were
used to test the accuracy of the Hi-Tag rumination monitoring system in
comparison to direct visual observation (Group 1: 25 ± 2 d, 64 ± 3 kg; Group
2: 42 ± 2 d, 80 ± 15 kg; Group 3: 62 ± 1 d, 90 ± 11 kg; Group 4: 95 ± 10 d,
118 ± 7 kg; Group 5: 185 ± 1 d, 207 ± 15 kg; Group 6: 282 ± 7 d, 342 ± 14 kg).
Coefficients of correlation were highest for Group 3 (r = 0.89; P < 0.001) and
Group 6 (Group 6: r = 0.88: P < 0.001), lower for Group 1 (r = 0.65; P =
0.009), Group 2 (r = 0.70; P = 0.004) and Group 5 (r = 0.72; P = 0.002), and
lowest for Group 4 (r = 0.47: P = 0.009). The differences were lowest in Group
2 (0 ± 12 min; P = 0.77), Group 3 (2 ± 10 min; P = 0.60), and Group 6 (-4 ± 8
min; P = 0.05), moderate in Group 1 (-8 ± 10 min; P = 0.01) and Group 5 (-8 ±
14 min; P = 0.03) and highest in Group 4 (-12 ± 16 min; P < 0.001). Variation
was low in Groups 6 (7.8 %) and 3 (11.8 %), but higher in Groups 1 (14.7 %), 2
(14.4 %), 4 (25.0 %), and 5 (22.8 %), respectively. In Experiment 3 I
determined whether distortion of the Hi-Tag rumination monitoring system
occurred when pre weaned calves suckled milk through a nipple. Each of 9
calves was fitted with a rumination logger just before milk feeding in the
morning and again in the afternoon and the loggers removed immediately after
the calves had finished suckling. They were stored in a quiet room for the
rest of the interval and another 2 h to create a negative control interval.
The coefficient of correlation between suckling time determined by direct
observation and the estimates provided by the Hi-Tag system was low (r = -0.1;
P = 0.70; n = 18). Only in 2 of the 18 2-h intervals (11.1%) did the Hi-Tag
system record a 2 min observation; whereas, no observations were recorded
during the other 16 intervals monitored during suckling or in the 18 intervals
that served as negative controls. The Hi-Tag rumination monitoring system
provides an accurate measure of rumination time in Holstein heifers older than
9 months. In animals younger than 9 months the variation of the data is high.
However, an automatic detection of rumination time in heifers and calves might
be a useful tool for detection of illness or studying rumen development in
calves. Considering that suckling does not confound rumination time measures
further research is encouraged to optimize the sound based detection system
for rumination in calves. Overall, the three studies clearly evaluated simple
and cow-side tests to detect cows at risk for disease. However, the user has
to be critical regarding accuracy and repeatability. Measuring body
temperature (objective parameter) in dairy cows has proven to provide reliable
information. Furthermore, care is required to interpret visually estimated
rumen fill scores (subjective parameter) and further research is needed to
test, if rumen fill scores can be used to detect cows at risk for disease.
Although the Hi-Tag rumination monitoring system does measure rumination time
accurate in cows and heifers older than 9 months the variation of the data is
high for younger animals.Eine frühe Erkennung von Zeichen einer Erkrankung und damit ein früher
Therapiebeginn erhöhen die Chance für eine erfolgreiche Therapie von
Erkrankungen bei Milchrindern. Wachsende Milchviehbestände sorgen für eine
Reduzierung der verfügbaren Arbeitskraft pro Kuh oder Kalb. Eine systematische
und regelmäßige Erhebung bestimmter klinischer Parameter könnte helfen Tiere
für eine klinische Untersuchung vorzuselektieren. Ziel dieser Arbeit war die
Validierung verschiedener Parameter, die bei einer frühzeitigen
Krankheitserkennung bei Milchkühen und Kälbern relevant sind. In der ersten
Studie wurde die Variabilität der rektal gemessenen Körpertemperatur bei
Milchkühen unter Berücksichtigung folgender Faktoren bestimmt: 1) die
Wiederholbarkeit der Messwerte sowohl innerhalb eines Untersuchers, als auch
zwischen unterschiedlichen Untersuchern, 2) mögliche Unterschiede im Ergebnis
bei der Verwendung unterschiedlicher digitaler Thermometer und 3) den Einfluss
von Eindringtiefe und Kotabsatz auf das Ergebnis. Im ersten Experiment wurde
bei 33 Kühen die rektale Temperatur mehrmals hintereinander gemessen, um die
Wiederholbarkeit der Messwerte innerhalb eines Untersuchers zu bestimmen. Die
Messwerte zeigten eine hohe Übereinstimmung innerhalb eines Untersuchers (39.5
± 0,5ºC, Variationskoeffizient = 0,2%). Innerhalb der zehn Messungen schwankte
die maximale Differenz zwischen 0,1 und 0,5ºC bei derselben Kuh. Im zweiten
Experiment wurde die rektale Temperatur von 38 Kühen durch zwei unabhängige
Untersucher gemessen, um die Wiederholbarkeit der Messung zwischen
unterschiedlichen Untersuchern zu testen. Die Korrelation zwischen den
Untersuchern war hoch (r = 0,98; P < 0,001) und die mittlere Abweichung lag
bei 0,1 ± 0,2ºC (P < 0,01). Die Ergebnisse dieser Experimente zeigen deutlich,
dass die rektale Temperatur mit einer hohen Wiederholbarkeit gemessen werden
kann. Trotzdem konnte bei einigen Kühen eine beträchtliche Abweichung zwischen
dem höchsten und dem niedrigsten Messwert festgestellt werden (0,5ºC bei 2
Kühen und 0,4ºC bei 5 Kühen). Im dritten Experiment wurde die Abweichung der
Messwerte bei der Verwendung unterschiedlicher Thermometer in vitro und in
vivo getestet. Ein Wasserbad wurde im Bereich von 35 bis 42ºC auf jedes volle
Grad justiert. Bei jeder Stufe wurde die Temperatur mit einem validierten und
mit den vier zu testenden Thermometern gemessen. Die Korrelation zwischen den
vier Thermometern und dem validierten Thermometer war in allen Fällen hoch (r
= 0,99; P < 0,001). Gleichzeitig war nur eine geringe mittlere Abweichung
zwischen den Thermometern zu verzeichnen (0,0 bis 0,1 ± 0,1ºC). Zur Testung
der Unterschiede zwischen den Thermometern in vivo wurde bei 37 Kühen mit
allen vier Thermometern die rektale Temperatur gemessen. Die Ergebnisse der
vier Thermometer zeigten eine hohe Korrelation (r = 0,94 bis 0,96; P < 0,001).
Die mittlere Abweichung zwischen den Thermometern variierte zwischen 0,1 und
0,3ºC, wobei die Übereinstimmung bei vergleichbarer Sondenlänge höher war. Im
vierten Experiment wurde der Einfluss der Eindringtiefe getestet. Ein einziger
Untersucher hat die rektale Temperatur von 33 Kühen gemessen, indem die Sonde
im ersten Fall 11,5 cm und im zweiten Fall 6,0 cm ins Rektum eingeführt wurde.
Die Ergebnisse zwischen den Eindringtiefen zeigten eine hohe Korrelation (r =
0,95; P < 0,001). Das Ergebnis der Messungen war bei 11,5 cm Eindringtiefe um
0,4 ± 0,2ºC höher als bei 6,0 cm (P < 0,001). Im fünften Experiment wurde die
rektale Temperatur vor und nach Kotabsatz bei 20 Kühen gemessen, um dessen
Einfluss auf das Ergebnis zu testen. Der Unterschied vor und nach Kotabsatz
war zu vernachlässigen. Während die gemessene Temperatur bei zwei Kühen vor
dem Kotabsatz höher war, war sie bei 3 Kühen danach höher. Bei den
verbleibenden 15 Kühen war der Unterschied kleiner als 0,3ºC. Insgesamt zeigen
die Ergebnisse dieser Studie, dass bei der Bewertung der rektalen Temperatur
ein wenig Vorsicht geboten ist. Bei der Entwicklung von Standardprotokollen
zur Überwachung von abgekalbten Kühen sollte die rektale Temperatur in einer
Herde immer mit demselben Thermometer bei derselben Eindringtiefe gemessen
werden, um eine Vergleichbarkeit der Ergebnisse sicherzustellen. Ziel der
zweiten Studie war es 1) die Wiederholbarkeit eines Punktesystems zur
Bewertung der Pansenfüllung von Milchkühen sowohl innerhalb eines Untersuchers
als auch zwischen unterschiedlichen Untersuchern zu testen, 2) die Variation
von Pansenfüllungsnoten bei ad libitum gefütterten Kühen im Verlaufe eines
Tages zu bestimmen, 3) den Zusammenhang zwischen Unterschieden der
Pansenfüllungsnoten innerhalb einer Kuh und Unterschieden in der
Trockenmasseaufnahme zu ermitteln und 4) Pansenfüllungsnoten mit einer exakten
Messung der Tiefe der Hungergrube zu vergleichen. Im ersten Experiment wurde
die Wiederholbarkeit eines Punktesystems zur Bewertung der Pansenfüllung von
Milchkühen zwischen unterschiedlichen Untersuchern und die Variation von
Pansenfüllungsnoten bei ad libitum gefütterten Kühen im Verlaufe eines Tages
bestimmt. Dazu vergaben drei Untersucher dreimal täglich Pansenfüllungsnoten
bei 42 Kühen (0800, 1400, 1900 h). Das zweite Experiment bestand aus drei
Wiederholungen (67, 70, 71 Kühe) ebenfalls mit drei unterschiedlichen
Untersuchern. In jeder Wiederholung wurden die Kühe von demselben Untersucher
zweimal bewertet um die Wiederholbarkeit innerhalb eines Untersuchers zu
testen. Innerhalb eines Untersuchers war die Wiederholbarkeit mittelmäßig (κw
= 0.69; rS = 0.66, P < 0.001). Zwischen unterschiedlichen Untersuchern war die
Wiederholbarkeit ebenfalls mäßig (κw = 0.68; rS = 0.71, P < 0.001). Weiterhin
wurden von allen Untersuchern im Mittel höhere Noten um 1900 h vergeben, als
um 0800 und 1400 h (Untersucher A: 0800 h: 3.1 ± 0.7, 1400 h: 3.4 ± 0.7, 1900
h: 3.6 ± 0.7; Untersucher B: 0800 h: 3.2 ± 0.8, 1400 h: 3.5 ± 0.8, 1900 h: 3.7
± 0.7; Untersucher C: 0800 h: 2.8 ± 0.7, 1400 h: 3.1 ± 0.8, 1900 h: 3.2 ± 0.7;
n = 210). Im dritten Experiment sollte die Beziehung zwischen Änderungen der
Pansenfüllungsnoten innerhalb einer Kuh und Änderungen der
Trockenmasseaufnahme untersucht werden. Dafür wurden Änderungen der
Pansenfüllungsnoten innerhalb einer Kuh mit Änderungen der
Trockenmasseaufnahme für ein 24-h Intervall verglichen. Weiterhin wurden Daten
aus Experiment 1 benutzt, um diese Beziehung bei Vergleich von Tag und Nacht
zu bestimmen. Es konnte sowohl eine Beziehung zwischen Änderungen der
Pansenfüllungsnote und Änderungen der Trockenmasseaufnahme innerhalb einer Kuh
beim 24-h Vergleich (rS = 0.1, P = 0.09) als auch beim Vergleich zwischen Tag
und Nacht (rS =0.68, P < 0.01; n = 257) nachgewiesen werden Das vierte
Experiment untersuchte zum einen die Variation der objektiv ermittelten Tiefe
der linken Hungergrube und zum anderen den Zusammenhang der Tiefe der
Hungergrube und der vergebenen Pansenfüllungsnote. Weiterhin wurde die
Variation der Tiefe der Hungergrube innerhalb der einzelnen
Pansenfüllungsnoten untersucht. Die mittlere Variation der Tiefe innerhalb
einer Kuh war moderat (5,59 ± 0,9 cm; Variationskoeffizient = 16%), wobei die
maximale Abweichung über 70 ± 5 min von 1,2 bis 4,8 cm schwankte. Innerhalb
der verschiedenen Pansenfüllungsnoten war die Abweichung ebenfalls hoch.
Spearman´s Rangkorrelation (rS) zwischen der Tiefe der Hungergrube und der
vergebenen Pansenfüllungsnote war mäßig (Untersucher A: rS = -0.64, P < 0.001;
Untersucher B: rS = -0.60, P < 0.001). Die Ergebnisse dieser Studie zeigen,
dass die Bewertung der Pansenfüllung sowohl innerhalb eines Untersuchers als
auch zwischen unterschiedlichen Untersuchern moderat wiederholbar ist.
Weiterhin besteht eine Beziehung zwischen den Pansenfüllungsnoten und einer
exakten Messung der Tiefe der linken Hungergrube. Diese variiert nicht
unerheblich über einen Zeitraum von 70 min innerhalb einer Kuh. Nichts desto
trotz konnte eine annehmbare Beziehung zwischen Unterschieden in der
Trockenmasseaufnahme und Unterschieden der Pansennote innerhalb einer Kuh bei
Vergleich von Tag und Nacht, zweier Intervalle mit bedeutsamen Unterschieden
in der Trockenmasseaufnahme, nachgewiesen werden. Unter diesem Aspekt sollte
eine Bewertung der Pansennote nur zum zeitlichen Vergleich innerhalb eines
Tieres genutzt werden. Fragestellungen der dritten Studie war 1)
festzustellen, ob die Wiederkauzeit von Färsen und Kälbern visuell von zwei
unterschiedlichen Untersuchern wiederholbar zu ermitteln ist, 2) die
Genauigkeit eines elektronischen Systems zur Erfassung der Wiederkauzeit (Hi-
Tag System) im Vergleich zur direkten visuellen Bestimmung bei Färsen und
Kälbern unterschiedlichen Alters zu ermitteln und 3) zu prüfen, ob das Saugen
an einem Nuckel die Daten des Hi-Tag Systems beeinflusst. In einem ersten
Experiment wurde bei 20 Tieren die Dauer der Wiederkauaktivität durch direkte
visuelle Beobachtung von zwei unabhängigen Untersuchern erfasst, um die
Wiederholbarkeit zu ermitteln. Jedes Tier wurde über 2 Stunden beobachtet. Die
von beiden Untersuchern erfassten Wiederkauzeiten korrelierten sehr gut
miteinander (r = 0,99, P < 0,001). Die mittlere Abweichung war gering (0 ± 2
min, P = 0,91). Sechs unterschiedliche Altersgruppen von je fünf Tieren
(Gruppe 4 = 10 Tiere) wurden im zweiten Experiment benutzt, um die Genauigkeit
des Hi-Tag Systems zur Überwachung der Wiederkautätigkeit im Vergleich zur
direkten visuellen Beobachtung zu bestimmen (Gruppe 1: 25 ± 2 d, 64 ± 3 kg;
Gruppe 2: 42 ± 2 d, 80 ± 15 kg; Gruppe 3: 62 ± 1 d, 90 ± 11 kg; Gruppe 4: 95 ±
10 d, 118 ± 7 kg; Gruppe 5: 185 ± 1 d, 207 ± 15 kg; Gruppe 6: 282 ± 7 d, 342 ±
14 kg). Die Korrelation war am höchsten in Gruppe 3 (r = 0,89; P < 0,001) und
Gruppe 6 (r = 0,88; P < 0,001), niedriger in Gruppe 1 (r = 0,65; P = 0,009),
Gruppe 2 (r = 0,70; P = 0,004) und Gruppe 5 (r = 0,72; P = 0,002) und am
niedrigsten in Gruppe 4 (r = 0,47; P = 0,009). Die mittlere Abweichung war am
niedrigsten in Gruppe 2 (0 ± 12 min; P = 0,77), Gruppe 3 (2 ± 10 min; P =
0,60) und Gruppe 6 (-4 ± 8 min; P = 0,05), mäßig in Gruppe 1 (-8 ± 10 min; P =
0,01) und Gruppe 5 (-8 ± 14 min; P = 0,03) und am höchsten in Gruppe 4 (-12 ±
16 min; P < 0,001). Die Variation der ermittelten Wiederkauzeiten war niedrig
in Gruppe 6 (7,8 %) und Gruppe 3 (11,8 %), dagegen hoch in den Gruppen 1 (14,7
%), 2 (14,4 %), 4 (25,0 %) und 5 (22,8 %). Das Ziel des dritten Experiments
war zu bestimmen, ob das Saugen an einem Nuckel die Daten des Hi-Tag Systems
bei nicht abgesetzten Kälbern beeinflusst. Neun Kälber wur
The effect of mixing piglets after weaning on the occurrence of tail-biting during rearing
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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