Residues of carbaryl,lindane and monocrotophos on rice treated for control of rice bug, Leptocorisa oratorius (Fab.)     

A.M. Argente  E.A. Heinrichs 《Crop Protection》1983,2(3):361-369

This study investigated the correlation between insect mortality and insecticide residue levels in rice grain during the developing stages and at harvest, and also determined the relative toxicities of three insecticides, monocrotophos (Azodrin 16·8 EC), lindane (Agrocide 26 DP), and carbaryl (Sevin 85 WP) to Leptocorisa oratorius (Fab.), (Hemiptera: Alydidae). The insecticides were applied on field plots at 0·75 kg a.i./ha at the start of the milk stage of the developing grains. Sampling was conducted at 2 hours and 1, 2, 3, 4 and 5 days after spraying, which covered the milk stage to the soft dough stage. Mortality of insects exposed to the treated grain, the residue analysis of the treated grain during development and at harvest, and the LD₅₀s of the insecticides were determined. Monocrotophos was the most effective insecticide against the rice bug; lindane provided control for only one day; carbaryl was ineffective. Maximum residue levels of lindane and carbaryl in the harvested grains were below the established tolerance limits provided by FAO/WHO. There is no established tolerance for monocrotophos in rice.  相似文献   

Correlated response in litter size components in rabbits selected for litter size variability          下载免费PDF全文

M.J. Argente  E.W. Calle  M.L. García  A. Blasco 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2017,134(6):505-511

A divergent selection experiment for the environmental variability of litter size (Ve) over seven generations was carried out in rabbits at the University Miguel Hernández of Elche. The Ve was estimated as the phenotypic variance within the female, after correcting for year‐season and parity‐lactation status. The aim of this study was to analyse the correlated responses to selection in litter size components. The ovulation rate (OR) and number of implanted embryos (IE) in females were measured by laparoscopy at 12 day of the second gestation. At the end of the second gestation, the total number of kits born was measured (TB). Embryonic (ES), foetal (FS) and prenatal (PS) survival were computed as IE/OR, TB/IE and TB/OR, respectively. A total of 405 laparoscopies were performed. Data were analysed using Bayesian methodology. The correlated response to selection for litter size environmental variability in terms of the litter size components was estimated as either genetic trends, estimated by computing the average estimated breeding values for each generation and each line, or the phenotypic differences between lines. The OR was similar in both lines. However, after seven generations of selection, the homogenous line showed more IE (1.09 embryos for genetic means and 1.23 embryos for phenotypic means) and higher ES than the heterogeneous one (0.07 for genetic means and 0.08 for phenotypic means). The probability of the phenotypic differences between lines being higher than zero (p) was 1.00 and .99, respectively. A higher uterine overcrowding of embryos in the homogeneous line did not penalize FS; as a result, this line continued to show a greater TB (1.01 kits for genetic means and 1.30 kits for phenotypic means, p = .99, in the seventh generation). In conclusion, a decrease in litter size variability showed a favourable effect on ES and led to a higher litter size at birth.  相似文献   

Effects of intrauterine crowding on available uterine space per fetus in rabbits     

M.J. Argente  M.A. Santacreu  A. Climent  A. Blasco 《Livestock Science》2008,114(2-3):211-219

The aim of this study was to examine the effects of uterine crowding on available uterine space per fetus and fetal development at 18 days of gestation in unilaterally ovariectomized and intact does from the sixth generation of a divergent selection experiment on uterine capacity. Uterine capacity was estimated as litter size in unilaterally ovariectomized (ULO) does. Records from 37 ULO and 26 intact does were used. All does were slaughtered on d 18 of gestation. Ovulation rate per side in ULO does was almost twice as much as intact does (12.41 ova vs. 6.47 ova, P < 0.001). ULO does showed higher intrauterine crowding at implantation than intact does (9.36 implanted embryos/uterine horn vs. 5.31 implanted embryos/uterine horn, P < 0.001) and a lower available uterine space per live fetus (3.60 cm vs. 4.44 cm, P < 0.001). The available uterine space per embryo decreased quadratically with the number of implanted embryos (b₁ = − 2.46 ± 0.18, b₂ = 0.13 ± 0.01), and showed a negative linear regression coefficient with number of dead fetuses (− 0.18 ± 0.08). The available uterine space affects quadratically the development of the maternal placenta, and to a lesser extent is linearly related to the development of the fetus and its fetal placenta. The coefficients of these regressions were higher in ULO does than intact does, due to the higher degree of uterine overcrowding in these females.

Although the fetal position within the uterus did not affect the proportion of dead embryos, the uterine position could affect the survival of fetuses with a lower available uterine space. A poor blood supply had a negative effect on survival of the fetus and its development. Probability of death for fetuses with placenta receiving less than 3 blood vessels was higher than those receiving more than 3 blood vessels in both ULO and intact does (75.61% vs. 7.32%). Probability of survival asymptotically increases with available uterine space, as a result of the greater availability of uterine space which allows more blood vessels to reach each implantation site. The uterine overcrowding of ULO does was therefore associated with less uterine space and blood supply available at each implantation site, which could be related to higher fetal mortality in these females. Blood supply also affects fetal development. The implantation sites receiving less than 3 blood vessels showed lighter placentas (1.31 g vs. 1.41 g, P < 0.05) and fetuses (2.02 g vs. 2.12 g, P < 0.05) than those receiving more than 3 blood vessels in both ULO and intact does. These results suggest that available uterine space is a limitation component of fetal survival, which is related to an adequate vascular supply for nutrient exchange from the maternal to fetal blood streams and an adequate surface area for development of the placenta.  相似文献   

A Bayesian analysis of response to selection for uterine capacity in rabbits     

Blasco  Argente  Santacreu  Sorensen  & Bidanel 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2001,118(2):93-100

A divergent, eight generation selection experiment on uterine capacity in rabbits was performed. Rabbit does were ovariectomized unilaterally before puberty, and selected for increased and decreased litter size by 'best linear unbiased prediction' using data from up to four parities. Two different analyses were performed to estimate the response to selection. The first was based on least squares analysis; the second was based on Bayesian methods using Gibbs sampling techniques. Three different priors were used for variance components, but these had little influence on the results. Posterior means of heritabilities for uterine capacity, varied from 0.09 to 0.12, and repeatabilities from 0.18 to 0.22. The response to eight generations of selection was symmetrical and led to a divergence of 0.16 young rabbits per generation, which amounts to about 2% of the average litter size of the base population per generation. The pattern of response however, was not linear: a high initial response was followed by a period where little further response was observed, and a final burst of response was obtained during the last two cycles of selection.  相似文献   

Cereal type and heat processing of the cereal affect nutrient digestibility and dynamics of serum insulin and ghrelin in weanling pigs     

Menoyo D  Serrano MP  Barrios V  Valencia DG  Lázaro R  Argente J  Mateos GG 《Journal of animal science》2011,89(9):2793-2800

The effects of feeding corn or rice, either raw or heat processed (HP), on apparent total tract digestibility (ATTD) and apparent ileal digestibility (AID) of nutrients and on insulin and ghrelin concentrations in the serum were studied in young pigs. Pigs were weaned at approximately 23 ± 3 d of age and weighed 7.4 ± 1.2 kg. Each of the 4 treatments was replicated 9 times, and the experimental unit was a pig individually housed. Pigs (5 males and 4 females/treatment) were fed their respective diets ad libitum from 23 to 47 d of age. At 37 d of age, the effects of dietary treatments on the fasting and postprandial concentrations of insulin and total and acylated ghrelin were studied. The ATTD of OM, GE, and ether extract were, respectively, 4.3, 5.4, and 3.6% greater (P < 0.05) for the rice than for the corn diets, but CP digestibility was not affected. Similar results were observed for AID. Heat processing of the cereal increased (P < 0.05) the ATTD by 2.1% for OM, 3.2% for GE, 7.1% for ether extract, and 2.2% for CP and tended to increase the AID of CP (P = 0.06) and starch (P = 0.09). The postprandial serum insulin response was greater and was more prolonged in pigs fed raw rice than in pigs fed raw corn (P < 0.05). In addition, the effects of HP on serum insulin response were more pronounced with corn than with rice (cereal × HP, P < 0.05). Total ghrelin concentration was not affected by treatment, but acylated ghrelin was greater (P < 0.05) at 6 h postprandially in pigs fed rice than in pigs fed raw corn. Feeding rice and HP corn increased nutrient digestibility and insulin response in the early postprandial period and increased the acylated ghrelin response in the late postprandial period compared with feeding raw corn.  相似文献   

Relationships between uterine and fetal traits in rabbits selected on uterine capacity     

Argente MJ  Santacreu MA  Climent A  Blasco A 《Journal of animal science》2003,81(5):1265-1273

The aim of this study was to investigate whether uterine capacity (UC) in rabbits was related to uterine horn length and weight and whether these uterine traits and vascular supply were related to fetal development and survival. Data from 48 unilaterally ovariectomized (ULO) does of the High and 52 ULO does of the Low UC lines of a divergent selection experiment on UC were used. Does were slaughtered on d 25 of fifth gestation. The High line showed higher ovarian weight (0.08 g, P < 0.05) linked to a higher ovulation rate (1 ovum, P < 0.05) and greater length of the empty uterine horn. There were no differences between lines in the remaining doe traits. The number of implanted embryos and live fetuses, fetal survival, and uterine weight and length were positively associated and explained most of the observed variation. Average weights of the live fetuses and their fetal and maternal placentae were not related to uterine weight and length. The linear regression coefficient of full uterine horn length on the number of live fetuses was 2.43 +/- 0.21. The weight of the full uterine horn showed a small quadratic relationship (P < 0.05) with the number of live fetuses. Full uterine horn length, after adjusting for the number of embryos, was negatively associated (P < 0.001) with the number of dead fetuses. The linear regression coefficient of average fetal placental weight of the live fetuses on number of implanted embryos was higher (P < 0.10) in the Low line (-0.23 +/- 0.04 vs. -0.12 +/- 0.04). The linear regression coefficient of average weight of the live fetuses on the average weight of their fetal placentae was higher (P < 0.10) in the High line (2.56 +/- 0.47 vs. 1.27 +/- 0.57). The High line was more efficient, most likely because an increase in intrauterine crowding has a lesser effect on the development of fetal placentae and fetuses. The fetal position within the uterus did not affect the proportion of dead embryos. Fetuses with placentae receiving a single blood vessel had a higher probability of death (P < 0.001) and the lowest weight. There was no difference between lines for individual weight of the live fetuses, but the High line showed higher individual weights of fetal (P < 0.01) and maternal placentae (P < 0.10). Live fetuses in the midportion of the uterus were lighter in weight (P < 0.05) than in the oviductal and cervical regions (20.3 vs. 21.6 and 21.7g). Increasing uterine capacity increases uterine length and decreases weights of fetus and fetal placenta in rabbits.  相似文献