The body composition and metabolic status of twin- and triplet-bearing ewes and their fetuses in late pregnancy     

P.R. Kenyon  K.J. Stafford  C.M.C. Jenkinson  S.T. Morris  D.M. West 《Livestock Science》2007,107(2-3):103-112

This study investigated the body composition and metabolic status of twin- and triplet-bearing ewes and their fetuses in late pregnancy. The aim was to identify factors that could explain the lower survival rates of triplet lambs compared with twin lambs. Ten twin- and 10 triplet-bearing ewes and their fetuses were euthanased on either day 139 or 140 of pregnancy and fetal and placental measurements recorded. The weights of the gravid uterus (P < 0.01) and mammary gland (P < 0.05) were significantly heavier (although not proportionally), in triplet-bearing than twin-bearing ewes (21.10 vs. 16.85 and 1.08 vs. 0.80 kg respectively). There were no other differences in the weight of ewe organs or in metabolite concentrations. The number of cotyledons per triplet fetus was significantly (P < 0.001) less compared to twins although this was countered by a tendency for greater (P = 0.05) individual cotyledon weight, resulting in no differences in either total fetal membrane plus cotyledon or total cotyledon weights.

The absolute weight of many organs were significantly (P < 0.05) heavier in twin fetuses than in triplet fetuses. However, after correction for fetal body weight the only differences observed were significantly (P < 0.05) lighter, by approximately 10%, semitendinosus muscle, liver and heart weights in triplet compared to twin fetuses (6.2 vs. 5.6, 88.9 vs. 80.4, 33 vs. 30 g respectively). The fetal fructose concentrations were significantly (P < 0.05) lower in triplet than in twin fetuses.

The mean weight of the lightest triplet fetus within each triplet set was 31% lighter than that of the heaviest triplet (P < 0.05), resulting in significantly (P < 0.05) lighter absolute weights of most fetal measurements taken. However, after correction for fetal body weight these differences disappeared. Within twin sets, the mean weight of the lightest fetus was only 16% lighter (P < 0.05) than its heavier counterpart but there were no significant differences in absolute organ weights. When corrected for fetal body weight, the lightest twin fetus had significantly (P = 0.05) greater kidney weights and tended to have heavier heart (P = 0.07) and lungs (P = 0.07). It is unknown why the relative organ weight relationships between the heaviest and lightest differ between twin and triplet fetuses.

In conclusion this study has identified three factors which may contribute to the lower survival rates observed in triplet-compared to twin-born lambs; low fructose concentrations, lighter fetal weights, especially in one fetus within each triplet set, and maternal mammary gland increases that are not proportional to the increase in numbers of fetuses. While these findings are not novel, there were no other factors identified that could account the lower survival rates reported in triplet-born lambs compared to twins. The other only other significant differences identified were the proportionally lighter livers and hearts in triplets although the possible effects of these on survival is unknown.  相似文献   

Plasma metabolite concentrations and hepatic enzyme activities in pregnant Romney ewes with restricted feeding     

Tanaka Y  Mori A  Tazaki H  Imai S  Shiina J  Kusaba A  Ozawa T  Yoshida T  Kimura N  Hayashi T  Kenyon PR  Blair H  Arai T 《Research in veterinary science》2008,85(1):17-21

Plasma metabolite concentrations and activities of enzymes related to energy metabolism in plasma, peripheral leukocytes and liver of pregnant Romney ewes with restricted feeding were measured to assess those metabolites and enzymes as indicators for evaluating metabolic conditions in the ewes. The body weights and plasma lactate concentrations of the low-feeding ewes (about 1.0 times maintenance) were significantly lower than those of the high-feeding ewes (about 1.5 times maintenance). There were no significant differences in plasma protein, glucose, triglyceride, cholesterol, pyruvate and immunoreactive insulin concentrations and plasma and leukocyte enzyme activities between both groups. Hepatic malate dehydrogenase activities were significantly higher and hexokinase activities were significantly lower in the low-feeding ewes than in the high-feeding ewes. Restricted feeding could maintain pregnancy and some plasma metabolites and peripheral leukocyte enzymes may be useful indicators for evaluating metabolic changes in ewes.  相似文献   

Changes in metabolite, energy metabolism related enzyme activities and peripheral blood mononuclear cell (PBMC) Populations in beef heifers with two differing liveweight change profiles in New Zealand     

Mori A  Kenyon PR  Mori N  Yamamoto I  Tanaka Y  Suzuki N  Tazaki H  Ozawa T  Hayashi T  Hickson RE  Morris ST  Blair H  Arai T 《Veterinary research communications》2008,32(2):159-166

Metabolite and immunoreactive insulin (IRI) concentrations, energy metabolism related enzymes activities and peripheral blood mononuclear cell (PBMC) populations were measured in blood of pregnant Angus heifers with differing liveweight change profiles (gaining or losing), in New Zealand to investigate the meanings of those parameters in the restricted feeding beef heifers. Beef heifers losing liveweight (−412 g/day) showed significantly lower concentrations of plasma IRI, and higher concentrations of plasma free fatty acid (FFA) than heifers gaining liveweight (483 g/day). The cytosolic and mitochondrial malate dehydrogenase (MDH) activities and MDH/lactate dehydrogenase (M/L) ratio in leukocytes of the liveweight losing heifers were significantly higher than those the liveweight gaining heifers. Percentages of cluster of differentiation (CD) 3 positive cells and natural killer (NK) cells in PBMC decreased significantly in the liveweight losing heifers compared to those in the liveweight gaining heifers. Plasma IRI and FFA concentrations, leukocyte cytosolic and mitochondrial MDH activities and CD3 positive and NK cell populations may be useful markers to evaluate metabolic conditions and immunity in the restricted feeding beef heifers.  相似文献   

Effect of the ratio of teaser rams used prior to breeding on the reproductive performance of ewe hoggets     

Kenyon PR  Morel PC  Morris ST  Burnham DL  West DM 《New Zealand veterinary journal》2007,55(6):342-345

AIM: To determine the effects of the ratio of vasectomised (teaser) rams to ewe hoggets used prior to breeding on the breeding performance and pregnancy rate of ewe hoggets. METHODS: Romney-composite ewe hoggets (n=1,180), 7-8 months of age, were randomly assigned to one of five treatment groups (Day 1) and either exposed to harnessed teaser rams at a teaser-ram:ewe-hogget ratio of 1:32 (n=193 hoggets), 1:66 (n=199), 1:98 (n=197), or 1:197 (n=395), for 17 days prior to the breeding period, or not exposed to teasers (unteased; n=196). Harnessed entire rams were then introduced for the duration of two oestrous cycles (34 days). Using crayon marks, ewe hoggets were identified as having been mated during the first 17 days only, during the second 17 days only, during both 17-day periods, or not mated. Hoggets were weighed on Days 1 and 18. All ewe hoggets were scanned for pregnancy using ultrasound, 57 days after the end of the breeding period. RESULTS: Hogget groups did not differ in liveweight at Day 1, but at Day 18 hoggets exposed to teasers at a ratio of 1:66 were lighter, and those exposed to teasers at a ratio of 1:32 were heavier than all other groups by up 3.0 kg (p<0.05). Unteased ewe hoggets were less likely to be pregnant to the first 17 days of breeding compared with all teased groups, by at least 16.4% (p<0.05). Over the entire 34-day breeding period, however, only those teased at a ratio of 1:32 were more likely to be pregnant, by 11.9%, than unteased hoggets (p<0.05). Within the teased hogget groups, there were no differences between groups for either the percentage mated in the first 17 days of breeding only, or those pregnant to either the first 17 days of breeding only or the entire breeding period. CONCLUSIONS: The results of this study indicate that teaser-ram:ewe-hogget ratios as high as 1:197 can increase the percentage of ewe hoggets bred in the first 17 days of mating by at least 16.4%. Across the range of ratios used there was little difference in breeding pattern or pregnancy rate, although results might suggest ratios 1:98.  相似文献   

Comparison of plasma metabolite concentrations and enzyme activities in beef cattle raised by different feeding systems in Korea, Japan and New Zealand   总被引：2，自引：0，他引：2  

Mori A  Urabe S  Asada M  Tanaka Y  Tazaki H  Yamamoto I  Kimura N  Ozawa T  Morris ST  Hickson R  Kenyon PR  Blair H  Choi CB  Arai T 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2007,54(7):342-345

Concentrations of metabolites and immunoreactive insulin (IRI) and activities of enzymes related to energy metabolism were measured in plasma of Korean and Japanese beef cattle, which were raised by the indoor feeding system programmed to feed larger amount of roughage in their growing periods and larger amount of concentrate diet in their finishing periods (Japanese feeding system), and grazing New Zealand beef cattle. By the Japanese beef grading system, Korean and Japanese beef cattle showed high beef quality score, average grade 3.3 and 3.6, respectively. The plasma free fatty acid and lactate concentrations and lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and aspartate aminotransferase (AST) activities in Korean beef cattle were significantly higher than those in Japanese beef cattle. The plasma lactate concentration in Korean beef cattle was 8.40 mmol/l, which was similar to the values observed in lactic acidosis. The higher activities of plasma LDH, MDH and AST may indicate slight liver damage by slightly acidotic conditions in Korean beef cattle. New Zealand beef cattle fed on pasture which they harvest by grazing showed significantly lower plasma glucose, cholesterol, lactate and IRI concentrations and enzyme activities than those in Korean and Japanese beef cattle fed on larger amount of concentrate diets. Plasma metabolite concentrations and energy metabolism-related enzyme activities may be good indicators for evaluating metabolic conditions of beef cattle raised by different feeding systems.  相似文献   

Rates of behavior and aging specified by mitochondrial function during development   总被引：2，自引：0，他引：2  

Dillin A  Hsu AL  Arantes-Oliveira N  Lehrer-Graiwer J  Hsin H  Fraser AG  Kamath RS  Ahringer J  Kenyon C 《Science (New York, N.Y.)》2002,298(5602):2398-2401

To explore the role of mitochondrial activity in the aging process, we have lowered the activity of the electron transport chain and adenosine 5'-triphosphate (ATP) synthase with RNA interference (RNAi) in Caenorhabditis elegans. These perturbations reduced body size and behavioral rates and extended adult life-span. Restoring messenger RNA to near-normal levels during adulthood did not elevate ATP levels and did not correct any of these phenotypes. Conversely, inhibiting respiratory-chain components during adulthood only did not reset behavioral rates and did not affect life-span. Thus, the developing animal appears to contain a regulatory system that monitors mitochondrial activity early in life and, in response, establishes rates of respiration, behavior, and aging that persist during adulthood.  相似文献   

Molecular characterization,comparison of screening methods,and evaluation of cross‐pathogenicity of black rot (Xanthomonas campestris pv. campestris) strains from cabbage,choy sum,leafy mustard and pak choi from Taiwan          下载免费PDF全文

R. R. Burlakoti  J.‐R. Chen  C.‐F. Hsu  P. Burlakoti  L. Kenyon 《Plant pathology》2018,67(7):1589-1600

Choy sum (Brassica rapa var. parachinensis), leafy mustard (Brassica juncea) and pak choi (B. rapa var. chinensis) are highly nutritious components of diets in Taiwan and other Asian countries, and bacterial black rot caused by Xanthomonas campestris pv. campestris (Xcc) is a major biotic constraint in these crops. As very little was known about the Xcc strains from these crops in these regions, including their cross‐pathogenicity and aggressiveness on different hosts, Xcc strains were obtained from cabbage (Brassica oleracea var. capitata), choy sum, leafy mustard and pak choi crops in Taiwan. Two previously published PCR‐based assays reliably distinguished the Xcc strains from other Xanthomonas species and subspecies. Phylogenetic analysis based on repetitive sequence‐based PCR assays placed the Xcc strains in a clade distinct from other Xanthomonas species, and also showed host specificity. Although all of the Xcc strains from the different host species were pathogenic on all five Brassica test species in both a detached leaf assay and an intact plant assay, in the intact plant assay they showed differences in virulence or aggression on the different test hosts. The Xcc strains from leafy mustard and pak choi were consistently highly aggressive on all the test host genotypes, but the strains from choy sum and cabbage were less aggressive on leafy mustard and choy sum. The intact plant assay proved more discriminating and reliable than the detached leaf assay for comparing the aggressiveness of Xcc strains on different host genotypes, and so, with the new Xcc strains isolated in this study, will be useful for screening leafy brassica germplasm accessions for resistance to black rot.  相似文献