Behavioral indexes of piglet welfare: Comparison of indoor and outdoor housing systems

The purpose of this experiment was to establish behavioral indexes of piglet welfare. Forty‐eight piglets were allocated to either four indoor pens or four outdoor pens (six piglets per pen). The indoor system was a commercial pen that consisted of a concrete floor and a slat floor. The outdoor system had a dirt paddock with a wooden hutch. Growth performance, salivary cortisol levels, skin lesions and behaviors of the piglets were monitored for 4 weeks. Sixteen types of behaviors were recorded by using 2‐min instantaneous scan sampling for 8 h/day. Growth performance and salivary cortisol levels did not significantly differ between the two housing systems. On the other hand, skin lesions and behaviors were significantly affected by the housing system. The number of skin lesions was higher in the indoor system. In addition, piglets in the outdoor system showed more investigative and social‐play behaviors than those in the indoor system. Piglets in the indoor system showed more resting, drinking, moving, fighting, and conflict behaviors than those in the outdoor system. We conclude that investigative, social‐play and conflict behaviors may be effective indexes of the welfare level of piglets, especially investigative and conflict behaviors.     

Characterization of 38 kDa and 42 kDa chitinase isozymes from the liver of Japanese common squid Todarodes pacificus

ABSTRACT: Characterization was investigated on the 38 kDa and 42 kDa chitinase (EC3.2.1.14) isozymes from the liver of Japanese common squid Todarodes pacificus . Optimum pH toward colloidal chitin was observed at pH 3.0 for the 38 kDa chitinase, and pH 3.0 and 9.0 for the 42 kDa chitinase. K _m and k _cat of the 38 kDa and 42 kDa chitinases toward a longer substrate, glycol chitin, were 0.071 mg/mL and 1.22/s, and 0.074 mg/mL and 0.196/s, respectively. Alternatively, strong substrate inhibition of both chitinases were observed toward a short substrate, N -acetylchitopentaose (GlcNAc₅). Both chitinases decomposed not only chitin but also chitosan (D. A. 95%). The cleavage pattern and reaction rate were investigated using N -acetylchitooligosaccharides (GlcNAc_n, n  = 2–6). Both chitinases hydrolyzed GlcNAc_n ( n  = 4,5, and 6). The release of GlcNAc was not observed. The speed of the reaction was observed to be in the following order: GlcNAc₄ > GlcNAc₅ > GlcNAc₆ for the 38 kDa chitinase, and GlcNAc₆ > GlcNAc₅ > GlcNAc₄ for the 42 kDa chitinase. Both the chitinases released p -nitrophenol from p -nitrophenyl GlcNAc_n ( n  = 2, 3, and 4). N-terminal amino acid sequences of the 38 kDa and 42 kDa chitinases were YLLSXYFTNWSQYRPGAGKYFPQNI and EYRKVXYYTNWSQYREVPAKFFPEN, respectively.     

Regulation of secondary follicle growth by theca cells and insulin-like growth factor 1

Ovaries contain follicles at various stages of development, including primordial, primary, secondary, antral and Graafian follicles. Although the growth of these follicles is controlled to maintain regular ovulation, the mechanism through which this occurs remains unclear. In our study, we found that the growth rate of cultured secondary follicles separated from mice ovaries differed between follicles. After 4 days of culture, the size of some secondary follicles was markedly increased, while that of others had either slightly increased, remained unchanged or shrunk. We compared the expression levels of growth factors between these secondary follicles and found that the growth rate of cultured secondary follicles correlated with the expression level of insulin-like growth factor 1 (Igf1) mRNA. Igf1 mRNA expression level in secondary follicles containing theca cells was higher than that in secondary follicles without theca cells, and the granulosa cell proliferation around follicles containing theca cells was increased. Furthermore, an IGF1 inhibitor also inhibited the granulosa cell proliferation, and administration of IGF1 to secondary follicles without growth promoted granulosa cell proliferation. These results indicated that the theca cells of secondary follicles induced the expression of IGF1 and promoted the follicle growth.     

Blood biochemical values in Japanese Black breeding cows in Kagoshima Prefecture,Japan

To obtain blood biochemical basic data of Japanese Black breeding cows in Kagoshima Prefecture, Japan, blood samples were obtained from 857 clinically healthy multiparous cows on 71 farms. Cows were divided into three stages: the prepartum stage (between 20 and 80 days before parturition, n=290), lactation stage (between 20 and 80 days after parturition, n=283) and maintenance stage (between 120 and 200 days after parturition, n=284). The mean concentration of total protein and total cholesterol, and the mean activities of aspartate aminotransferase in the lactation stage tended to be higher than those in the prepartum and maintenance stages. The mean concentration of glucose in the prepartum stage tended to be lower than that in the lactation and the maintenance stages. The mean concentration of nonesterified fatty acids and beta-hydroxybutyrate in the prepartum stage tended to be higher than those in the lactation and maintenance stages. The mean concentration of serum retinol was approximately 30 µg/dl in all stages. These results suggest that the blood biochemical values of multiparous Japanese Black cows vary with breeding stages, and it is considered that the blood parameters obtained in this study are useful as indices for health management of Japanese Black breeding cows.     

Effect of extracts from <Emphasis Type="Italic">narezushi</Emphasis>, a fermented mackerel product,on cholesterol metabolism in Wistar rats

Narezushi extract was separated into peptide and nonpeptide fractions by ion-exchange column chromatography. The narezushi extract and fractions were administered to rats in a diet enriched with lipid and cholesterol for 30 days. In the narezushi extract and nonpeptide fraction groups, increases in triglyceride, total cholesterol, and low-density lipoprotein-cholesterol levels in the plasma and accumulation of total lipids and triglyceride in the liver were suppressed, while both lipid and cholesterol fecal excretion were increased. In the peptide fraction group, these effects were also observed, except for the suppressing effect on liver lipid accumulation. Narezushi extract administration tended to increase fecal bile acids and promoted the activity of cholesterol 7α-hydroxylase, the rate-limiting enzyme in the synthesis of bile acid from cholesterol in the liver. However, the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme in the cholesterol synthesis system in the liver, decreased due to regulation by the feedback of lipid transportation from diet to the liver. These results suggest that both the increase in cholesterol and bile acid fecal excretion and the promotion of cholesterol 7α-hydroxylase activities are related to the hypocholesterolemic effects of narezushi extract. Amino acids and organic acids, which are abundantly contained in the nonpeptide fraction, seemed to have more intensive hypocholesterolemic effects than peptides existing in the peptide fraction.     

The activity of matrix metalloproteinases (MMPS) and tissue inhibitors of metalloproteinases (TIMPs) in mammary tumors of dogs and rats

We conducted zymography for detecting the activity of matrix metalloproteinases (MMPs) and reverse zymography for the activity of tissue inhibitors of metalloproteinases (TIMPs) in canine spontaneous and rat 7, 12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumor tissues. The activities of MMPs of canine mammary tumors were quite higher than those of the rat chemically induced tumors. The activities of MMPs were significantly higher in malignant tissues than in benign ones of canine tumors, whereas the activity of only MMP-2 was higher in both benign and malignant rat tumors compared to normal tissues. There were no differences of MMPs activities between benign and malignant rat tumors. The results of reverse zymography indicated that the activities of TIMP-1, -2 and -3 were strikingly higher in rat tumors than in canine tumors. The activities were higher in malignant tissues than in benign ones of dogs, and higher in tumor tissues than in normal mammary tissues of rats. The results of film in situ zymography for tissue localization of gelatinolytic activity showed that the digested area was more extended in malignant tumors than in benign ones of dogs. However, the area was similarly extended in both benign and malignant rat tumors. These results may indicate that the canine spontaneous malignant mammary tumors possess more aggressive nature than the rat chemically induced counterpart, resulting from the high level of MMPs and low level of TIMPs activities of the tumor tissues.     

Genetic variation affects de novo translocation frequency

Translocation is one of the most frequently occurring human chromosomal aberrations. The constitutional t(11;22)(q23;q11), which is the only known recurrent non-Robertsonian translocation, represents a good model for studying translocations in humans. Here we demonstrate polymorphisms of the palindromic sequence at the t(11;22) breakpoint that affect the frequency of de novo translocations in sperm from normal males. A typical allele consists of a perfect palindrome, producing ~10-5 de novo t(11;22) translocations. Alleles with an asymmetric center do not form the t(11;22). Our data show the importance of genome sequence on chromosomal rearrangements, a class of human mutation that is thought to be random.     

Serological and virological studies of Newcastle disease and avian influenza in slaughter-age ostriches (Struthio camelus) in Japan

Serum samples from 191 ostriches (Struthio camelus) in Japan were tested for antibodies to Newcastle disease virus (NDV) and avian influenza virus (AIV). Twenty-two (12%) contained NDV-specific neutralizing antibodies by a virus-neutralization (VN) test without vaccination. Antibodies to AIV were not detected in the any sera by an agar gel precipitation test. Seven serum samples that had vaccinated with live NDV by eye drop were all positive by the VN test at 1 month post vaccination. A haemagglutination inhibition (HI) test for NDV seemed not to be suitable for ostriches because of non-specific agglutination of chicken red blood cells. No haemagglutinating viruses were isolated. This is the first report on detection of antibodies against NDV in ostriches in Japan.     

Effect of group culture and embryo-culture conditioned medium on development of bovine embryos

We investigated the effect of group culture on bovine embryo development, and also investigated the effect of embryo-culture conditioned medium on developmental competence of individually cultured bovine embryos. Slaughterhouse-derived bovine oocytes were matured and fertilized in vitro. The presumptive zygotes were cultured individually or cultured in groups of 2 to 5 embryos with a constant culture density (5 mul/embryo). After 7 days of culture, the rates of embryos developed to the blastocyst stage were significantly higher (P < 0.05) in group cultures of more than 3 embryos/drop than for embryo culture of 1 or 2 embryos/drop. These results suggest a beneficial effect of group culture may be exerted by possible growth promoting factors secreted by embryos. In the next experiment, we investigated the effect of timing of fresh medium replacement on the development of embryos cultured in groups. The blastocyst formation rate was lower when culture medium was replaced freshly on days 2-4 after fertilization than on days 5-6. The blastocyst formation rates of single-cultured embryos were significantly (p < 0.05) increased by the addition of conditioned medium derived from multiple-embryo culture. These results indicate that group culture promotes embryo development and that embryo culture-derived conditioned medium is effective for supporting development of single cultured embryos.