Bovine lymphosarcoma in twin calves.

Lymphosarcoma in twin female calves, apparently the first to be observed in Canada, is reported here. Peripheral blood and cultured mononuclear cells of one of the calves showed aneuploidy of the chromosomes. No hematological or serological evidence of bovine leukemia virus infection was observed in the other members of the herd. Bovine leukemia virus infection of the leukemic cells could not be detected by electron microscopy or by tissue culture procedures. There is a need to clarify the relationship of the calf form of the disease to the adult form of enzootic bovine leukosis.     

Production of sexed calves from frozen-thawed embryos

Three experiments have been conducted with the aim of producing calves from frozen, sexed embryos by combining embryo splitting and cytogenetic methods. In the first experiment, the efficacy of the bisection technique was assessed by transcervical transfer of 10 monozygotic pairs of half embryos to 10 synchronised heifers. Thirteen calves were produced, including four sets of identical twins. In the second experiment, one of the halves of each of eight split embryos was transferred while the other was processed for sexing by identification of the sex chromosomes. In the third experiment, one of the halves from each of 28 embryos was frozen while the other half was used for sexing. Eleven of the 16 which were sexed have been transferred with the production of three calves of the predicted sex. The overall sexing rate was 60 per cent and the calving rate following transfer of sexed embryos was 60 per cent and 23 per cent for fresh and frozen halves respectively.     

Intestinal transmission of macromolecules in newborn dairy calves of different ages at first feeding

Four groups of eight newborn calves were used to study the intestinal transmission of colostral immunoglobulin from the intestinal lumen to the blood circulation. The first feed was given one, eight, 16 or 24 hours after birth. Thereafter, three feeds were given with eight hour intervals. All feeds were from the same pool of colostrum and the amount fed each time corresponded to 3 per cent of the calves birthweight. To estimate the transmission of macromolecules in each feed four different macromolecules were used as markers. For the first feed, the marker was bovine IgG, in the second FITC-dextran, in the third ovalbumin and in the fourth human serum albumin. Blood samples were taken eight hours after each feed and at one week old. There were no differences in transmission for the first feed although the calves varied in age between one and 24 hours, but in the second, third and fourth feeds the calves that received a first feed at one hour old, transmitted significantly more of the marker molecules than did the other three groups. The substantial transmission of macromolecules at the first feed in all four groups indicates that a base level of transmission capacity is maintained during the first 24 hours or longer and that, under certain conditions, acceptable passive immunisation is possible in calves given their first colostrum as late as 24 hours after birth.     

Uniformity of response of identical twin cattle to sporidesmin intoxication

Sixteen pairs of identical twin dairy calves were reared together and at one year of age subjected to a test of uniformity of response to sporidesmin intoxication. The response was measured by scoring livers for toxic injury and by measuring serum gamma-glutamyltransferase at weekly intervals after dosing. Within pair variance in serum gamma-glutamyltransferase was greatest at two and six weeks after sporidesmin dosing when enzyme levels were rising and falling. Within twin variance and the interclass correlation coefficients were least and greatest respectively at five weeks after dosing. At five weeks the GGT correlation coefficient was 0.89 and for liver injury score 0.76. High consistency among twins of a pair, compared with differences among pairs indicates a high relative efficiency in using identical twins rather than singles for experimental work (approximately x 5). It is also consistent with a high heritability of resistance to sporidesmin intoxication in dairy cattle.     

Conjoined twin calves: A case report and cytogenetic considerations

Summary

A case of bovine embryonic duplication is described The genetic sex of each of the conjoined twin calves was determined mainly as a result of ambiguity in the phenotypic sex of one of the twins. Chromosome analysis was based on fibroblast cultures initiated from skin tissue.

Although genetically isosexual and therefore indicative of monozygosity, an alternative origin for isosexual twinning is highlighted The probable etiology of the conjoined twinning is discussed.     

Conjoined twin calves: a case report and cytogenetic considerations

A case of bovine embryonic duplication is described. The genetic sex of each of the conjoined twin calves was determined mainly as a result of ambiguity in the phenotypic sex of one of the twins. Chromosome analysis was based on fibroblast cultures initiated from skin tissue. Although genetically isosexual and therefore indicative of monozygosity, an alternative origin for isosexual twinning is highlighted. The probable etiology of the conjoined twinning is discussed.     

不同刺五加产品对哺乳犊牛消化道微生物区系的影响

刺加[Acanthopanax senticosus (Rupr.et Maxim.)Harms],又称五加参,主要药用部位是根、茎、叶,与人参同属五加科植物,其味辛、微苦、性温、无毒[1].近代研究发现,刺五加含有与人参等相似的多种皂苷、多糖、黄酮等药理成分,具人参样药理功效.此外刺五加中富含Zn、Fe、Ca等生命必需元素[2].     

不同年龄草地型藏羊屠宰性能及肉品质比较

选择15只1～6岁的甘南草地型藏羊进行屠宰性能和肉品质测定,比较不同年龄藏羊产肉力及食用品质优劣。结果表明:随着藏羊年龄的增长,屠宰指标相应变化。5岁时,宰前活重、胴体重分别达到64.50 kg和29.39 kg,4岁时屠宰率和眼肌面积分别为45.54%和20.86 cm2;1～3岁羯羊GR值较低,3岁之后脂肪含量逐渐增多。在肉品质指标中,5岁以上藏羊肌肉中氢离子浓度增高,不宜贮存过久;3～5岁的羯羊嫩度好,剪切力值低;1～3岁的藏羊失水率偏高,但熟肉率好;4～6岁藏羊的失水率低,但熟肉率较低。因此,从甘南草地型藏羊的肉用性能和肉品质指标来看,5岁之前的藏羊肉仍然有较好的利用价值。     

D-lactate production and excretion in diarrheic calves

The origin of D-lactate, the most important acid contributing to metabolic acidosis in the diarrheic calf, is unknown. We hypothesized that because D-lactate is produced only by microbes, gastrointestinal fermentation is the source. The objective of this study was to determine whether D-lactate production occurs in the rumen, colon, or both, and to measure D- and L-lactate concentrations in urine. Fecal, rumen, blood, and urine samples were obtained from 16 diarrheic and 11 healthy calves. Serum electrolyte concentrations were measured in both groups, and blood gas analyses were performed for diarrheic calves. All samples were analyzed for D- and L-lactate by high performance liquid chromatography (HPLC). Diarrheic calves were generally hyperkalemic with high serum anion gap, depressed serum bicarbonate, and low blood pH. L-lactate was markedly higher in rumen contents (22.7 mmol/ L [median]) and feces (8.6 mmol/L) of diarrheic calves than healthy calves (0.5 mmol/L and 5.1 mmol/L, respectively), but not different in serum or urine. Rumen, fecal, serum, and urine D-lactate concentrations were all significantly higher (P < .05) in diarrheic calves (17.0, 25.4, 13.9, and 19.2 mmol/L, respectively) than in healthy calves (0.5, 9.1, 1.4, and 0.5 mmol/L, respectively). Higher D-lactate concentrations in the rumen and feces of diarrheic calves suggests these sites as the source of D-lactate in blood and urine.     

The utilisation of various fats by turkeys of different ages.

1. The utilisation of fat and fatty acids supplied as maize oil, tallow or lard in the diet of 2-, 4- and 8-week old turkeys has been investigated: a mixture of 10% fat and 15% cellulose replaced glucose monohydrate in a low-fat basal diet. 2. At 2 weeks of age the absorbabilities of the fats were 96, 57 and 91% for maize oil, tallow and lard respectively; at 4 and 8 weekds of age the corresponding figures were 97, 70 and 92% and 98, 74 and 90%. 3. The unsaturated fatty acids (18:1, 18:2) were highly absorbed from all fats; this was true also of the saturated acids (16:0, 18:0) in the maize oil, but in lard and, especially, tallow the absorbability of these fatty acids was lower. 4. The effect of age on the utilisation of tallow could be explained by the improvement in the absorption of these fatty acids. 5. The determined and calculated ME values of the fats are given.     

Diprosopus in calves of different breeds

Three calves of the breeds German Holstein, German Angus and German Fleckvieh from three farms were born showing different forms of facial duplication. Two calves were classified as diprosopus with tetraophthalmus and in one calf a partial duplication of the forehead with a third nostril was observed. Further relatives of these affected calves or animals in the same herds were not affected by diprosopus. The calves with diprosopus were examined by means of clinical and pathological-anatomical methods. The increased occurrence of twin births and inbreeding could be of importance for the observed congenital anomaly, whereas conception early in life and conception during the winter months of the mothers of the affected calves are unlikely as reasons for the observed congenital anomaly of these calves. Even if the cases of diprosopus showed no increased frequency by paternal half sib groups, it is likely that diprosopus is genetically influenced and a larger number of genes may determine the phenotype.     

稀释液不同渗透压对鸡颗粒冷冻精液冻后活率的影响

用两种配方各10个渗透压水平配成的鸡精液冷冻稀释液,在各自不同的渗透压下进行冷冻试验。结果表明,基础液A液中活率最好的为渗透压6号液(0.383 3±0.021 1),并且差异显著(P<0.05),基础液B液效果最好的为6号液(0.425 0±0.085 8)与7号液(0.459 1±0.122 1),并且差异显著(P<0.05)。相关性分析发现鸡精液冻前活率与冻后活率存在强正相关且差异极显著(r=0.611,n=162,P<0.01)。     

Genotypic expression at different ages: II. Wool traits of sheep.

Genetic parameters for wool traits for Columbia, Polypay, Rambouillet, and Targhee breeds of sheep were estimated with single- and multiple-trait analyses using REML with animal models. Traits considered were fleece grade, fleece weight, and staple length. Total number of observations ranged from 11,673 to 34,746 for fleece grade and fleece weight and from 3,500 to 11,641 for staple length for the four breeds. For single-trait analyses, data were divided by age of ewe: young ages (age of 1 yr), middle ages (ages of 2 and 3 yr), and older ages (age greater than 3 yr). Heritability estimates averaged over breeds for fleece grade decreased from .42 at a young age to .37 for older ages. For fleece weight, heritability estimates averaged .52, .57, and .55 within the successively older groups. Heritability estimates for staple length averaged .54 for young and middle age classes. Few older ewes had staple length measurements. After single-trait analyses, new data sets were created for three-trait analyses with traits defined by three age classes when animals were measured. Heritability estimates with three-trait analyses, except for a few cases, were somewhat greater than those from single-trait analyses. For fleece grade, the genetic correlations averaged over breeds were .72 for young with middle, .42 for young with older, and .86 for middle with older age classes. For fleece weight, the average genetic correlations were .81, .83, and .98. For staple length, the average genetic correlation for young with middle age classes was .82. Estimates of genetic correlations across ages varied considerably among breeds. The average estimates of correlations suggest that fleece grade may need to be defined by age, especially for the Columbia and Rambouillet breeds. For fleece weight and staple length, however, the average correlations suggest no need to define those traits by age.     

Genotypic expression at different ages: I. Prolificacy traits of sheep.

Genetic parameters for prolificacy traits for Columbia (COLU), Polypay (POLY), Rambouillet (RAMB), and Targhee (TARG) breeds of sheep were estimated with REML using animal models. Traits were number of live births (LAB), litter size at birth (LSB) and weaning (LSW), and litter weight weaned (LWW). Numbers of observations ranged from 5,140 to 7,095 for prolificacy traits and from 5,101 to 8,973 for litter weight weaned for the four breeds. For single-trait analyses, ewes were classified as young (1 yr old), middle-aged (2 and 3 yr old), or older (> 3 yr old). After single-trait analyses, three-trait analyses were done for each characteristic with traits defined by age class. Generally, heritability estimates from single-trait analyses were low and ranged from .01 to .17 for LAB and LSB and from .00 to .10 for LSW. Heritability estimates obtained for LWW ranged from low to moderate (.00 to .25) and were less for older ewes. Heritability estimates from the three-trait analyses were generally similar to estimates from single-trait analyses. Heritabilities for LAB and LSB were similar, and, for three-trait analyses, they ranged across age groups from .07 to .13 for COLU, .13 to .16 for POLY, .10 to .16 for RAMB, and .01 to .16 for TARG. Estimates for LSW from three-trait analyses ranged from .07 to .12 for COLU, .04 to .09 for POLY, .01 to .11 for RAMB, and .03 to .11 for TARG. For LWW, heritabilities ranged from .00 to .21 for COLU, .05 to .08 for POLY, .12 to .15 for RAMB, and .18 to .29 for TARG. Genetic correlations for LAB, LSB and LSW among age-defined traits ranged from .25 to 1.00. Genetic correlations for LAB and LSB between young and middle and between young and older age classes were less than .80 in COLU, POLY, and RAMB breeds. Only genetic correlations between middle and older age classes for these breeds were greater than .80. For TARG, genetic correlations among all age classes were greater than .80 (.88 to 1.00) for those traits. All genetic correlations among ages for LSW were greater than .80 for POLY and TARG. For RAMB, only the correlation between young and older age classes for LSW was less than .80 (.45). None was greater than .80 for COLU. For LWW, genetic correlations among all age classes in POLY and RAMB were greater than .80 (.82 to 1.00). For COLU, genetic correlation between young and middle was low (.07), between young and older was high (.88), and between middle and older classes was moderately high (.54). For TARG, genetic correlations were .49, .65, and .98 for young-middle, young-older, and middle-older age classes, respectively. Results indicate that more progress could be made in selection programs for prolificacy traits in some sheep breeds by considering age of ewe as a part of the trait rather than by simply adjusting for ages of ewes.     

Gastrointestinal allergy to soyabean protein in preruminant calves. Antibody production and digestive disturbances in calves fed heated soyabean flour

Preruminant calves were fed heated soyabean flour as a constituent of a milk based diet. Within two weeks IgG and IgE antibodies specific for soyabean proteins appeared in their serum. To measure the rate of flow of digesta through the small intestine, other calves were cannulated in the abomasum and distal ileum. They were given single experimental feeds containing heated soyabean flour as the sole source of protein. The production of similar antibodies in these animals coincided with an increase in the rate of flow of digesta produced from an experimental feed. These results suggest the development of a gastrointestinal allergy to soyabean proteins.