Effects of Cage Design and Bird Density on Layers
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Two experiments, one with a commercial strain and one with an experimental strain of Single Comb White Leghorns, compared the effects of cage shape, feeder space, cage barrier, bird density, level of feeding, and period observed on feeding behavior and bird movement. In Experiment 1, only period observed significantly affected time spent feeding; the commercial strain of hens generally ate more in the p.m. (1700 to 1900 hr) than in the a.m. (0700 to 0900 hr). A significant (P<.05) feeder-space × period observed interaction indicated that increased feeder space is important in reducing feeder competition during peak feeding times. Only feed consumption of the experimental strain was significantly (P<.05) affected by bird density; hens housed 2 birds per cage ate 10.5 g per hen per day more than those housed 3 per cage (Experiment 2). Birds spent 38. 4 sec more eating during 0600 to 0700 hr than 1700 to 1800 hr (P<.05). Maximum number of birds feeding simultaneously was significantly (P<.05) affected by feeder space, bird density, and level of feeding. Hens with 45.7 cm of feeder space per cage, housed 3 per cage and receiving 90% of full feed had more simultaneous feeding than hens with 25.4 cm of feeder space, housed 2 per cage and on full feed. Hens in deep cages had significantly (P<.05) more quadrant-to-quadrant moves than hens in shallow cages.Keywords:
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Two studies were conducted to determine whether cage density and prior dietary nonphytate P (NPP) level affect hens' P requirements. In Experiment 1, hens were housed at three cage densities (300, 400, and 600 cm2 or 46.5, 62.0, and 93.0 inches2/hen) and fed four levels of NPP (0.15, 0.25, 0.35, and 0.40%) for 6 wk to determine the effect of cage density on the P requirement. Egg production (EP), feed consumption (FC), egg weight (EW), and egg specific gravity (ESG) were measured to evaluate performance. Cage density influenced EP within Week 1 (P < 0.01), and during Weeks 5 and 6, there was a cage density x NPP-level interaction (P < 0.05). At 300 cm2, EP was more severely affected by 0.15 and 0.25% NPP than at 400 and 600 cm2. A linear decrease (P < 0.001) in FC was observed because of decreased NPP. Hens at 300 cm2 consumed 4 g less feed/hen per d than hens at 400 cm2. A linear decrease in EW was observed as the NPP level decreased (P < 0.01) from 0.25 to 0.15%, and there was no effect of cage density. Experiment 2 was conducted to determine the effect of prior dietary P levels on time required to create a P deficiency. Hens fed 0.4% NPP were divided into two groups and fed 0.25 and 0.4% NPP for 4 wk. At the end of 4 wk, hens fed 0.25% NPP were further divided into three groups and were fed diets containing 0.09, 0.25, and 0.30% NPP for an additional 6 wk. Hens fed 0.4% NPP were divided into three groups and fed diets containing 0.09, 0.4, and 0.45% NPP. Reduction of NPP from 0.4 and 0.25% to 0.09% reduced EP by 8.5 and 6.8%, respectively, within 3 wk. Prior NPP levels had no influence on time required to create a P deficiency in terms of EP. Reduction of NPP from 0.4 and 0.25% to 0.09% reduced (P < 0.05) FC. A decline in FC occurred 2 wk earlier in hens previously fed 0.4% than those fed 0.25% NPP. This result indicates that hens fed 0.4% NPP became P deficient more quickly than hens fed 0.25%. We concluded that cage density and prior NPP level affect the hen P requirements or time required to create a P deficiency.
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In a soil bioassay, adult Deroceras reticulatum (Stylommatophora: Limacidae) and three different weight-classes of young Arion lusitanicus (Stylommatophora: Arionidae) were exposed to a single dosage (170 dauer larvae per g of soil) of the nematode Phasmarhabditis hermaphrodita monoxenically associated with the bacterium Moraxella osloensis. Groups of 10 slugs were continuously exposed to nematodes for 4 days, and then transferred individually to Petri-dishes containing a disc of Chinese cabbage as food. Food consumption—measured by image analysis—and slug mortality were recorded daily for 10 days. Food consumption was inhibited in both slug species tested. D. reticulatum stopped feeding 6 days after the start of nematode treatment, while all A. lusitanicus continued to feed. However, in the three weight-classes of A. lusitanicus (0.15 g, 0.24 g, 0.45 g), food consumption was reduced by at least 50 %. The greatest reduction in feeding, nearly 90 %, was noted in the smallest A. lusitanicus. The nematodes successfully killed D. reticulatum but were less efficient at killing young A. lusitanicus. At the end of the experiment, mortality was highest in D. reticultatum (98 %) and the smallest weight-class of A. lusitanicus (47 %). There was almost no mortality in the largest weight-class of A. lusitanicus treated with nematodes. P. hermaphrodita associated with M. osloensis can thus be considered as a biological control agent for young stages of A. lusitanicus for its effect as a feeding inhibitor, rather than for its ability to kill the slugs.
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Meiosis is critical for sexual reproduction. During meiosis, the dynamics and integrity of homologous chromosomes are tightly regulated. The genetic and molecular mechanisms governing these processes in vivo, however, remain largely unknown. In this study, we demonstrate that Bat3/Scythe is essential for survival and maintenance of male germ cells (GCs). Targeted inactivation of Bat3/Scythe in mice results in widespread apoptosis of meiotic male GCs and complete male infertility. Pachytene spermatocytes exhibit abnormal assembly and disassembly of synaptonemal complexes as demonstrated by abnormal SYCP3 staining and sustained γ-H2AX and Rad51/replication protein A foci. Further investigation revealed that a testis-specific protein, Hsp70-2/HspA2, is absent in Bat3-deficient male GCs at any stage of spermatogenesis; however, Hsp70-2 transcripts are expressed at normal levels. We found that Bat3 deficiency induces polyubiquitylation and subsequent degradation of Hsp70-2. Inhibition of proteasomal degradation restores Hsp70-2 protein levels. Our findings identify Bat3 as a critical regulator of Hsp70-2 in spermatogenesis, thereby providing a possible molecular target in idiopathic male infertility.
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In response to DNA damage, p53 undergoes post-translational modifications (including acetylation) that are critical for its transcriptional activity. However, the mechanism by which p53 acetylation is regulated is still unclear. Here, we describe an essential role for HLA-B-associated transcript 3 (Bat3)/Scythe in controlling the acetylation of p53 required for DNA damage responses. Depletion of Bat3 from human and mouse cells markedly impairs p53-mediated transactivation of its target genes Puma and p21 . Although DNA damage-induced phosphorylation, stabilization, and nuclear accumulation of p53 are not significantly affected by Bat3 depletion, p53 acetylation is almost completely abolished. Bat3 forms a complex with p300, and an increased amount of Bat3 enhances the recruitment of p53 to p300 and facilitates subsequent p53 acetylation. In contrast, Bat3-depleted cells show reduced p53–p300 complex formation and decreased p53 acetylation. Furthermore, consistent with our in vitro findings, thymocytes from Bat3-deficient mice exhibit reduced induction of puma and p21, and are resistant to DNA damage-induced apoptosis in vivo. Our data indicate that Bat3 is a novel and essential regulator of p53-mediated responses to genotoxic stress, and that Bat3 controls DNA damage-induced acetylation of p53.
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Two experiments, one with a commercial strain and one with an experimental strain of Single Comb White Leghorns, compared the effects of cage shape, feeder space, cage barrier, bird density, level of feeding, and period observed on feeding behavior and bird movement. In Experiment 1, only period observed significantly affected time spent feeding; the commercial strain of hens generally ate more in the p.m. (1700 to 1900 hr) than in the a.m. (0700 to 0900 hr). A significant (P<.05) feeder-space × period observed interaction indicated that increased feeder space is important in reducing feeder competition during peak feeding times. Only feed consumption of the experimental strain was significantly (P<.05) affected by bird density; hens housed 2 birds per cage ate 10.5 g per hen per day more than those housed 3 per cage (Experiment 2). Birds spent 38. 4 sec more eating during 0600 to 0700 hr than 1700 to 1800 hr (P<.05). Maximum number of birds feeding simultaneously was significantly (P<.05) affected by feeder space, bird density, and level of feeding. Hens with 45.7 cm of feeder space per cage, housed 3 per cage and receiving 90% of full feed had more simultaneous feeding than hens with 25.4 cm of feeder space, housed 2 per cage and on full feed. Hens in deep cages had significantly (P<.05) more quadrant-to-quadrant moves than hens in shallow cages.
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Holcus lanatus
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SUMMARY A hitherto unrecorded virus having flexible rod‐shaped particles about 740–760 × 13 nm was isolated from Anthoxanthum odoratwn L. It was transmitted by sap inoculation, but not by several species of insect, seed or soil to 18 species of Gramineae including wheat, oats and barley. In susceptible species the virus normally produced a mosaic mottling of the leaves which was sometimes followed by a necrotic streaking or striping.
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HLA-B-associated transcript 3 (BAT3) was originally identified as one of the genes located within human major histocompatibility complex. It encodes a large proline-rich protein with unknown function. In this study, we found that a fragment of the BAT3 gene product interacts with a candidate tumor suppressor, DAN, in the yeast-based two-hybrid system. We cloned the full-length rat BAT3 cDNA from a fibroblast 3Y1 cDNA library. Our sequence analysis has demonstrated that rat BAT3 cDNA is 3617 nucleotides in length and encodes a full-length BAT3 (1098 amino acids) with an estimated molecular mass of 114,801 daltons, which displays an 87.4% identity with human BAT3. The deletion experiment revealed that the N-terminal region (amino acid residues 1-80) of DAN was required for the interaction with BAT3. Green fluorescent protein-tagged BAT3 was largely localized in the cytoplasm of COS cells. Northern hybridization showed that BAT3 mRNA was expressed in all the adult rat tissues examined but predominantly in testis. In addition, the level of BAT3 mRNA expression was more downregulated in some of the transformed cells, including v-mos- and v-Ha-ras-transformed 3Y1 cells, than in the parental cells.
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