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This study compares two groups of 23 and 24 goats with different CSN1S1 genotypes, matched for lactation number and stage. During the first experimental period (4 weeks) half of the goats of each genotype received the control diet (CT) and the second half received a similar diet containing extruded linseed (EL diet). During the second experimental period, the two groups of goats were switched from the CT to the EL diet and from the EL to the CT diet, respectively. Results confirm the lower milk protein (-4.8 g/kg) and fat (-6.5 g/kg) concentrations in the low genotype group, whereas milk yield was slightly higher (+0.49 kg/d) and lactose concentration was unchanged. Between the genotype groups, there were differences in milk fat proportions of at least 25 FAs, particularly the C7 to C13 saturated FAs and C16:0, C18:0, C18:2n-6 and cis9,trans11-C18:2 acids. In addition, delta-9 desaturation ratios were higher in the low CSN1S1 group for C10:0, C14:0, C18:0, trans11-C18:1 and trans13-C18:1. This strongly suggests an effect on mammary delta-9 desaturase activity, especially for C18:0 and trans11-C18:1. It is likely that higher desaturation ratios in the low genotype, as well as observed changes in other FAs, could compensate for the lower synthesis of medium-chain FAs (C7:0-C13:0), thus contributing to maintenance of the melting point of milk fat in this genotype. The effect of the EL diet on milk FA proportions was highly significant for almost all FAs, along with increased milk fat content and decreased post-milking free FA concentration. Numerous interactions (significant but Of limited quantitative extent) between the CSN1S1 genotype and EL feeding were shown on milk composition, including 26 FA proportions or delta-9 desaturation ratios, and post-milking free FA concentration. (C) 2013 Elsevier B.V. All rights reserved.

Residual feed intake (RFI) has been explored as an alternative selection criterion to feed conversion ratio to capture the fraction of feed intake not explained by expected production and maintenance requirements. Selection experiments have found that low RFI in the growing pig is genetically correlated with reduced fatness and feed intake. Selection for feed conversion ratio also reduces sow appetite and fatness, which, together with increased prolificacy, has been seen as a hindrance for sow lifetime performance. The aims of our study were to derive equations for sow RFI during lactation (SRFI) and to evaluate the effect of selection for RFI during growth on sow traits during lactation. Data were obtained on 2 divergent lines selected for 7 generations for low and high RFI during growth in purebred Large Whites. The RFI was measured on candidates for selection (1,065 pigs), and sow performance data were available for 480 sows having from 1 to 3 parities (1,071 parities). Traits measured were sow daily feed intake (SDFI); sow BW and body composition before farrowing and at weaning (28.4 ± 1.7d); number of piglets born total, born alive, and surviving at weaning; and litter weight, average piglet BW, and within-litter SD of piglet BW at birth, 21 d of age (when creep feeding was available), and weaning. Sow RFI was defined as the difference between observed SDFI and SDFI predicted for sow maintenance and production. Daily production requirements were quantified by litter size and daily litter BW gain as well as daily changes in sow body reserves. The SRFI represented 24% of the phenotypic variability of SDFI. Heritability estimates for RFI and SRFI were both 0.14. The genetic correlation between RFI and SRFI was 0.29 ± 0.23. Genetic correlations of RFI with sow traits were low to moderate, consistent with responses to selection; selection for low RFI during growth reduced SDFI and increased number of piglets and litter growth, but also increased mobilization of body reserves. No effect on rebreeding performance was found. Metabolic changes previously observed during growth in response to selection might explain part of the better efficiency of the low-RFI sows, decreasing basal metabolism and favoring rapid allocation of resources to lactation. We propose to consider SRFI as an alternative to SDFI to select for efficient sows with reduced input demands during lactation.

Genetic trends for growth, feed efficiency, composition, and morphometry of carcasses were estimated in a French Large White (LW) pig population using frozen semen. Two groups of pigs were produced by inseminating LW sows with either stored, frozen semen from 17 LW boars born in 1977 or with semen from 23 LW boars born in 1998. In each group, 15 males and 90 females were randomly chosen and mated to produce approximately 1,000 pigs/group. These pigs were performance tested with individual ADFI and serial BW and backfat thickness measurements, slaughtered at 105 kg of BW, and measured for carcass traits. The data were analyzed using mixed linear animal models, including the fixed effect of the experimental group (offspring of 1977 or 1998 boars), the random effect of the additive genetic value of each animal, and, when significant, the fixed effects of sex, fattening batch, and slaughterhouse, the linear regression on BW, and the random effect of the common environment of birth litter. For each trait, the genetic trend was estimated as twice the difference between the 2 experimental groups. Results showed moderately favorable trends for on-test ADG (3.7 +/- 1.3 g/d per year) and feed conversion ratio (-0.014 +/- 0.005 kg/kg per year) in spite of a tendency toward an increase in ADFI (7.6 +/- 4.7 g/yr). A strong reduction in carcass fatness (-0.35 +/- 0.07 mm/yr for carcass average backfat thickness) and a large improvement in carcass leanness (0.31 +/- 0.10 mm(2)/yr and 0.41 +/- 0.08%/yr for loin eye area and carcass muscle content, respectively) were observed. Carcass shape measurements (back and leg length, back width, muscle thickness of hind limbs) were not affected by selection. Serial measurements of BW and backfat thickness showed that the major part of the genetic gains occurred during late growth and that the reduction in the backfat layer was more pronounced in the rear than in the front part of the carcass. The use of frozen semen appears to be a powerful practice to thoroughly investigate changes attributable to selection.

International audience; The objective of this study was to evaluate genetic and non-genetic factors influencing characteristics of young buck semen production using a multivariate model that takes into account the longitudinal structure of data. Data were collected from 1989 to 2002 at two French A.I. centres. The data corresponded to 13151 and 9206 ejaculates of 758 Alpine and 535 Saanen bucks respectively, collected at the beginning of the first breeding season (September–December). The semen volume, the total number of spermatozoa, the concentration, the motility score of spermatozoa after freezing and the percentage of motile spermatozoa after freezing were registered for each ejaculate. Within-breed heritabilities and repeatabilities were estimated using a multivariate animal model using a power spatial covariance structure for environmental effect. For all characteristics and the two breeds, the main source of variation was the year–month interaction that interacted with the centre. We observed a decrease in years of motility score after freezing. Age and frequency of collection had a significant effect on semen volume and number of spermatozoa for both breeds, and on concentration of spermatozoa for the Alpine breed. No effect of these factors was found on the characteristics observed after freezing. Heritabilities for concentration, number of spermatozoa, semen volume, motility score after freezing and percentage of motile spermatozoa after freezing per ejaculate were respectively, 0.32, 0.15, 0.25, 0.12 and 0.05 for the Saanen breed and 0.34, 0.25, 0.29, 0.17 and 0.03 for the Alpine breed. Genetic correlations between volume and number of spermatozoa were respectively, 0.74 for the Alpine breed and 0.86 for the Saanen breed. Further study is required to compare the semen characteristics of young bucks with their mature production.

The milking ability of Lacaune ewes was characterised by derived traits of milk flow patterns, in an INRA experimental farm, from a divergent selection experiment in order to estimate the correlated effects of selection for protein and fat yields. The analysis of selected divergent line effects (involving 34 616 data and 1204 ewes) indicated an indirect improvement of milking traits (+17% for maximum milk flow and -10% for latency time) with a 25% increase in milk yield. Genetic parameters were estimated by multi-trait analysis with an animal model, on 751 primiparous ewes. The heritabilities of the traits expressed on an annual basis were high, especially for maximum flow (0.54) and for latency time (0.55). The heritabilities were intermediate for average flow (0.30), time at maximum flow (0.42) and phase of increasing flow (0.43), and low for the phase of decreasing flow (0.16) and the plateau of high flow (0.07). When considering test-day data, the heritabilities of maximum flow and latency time remained intermediate and stable throughout the lactation. Genetic correlations between milk yield and milking traits were all favourable, but latency time was less milk yield dependent (-0.22) than maximum flow (+0.46). It is concluded that the current dairy ewe selection based on milk solid yield is not antagonistic to milking ability.

New transgenic pigs expressing combinations of regulators of complement activation and other molecules are needed to resist xenograft hyperacute rejection (HAR) and to further analyze and treat xenograft rejection. Double transgenic pigs for human CD55 (hCD55) and human CD59 (hCD59) using the promoter of the human elongation factor 1 alpha gene were generated, and their kidneys were transplanted into nonimmunosuppressed baboons. hCD55 and hCD59 were mainly expressed by the endothelial cells, and these cells showed increased resistance to complement-mediated lysis. Baboons receiving kidneys from hCD55hCD59 pigs survived for 5 and 6 days, and displayed alterations in coagulation. Thrombocytopenia and platelet microthrombi were present within the kidneys. Nontransgenic kidneys showed HAR in less than 2 days. Kidneys from pigs expressing hCD55hCD59 displayed protection against HAR in the absence of immunosuppression. Rejection was associated with coagulopathy leukocyte infiltration and a rebound of anti-alpha Gal antibodies.

Three experiments were carried out to evaluate the use of ultrasonography in assessing the onset of puberty in gilts. In experiment 1, gilts (n = 17) were scanned 3 times per week beginning at 133 and continuing until 187 days of age. The ultrasonic appearance of the uterus was described, quantified and compared with the reproductive status observed at slaughter. The quantification of the pictures showed a different correlation in time for infantile, impubertal, prepubertal and pubertal stages. For pubertal females, "uterine area" increased at around 180 days of age, well-defined sec- tions of the uterine horns appeared 3 ± 0.5 days before puberty. In infantile and impubertal gilts dur- ing the same period of age, uterine images remained dark and homogeneous; no significant change in the "uterine area" was observed. This difference in images allowed an evaluation of the diagnosis of puberty. In experiment 2, the gilts (n = 123) were scanned, the result was verified at slaughter the day after by examination of the genital tract. The uterine weight of the gilts that had reached a prepubertal or pubertal stage was significantly greater (P = 0.0001) than that in impubertal gilts. The sensitivity and the specificity of the diagnosis were 91.9% and 96.5% respectively. Experiment 3 was performed on a farm and echographic examinations were carried out one and five days after gilts (n = 117) arrived at the piggery. Oestrus detection or blood sampling for progesterone determina- tions were used as tools to determine the reproductive status. The sensitivity and the specificity of the diagnosis were 98.9% and 100% respectively. This diagnosis of puberty is thus accurate. pig / puberty / detection / ultrasonography

In large flocks of dairy ewes, classical concepts of animal feeding can no longer be applied because of the increasing variability of performances. Simplified feeding practices by means of generalised group-feeding rarely impair animal health and apparent productivity because many physiological regulations permit each animal to adapt to imperfect nutrient supply (either excess or deficit). However, in these conditions, predictions of ewe’s performances are almost impossible since animal responses to such a variation in nutrient balance is mostly unknown. In this paper, main production factors accounting for the variability of requirements are described and their usefulness is discussed with respect to the efficiency of allocation criteria into smaller sized group-feeding. In a trial, two identical small flocks of 96 ewes were either conducted together (Mixed) or separated in two groups according to milk yield (Separated-High n = 48 and Separated-Low n = 48). Within each group the feeding objective was to supply concentrates in order to satisfy 85 % of the ewes, with forages available ad libitum. After 100 days, for each of the two treatments ments (Mixed vs Separated), mean consumptions were very close and mean milk yield were non significantly different (resp. 171 vs 1751/100 d). Concentrate distribution could have been decreased in Separated-Low group to earn concentrate. That’s what was done in an on farm trial without control of forage intake. Comparison was made between a group (n = 67 ewes) receiving classical amounts of concentrate (Classical) while the other group was divided in four sub-groups receiving adjusted amounts of concentrates according to their milk yield by means of an electronic feeder. On the whole experimental period, mean milk yield were the same (Classical 284.6 1/180 d vs Adjusted 282.2 U180 d), with a difference of 51 kg concentrate less per ewe for adjusted treatments. The future of such techniques, in order to increase nutrient efficiency and performance of dairy ewes, will depend on the development of electronic recognition devices (individual feeding, electronic gates) and automated measurements (milk control, body weight)., Les techniques simplifiées d’alimentation collective mettent rarement en péril la santé des brebis ou leur productivité apparente, car de nombreuses régulations physiologiques leur permettent de s’adapter aux excès ou aux déficits alimentaires. Mais elles conduisent à un gaspillage d’aliments concentrés ou à une baisse des productions selon le niveau initial de performance de chaque brebis. La mise en lots des animaux en fonction de leurs besoins alimentaires est un moyen de mieux ajuster les apports alimentaires aux performances de production attendues. Les principaux facteurs de variation des besoins sont décrits et leur intérêt comme critère pour la constitution de lots homogènes est discuté. Deux essais de mise en lots ont été réalisés. Le premier comparait deux troupeaux de performances moyennes identiques, l’un dans lequel les brebis étaient conduites ensemble (Mélangées, n = 96), l’autre dans lequel les brebis étaient réparties en deux lots selon leur production laitière (Séparées-Bas, n = 48 et Séparées-Haut, n = 48). Au sein de chaque groupe les apports en concentrés ont été ajustés pour satisfaire les besoins de 85 % des brebis, les fourrages étant distribués à volonté. Après 100 jours d’essai les consommations totales de fourrages et de concentrés ont été identiques ainsi que les productions laitières moyennes (Mélangées : 171 vs Séparées : 1751/100 j). Pour économiser des concentrés, il aurait fallu diminuer plus fortement les apports aux brebis du lot Bas. C’est ce que nous avons fait dans un deuxième essai où les apports de concentrés ont été soit identiques pour toutes les brebis (conduite classique, n = 67), soit ajustés selon la production laitière, grâce à un distributeur automatique de concentré. Sur la période expérimentale, les productions laitières moyennes ont été identiques (Classique : 284,61/180 j vs Ajusté : 282,21/180 j), avec une distribution plus faible de concentré de 51 kg par brebis lorsque les apports sont ajustés. Les perspectives d’utilisation de telles techniques d’alimentation en lot dépendront des développements de l’identification électronique et de l’automatisation du contrôle de performances.

The objective of this study was to determine if administration of a set dose (10 mu g) of a gonadotropin-releasing hormone agonist, buserelin (Receptal; Rc), at set times after altrenogest (Regumate; RU) treatment or after weaning was able to induce and synchronize ovulation in female swine (gilts and sows). The pubertal (n = 187) gilts were allocated to four groups, all synchronized with RU. Group 1 (RU) was inseminated twice at detected estrus, Group 2 (RU+Rc120) and Group 4 (RU+Rc104) received 10 mu g Rc at 120 or 104 h after the end of RU treatment, respectively, and Group 3 (RU+eCG+Rc104) was treated with 800 IU equine chorionic gonadotropin (eCG) at 24 h and Re 104 h after the end of RU treatment, respectively. Gilts were inseminated twice at predetermined times, namely 144 and 168 h (Group 2), 128 and 144 h (Group 3), and 144 and 152 h (Group 4) after the end of RU treatment, respectively. Pregnant gilts were slaughtered at 30 d. Administration of Re 104 h after the end of RU feeding synchronized ovulation over a 24-h time window in 97.9% and 100% of the gilts of Groups 3 and 4, respectively, whereas Re administration at 120 h (Group 2) only successfully synchronized 88.9% of the gilts over 24 h. Ovulation rates of gilts of Groups 2 and 4 were similar to that of the control group. Pregnancy rates were numerically higher in Groups 2 and 3 (92% and 96%, respectively) compared with those of Groups I and 4 (84% and 81%, respectively). Combination of eCG with Re administration at 104 h (Group 3) increased ovulation rate (+4 CL) but decreased embryo survival to 62% at Day 30. The weaned sow experiment involved 61 sows of a range of parities (2.7 +/- 0.9), allocated to two control groups (Control 104 group and Control 94 group) and two treated groups (Re 104 group and Rc94 group), which received 10 mu g Re at 104 and 94 h after weaning, respectively. The females were inseminated at detected estrus. All pregnant sows farrowed. After treatment with Re 94 h after weaning, 100% of sows ovulated over a 24-h time window versus only 68.7% of controls. Farrowing rate and litter size of the sows treated with Re at that time were unaffected compared with that of control sows. In contrast, Re administration at 104 h after weaning may have been too late; only 66.7% of the treated sows ovulated during a 24-h period. This proportion was numerically lower but not significantly different than that for control sows. Farrowing rate and litter size of treated sows were not significantly different than that of controls. Administration of Rc at the dose and times selected in this study tightened synchrony of ovulation in gilts and in sows after weaning. It remains to be established if such a synchrony is suitable to obtain good fertility after a single artificial insemination at a predetermined time.

Prediction of the future fertility of a given ejaculate with a simple laboratory test is still considered a real issue in domestic mammal breeding. This study showed that a subjective assessment of the percentage of motile spermatozoa, measured 120 min after thawing (mob120), can predict a significant part (~50%) of the variation of the future fertility of buck ejaculates. The predictive model was calculated using a calibration data set composed of 40 ejaculates from four Alpine and six Saanen bucks. A fertility trial using split ejaculates was conducted in order to estimate ejaculate fertility. Taken into account were the herd within breed factor and the year, month, and inseminator factors. On average, one ejaculate was used to inseminate two females per herd in 10 different herds. This calibration set allowed us to choose the mob120 variable among a set of laboratory tests: mitochondrial activity, acrosomal status, membrane integrity, osmotic resistance test assessed by flow cytometry, velocity and motion characteristics assessed by computer-assisted sperm analysis, visually assessed percentage of motile, and motility score measured 5 and 120 min after thawing. For the calibration step, the best model used the logarithm of mob120 and gave a correlation coefficient of 0.71 between the field fertility and the predicted fertility and a standard error of 0.17. We tested this model on 3 different validation data sets adding up to 95 ejaculates that were all different from those of the calibration data set. The correlation coefficients between field fertility and predicted fertility were always significant and the bias corrected standard error ranged from 0.15 to 0.18 on these validation data sets. A Monte Carlo simulation showed that about 20% of the fertility variation remained to be explained.

Hypoosmotic swelling test (HOS) has been proposed by many authors to evaluate the functional integrity of the sperm membrane. Our approach in this experiment has consisted in exposing spermatozoa to a wide range of osmotic pressures then evaluating the reacted sperm cells by flow cytometry and finally modelling the sperm cell responses. Semen samples were diluted in skim milk or NPPC (native phosphocaseinate) extenders, and stored at 4 °C for 3 days. At D0 and D3 aliquots from each ejaculate (n = 12) were submitted to seven hypoosmotic solutions varying from 230 to 10 mOsm/kg. Sperm samples were analyzed using flow cytometry to determine two populations of spermatozoa identified by propidium iodide (PI): PI+ (including PI, red fluorescence) and PI− (excluding PI, no fluorescence). Spermatozoa PI+ were considered as spermatozoa with membrane damages. PI+ exhibited a high variation from 230 to 10 mOsm/kg which was considered as a dose–response curve. Data were modelled using Mixed procedure and probit analysis to a sigmoid curve. Each model curve characterized the profile of response of the variable PI+ to the range of osmotic pressure from 230 to 10 mOsm/kg. The estimated parameters modelling the sigmoid curves are discussed in order to evaluate the effect of extender (skim milk versus NPPC) and duration of preservation (D0 versus D3). Such modelling could help to differentiate storage method ejaculates within males or between male, contributing therefore to improve semen technology.

The storage of frozen semen for artificial insemination is usually performed in the presence of egg yolk or skimmed milk as protective agents. In goats, the use of skimmed milk extenders requires, however, that most of the seminal plasma is removed before dilution of spermatozoa because it is deleterious for their survival. It has been previously demonstrated that a lipase (BUSgp60) secreted by the accessory bulbourethral gland was responsible for the cellular death of goat spermatozoa, through the lipolysis of residual milk lipids and the release of toxic free fatty acids. This lipase was purified from the whole seminal plasma of goat and was found to display both lipase and phospholipase A activities, this latter activity representing the main phospholipase activity detected in goat seminal plasma. Based on its N-terminal amino acid sequence, identical to that of BUSgP60 purified from bulbourethral gland secretion, and the design of degenerated oligonucleotides, the lipase was cloned from total mRNA isolated from bulbourethral gland. DNA sequencing confirmed it was the goat pancreatic-lipase-related protein 2 (GoPLRP2). The physiological role of GoPLRP2 is still unknown but this enzyme might be associated with the reproductive activity of goats. A significant increase in lipase secretion was observed every year in August and the level of lipase activity in the semen remained high till December, i.e., during the breeding season. A parallel increase in the plasmatic levels of testosterone suggested that GoPLRP2 expression might be regulated by sexual hormones. The lipase activity level measured in goat seminal plasma, which could reach 1000 U/ml during the breeding season, was one of the highest lipase activity measured in natural sources, including gastric and pancreatic juices.

New transgenic pigs expressing combinations of regulators of complement activation and other molecules are needed to resist xenograft hyperacute rejection (HAR) and to further analyze and treat xenograft rejection. Double transgenic pigs for human CD55 (hCD55) and human CD59 (hCD59) using the promoter of the human elongation factor 1 alpha gene were generated, and their kidneys were transplanted into nonimmunosuppressed baboons. hCD55 and hCD59 were mainly expressed by the endothelial cells, and these cells showed increased resistance to complement-mediated lysis. Baboons receiving kidneys from hCD55hCD59 pigs survived for 5 and 6 days, and displayed alterations in coagulation. Thrombocytopenia and platelet microthrombi were present within the kidneys. Nontransgenic kidneys showed HAR in less than 2 days. Kidneys from pigs expressing hCD55hCD59 displayed protection against HAR in the absence of immunosuppression. Rejection was associated with coagulopathy leukocyte infiltration and a rebound of anti-alpha Gal antibodies.

The present study was designed to determine the effect of pooling embryos from two donors on the reproductive success of transfer of vitrified/warmed porcine blastocysts. Intact blastocysts were collected from superovulated Large White Hyperprolific gilts (n = 24) on Days 5-5.5 after artificial insemination. Embryos were recovered by flushing the uterine horns, and unhatched blastocysts were selected. Vitrification and warming were performed as described by Berthelot et al. [Cryobiology 41(2000) 116]. To evaluate in vitro development, 37 vitrified/warmed blastocysts were cultured, non-vitrified embryos (n = 48) were used as controls. Embryo transfers were conducted in asynchronous (-24 h) Meishan gilts (n = 20). Twenty vitrified/warmed blastocysts were surgically transferred into one uterine horn. Ten recipients received embryos from one donor (Group 1) and the other 10 transfers were performed with mixed embryos from two donors (Group 2). Pregnancy was assessed ultrasonographically at Day 25 after estrus and recipients were slaughtered at Day 30 after transfer. In vitro survival rate of the vitrified/warmed blastocysts was lower (P0.01) than that from control embryos (73.0% versus 93.7%). The pregnancy rate for Group 1 (70%) was not different (P0.05) than that from Group 2 (90%). No significant differences were detected between Groups 1 and 2 for in vivo embryo development (number fetuses/transferred embryos in pregnant recipients) or in vivo embryo survival (number viable fetuses/transferred embryos in pregnant recipients). However, the in vivo efficiency (number viable fetuses/total transferred embryos) was higher (P0.05) when transfers were performed with embryos from two donors (19.5% versus 30.5%). These results indicate that pooling embryos from two donors increases the in vivo efficiency after transfer of vitrified/warmed porcine blastocysts.

The aims of this study were: (1) to evaluate the effect of the number of previous estrus of recipient gilts on effectiveness of intrauterine insertion of a flexible catheter designed for non-surgical deep intrauterine catheterization during diestrus in pigs; and (2) to determine the farrowing rate and the litter size after non-surgical deep intrauterine embryo transfer (ET) of porcine blastocysts vitrified by the open pulled straw (OPS) method. In experiment 1, 27 large white hyperprolific gilts (LWh) with 2–6 previous estrus were used. Intrauterine insertions of the flexible catheter were carried out at day 5.5–6 of the estrous cycle (D0 = onset of estrus). During insertions, no or only moderate reactions were observed in 88.9% of gilts and was not related (P > 0.05) to the number of estrus prior to the insertion periods. The number of the estrus had a significant effect (P < 0.05) on the difficulties found during the procedure. In the 100% of gilts with two estrus (N = 6) it was not possible to insert the flexible catheter through the cervix. In gilts with three or more estrus, it was possible to pass the cervix and to progress along a uterine horn in 80.9% of the cases. In 86.7% of the gilts, the tip of the flexible catheter achieved the second or third quarter of the uterine horn. In experiment 2, following non-surgical deep intrauterine transfer of 20 vitrified/warmed blastocysts, 9 Meishan recipients (42.9%) farrowed an average of 5.4 ± 0.8 piglets (range 3–9) of which 0.6 ± 0.3 piglets (range 0–2) were born dead. In conclusion, this study shows that it is possible to obtain birth of piglets following non-surgical deep intrauterine embryo transfer (ET) of vitrified/warmed blastocysts. Non-surgical deep intrauterine ET and OPS vitrification methods are promising procedures to be used together for the introduction of new genetic material in a farm.

Sperm cryopreservation is used for preservation and diffusion of genetic diversity and genetic progress. One approach to improve cryopreservation is to identify and control the cellular parameters responsible for intrinsic sperm fitness for cryopreservation. The aim of this study was to determine if a relationship exists between sperm cholesterol/phospholipid molar ratio (CHO/PL) and sperm fitness for cryopreservation. CHO/PL in goat and boar semen were respectively 0.281 ± 0.048 (n = 112) and 0.375 ± 0.043 (n = 47). CHO/PL of washed stallion spermatozoa was 0.541 ± 0.072 (n = 17). In stallion spermatozoa and goat semen, CHO/PL and sperm motility after thawing were negatively correlated, although the significance of this relation fluctuated between ejaculates (stallion) and between months of collection (goat). In boar, mobility parameters after thawing were not related to CHO/PL, but a positive correlation was noted between CHO/PL and the percentage of spermatozoa alive and normal 120 min after thawing. No relationship was found between blood plasma cholesterol (goat: 1160 nmol.mL(−1) ± 186; boar: 1410 nmol.mL(−1) ± 200) or seminal plasma cholesterol (boar sperm rich fraction: 104 nmol.mL(−1) ±52) and sperm CHO/PL. To conclude, sperm CHO/PL is not a direct indicator of sperm fitness for cryopreservation. However, as supported by the observed correlation, it could not be ruled out that CHO/PL is involved in the cryopreservation success.

Two methods for the determination of ovulation were compared to one ultrasonography performed 5 times a day. Time of ovulation by echography was 40 ± 5.8 h (mean ± SD) after the onset of oestrus. Preovulatory LH rise (two blood samples per day) began near the onset of oestrus but, in our conditions, this parameter could not be used to predict ovulation. The basal level of progesterone (two blood samples per day) was determined with a non-linear model, the timing when progesterone rose more than one SD (0.3 ng.mL -1 ) coincided with the timing of ovulation determined by echography (R 2 = 0.98). This method was efficient and was used in a field trial to measure the consequences of the variability of the interval between AI and ovulation on litter size. The interval between AI and ovu- lation had an effect on litter size; litter size decreased by one piglet when this interval increased by 10 h. pig / progesterone / echography / ovulation / prolificacy

Three methods for estimating in vivo body fat in sheep, by the assessment of body water using the deuterium oxide (Ddilution technique, adipose cell size (ACS) measurement and body condition scoring (BCS), were studied in mature ewes and compared to results obtained after slaughter and chemical analyses. Twenty Lacaune dairy ewes were slaughtered at three stages of lactation (30 days (n = 8), 60 days (n = 8) and 110 days (n = 4)), with a mean body weight (BW) of 72.7 ± 7.6 kg, 16.0 t 4.7 kg of body lipids (LIP) and 42.7 ± 3.8 kg of total body water. Body fatness ranged from 10.3 to 28.8 % of empty body weight. Although the ewes were relatively fat, the mean adipose cell volume of subcutaneous pericaudal or sternal adipose tissue (209 or 287 pl, respec- tively) was in the lower range of previously reported values, while cells from omental adipose tissue had a larger mean volume (804 pl) than has been previously reported. Due to differences in the frame of ewes, prediction of body lipids through D,O, ACS and BCS was improved by including body weight in the model. The best equations using ACS were obtained with subcutaneous fat tissues (sternal tissue: residual coefficient of variation (rCV) = 13.9 % and pericaudal: rCV = 17.8 %), fol- lowed by internal tissue (omental: rCV = 19.5 %). The rCVs of the prediction of body lipids with these in vivo methods were in general agreement with published works on cattle or sheep i.e. D 8.8 %, pericaudal ACS: 13.9 % and BCS: 16.7 %. The interest and limitations of the methods studied are dis- cussed in terms of different experimental objectives and constraints. (© Elsevier / Inra)

The present study was designed to determine the effect of pooling embryos from two donors on the reproductive success of transfer of vitrified/warmed porcine blastocysts. Superovulated Large White hyperprolific gilts (n=24) were used as embryo donors. Gilts were artificially inseminated 12 and 24h after initial detection of estrus using fresh semen, and slaughtered on Days 5.5 to 6 of the estrous cycle (Day 0=Onset of estrus). Embryos were recovered by flushing the uterine horns, and unhatched blastocysts were selected. Vitrification and warming were performed as reported previously (Berthelot et al., 2000 Cryobiology 41, 116–124). Embryo transfers were conducted in asynchronous (−24h) Meishan gilts (n=20). Twenty vitrified/warmed blastocysts were surgically transferred into one uterine horn. Ten recipients received embryos from one donor (group 1) and the other ten transfers were performed with mixed embryos from two donors (group 2). Pregnancy was assessed ultrasonographically at Day 25 after estrus and recipients were slaughtered five days later. The pregnancy rate from the different groups was compared using Fisher exact test. The GLM procedure of SAS was used to determine the effect of the origin of embryos (one or two donors) on the number of developed fetuses and viable fetuses at Day 30 of pregnancy. The ovulation rate was 32.5±11.8 (mean±SD). The total number of embryos collected was 634, of which 57 (9.0%), 36 (5.7%), 513 (80.9%) and 28 (4.4%), were unfertilized oocytes and degenerated embryos, morulae, unhatched blastocysts and hatched blastocysts, respectively. The ratio of collected embryos to the number of corpora lutea was 81.3%. The pregnancy rate for group 1 (70%) was not different (P>0.05) than that for group 2 (90%). No significant differences were detected between group 1 and group 2 for in vivo embryo development (number fetuses/transferred embryos in pregnant recipients; 33.3% v. 40%) or in vivo embryo survival (number viable fetuses/transferred embryos in pregnant recipients; 27.9% v. 33.9%). However, the in vivo efficiency (number viable fetuses/total transferred embryos) was higher (P

Le pâturage des prairies par les caprins, pratique traditionnelle délaissée lors du processus d'intensification, est un moyen de répondre aux enjeux émergents et futurs. La conduite du pâturage a fait l'objet de divers travaux, prenant en compte les particularités des caprins (notamment leur comportement alimentaire et leur sensibilité aux parasitisme), rassemblés dans ce n° thématique. D'autres études de Recherche et Développement sont également en cours à l'initiative de la filière caprine, en partenariat étroit entre recherche et professionnels.

National audience; In western France, which concentrates over half of the country's capacity in terms of dairy goat production, livestock farms have gradually turned to intensive farming over the last 10 years, thereby significantly increasing their need for purchased input. Professional goat farming organizations have recently implemented 2 coordinated Research and Development schemes. The Patuchev platform is an experimental facility aimed at developing and assessing innovative goat farming systems, essentially based on comparing 3 types of systems : one based onpasture with parturition at the end of the winter, and 2 others based on parturition in the autumn, one herd grazed on grassland and the other fed on hay indoors. The REDCap scheme will be surveying 34 volunteer goat farms with an aim to improving grazing practices and feed self-sufficiency. The 2 projects are being conducted by 2 different organizations, but with a strong wish to work in interaction with each other, and all those involved.; Dans le bassin caprin laitier de l'ouest de la France, qui concentre plus de la moitié de la production nationale, les élevages se sont intensifiés depuis 10 ans, en accroissant fortement leurs achats d'intrants. La filière caprine vient de mettre en place 2 dispositifs de Recherche et Développement coordonnés. Ces 2 dispositifs s'inscrivent dans un contexte en évolution qui encourage les systèmes plus autonomes et économes. La plate-forme Patuchev est un dispositif expérimenta ldestiné à la conception et l'évaluation de systèmes d'élevages caprins innovants ; trois conduites sont notamment comparées : l'une au pâturage avec une période de reproduction saisonnée ; les deux autres en contre-saison, un troupeau pâturant et l'autre étant conduit en chèvrerie. Le réseau REDCap va suivre 34 élevages caprins volontaires avec l'objectif d'améliorer l'alimentation à l'herbe et l'autonomie alimentaire des exploitations. Les deux projets sont portés par des structures différentes, avec le désir de travailler en interaction ainsi qu'avec de nombreux autres partenaires de la filière.