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PubMed2001

Dopaminergic neurons in the brain and dopaminergic innervation of the albumen gland in mated and virgin helisoma duryi (mollusca: pulmonata).

BACKGROUND: Dopamine was shown to stimulate the perivitelline fluid secretion by the albumen gland. Even though the albumen gland has been shown to contain catecholaminergic fibers and its innervation has been studied, the type of catecholamines, distribution of fibers and the precise source of this neural innervation has not yet been deduced. This study was designed to address these issues and examine the correlation between dopamine concentration and the sexual status of snails. RESULTS: Dopaminergic neurons were found in all ganglia except the pleural and right parietal, and their axons in all ganglia and major nerves of the brain. In the albumen gland dopaminergic axons formed a nerve tract in the central region, and a uniform net in other areas. Neuronal cell bodies were present in the vicinity of the axons. Dopamine was a major catecholamine in the brain and the albumen gland. No significant difference in dopamine quantity was found when the brain and the albumen gland of randomly mating, virgin and first time mated snails were compared. CONCLUSIONS: Our results represent the first detailed studies regarding the catecholamine innervation and quantitation of neurotransmitters in the albumen gland. In this study we localized catecholaminergic neurons and axons in the albumen gland and the brain, identified these neurons and axons as dopaminergic, reported monoamines present in the albumen gland and the brain, and compared the dopamine content in the brain and the albumen gland of randomly mating, virgin and first time mated snails.

Albumins↗
PubMedDate not supplied

[Joint research on the precise determination of the energy and protein requirements of fattening pigs. 7. The effect of various energy levels on the performance and feed expenditure of fattening pigs].

Scientific feeding experiments were carried out with 7 male castrated pigs of the genetic origin land race pig X large white with the test animals fed individually and the rations containing approximately the same amounts of protein, amino acids, minerals and vitamins but varied amounts of energy. Energy intake was adjusted to three levels: 100%, 85% and 70% of semi-ad-libitum intake (group 1 = 100%). With regard to protein supply there was a subdivision into 30-60 and 60-100 kg live weight. In addition to this, the digestibility of the feed mixture used and the N-balance were determined in both fattening periods. Having reached 100 kg live weight, the animals were slaughtered and a number of slaughtering parameters was determined. The average daily live weight gain in the three test groups was 749, 664 and 540 g over the whole fattening period. The feed expenditure was 3.7, 3.9 and 4.3 kg mixed feed per kg live weight gain so that, with regard to live weight performance and feed expenditure the group with the highest energy supply showed the best results. The level of energy supply had a remarkable influence on the composition of weight gain; thus the amount of fat in the carcass of the animals of groups 3 was by 1.8 kg and 2.5 kg resp. lower than of the animals in groups 2 and 1.

Animal Feed↗
PubMed2004

Comparison of three methods of feeding sows in gestation and the subsequent effects on lactation performance.

A total of 684 sows from breeding groups over 6 wk was used to compare three methods of feeding during gestation on gestation and lactation performance. Control gilts and sows were fed according to body condition based on a scale of 1 to 5 (1 = thin, 5 = fat). Sows were visually assessed for body condition at breeding and were assigned a daily feed allowance to achieve a BCS of 3 at farrowing. Treatment 2 used feeding levels based on backfat thickness (measured between d 0 and 5 after breeding) and weight at weaning for sows or service for gilts. Feed allowance was calculated to achieve a target backfat of 19 mm at farrowing, and remained constant from d 0 to 101 of gestation. Feed allowances were based on modeled calculations of energy and nutrient requirements to achieve target sow maternal weight and backfat gains. Treatment 3 was identical to Treatment 2, except that feeding pattern was altered for thin sows and gilts (<15 mm at service) in an attempt to reach 19 mm by d 36 of gestation. Sows were weighed at the previous weaning, and gilts were weighed at service, with both weighed again between d 112 and 114 of gestation. Backfat was measured between d 0 and 5, and again between d 108 and 113 of gestation. At farrowing, sows on Treatments 2 and 3 had 19 and 19.1 mm of backfat, respectively, whereas control sows tended to have greater (P < 0.07) backfat (20 mm). On average, sows targeted to gain 6 to 9 mm of backfat failed to reach target gains regardless of feeding method. Feeding sows in gestation based on backfat (Treatments 2 and 3) resulted in a numerically higher proportion of sows in the target backfat range of 17 to 21 mm (40.2, 53.3, and 52.6% for control and Treatments 2 and 3, respectively) at farrowing and a numerically lower percentage of fat sows (>21 mm), but no difference in the percentage of thin sows (<17 mm) compared with feeding based on body condition. In conjunction with this observation, sows fed based on BCS were fed higher (P < 0.05) feeding levels in gestation than were sows fed based on backfat depth. Gestation feeding method had no effect on performance during lactation. Feed intake in lactation was lower (P < 0.05) for high backfat sows (>21 mm) at farrowing compared with sows with <21 mm. The high proportion of sows in the optimal backfat category demonstrates that feeding based on backfat and BW has potential for facilitating more precise feeding during gestation.

Adipose Tissue↗
PubMedDate not supplied

[Joint research on the precise determination of the energy and protein requirements of fattening pigs. 4. The effect of the energy level on the fattening of Camborough-type hybrid swine].

Scientific feeding experiments were carried out with 5 castrated male pigs and 4 female animals of the genetic origin "Camborough" in the live weight range between 30 and 100 kg with a subdivision at 60 kg. In each test group the animals were fed individually and received rations with approximately equal contents of protein, amino acids, minerals and vitamins but different energy contents. Energy intake was adjusted to 3 levels of 100%, 85% and 70% of semi-ad-libitum intake. Apart from that, the digestibility of the feed mixtures used in the 2 fattening periods was determined. Having reached a live weight of 100 kg, 7 representative animals per group were slaughtered and a number of slaughtering parameters were registered. In all three test groups the daily live weight gain over the complete fattening period was very high (846, 819 and 778 g). Though the weight gain in group 3 with 70% of the energy supply of group 1 is significantly lower than in the other two groups, it is, however, only 70 g lower than in group 1. Consequently, the feed expenditure (2.6 kg mixed feed per kg live weight gain) in group 3 is by 20% lower than in group 1, in which the feed expenditure is 3.2 kg mixed feed per kg live weight gain. There were no significant differences on the weight gain performances and the registered carcass parameters between sows and castrated male pigs. Observed deviating tendencies are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1999

Synchronization rate, size of the ovulatory follicle, and pregnancy rate after synchronization of ovulation beginning on different days of the estrous cycle in lactating dairy cows.

Recently a protocol was developed that precisely synchronizes the time of ovulation in lactating dairy cows (Ovsynch; GnRH-7d-PGF2 alpha-2d-GnRH). We evaluated whether initiation of Ovsynch on different days of the estrous cycle altered the effectiveness of this protocol. The percentage of cows (n = 156) ovulating to the first GnRH was 64% and varied (P < 0.01) by stage of estrous cycle. Treatment with PGF2 alpha was effective, with 93% of cows having low progesterone at second GnRH. The overall percentage of cows that ovulated after second GnRH (synchronization rate) was 87% and varied by response to first GnRH (92% if ovulation to first GnRH vs 79% if no ovulation; P < 0.05). There were 6% of cows that ovulated before the second injection of GnRH and 7% with no detectable ovulation by 48 h after second GnRH. Maximal diameter of the ovulatory follicle varied by stage of estrous cycle, with cows in which Ovsynch was initiated at midcycle having the smallest follicles. In addition, milk production and serum progesterone concentration on the day of PGF2 alpha affected (P < 0.05) size of the ovulatory follicle. Using these results we analyzed pregnancy rate at Days 28 and 98 after AI for cows (n = 404) in which Ovsynch was initiated on known days of the estrous cycle. Pregnancy rate was lower for cows expected to ovulate larger follicles than those expected to ovulate smaller follicles (P < 0.05; 32 vs 42%). Thus, although overall synchronization rate with Ovsynch was above 85%, there were clear differences in response according to day of protocol initiation. Cows in which Ovsynch was initiated near midcycle had smaller ovulatory follicles and greater pregnancy rates.

Animals↗
PubMed1995

[Cryptosporidia and other endoparasites in heifers imported into the Czech Republic].

Totally 887 heifers of Holstein-Friesian breed mostly in late pregnancy imported to the Czech Republic from France (597), Germany (89), Denmark (181) and Holland (20) were examined coprologically from September 1993 to March 1995 in the parasitological laboratory of the National Veterinary Institute (NVI). Prague. Feces were sampled individually, rectally, always on days 1-3 following importation from heifers housed in particular quarantine sheds. In compliance with presently valid veterinary regulations, all animals were examined for liver fluke disease (fascioliasis) and lungworm. Moreover, 634 heifers were submitted to qualitative coprological examination aimed at revealing the presence of cysts and oocysts of protozoa, eggs of taenias and nematodes of gastrointestinal tract. The method according to Pavlásek (1991), especially designed for proving oocysts of the genus Cryptosporidium, was applied in all fecal specimens delivered to the SVI from animals in quarantine (N = 887). From trematodes, 12 heifers imported from France were positive for eggs of Fasciola hepatica and in other two animals eggs of the genus Paramphistomum were found. None of the imported heifers showed lungworm disease. Summary of data on occurrence of endoparasites gained during qualitative examination of samples of feces taken from heifers imported from France, Germany and Denmark is presented in Tab. I. Parasitologically, 91.2 to 100% of imported animals were positive. Taeniasis (the genus Moniezia) was detected in 2.8% of heifers imported from France and in 9.8% animals from Denmark. Protozoal parasites were found in 58.8% (Denmark) and 92.8% (Germany) heifers. Coccidial oocysts most frequently observed represented the genus Eimeria (E. bovis, E. auburnensis and E. zuernii). Gastrointestinal nematodes of nine genera were found in 72.5 to 80.8% of heifers. The most frequent findings were genera Ostertagia, Haemonchus and Trichostrongylus. Oocysts, morphologically identical with Cryptosporidium muris Tyzzer (1907), 1910, were detected in 4.5% of heifers imported into the Czech Republic from France and in 7.9% of those from Germany. In view of the fact the imported heifers were sampled always on days 1-3 of their quarantine following their importation it is quite impossible, considering the development of the protozoon, they could become infected just in the territory of the Czech Republic. Therefore, with the highest probability, our findings of C. muris-like oocysts in heifers are of priority importance for France and Germany because in the literature these countries do not report cattle as a host of this protozoon. We have found out 57.9% out of 19 animals positive for C. muris on one farm of a private cattle keeper. On the basis of a long-term monitoring of three dairy cows and one bull, the duration of the patent period is longer than 18 months, while we do not know precise onset of shedding oocysts of the protozoon in these naturally infected animals. Furthermore, the paper discusses the need of future studies of C. muris from the point of view of spread, pathogenicity, specificity and host spectrum. The author proposes and recommends obligatory examinations of imported animals with special attention paid to presence of coccidia of the genus Cryptosporidium in order to maintain, with respect to their zoonotic character, these protozoal infections under proper control. At present the parasitological laboratory of the NVI in Prague has a bank of oocyst isolates of the C. muris type from cattle (Bos taurus), from desert hamsters (Phodopus roborovskii Satunin, 1903) and camels (Camelus bactrianus). Experimental infections is permanently kept in laboratory mice following successful transmission from desert hamsters.

Animals↗
PubMedDate not supplied

[Joint research on the precise determination of the energy and protein requirements of fattening pigs. 9. The effect of various levels of energy and protein nutrition on the performance and feed expenditure of fattening pigs].

In the scope of a joint international experiment, 2 scientific feeding experiments were carried out in combination with measurings of the metabolism for the determination of the digestibility and the N-balance with hybrid pigs of modern genetic origin in the fattening period between 30 and 100 kg live weight. In the first experiment with isocaloric feeding the influence of 3 levels of protein supply (18, 16 and 14% crude protein in the first fattening period and 16, 14 and 12% crude protein in the second fattening period) on the fattening performance and the expenditure of feed, protein and energy per kg live weight gain and in the 2nd experiment with equal crude protein supply per animal and day the influence of 3 levels of energy supply (100 : 85 : 70%) on fattening performance and expenditure were tested. In addition to that, the composition of the carcass was ascertained of a total of 51 animals. The average live weight gain in the 3 variants and over the complete fattening period between 30 and 100 kg in experiment 1 amounted to 772 g, 753 g and 687 g and in experiment 2 to 778 g, 713 g and 583 g. The best fattening performance was achieved with the highest energy and protein supply, and an energy supply reduced by 15% nevertheless resulted in fattening performance 753 and 713 g resp. per animal and day. The expenditure values are discussed; a detailed evaluation is given in the 10th contribution to this series of publications on the total results of this joint international experiment. The carcass analysis shows the tendency of a decreasing protein content in the carcass caused by a decreasing protein supply and an increasing fat and energy content whereas a decrease of the energy supply has no effect on the protein content but a distinct effect with regard to the decrease of the fat content of the carcass caused by the decreased energy supply.

Animal Feed↗
PubMed2002

The control of follicular wave development for self-appointed embryo transfer programs in cattle.

Our expanding knowledge of the control of follicular wave dynamics during the bovine estrous cycle has resulted in renewed enthusiasm for the prospects of precisely controlling the follicular and luteal dynamics and finely controlling the time of ovulation. Follicular wave development can be controlled mechanically by ultrasound-guided follicle ablation or hormonally by treatments with GnRH or estradiol and progestogen/progesterone in combination. Treatment of cattle with GnRH in combination with prostaglandin F2 alpha (PGF) 7 d later and a second GnRH 48 h after PGF (known as Ovsynch) has resulted in acceptable pregnancy rates after fixed-time AI in lactating dairy cows and in recipients in which embryos were transferred without estrus detection. Alternatively, treatments with estradiol and progestogen/progesterone-releasing devices resulted in synchronous emergence of a new follicular wave and, when a second estradiol treatment was given 24 h after device removal, synchronous ovulation and high pregnancy rates to fixed-time AI. Self-appointed embryo transfer (without estrus detection) using estradiol and progesterone treatments have resulted in pregnancy rates comparable with those obtained with recipients transferred 7 d after estrus. Furthermore, estradiol and progesterone treatments combined with PGF and eCG (given 1 d after the expected time of wave emergence) have resulted in high rates of recipients selected for transfer (84.6%) and an overall pregnancy rate of 48.7% (recipients pregnant/recipients treated). Estradiol and progestogen/progesterone treatments have also been widely used for self-appointed superstimulation protocols with equivalent embryo production to that of donor cows superstimulated using the traditional approach beginning 8 to 12 d after estrus. In summary, exogenous control of luteal and follicular development facilitates the application of assisted reproductive technologies in cattle by offering the possibility of planning the superstimulation of donors and synchronization of recipients at a self-appointed time, without the necessity of estrus detection and without sacrificing results.

Animals↗
PubMed1999

Regulation of follicle waves to maximize fertility in cattle.

Cattle have recurrent follicular waves every 7-10 days in most physiological situations; an FSH increase is associated with emergence of the wave and LH pulse frequency determines the fate of the dominant follicle. To control oestrus with hormones it is necessary to ensure that either induced corpus luteum regression or the termination of a progestogen treatment coincides with the selection of the dominant follicle during the wave, to give a precise onset of oestrus and high fertility. The exogenous administration of progesterone or progestagen blocks the normal turnover of the dominant follicle once the corpus luteum regresses. Thus, the effects of duration of dominance of the preovulatory follicle on onset of oestrus and fertility were examined. The variation in onset of oestrus was reduced but occurred 5-9 h later after 4 versus 8 days of dominance; pregnancy rate was also affected with dominance periods of 2-4, 4-8 and > 10 days resulting in 0, 10-15% or 20-50% reduction in pregnancy rates, respectively. The necessity for short duration of dominance of the preovulatory follicle means that to ensure high fertility the follicular wave needs to be regulated when using hormones to control oestrus. Two approaches were examined, namely the use of GnRH or oestradiol at time of progesterone intravaginal releasing device insertion. The effect of 250 micrograms of synthetic GnRH on the fate of an existing follicle wave was to ovulate the dominant follicle (20/20 cows) and a new wave emerged 1.6 +/- 0.3 days later; however, there was no effect of GnRH on the wave if administered before dominant follicle selection. The effect of oestradiol concentrations on suppression of FSH in ovariectomized heifers showed that increasing oestradiol to 10-15 pg ml-1 caused a 37 +/- 6.9% decrease in FSH for 24 h, with a subsequent increase to pretreatment values by 57 +/- 13 h. In cyclic heifers, increasing oestradiol to > 10 pg ml-1 in conjunction with progesterone treatment at emergence of the first wave of the cycle affected the current follicle wave by either preventing dominant follicle selection or decreasing diameter of the dominant follicle, without consistently affecting the interval to new wave emergence. Increase of oestradiol after dominance, however, delayed new wave emergence by 2-5 days. A better understanding of the hormonal control of follicle waves will lead to development of improved hormonal regimens to control oestrus sufficiently to give high pregnancy rates to a single AI without recourse to detection of oestrus.

Animals↗
PubMedDate not supplied

[Joint research on the precise determination of the energy and protein requirements of fattening pigs. 2. Energy and nitrogen metabolism of fattening hybrids in the fattening range of 30 to 120 kg].

In 3 experiments a total of 242 total metabolism experiments with ad libitum feeding (experiment 1), 75% (experiment 2) and 62% (experiment 3) of the energy level of the 1st experiment and approximately equal protein and amino acid doses in experiments 1-3 were carried out with 8 castrated male fattening hybrids each (large white X land race pig) X line 150) in the live weight range between 30 and 120 kg. On average, feed intake over the whole live weight range was 2.24; 1.79 and 1.50 kg/animal and day, the corresponding daily live weight gain was 729, 533 and 396 g. With regard to the digestibility of the energy and the nutrients and the metabolisable energy in % of the gross energy there was no relation to the development of the animals. The intake of metabolisable energy per kg live weight decreased with ad libitum feeding and with the advancing development at the end of the experiment in contrast to the beginning of the experiment to 53%, energy retention to 56%. The utilisation of metabolisable energy for body energy retention, taking account of a maintenance requirement of 450 kJ/kg live weight 0,62 on the average of the 3 experiments was 68.4 +/- 1.9, 70.3 +/- 2.0 and 64.3 +/- 2.6%. Energy retention in experiments 1 to 3 amounted to 8.6, 6.8 and 5.3 MJ at the beginning and to 18.1, 12.2 and 8.0 MJ per animal and day at the end of the experiment. Protein energy retention of the pigs (live weight 40 kg) was 26% of the total energy retention in experiments 1 and 2 and 49% in experiment 3. In experiments 1 and 3 protein retention decreased to 15% of the total energy retention, in experiment 2 protein retention remained constantly at 22% between 60 and 110 kg live weight and then decreased to 18%. Consequently, the N-balances were 23-16 g, 16-20 g and 16-9 g/animal and day. The chemical composition of the carcasses was strongly influenced by the level of nutrition. At the beginning of the experiment the protein content averaged between 49 and 57% and the total fat content between 31 and 38% of the dry matter. At the end of the experiment the carcasses of the animals from experiments 1-3 had crude protein contents of 28, 33 and 42% and total fat contents of 66, 61 and 50% of the dry matter.

Animal Feed↗