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Number of results: 9
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Abstract

The aim of this research was to determine rumination time (RT) and the subsequent milk yield, along with trait changes during lactation dependent on the reproductive status of dairy cows. 728 cows were selected for evaluation in regards to 1–150 days of milk production (DIM). According to their period of lactation and reproductive status, the cows were selected for the following groups: Inseminated (1–35 days after insemination, n=182), Open (45–90 days after calving, n=126), Fresh (1–44 days after calving, n=45); Not-pregnant (>35–60 days after inse- mination and not-pregnant, n=55); Pregnant (35–60 days after insemination and pregnant (n=320). The animals were milked with Lely Astronaut® A3 milking robots. The daily milk yield, rumination time, bodyweight, milk composition (fat, protein, lactose, somatic cell count and gynecological status date) were collected from the Lely T4C management program for analysis. We estimated the lowest productivity in the pregnant cows, where the average milk yield was 28.72 kg and the highest productivity in the fresh cow (p<0.001) (Table 1). The longest rumina- tion time was determined for the inseminated cows, statistically significantly higher at 9.92% (p<0.001) than in the non-pregnant cows, whose rumination time was the shortest. The statisti- cally reliably RT positively correlated with productivity (r=0.384, p<0.001) of the cows (from r=0.302 in the second lactation and r=0.471 in the first lactation to r=0.561 in multiparous cows; p<0.001). Rumination time, according to groups of cows by milk yield, had a tendency to increase (2.14 times) from 202.0± 87.38 (in cows with a productivity of less than 10 kg milk) to 431.6±33.91 (in cows with a milk yield higher than 50 kg) by the linear regression equation: y = 38.02x + 232, R² = 0.721 (p<0.001). The relation between the gynecological status and milk fat-protein ratio of the cows was statistically significant (χ2=2.974, df= 8, p <0.0001). The longest rumination time was determined for the inseminated cows (1 – 35 days after insemination), and the shortest for the not-pregnant cows (>35 – 60 days after insemination and not-pregnant). We can conclude that rumination time, subsequent yield, and milk trait change depends on the period of lactation and reproductive status of a dairy cow.
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Abstract

This study investigated changes in the real-time measured levels of milk β-hydroxybutyrate according milk yield, lactation number and status of reproduction in dairy cows. A total of 378 cows were selected. According to their reproductive status the cows were classified as belonging to the following groups: Fresh (1 – 44 days after calving. n=43). Open (45 – 65 days after calving. n=78), Inseminated (1 – 35 days after insemination. n=133). Pregnant (35 – 60 days after insemination and pregnant (relatively pregnant) (n=124). The cows were milked with DeLaval milking robot (DeLaval Inc., Tumba, Sweden) in combination with a Herd Navigator (Lattec I/S. Hillerød. Denmark) analyser. We observed that milk β-hydroxybutyrate (BHB) had a tendency of increasing with an increase of lactation number. The average BHB in multiparous cows was 11.111% higher in comparison with primiparous cows (p<0.001). We found higher BHB concentration in the multiparous cows in all reproduction status groups (p<0.001). A strong positive statistically significant (p<0.001) relationship has been found between BHB and the average milk yield within all groups of primiparous cows although we found a statistically unreliable coefficient of correlation (from -0.202 to 0.057) between highest milk yield and BHB in primiparous and multiparous cows.
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Abstract

Observations indicate a constantly decreasing mean age of shoal. In consecutive years of investigations a loss of older individuals was recorded. At present the catches consist of 3—14 years old fishes; 9—10 years old dominate. During the austral summer the fish most probably do not migrate. The shoal of the shelf maintains approximately constant frequency and dominance in classes of length.
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Abstract

Tonnacypris glacialis (G.O. Sars, 1890) is a meiobenthic species widely distributed in Arctic freshwater lakes. Field study of its life cycle as well as the laboratory experiments showed clearly that only one generation of this ostracod species occurs during the vegetation season, and that the condition necessary for the next generation to appear is eggs freezing.
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Abstract

Our macroscopic observations and microscopic studies conducted by means of a light microscope (LM) and transmission electron microscope (TEM) concerning the reproduction biology of Colobanthus quitensis (Caryophyllaceae) growing in natural conditions in the Antarctic and in a greenhouse in Olsztyn (northern Poland) showed that this plant develops two types of bisexual flowers: opening, chasmogamous flowers and closed, cleistogamous ones. Cleistogamy was caused by a low temperature, high air humidity and strong wind. A small number of microspores differentiated in the microsporangia of C. quitensis , which is typical of cleistogamous species. Microsporocytes, and later micro − spores, formed very thick callose walls. More than twenty spheroidal, polypantoporate pollen grains differentiated in the microsporangium. They germinated on the surface of receptive cells on the dry stigma of the gynoecium or inside the microsporangium. A monosporic embryo sac of the Polygonum type differentiated in the crassinucellar ovule. During this differentiation the nucellus tissue formed and stored reserve materials. In the development of generative cells, a male germ unit (MGU) with differentiated sperm cells was observed. The smaller cell contained mainly mitochondria, and the bigger one plastids. In the process of fertilization in C. quitensis only one nucleus of the sperm cell, without cytoplasm fragments, entered the egg cell, and the proembryo developed according to the Caryophyllad type. Almost all C. quitensis ovules developed and formed perispermic seeds with a completely differentiated embryo both under natural conditions in the Antarctic and in a greenhouse in Olsztyn.
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Abstract

The development of in vitro embryo production (IVEP) techniques in Felis catus is a fitting model with potential application to the conservation of endangered felid species. To improve the quality of IVEP techniques an appropriate balance of pro- and antioxidants should be provided. Under in vitro conditions, high levels of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) mRNA provide a defence mechanism against oxidative stress for embryos. In order to improve the development of cat oocytes, the effects of SOD and CAT supplemented to in vitro maturation (IVM) medium and of GPx supplemented to in vitro fertilization (IVF) medium on development and embryo production in vitro were evaluated. Data showed an increase of 70 and 77 % of cleaved embryo and blastocyst formation, respectively, in the experiment with SOD and CAT addition to IVM medium; in the experiment with GPx addition to IVF medium the number of cleaved embryos doubled and the number of embryos increased by 96 %. Therefore, our results were positive and encourage us to continue studies on cat oocytes evaluating the effects of various dosages and combination of antioxidants.
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Abstract

The authors report the first discovery of diploid populations of Hieracium naegelianum Panč. subsp. naegelianum and H. naegelianum subsp. ljubotenicum Behr & Zahn., and give the first chromosome counts for H. cernuum Friv., H. gymnocephalum Griseb. ex Pant., H. sparsum Friv., Pilosella pavichii (Heuff.) Holub and P. serbica (F. W. Schultz & Schultz-Bip.) Szeląg from Macedonia and/or Montenegro. A diploid chromosome count for Hieracium renatae Szeląg is confirmed based on material from the whole distribution range of the species. An emasculation experiment showed that all the analyzed diploid Hieracium taxa reproduce sexually.
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Abstract

The head-related transfer function (HRTF) is dependent on the position of the sound source (both direction and distance) and is also affected by individual anatomical parameters. Individualized HRTFs have been shown to affect the perception of sound direction, but have not been considered in distance perception. This work aims to discover, by means of psychoacoustic experiments for a virtual reproduction system through a pair of in-ear headphones, the effect of individualized HRTF on auditory distance perception for a nearby sound source. The individualized HRTFs of six subjects and the non-individualized HRTFs of a mannequin at seven distances between 0.2 and 1.0 m and five lateral azimuths between 45X and 135X in the horizontal plane were processed with white noise to generate binaural signals. Further, the individualized and non-individualized HRTFs were used in the auditory distance perception experiments. Results of distance perception show that the variance of distance perception results among subjects is significant, the reason could be the stimuli are lack of dynamic cue and early reflections, or the auditory difference of distance perception among subjects. However, via the analyses of mean slope of perceptual distance and correlation between the perceptual and real distance, we find that the individualized HRTF cue has insignificant influence on distance perception.
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Abstract

In virtual acoustics or artificial reverberation, impulse responses can be split so that direct and reflected components of the sound field are reproduced via separate loudspeakers. The authors had investigated the perceptual effect of angular separation of those components in commonly used 5.0 and 7.0 multichannel systems, with one and three sound sources respectively (Kleczkowski et al., 2015, J. Audio Eng. Soc. 63, 428-443). In that work, each of the front channels of the 7.0 system was fed with only one sound source. In this work a similar experiment is reported, but with phantom sound sources between the front loud- speakers. The perceptual advantage of separation was found to be more consistent than in the condition of discrete sound sources. The results were analysed both for pooled listeners and in three groups, according to experience. The advantage of separation was the highest in the group of experienced listeners.
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