A blind climber: The first evidence of ultrasonic echolocation in arboreal mammals

The means of orientation is studied in the Vietnamese pygmy dormouse Typhlomys chapensis, a poorly known enigmatic semi‐fossorial semi‐arboreal rodent. Data on eye structure are presented, which prove that Typhlomys (translated as “the blind mouse”) is incapable of object vision: the retina is folded and retains no more than 2500 ganglion cells in the focal plane, and the optic nerve is subject to gliosis. Hence, Typhlomys has no other means for rapid long‐range orientation among tree branches other than echolocation. Ultrasonic vocalization recordings at the frequency range of 50–100 kHz support this hypothesis. The vocalizations are represented by bouts of up to 7 more or less evenly‐spaced and uniform frequency‐modulated sweep‐like pulses in rapid succession. Structurally, these sweeps are similar to frequency‐modulated ultrasonic echolocation calls of some bat species, but they are too faint to be revealed with a common bat detector. When recording video simultaneously with the ultrasonic audio, a significantly greater pulse rate during locomotion compared to that of resting animals has been demonstrated. Our findings of locomotion‐associated ultrasonic vocalization in a fast‐climbing but weakly‐sighted small mammal ecotype add support to the “echolocation‐first theory” of pre‐flight origin of echolocation in bats.     

Patterns and causes of geographic variation in bat echolocation pulses

Evolutionary biologists have a long‐standing interest in how acoustic signals in animals vary geographically, because divergent ecology and sensory perception play an important role in speciation. Geographic comparisons are valuable in determining the factors that influence divergence of acoustic signals. Bats are social mammals and they depend mainly on echolocation pulses to locate prey, to navigate and to communicate. Mounting evidence shows that geographic variation of bat echolocation pulses is common, with a mean 5–10 kHz differences in peak frequency, and a high level of individual variation may be nested in this geographical variation. However, understanding the geographic variation of echolocation pulses in bats is very difficult, because of differences in sample and statistical analysis techniques as well as the variety of factors shaping the vocal geographic evolution. Geographic differences in echolocation pulses of bats generally lack latitudinal, longitudinal and elevational patterns, and little is known about vocal dialects. Evidence is accumulating to support the fact that geographic variation in echolocation pulses of bats may be caused by genetic drift, cultural drift, ecological selection, sexual selection and social selection. Future studies could relate geographic differences in echolocation pulses to social adaptation, vocal learning strategies and patterns of dispersal. In addition, new statistical techniques and acoustic playback experiments may help to illustrate the causes and consequences of the geographic evolution of echolocation pulse in bats.     

Social vocalizations of big‐footed myotis (Myotis macrodactylus) during foraging

Acoustic signals play a crucial role in transmitting information and maintaining social stability in gregarious animals, especially in echolocating bats, which rely primarily on biological sonar for navigating in the dark. In the context of foraging without relying on tactile, visual or olfactory cues, acoustic signals convey information not only on food but also on ownership and defense of resources. However, studies on such information remain fragmentary. In the present study, we aim to document the social vocal repertoire of Myotis macrodactylus at natural foraging sites. Multiple acoustic analyses and spectrographic classification revealed a rich foraging vocal repertoire comprising 6 simple syllables and 2 composites. Discriminant function analyses associated with a subset‐validation procedure provided an optimal method to spectrographically classify all recorded sounds into different syllable types. Multidimensional scaling of median values of multiple parameters further confirmed notable differences among these syllables in a 3‐D space. In addition, Euclidean distance analysis showed that there were some spectral similarities between specific social vocal syllables and feeding buzzes, which implied a potential jamming role. Altogether, the data indicate that bats at foraging sites under natural conditions used variant social vocalizations with different functions in addition to echolocation calls, providing supporting evidence for further work on the function and vocal mechanisms of acoustic communication in mammals.     

Improved visualization of the lumbar spine nerve roots in dogs using water excitation (ProSet) as opposed to short tau inversion recovery: A retrospective study of two fat suppression MRI sequences

Magnetic resonance imaging fat suppression techniques are commonly used for diagnosis of canine spinal disease, however, studies comparing different techniques are currently lacking. This retrospective, methods comparison study aimed to evaluate water excitation and STIR MRI pulse sequences for visualization of canine lumbar spinal nerve roots. For inclusion, all dogs had to have dorsal planar MRI studies of the lumbar spine using both sequences. Visual grading analysis was used for scoring the following five criteria: degree of fat suppression; nerve root visualization; subjective tissue contrast; presence of noise; and overall better image quality. Scores were independently recorded by three board‐certified veterinary radiologists on two separate occasions, 3‐6 weeks apart. A total of 90 dogs were sampled. A two‐tailed t‐test showed that there were significant differences in all scored parameters (P < 0.00001), with the exception of noise (P = 0.47343), and that the water excitation sequence scored higher in all cases excluding noise. A Gwets AC kappa for intraobserver and interobserver reliability showed “almost perfect” agreement for the nerve roots in both tests (intra: k = 0.88; inter: k = 0.90). Intraobserver agreement was “substantial” for the degree of fat suppression (k = 0.68), subjective tissue contrast (k = 0.75), and overall better image quality (k = 0.76) and it was “fair” for the noise (k = 0.46). Interobserver agreement was “moderate” for the degree of fat suppression (k = 0.53), subjective tissue contrast (k = 0.63), and overall better image quality (k = 0.66) and “slight” for noise (k = 0.25). These findings supported using the water excitation pulse sequence for fat‐suppressed MRI of canine lumbar spinal nerve roots.     

Progesterone and Luteinizing hormone secretion patterns in early pregnant gilts

We studied luteinizing hormone (LH) pulsatility and episodic progesterone release of the corpus luteum (CL) on Day 11 and Day 21 in inseminated gilts and aimed to establish a relationship between these two hormones. Blood was collected at 15-min intervals for 12 hr on Days 11, 16 and 21 from a vena cava caudalis catheter. At euthanasia, eight gilts were pregnant and six gilts were not pregnant. Progesterone parameters (basal, mean, pulse frequency and pulse amplitude) did not differ between pregnant and non-pregnant gilts on Day 11, LH pulse frequency and amplitude tended to differ (p = .07 and p = .079). In pregnant gilts, basal and mean progesterone, progesterone pulse amplitude and frequency declined significantly from Day 11 to Day 21 (p < .05). A significant decline was also seen in the LH pulse amplitude from Day 11 to Day 21 (p < .05). None of the LH pulses was followed by a progesterone pulse within 1 hr on Day 21. On Day 11 and Day 21 appeared a synchronicity in the LH pulse pattern, as there were two or three LH pulses in 12 hr and these LH pulses appeared in the same time window. We conclude that on Day 11 and Day 21 of pregnancy in gilts, progesterone pulses do not follow an LH pulse within one hour. Further we demonstrated that the successful or not successful formation of a CL of pregnancy is independent of progesterone release on Day 11 after insemination. We confirmed the decline of progesterone from Day 11 to Day 21 in the vena cava caudalis and could demonstrate that this decline is partly due to lower progesterone pulse amplitude and frequency and that the decline occurs simultaneously with a decline in LH pulse amplitude.     

MAGNETIC RESONANCE IMAGING OF THE CANINE ABDOMEN: EFFECT OF PULSE SEQUENCE ON DIAGNOSTIC QUALITY

Motion artifact is an important limiting factor for abdominal magnetic resonance imaging (MRI) in veterinary patients. The purpose of this study was to determine the effects of pulse sequence on abdominal MRI diagnostic quality in dogs. Ten normal dogs were each scanned using 16 MRI pulse sequences. Sequences included breath‐holding sequences, respiratory navigation sequences, and traditional spin‐echo sequences. Four observers independently scored diagnostic quality for each sequence based on the appearance of specific organs, overall diagnostic quality, and degree of artifactual interference. Signal‐to‐noise ratio and contrast‐to‐noise ratio were also calculated for each sequence. The sequence with the highest overall mean diagnostic quality score was the dorsal T2 turbo spin echo (TSE) with fat saturation and breath‐holding. The sequence with the lowest mean diagnostic quality score was the dorsal T2 fast spin echo. The sequence with the highest signal‐to‐noise ratio for all evaluated organs was the sagittal T1 spin echo. Signal‐to‐noise and contrast‐to‐noise ratios did not correlate with subjective assessment of overall diagnostic quality for the majority of the sequences evaluated (P < 0.05). The three sequences considered to have the highest diagnostic quality for the cranial abdomen were the dorsal T2 TSE with fat saturation and breath‐hold, transverse T1 turbo fast low‐angle shot gradient echo with breath‐hold, and dorsal T2 half‐Fourier acquisition single shot TSE with respiratory navigation. These sequences had short acquisition times, yielded studies of similar diagnostic quality, provided complementary information, and are therefore recommended for routine canine abdominal MRI protocols.     

Luteolysis and associated interrelationships among circulating PGF2α, progesterone, LH, and estradiol in mares

The changing concentrations and temporal relationships among a PGF2α metabolite (PGFM), progesterone (P₄), LH, and estradiol-17β (E₂) before, during, and after luteolysis were studied in 10 mares. Blood samples were collected every hour for ≥4 d beginning on day 12 after ovulation. The luteolytic period extended from a decrease in P₄ at a common transitional hour (Hour 0) at the end of preluteolysis and beginning of luteolysis to a defined ending when P₄ reached 1 ng/mL. The length of luteolysis was 22.9 ± 0.9 h, contrasting with 2 d in published P₄ profiles from sampling every 6 to 24 h. In mares with complete data for Hours −40 to −2 (n = 6), PGFM concentrations remained below assay sensitivity (n = 2) or two or three small pulses (peak, 29 ± 4 pg/mL) occurred. During luteolysis, the pulses became more prominent (peak, 193 ± 36 pg/mL). Rhythmicity of PGFM pulses was not detected by a pulsatility program during preluteolysis but was detected in seven of nine mares during luteolysis and postluteolysis combined. The nadir-to-nadir interval for LH pulses and the peak-to-peak interval between adjacent pulses were longer (P < 0.05) during preluteolysis than during luteolysis (nadir to nadir, 5.2 ± 0.3 h vs 3.6 ± 0.4 h; peak to peak, 9.4 ± 1.0 h vs 4.7 ± 0.5 h). Unlike reported findings in cattle, concentrations of P₄ decreased linearly within the hours of each PGFM pulse during luteolysis, and a positive effect of an LH pulse on P₄ and E₂ concentration was not detected. The reported balancing of P₄ concentrations between a negative effect of PGF2α and a positive effect of LH in heifers was not detected in mares.     

Do nocturnal birds use acoustic and visual cues to avoid predation by bats?

Anti-predation strategies are critical to animal survival and are fundamental to deciphering predator–prey interactions. As an important defense strategy, sensory predator detection (such as through acoustic and visual cues) enables animals to assess predation risk and execute predator-avoidance behavior; however, there are limited studies on the anti-predation behavior of nocturnal animals. The prey of bats provides an excellent representative system for examining the anti-predation behavior of nocturnal animals. Here, we broadcasted different types of echolocation calls of the bird-eating bat Ia io to two wild passerine birds, namely, Zosterops japonicus and Sinosuthora webbiana, that are preyed upon by I. io, and presented the birds with individual bats under different light intensities. The results showed that both bird species were able to perceive the low-frequency audible portion of the bats’ echolocation calls; however, they did not exhibit escape responses to the acoustic stimuli. In the dark and under moonlit conditions, both bird species were unable to respond to active bats at close range and the birds only exhibited evasive flight behavior when bats approached or touched them. These results suggest that nocturnal passerine birds may not be able to use acoustic or visual cues to detect bats and adopt evasive maneuvers to avoid predation. This work suggests that bat predation pressure may not elicit primary predator-avoidance responses in nocturnal passerine birds. The results provide new insights into the anti-predation behavior of nocturnal animals.     

Neotropical Bats from Costa Rica harbour Diverse Coronaviruses

Bats are hosts of diverse coronaviruses (CoVs) known to potentially cross the host–species barrier. For analysing coronavirus diversity in a bat species‐rich country, a total of 421 anal swabs/faecal samples from Costa Rican bats were screened for CoV RNA‐dependent RNA polymerase (RdRp) gene sequences by a pancoronavirus PCR. Six families, 24 genera and 41 species of bats were analysed. The detection rate for CoV was 1%. Individuals (n = 4) from four different species of frugivorous (Artibeus jamaicensis, Carollia perspicillata and Carollia castanea) and nectivorous (Glossophaga soricina) bats were positive for coronavirus‐derived nucleic acids. Analysis of 440 nt. RdRp sequences allocated all Costa Rican bat CoVs to the α‐CoV group. Several CoVs sequences clustered near previously described CoVs from the same species of bat, but were phylogenetically distant from the human CoV sequences identified to date, suggesting no recent spillover events. The Glossophaga soricina CoV sequence is sufficiently dissimilar (26% homology to the closest known bat CoVs) to represent a unique coronavirus not clustering near other CoVs found in the same bat species so far, implying an even higher CoV diversity than previously suspected.     

Vocalizations During Electroejaculation in Anaesthetized Adult and Young Pampas Deer (Ozotoceros bezoarticus) Males

The aim of this study was to characterize the vocalizations produced during electroejaculation under general anaesthesia in pampas deer males and to determine whether the characteristics of those vocalizations differ in adult and young pampas deer males. Electroejaculation was applied to 13 adults (AM) and 13 young (YM) males under general anaesthesia. Vocalizations were digitally recorded, and the number and duration of vocalizations, the latency in relation to each voltage, the total time vocalizing, and the structure of the fundamental frequency (F₀) [initial frequency (F_start), maximal frequency (F_max), minimal frequency (F_min) and final frequency (F_end)] were analysed. No male vocalized with 0 V; the number of animals that vocalized increased at 2 and 3 V and increased again at 4, 5 and 6 V (p < 0.05). The latency time from the beginning of each series (each voltage) decreased until 4 V (p < 0.01). The number of vocalizations/voltage increased from 4 V (p < 0.05). The length of each vocalization and the total time during which animals vocalized were greater in YM than AM (p = 0.02 and p = 0.01, respectively). Similarly, the fundamental frequencies were higher in YM than AM (p ≤ 0.05). Overall, we concluded that the vocalizations emitted during electroejaculation in pampas deer under general anaesthesia are related to the voltage applied during the process. Young males vocalize more time, probably due to a greater sensibility to the electric stimulation. The differences in the characteristics of the vocalizations between adult and young males may be related to the anatomic differences in the neck of adult or young males.     

Transportation decreases the pulse frequency of growth hormone in the blood of prepubertal male calves

Both the mean concentration and the pulse pattern of growth hormone (GH) in the blood are important for the metabolism and body growth of calves. Transportation is reported to decrease blood GH concentrations in prepubertal male calves. However, the effect of transportation on GH pulsatility remains unknown. Because transportation is important in moving these calves from calf‐production farms to markets or fattening farms, we tested whether transportation decreases their GH pulse frequency. Five calves were subjected to transportation by trucking (transport group), while five were left in their shed (non‐transport group). Both groups were subsequently subjected to frequent blood sampling at 15‐min intervals for 5 h. In the transport group, the cortisol concentrations increased in the first hour (P < 0.05) but significantly decreased thereafter (P < 0.05) to lower than those of the non‐transport group. During the 5‐hour study period, the transport group displayed a similar mean GH concentration relative to the non‐transport group, but displayed a delayed first GH pulse, and a lower number of GH pulses than the non‐transport group (P < 0.05). Hence, transportation is suggested to decrease GH pulse frequency under abnormal cortisol states, presumably suppressing metabolism and body growth in prepubertal male calves.     

Effects of voltage strength during electroporation on the development and quality of in vitro‐produced porcine embryos

This study was conducted to determine suitable conditions for an experimental method in which the CRISPR/Cas9 system is introduced into in vitro‐produced porcine zygotes by electroporation. In the first experiment, when putative zygotes derived from in vitro fertilization (IVF) were electroporated by either unipolar or bipolar pulses, keeping the voltage, pulse duration and pulse number fixed at 30 V/mm, 1 msec and five repeats, respectively, the rate of blastocyst formation from zygotes electroporated by bipolar pulses decreased compared to zygotes electroporated by unipolar pulses. In the second experiment, the putative zygotes were electroporated by electroporation voltages ranging from 20 V/mm–40 V/mm with five 1‐msec unipolar pulses. The rate of cleavage and blastocyst formation of zygotes electroporated at 40 V/mm was significantly lower (p < .05) than that of zygotes electroporated at less than 30 V/mm. Moreover, the apoptotic nuclei indices of blastocysts derived from zygotes electroporated by voltages greater than 30 V/mm significantly increased compared with those from zygotes electroporated by voltages less than 25 V/mm (p < .05). When zygotes were electroporated with Cas9 mRNA and single‐guide RNA (sgRNA) targeting site in the FGF10 exon 3, the proportions of blastocysts with targeted genomic sequences were 7.7% (2/26) and 3.6% (1/28) in the embryos derived from zygotes electroporated at 25 V/mm and 30 V/mm, respectively. Our results indicate that electroporation at 25 V/mm may be an acceptable condition for introducing Cas9 mRNA and sgRNA into pig IVF zygotes under which the viability of the embryos is not significantly affected.     

Dynamics of GHRH in third-ventricle cerebrospinal fluid of cattle: Relationship with serum concentrations of GH and responses to appetite-regulating peptides

Objectives were to (1) characterize the relationship of third-ventricle (IIIV) cerebrospinal fluid (CSF) concentrations of growth hormone–releasing hormone (GHRH) with concentrations of GH in the peripheral circulation; and (2) assess the influence of acute administration of appetite-regulating peptides leptin (anti-orexigenic) and neuropeptide Y (NPY; orexigenic) on the release of GHRH. Six mature beef cows fitted with IIIV and jugular vein cannulae were treated intracerebroventricularly with saline, and leptin (600 μg) and NPY (500 μg) in saline, in a replicated 3 × 3 Latin square design. Third-ventricle CSF and blood were collected 10 min before and continued 220 min after treatments. Mean concentrations of GHRH and frequency of pulses after treatments were 2.2 ± 0.13 ng/mL and 1.2 ± 0.15 pulses/220 min, respectively. These measures were not influenced by treatments. Concentrations of GHRH in CSF were weakly correlated (r = 0.15; P < 0.03) with serum concentrations of GH; however, 58% of the GH pulses were preceded by a pulse of GHRH and 90% of the GHRH pulses occurred within 20 min preceding a pulse of GH. Leptin tended (P < 0.10) to suppress GH area under the curve (AUC) compared to saline. Concomitantly, NPY tended (P < 0.10) to increase GH AUC, which appeared to be a consequence of increased (P < 0.05) pulse amplitude. Infusion of NPY also increased (P < 0.05) AUC of GHRH relative to saline. No differences were detected among treatments in serum concentrations of insulin-like growth factor-I or its AUC. Sampling CSF from the IIIV appears to be a viable procedure for assessing hypothalamic release of GHRH coincident with anterior pituitary gland secretion of GH in cattle. These data also demonstrate the differential responsiveness of the GH axis to appetite-regulating peptides.     

Echolocation calls of twenty southern African bat species

Echolocation data and sonograms are reported for twenty southern African bat species from 13 localities, recorded with the Pettersson D980 time-expansion bat detector. Data for eight species have not previously been reported. For seven species, two or more individuals were analysed in a range of situations, including handheld, tethered and free-flying (in a room and in different natural habitats). Sonograms, and seven echolocation call parameters agreed, with a few exceptions, with published data for individual species. Although intraspecific variation in echolocation call structure was documented, species tended to have recognisable ‘vocal signatures’, particularly when dominant frequency and harmonic structure were considered. The latter variables are readily retrieved by time expansion detectors, but not by frequency division or heterodyne detectors. Although generally they should be interpreted with caution, recordings from room-flown (five species) and hand-held (six species) bats obtained during this study matched, reasonably closely, additional recordings and observations of naturally flying individuals of the same species, using time expansion and heterodyne bat detectors. In four species, recordings obtained from a known species flying in a room or hand-held enabled the accurate, a posteriori species identification of unknown call sequences obtained during subsequent general recordings from bat feeding areas.     

Effects of photoperiod on the secretion of growth hormone in female goats

The aim of the present study was to clarify the effect of photoperiod on the secretion of growth hormone (GH) in goats. Adult female goats were kept at 20°C with an 8‐h or 16‐h photoperiod, and secretory patterns of GH for 4 h (12.00 to 16.00 hours) were compared. In addition, the goats were kept under a 16‐h photoperiod and orally administered saline (controls) or melatonin, and the effects of melatonin on the secretion of GH were examined. GH was secreted in a pulsatile manner. There were no significant differences in pulse frequency between the 8‐ and 16‐h photoperiods; however, GH pulse amplitude tended to be greater in the group with the 16‐h photoperiod (P = 0.1), and mean GH concentrations were significantly greater in the 16‐h photoperiod (P < 0.05). The GH‐releasing response to GH‐releasing hormone (GHRH) was also significantly greater for the 16‐h photoperiod (P < 0.05). There were no significant differences in GH pulse frequency between the saline‐ and melatonin‐treated groups. However, GH pulse amplitude and mean GH concentrations were significantly greater in the saline‐treated group (P < 0.05). The present results show that a long photoperiod enhances the secretion of GH, and melatonin modifies GH secretion in female goats.     

Widespread infection with hemotropic mycoplasmas in bats in Spain,including a hemoplasma closely related to “Candidatus Mycoplasma hemohominis”

Molecular analyses of blood samples revealed infection with hemoplasmas in 97% of 31 cave bats captured in three caves in North-Eastern Spain. The characterization of 1250 bp of the 16S rRNA gene in 29 of the positive bats identified two different groups of sequences. Twenty-two Schreibers’ bats (Miniopterus schreibersii) and one long-eared bat (Myotis capaccinii) shared one group, composed of seven closely related sequences. These sequences showed an identity of about 97% with “Candidatus Mycoplasma hemohominis” and the phylogenetic branch including bat and human sequences showed a 100% bootstrap value, supporting a close phylogenetic relationship between these hemoplasmas. The second group, representing a potentially novel species, was composed of a single sequence shared by six Schreibers’ bats that had 91% identity with the recently reported hemoplasma from little brown bats in North America. Large bat aggregations in roosting caves probably benefits intra and inter-species transmission explaining the high observed prevalence.     

Effects of temperature and temperature‐humidity index on the reproductive performance of sows during summer months under a temperate climate

Heat stress is known to influence sow reproduction, but it is unknown to which extent under temperate climates. Therefore, the impact of temperature and temperature‐humidity index (THI) on the reproductive performance of sows during summer months from 2009 to 2011 were studied. Reproductive parameters of 22 264 inseminations and 21 610 resulting farrowings of 22 German commercial farms were analyzed. Climatic records were available from the nearest weather station. Effects of temperature and THI at different periods of the reproductive cycle were estimated from May to September where temperatures were expected to influence climatic conditions indoors. High temperatures and THI values 5 days pre‐ and 14 days post‐breeding reduced litter size by 0.01 to 0.03 piglets (P < 0.05). Prior to farrowing, the number of liveborn piglets was reduced (P < 0.05) and of stillborns increased with rising climatic variables (P < 0.001). On the day of farrowing, reduced numbers of weaned piglets were observed when temperature and THI values were elevated (P < 0.05), but pre‐weaning mortality was not influenced (P > 0.05). In conclusion, even under temperate conditions adverse effects of climatic variables on the reproductive performance of sows are present. Thereby, the number of liveborn piglets can be considered as the most sensitive parameter to heat stress. Considering the impact of climate change and predicted heat waves, strategies to mitigate the impact of heat stress are necessary.     

Supplementation of cottonseed,linseed, and noug seed cakes on feed intake,digestibility, body weight,and carcass parameters of Sidama goats

A digestibility, feed intake, and carcass evaluation experiment using 20 yearling intact male Sidama goats weighing 16.4 ± 0.63 kg (mean ± SD) was conducted in Ethiopia with the objectives to determine feed intake, digestibility, body weight (BW) gain, and carcass parameters. The treatments included feeding natural pasture hay (T1, control) and supplementation with cottonseed cake (284 g—T2), linseed cake (250 g—T3), and noug seed cake (296 g—T4) on dry matter (DM) basis to supply 85 g crude protein (CP) per head per day. Randomized complete block design for feed intake and BW parameters and complete randomized design for digestibility and carcass parameters were used. Hay DM intake was higher (P < 0.01) for T1 than for the other treatments. T3 promoted higher (P < 0.01) DM (29.3 g/kg W^0.75/day) and CP (14.1 g/kg W^0.75/day) intake than T4 (8.9 g/kg W^0.75/day DM and 4.1 g/kg W^0.75/day CP). T3 showed better (P < 0.05) organic matter and CP digestibility than T2. Goats in T3 had higher nitrogen intake (P < 0.01) and retention (P < 0.05) than those in T1. Goats in T2 and T3 showed higher (P < 0.05) daily BW gain and final BW than those in T4 and T1. Goats in T2 and T3 had higher (P < 0.05) slaughter weight, empty BW, hot carcass weight, rib-eye muscle area, and dressing percentage on slaughter weight basis than those in T1. The results showed that T2 and T3 had similar effect on CP intake, daily BW gain, and carcass parameters for growing Sidama goats fed natural pasture hay.     

Parity and litter size effects on maternal behavior of Small Tail Han sheep in China

The effects of parity and litter size on maternal behavior of Small Tail Han sheep was investigated at Linyi University, China. Sixty‐eight ewes were observed from parturition to weaning. Continuous focal animal sampling was used to quantify the duration of maternal behaviors. Ewe feces were collected every 2 days and estradiol concentration was measured with an enzyme immunoassay kit. All lambs were weighed 24 h after parturition and again at 35 days of age. Parity increased sucking, following, grooming, low‐pitched bleat, head‐up and udder‐refusal behavior and decreased aggressive behavior (P < 0.01, P < 0.01, P < 0.05, P < 0.05, P < 0.05, P < 0.05, P < 0.01, respectively), and litter size showed significant effect on sucking, following and low‐pitched bleat behavior (P < 0.05, P < 0.01, P < 0.05, respectively). The lambs of multiparous ewes were significantly heavier than primiparous ewes at birth (P < 0.01) and were significantly heavier at weaning age (P < 0.01). Similar results were founded for birth weight and weaning weight gain in litter size (P < 0.01, P < 0.01, respectively). Estradiol concentration in feces was higher in multiparous ewes than primiparous ewes. Parity and litter size may have effects on maternal behavior during lactation. Ewes that have 2–3 lambs may be more suitable for production of Small Tail Han sheep in China.     

Efficacy of Tilmicosin Phosphate (Pulmotil® Premix) in Feed for the Treatment of a Clinical Outbreak of Actinobacilluspleuropneumoniae Infection in Growing–Finishing Pigs

A double‐blind randomized clinical trial was carried out to investigate the efficacy of tilmicosin (Pulmotil^® premix) for the treatment of a clinical outbreak of Actinobacillus pleuropneumoniae infection in growing–finishing pigs. The effects of tilmicosin administration in the feed at 400 mg/kg and an injection therapy of clinically diseased pigs with long‐acting oxytetracycline (Terramycine^® LA) at 20 mg/kg bodyweight were compared. Both groups, totalling 147 pigs, were compared during a medication period of 15 days and a post‐medication period of 11 days by means of different clinical and performance parameters. During the medication period, the tilmicosin group showed a significant advantage with respect to the number of new disease cases (P < 0.01), and a non‐significant advantage regarding the number of removed pigs (P=0.16), the number of sick pigs that recovered (P=0.27) and the time to recovery (P=0.42). During the post‐medication period, the pigs of the tilmicosin group showed numerical non‐significant benefits (P > 0.05) with respect to the clinical parameters. During the overall study period (26 days), the average daily gain and the feed conversion ratio were both significantly (P < 0.01) better in pigs from the tilmicosin group compared with pigs from the oxytetracycline group. This study demonstrated that in‐feed medication of tilmicosin at a dosage of 400 mg/kg is efficacious for the treatment of a clinical respiratory disease outbreak of A. pleuropneumoniae infection in growing–finishing pigs. Compared with oxytetracycline injection of clinically diseased pigs, the tilmicosin treatment is particularly beneficial in the prevention of new disease cases while increasing or maintaining the performance of the pigs.