White Roman Research Articles

Effects of lighting intensity on growth and reproductive performance of breeder geese

This study investigated the effects of lighting intensity on egg production among white Roman geese kept in an environmentally controlled house. Two hundred and fifty-two White Roman geese aged 10 mo were randomly distributed among 12 pens, with each pen containing 5 ganders and 16 females on the floor, based on a completely random design (CRD). At the beginning of the study, each treatment group was comprised of 5 ganders and 16 geese in each pen; these groups included: control (40 lux group), geese under 170 lux (170 lux group), geese under 300 lux (300 lux group), and geese under 430 lux (430 lux group). The age of the geese at first lay was 10 mo, on average. The results showed that geese under 40 lux in egg number per goose or laying rate had lower than those of the 430 lux group. The reproductive characteristics were no different for the 170 lux, 300 lux, or 430 lux light groups. The hatchability in the 170 lux light group was significantly higher than in the 40 lux light group (P < 0.05). Moreover, the egg weight in the 170 lux and 430 lux groups was significantly heavier than the 40 lux light group (P < 0.05). Therefore, if lighting intensity supplementation of lux is defined as X (lux/geese), and egg number production is defined as Y4 (egg), then Y4 = 35.7 + 0.46X-0.002X2+0.00000296X3 (R2 = 0.868, P < 0.001) for the entire experimental period. In conclusion, geese raised under 170 lux lighting intensity in an environmentally controlled house achieved higher hatchability and egg weight during the laying season.

Effects of spent mushroom compost meal on growth performance and meat characteristics of grower geese

The objective of this study was to determine the effect of spent mushroom compost (SMC) meal on the growth performance and meat characteristics of geese. The SMC extracts contained 2.49±0.62 mg gallic acid equivalent/g dry weight (DW) and 1.08±0.15 mg quercetin equivalent/g DW of the total phenolic and flavonoid contents. A total of 120 White Roman geese, aged five weeks, were randomly distributed among 12 pens and fed a grower diet ad libitum during the growing period, with each pen containing five males and five females in a completely randomized design. Each treatment comprised three pens (total of 30 geese), including control (corn-soybean meal); supplementation with 5% SMC meal (5% SMC); supplementation with 10% SMC (10% SMC); and supplementation with 15% SMC (15% SMC), for eight weeks. The results revealed that the body weight of the 15% SMC group was significantly lower than that of the control group at the age of 12 weeks. There were no significant effects among the groups on feed conversion ratio or intake. The malondialdehyde content of the serum in the 15% SMC group was lower than that of the control group at week 12. There were no significant effects among the groups for blood biochemical parameters in grower geese at week 12. The color values of meats in the SMC groups were higher than those obtained with control group. The flavor and acceptability score of meats in the 5% SMC group were significantly higher than for the 15% SMC and control group. Supplementation with SMC at 5% in the diet has no adverse effects on the growth performance of grower geese. However, SMC meal at 5% in the diet favorably affects sensory attributes (meat flavor and acceptability).

Effects of short light regimes and lower dietary protein content on the reproductive performance of White Roman geese in an environment-controlled house

The objective of this study is to investigate the effects of short light regimes and lower dietary protein content on the reproductive performance of White Roman geese in an environment- controlled house. Thirty-two ganders and 80 geese during the third laying period were allotted into 16 pens, randomly assigned into a split-plot design with two different lighting regimes: (1) short light regimes (SL) with 6.5h of light and 17.5h of dark (6.5L:17.5D), and (2) long light regimes (LL) with 19L:5D during the 6-wk prelaying period, followed by two different levels of protein diets (Low CP: 15% vs. High CP: 18%) for the laying period. The results showed that birds treated with the SL light regime had a heavier body weight compared to those treated with LL at the arrival of the peak period of egg production (6.19 vs. 5.87kg, P<0.05). Geese under LL had a longer laying period than those under SL treatment (277 vs. 175day, P<0.05), while the geese under SL treatment had a higher laying intensity (15.4% vs. 12.6%, P<0.05), fertility and hatchability than those under LL treatment. Our results suggest that the White Roman geese treated with 6-wk short light regime during the prelaying period and on the low CP diet during the laying period found conditions sufficient to sustain their regular reproduction performance, which would benefit geese farmers in the perspectives of energy saving and prolonged laying period.

Effects of monochromatic light sources on sex hormone levels in serum and on semen quality of ganders

Light is an essential external factor influencing various physiological processes, including reproductive performance, in birds. Although several attempts have been made to understand the effect of light on poultry production, the effect of light of a particular wavelength (color) on the reproductive function in geese remains unclear. This study evaluated the effect of various monochromatic light sources on the levels of sex hormone and on semen quality of ganders. Of 30 male White Roman geese in their third reproductive season (average age=3years), 27 were divided into three groups receiving monochromatic white or red or blue lights. The birds were kept in an environmentally controlled house with a lighting photoperiod of 7L:17D for six weeks as the adaptation period. The photoperiod was subsequently changed to 9L:15D and maintained for 24 weeks. Three ganders at the beginning of the study and three from each group at the end of the adjusting period and the 20th and 30th week of the study period were sacrificed, and their testes and blood samples were collected for determining the sex hormone levels. Semen samples were collected for determining semen quality parameters, including the semen collection index, sperm concentration, semen volume, sperm motility, sperm viability, sperm morphology, and semen quality factor. The results showed that the testosterone and estradiol levels remained unchanged in all three groups at all time points. The ratio of testosterone to estradiol of ganders exposed to white light was significantly higher than that of ganders exposed to red light at the 30th week (P<0.05). Semen collection index and sperm viability of ganders exposed to blue light were significantly the lowest (P<0.05). Moreover, sperm motility, sperm viability, and percentage of morphologically normal spermatozoa of ganders in white light were the highest (P<0.05). In conclusion, the results of this study suggested that artificial illumination with white light may maintain a better semen quality than that with red or blue lights in ganders.

Effects of dietary garlic scape meal on the growth and meat characteristics of geese

This study evaluated the growth performance and meat characteristics of grower geese whose diets included garlic scape meal (GSM), a by-product of garlic production. Scape is the leaf-less flower stem of garlic.Garlic scape (GS) extracts contained 84.7 ± 3.8 μg/g dry weight (DW), 81.4 ± 8.2 μg/g DW, 0.78 ± 0.05 mg gallic acid equivalent/g DW and 31.67 ± 2.25 μg/g DW of allicin, alliin, total phenolics and flavonoid contents, respectively.In total, 120 White Roman geese aged 5 weeks were randomly distributed among 12 pens and fed on a grower diet ad libitum during the growth period. Employing a completely random design, 5 males and 5 females were placed in each pen.Each treatment was applied to three pens (in total 30 birds) and the treatments comprised the following: 1) control (maize–soybean meal), 2) 5% of maize replaced with 5% of GSM (5% GSM), 3) 10% of maize replaced with 10% of GSM (10% GSM) and 4) 15% of maize replaced with 15% of GSM (15% GSM). Each group of 30 birds was treated for 8 weeks.The results revealed that the 15% GSM group was characterised by a lower feed conversion ratio than the control group; however, these groups did not differ significantly in their body weights (BWs). In addition, the 10% GSM group did not differ in both the feed conversion ratio and consumption.The flavour intensity score of meats in the 10% GSM group was significantly lower than those of meats in the 5% GSM and control groups. The general acceptability scores of meats in the 5% GSM and control groups were higher than those of meat in the 10% GSM group.The study concluded that 5% dietary GSM in the feed did not adversely affect the growth performance, meat characteristics or sensory evaluation of grower geese. Hence, the environment can be protected by including agricultural waste in goose diets.

In vitro antioxidant capability and performance assessment of White Roman goose supplemented with dried Toona sinensis

ABSTRACTToona sinensis (TS) leaf is a well-known traditional oriental medicine herb. The purpose of this study was to evaluate in vitro antioxidant capability and performance assessment of White Roman goose supplemented with dried TS leaves (TSL). The TSL extracts contained 22.23 ± 1.13 mg gallic acid equivalent/g dry weight (DW) and 1.38 ± 0.06 mg quercetin equivalent/g DW of total phenolics and flavonoid contents. The scavenging action of 1, 1-diphenyl-2-picrylhydrazyl free radical and superoxide anion was as good as that of the butylated hydroxytoluene (BHT) and ascorbic acid, respectively. Inhibition of lipid peroxidation of TSL extracts at 2.5 mg/mL reached nearly 40% compared with the BHT. One hundred and eight White Roman geese aged 6 weeks were distributed to six pens randomly, and fed a grower diet ad libitum during the growing period, with each pen containing nine males and nine females following completely randomized design. Diets were supplemented with the following levels of dried TSL: 0% (control), 0.1% or 0.2% groups for 6 weeks, respectively. The results revealed no significant effects among treatments in the growth performance, blood biochemical parameters and muscle fibre of the grower geese. Superoxide dismutase (SOD) content of the serum in the 0.2% TSL group was significantly higher than that of the control group. In conclusion, dried TSL powder has antioxidative effects in vitro and could serve as a promising natural feed additive to improve the serum SOD content of grower geese.

Effect of Monochromic Light-emitting Diode Light with Different Color on the Growth and Reproductive Performances of Breeder Geese.

The purpose of this study was to investigate the effect of monochromic light-emitting diode (LED) light with different color on the growth and reproductive performances of white Roman breeder geese. A randomized complete batch design was utilized for the trial, and the replicate was regarded as one batch. Twenty ganders and fifty-five dames were used in batch 1 (started on 2011/6/17 and ended on 2012/1/31), thirty ganders and eighty-four dames were used in batch 2 (started on 2012/3/23 and ended on 2012/10/26), and thirty ganders and seventy-two dames were used in batch 3 (started on 2013/3/12 and ended on 2013/12/20). Two hundred and ninety-one geese were randomly assigned to 6 rooms in an environmentally controlled house. They were randomly allotted into one of three monochromatic light treatments: Blue, red, or white. The results showed that there was no significant difference in body weight among the three lighting groups at any point throughout the experimental period. However, compared to the blue light group, significantly more eggs were produced by the red and white light groups (p<0.05). Furthermore, the laying period of the red light group was significantly longer than that of other two groups (p<0.05). In conclusion, our results suggested that red LED-light has the best effect on reproductive performance (i.e. longer laying period and higher total eggs number) at 30 lux light intensity, and is therefore a better choice for the management of breeding geese than blue or white LED-light.

Factors Affecting the Incidence of Angel Wing in White Roman Geese: Stocking Density and Genetic Selection.

The present study investigated stocking density and genetic lines, factors that may alter the severity and incidence of angel wing (AW), in White Roman geese. Geese (n = 384) from two genetically selected lines (normal- winged line, NL, and angel-winged line, AL, respectively) and one commercial line (CL) were raised in four pens. Following common commercial practice, low-stocking-density (LD), medium-stocking-density, and high-stocking-density treatments were respectively administered to 24, 32, and 40 geese per pen at 0 to 3 weeks (1.92 m2/pen) and 4 to 6 weeks (13.2 m2/pen) of age and to 24, 30, and 36 geese at 7 to 14 weeks (20.0 m2/pen) of age. The results revealed that stocking density mainly affected body weight gain in geese younger than 4 weeks, and that geese subjected to LD had a high body weight at 2 weeks of age. However, the effect of stocking density on the severity score of AW (SSAW) and incidence of AW (IAW) did not differ significantly among the treatments. Differences were observed among the genetic stocks; that is, SSAW and IAW were significantly higher in AL than in NL and CL. Genetic selection generally aggravates AW, complicating its elimination. To effectively reduce IAW, stocking density, a suspected causal factor, should be lower than that presently applied commercially.

Effects of laying period modulation on the reproductive performance of breeding geese reared in a water pad windowless building

The objectives of this study were applying environmental control technologies for comparing the reproductive capacity, the reproductive period and the adjusted period of the breading geese among three production types. A total of 7136 White Roman geese (5947 female geese and 1189 male geese) at 68 weeks of age were randomly divided into period adjustment with a water pad windowless building set (set A), natal period adjustment with traditional open building set (set B) and natural period with traditional open building set (set C).The experimental results indicated that the laying period of the set A, set B and set C are 177, 94 and 147 days respectively. The average laying rate, hatchability and fertilization rate of set A were the highest, but there were not significantly different among three sets (p > 0.05). The average egg production number per female goose for set A was 55 eggs which was the highest. The average product gosling number per female goose of the set A was 41 birds which was more than that of set B (19 birds) and that of set C (26 birds).Therefore, the laying period of goose could be successful adjusted to the non-breeding season and extended it with the water pad environment of control building for reducing summer temperature and short light time.

THE WHITE ROMAN GOOSE AS A HOST FOR INFECTION AND VIRAL SHEDDING OF MUSCOVY DUCK PARVOVIRUS

Waterfowl parvoviruses are divided into two groups: the goose parvovirus (GPV) group and the Muscovy duck parvovirus (MDPV) group. Previous study shows that GPV causes the disease in both geese and Muscovy ducks whereas MDPV causes the disease only in ducks but not in geese. However, the possibility remains that MDPV might cause asymptomatic infection in geese. In this study, the white Roman geese were experimentally inoculated with MDPV. Polymerase chain reaction (PCR) analysis showed that the geese inoculated with MDPV shed virus from cloaca from one to four weeks post-inoculation. Western blot analysis showed that these geese also produced antibodies against MDPV from three weeks post-inoculation. In addition, the presence of MDPV in field samples collected from geese was confirmed by PCR and sequencing analysis. Taken together, these results indicated that the goose is a host for infection and viral shedding of MDPV. This finding is important for the control of MDPV infection in the field.

Effects of sequential feeding with low- and high-protein diets on growth performances and plasma metabolite levels in geese

This study was conducted by two trials to investigate effects of sequential feeding with low- and high-protein diets on growth traits and plasma metabolites in geese. In Trial I, the effect of sequential feeding under time-restricted feeding system was investigated. Seventy-two White Roman goslings were randomly allotted into either sequential feeding (S1) or control feeding (C1) group. All goslings were fed for 1 h at morning and at evening, respectively, from 2 to 8 weeks of age. S1 group was offered 13% CP diet at morning and 19% CP diet at evening. C1 group was offered the same diet (16% CP; mixed equally with the two diets mentioned above) at both morning and evening. Blood samples were hourly collected for 4 h after feeding at both morning and evening for the determination of the postprandial plasma levels of glucose, triacylglycerol and uric acid at the end of experiment. Results showed that BW, average daily gain (ADG), and daily feed intake (FI) were not different between groups, but the feed efficiency (FE) in S1 group was significantly higher than that in C1 group (P<0.05). The areas under curve (AUC) of plasma postprandial levels of glucose, triacylglycerol and uric acid were not affected by treatment, but the AUC of triacylglycerol and uric acid in morning were lower than those in evening (P<0.05). In Trial II, the effect of sequential feeding under ad libitum feeding system was investigated. Twenty-four goslings were randomly allotted into either sequential feeding (S2) or control feeding (C2) group. Diets were altered at 0600 and 1800 h, respectively, and geese were fed ad libitum from 4 to 8 weeks of age. S2 group was offered 14% CP diet at morning and 20% CP diet at evening. C2 group was supplied the same diet (mixed with the two diets according to the ratio of diets consumed by S2 group on the preceded day) at both morning and evening. Results showed that the ADG in S2 group was higher than those in C2 group (P<0.05). Summarized data from both trials showed that sequential feeding improves daily gain and FE in growing geese.

The effects of feeding time and time-restricted feeding on the fattening traits of White Roman geese

This study comprises two trials that investigated the effects of feeding time and time-restricted feeding on the fattening traits and plasma metabolite levels of White Roman geese. In Trial I, 24 geese aged 8 weeks of each sex were allowed free access to a fattening diet for 1 h either in the morning (morning-feeding group) or afternoon (afternoon-feeding group). At 12 weeks of age, blood samples were collected hourly for 4 h, beginning 1 h after feeding to determine the plasma levels of glucose, triacylglycerols and uric acid. The results showed a lower (P<0.05) daily feed intake (DFI) and daily gain (DG) and higher (P<0.05) feed efficiency (FE) for the morning-feeding group compared with those of the afternoon-feeding group. In addition, the postprandial plasma levels of glucose, triacylglycerols and uric acid did not differ (P>0.05) between groups. In Trial II, 12 geese aged 8 weeks of each sex were randomly assigned to either the ad libitum feeding group (control group) or time-restricted feeding group (restricted group). The geese in the control group were fed a fattening diet ad libitum, whereas those in the restricted group were allowed access to the diet for 2 h every morning. All geese were killed at 13 weeks of age and their carcass traits were evaluated. The results showed a lower DFI and DG and higher FE for the restricted group compared with those of the control group (P<0.05). In addition, the restricted group exhibited lower visceral and abdominal fat and higher empty digestive tract and liver weights than those of the control group (P<0.05). The results showed that time-restricted feeding in the morning resulted in superior DG and FE compared with feeding in the afternoon. Moreover, time-restricted feeding implemented in the morning during the fattening period reduced DFI and increased FE in geese compared with ad libitum feeding.

Methane Generation from the Intestine of Muscovy Ducks, Mule Ducks and White Roman Geese

Livestock are one of the largest single sources of methane emissions, which is a greenhouse gas. In this study, alfalfa meal was tested as a feed additive to lower the methane generation in the three species of waterfowl. Four experiments were conducted to determine methane generation in the intestines of Muscovy ducks, mule ducks and White Roman geese of the same age and with the same diet. In experiment I, the in vitro methane generation of the cecal contents was the largest compared to other intestinal compartments in each species (p < 0.05). Moreover, the methane generation of the cecal content or colon and rectum in goslings was higher than in mule and Muscovy ducklings (p < 0.05) at six weeks of age. In experiment II, the cumulative methane generation in the cecal content of mule ducks at 8 weeks of age was the largest among all species (p < 0.05). In experiment III, 4-month-old Muscovy ducks had the highest average methane generation per bird per day among the three species (p < 0.05). In experiment IV, the methane generation of the cecal content in birds fed a grower diet supplemented with a 30% alfalfa meal diet was lower than that of birds fed grower diet for all three species. Based on the above results, it is suggested that age, the method of measurement (in vitro vs. in vivo) and composition of diet significantly affect the level of methane generation in the intestine for Muscovy ducks, mule ducks and White Roman geese. The amounts of methane generation of the cecal contents in the three species were 36.1, 13.9, and 34.2 µg/g/4 h, respectively. By adding 30% alfalfa meal, the cumulative methane generation of the cecal contents for the three species were reduced by 63.3–95.5%. The addition of alfalfa meal to feed thus has good potential with regard to decreasing greenhouse gases emissions from waterfowl.

Matrilineal Genetic Structure of Domestic Geese

In contrast to other farm animals, the matrilineal structure of domestic goose has remained an open question. In this study, we analyzed mitochondrial DNA control region sequence variation of 245 domestic geese to discern the main matrilineal c omponents and their phylogeneticrelationships. The result of phylogeneticanalysis indic ated the distinct lineage of clade II and the result of network analysis further suggested the major group of Chinese native goose breeds (subclade S) and introgressive goose breeds (subclade G). Except Yili geese, all Chinese domestic goose breeds were clustered in S, whereas clade II were widely distributed in 2 European breeds, Yili geese as well as 3 domesticGraylag geese. The results support that Chinese domesticgoose breeds (except the Yili breed) originated from Swan goose (Anser cygnoides) while European goose breeds originated from Graylag goose (Anser anser). In total, 17 Landoise and 16 White Roman geese were clustered in subclade G together with 1 domestic goose (A. anser, AY112966), which supported the previous finding that European geese originated from Graylag goose (A. anser). But 9 unanticipated samples of two Chinese domestic goose breeds including 7 Lion-head geese and 1 Zhedong White goose in haplotype H9 were also clustered in subclade G as well as 3 Lion-head geese in haplotypes H13, H15 and H16 and 2 Zhedong White geese in haplotypes H18 and H19, which may be caused by the potential gene introgressions between swan goose breeds and graylag breeds with a directional contribution towards graylag geese.

Morphological development of the small intestine in white Roman goslings

The objective of this study was to investigate the morphological development of small intestinal segments in white Roman goslings from hatching to 28 days of age. Forty day-old male goslings were used in this experiment. Eight goslings were selected randomly at hatching, 7, 14, 21 and 28 days of age, respectively. The small intestinal segments were sampled from six goslings for intestinal structure observation by light microscopy and from two male goslings for scanning electron microscopy (SEM). The villus height, width, perimeter, area, crypt depth, muscle thickness and height/width ratio significantly (P < 0.05) increased during the first four weeks post-hatching. The villus width of duodenum continued to increase (P < 0.05) until 28 days of age, whereas the jejunum and ileum villus width reached a peak at 21 days of age. The development of villus height, area and crypt depth increased two to three times in the small intestine of goslings from hatching to 28 days of age. The area of villi in the duodenum and jejunum were significantly larger (P < 0.05) than that in the ileum. The villus muscle depth of the ileum was greatest (P < 0.05) and villus height and perimeter of jejunum were greatest (P < 0.05) among the intestinal segments at 28 days of age. Duodenal villus width increased faster but crypt and muscle thickness became thinner than other intestinal segments (P < 0.05). The variables regressing the size and shape of villi in the smal intestine increased linearly (P < 0.05 to 0.001) in the small intestine. The surface of each segment villi of the small intestine exhibited different types. At hatching, the villi of duodenum and jejunum had a small and dense finger-like shape, followed by a more developed plate or tongue-like at four weeks of age. Ileal villi developed to finger-like with a round tip during the early growth period. Key words: Geese, small intestine, villi, morphological development.

Large-scale mitochondrial DNA deletions in weak goslings

1. Evidence has accumulated in mammals to support the idea that mitochondrial DNA (mtDNA) deletions and mutations might contribute to ageing and reproductive failure. White Roman geese were monitored to evaluate the effect of large-scale deletions of mtDNA in an avian species. 2. A total of 340 samples from 114 dead embryos, 111 weak goslings, and 115 normal goslings were used in this experiment. The regions of these two large-scale mtDNA deletions, ΔmtDNA6829 and ΔmtDNA6992, were between the COI and ND5 genes. A 3·6% (4 out of 111) positive sample was detected in the weak goslings. In contrast, no large-scale mitochondrial DNA deletions were detected in either the dead embryos (0 out of 114) or the normal goslings (0 out of 115). 3. Large-scale mtDNA deletions may be a factor causing weak goslings.

The Origin of the White Roman Goose

In order to avoid interference from nuclear copies of mitochondrial DNA (numts), mtDNA of the white Roman goose (domestic goose) was extracted from liver mitochondria. The mtDNA control region was amplified using a long PCR strategy and then sequenced. Neighbor-joining, maximum parsimony, and maximum-likelihood approaches were implemented using the 1,177 bp mtDNA control region sequences to compute the phylogenetic relationships of the domestic goose with other geese. The resulting identity values for the white Roman geese were 99.1% (1,166/1,177) with western graylag geese and 98.8% (1,163/1,177) with eastern graylag geese. In molecular phylogenetic trees, the white Roman goose was grouped in the graylag lineage, indicating that the white Roman goose came from the graylag goose (Anser anser). Thus, the scientific name of the white Roman goose should be Anser anser 'White Roman.'

Effects of different sources of dietary non-starch polysaccharides on the growth performance, development of digestive tract and activities of pancreatic enzymes in goslings

1. The purpose of this study was to investigate the effects of different sources of dietary non-starch polysaccharides (NSP) on growth performance, development of gastrointestinal tract, and activities of pancreatic enzymes in goslings from 0 to 21 d of age. 2. A total of 100 one-day-old White Roman female goslings were selected and randomly divided into 5 dietary treatment groups. Each group had 4 replicate cages (100 × 60 × 58 cm) of 5 goslings. Goslings in each group were given one of 5 isoenergetic and isonitrogenous semi-purified diets. Experimental diets were designed to contain 90 g/kg of different sources of dietary NSP from maize (control), barley hull, rice bran, wheat bran, or pectin, respectively, and 97·4 g/kg NSP were supplied by soybean meal. 3. The goslings receiving the pectin diet had significantly higher viscosity in intestinal digesta than the other treatment diets. However, the daily feed intake, daily weight gain, and feed conversion ratio of goslings in the pectin group were significantly lower than those given the other diets. 4. The relative weights of proventriculus, gizzard, liver and pancreas, as well as the relative weights and lengths of various intestinal segments in the goslings that received the pectin diet, were significantly higher than those receiving the other diets. The specific activities (SA) of amylase, lipase, trypsin, and chymotrypsin in the pancreatic tissue of goslings in the pectin group were significantly lower than those in the other groups. 5. Goslings given a soluble NSP source (pectin) diet tended to exhibit inhibited growth and decreased activity of pancreatic enzymes. However, compared with maize, the inclusion of insoluble NSP sources from barley hull, rice bran, and wheat bran did not negatively affect growth and also were not significantly different among the treatment diets.

In vivo Methane Production from Formic and Acetic Acids in the Gastrointestinal Tract of White Roman Geese

Three experiments were conducted to determine the conversion rate of formic and acetic acids into methane in the gastrointestinal tracts of geese. In experiment I, two sets of two 4-month-old male White Roman geese were allocated to one of two treatment groups. Each set of geese was inoculated either with formic acid or with phosphate buffer solution (PBS). After the acid or the PBS was inoculated into the esophagi of the geese, two birds from each treatment were placed in a respiratory chamber as a measurement unit for 4 h in order to determine methane production rate. In experiment II and III, 6- and 7-wk-old male White Roman goslings were used, respectively. Birds were allocated to receive either formic acid or PBS solution injected into the ceca in experiment II. Acetic acid or PBS solution injected into the cecum were used for experiment III. After either the acids or the PBS solution were injected into the cecum, two birds from each treatment were placed in a respiratory chamber as a measurement unit for 3 h; each treatment was repeated 3 times. The results indicated that formic acid inoculated into the oesophagi of geese was quickly converted into methane. Compared with the PBS-injected group, methane production increased by 5.02 times in the formic acid injected group (4.32 vs. 0.86 mg/kg BW/d; p<0.05). Acetic acid injected into the ceca did not increase methane production; conversely, it tended to decrease methane production. The present study suggests that formic acid may be converted to methane in the ceca, and that acetic acid may not be a precursor of methane in the ceca of geese.

Isolation, identification, and complete genome sequence of an avian reticuloendotheliosis virus isolated from geese

Naturally occurring lymphoreticular tumors in geese have been found from time to time in Taiwan, but their etiology has not been determined except through morphological descriptions. This study observed a reticuloendotheliosis virus (REV) infection occurring in a white Roman goose ( Anser anser) farm in Yunlin, Taiwan in 2006. These geese showed growth-retarded and nodular lymphoma-like tumors in the liver, lung, kidney, and pancreas. Thirty blood samples were taken for REV detection and 21 (70%) of them contained REV genetic sequences using polymerase chain reaction (PCR). Virus isolation was attempted from 11 blood samples by inoculating the buffy coat onto DF1 cells. Nine (81%) REVs were isolated after three blind passages. The complete proviral sequence from one isolate was determined for phylogenetic analysis by direct sequencing using overlapping PCR products. The length of the provial genome is 8284 nucleotides. By comparing with other published REV complete sequences, the nucleotide percent identity ranged from 93.5% to 99.8% with most LTR varieties, ranging from 74.9% to 99.8%. The present isolated goose REV is most close to REV APC-566, a REV isolated from Attwater's Prairie chickens.