Effect of timing of artificial insemination on the prolificacy and sex ratio in canine species
Notice bibliographique
Résumé
The importance of artificial insemination to canine reproduction is steadily increasing. On this regard, the knowledge of the factors that may affect success of the insemination techniques is determinant to obtain successful pregnancies and an adequate number of offspring per litter. Results archived in a four years database of reproduction visits of one veterinary hospital in Portugal were analyzed and complemented with questionnaires and phone calls to the bitches’ owners. Data consists of a total of 502 newborns from 86 whelping records from 52 bitches from ten different breeds aged 15 to 99 months monitored from breeding to whelping. In this database progesterone determinations were used to establish the day of LH surge; the later being used to estimate the gestational age. Delimitation of the bitch´s fertile period was based on the combined information from serum progesterone determinations and vaginal cytology. The day the plasma concentration of progesterone exceeded 2 ng /mL was considered the day of the LH surge. Two intravaginal inseminations with 48h of interval were performed on all females, with fresh semen from males with proven fertility. The objective of the present study was to determine whether different intervals between insemination and ovulation have an influence on the fertility, prolificacy and sex ratio in bitches. Three time periods of AI, relative to ovulation day, were used in this study and bitches were divided according into these three groups. Group A (early): AI was performed more than 24 hours before ovulation, n=11; group B (intermediate): AI was performed between 24 hours before and 24 hours after ovulation, n=34; group C (late): AI was performed more than 24 hours after ovulation, n=41. Factors that may affect secondary sex ratio and prolificacy in bitches were also determined using multiple regression analysis. Month and season of the year at insemination; breed, age at first heat, weight and age of bitches at AI, days after the onset of proestrus, duration of gestation, cesarean delivery, parity, embryonic and neonatal death, sexual behaviour at AI, vulvar anatomy, male’s experience, incidence of reproductive pathologies and whelping problems were analysed together. This study did not supported the hypothesis that changing the moment of artificial insemination in relation to ovulation affected secondary the litter size and the proportion of males and females at birth. However, the results showed that breed has an influence on prolificacy, gestation length, probability of having cesarean section and proportion of males and females at birth. Breeds with highest prolificacy are more likely to have longest gestation duration, high probability of having newborn females and less probability of having cesarean delivery. German Shepherd Dog had a greater likelihood of having longest gestation, followed by French Bulldog and Doberman, Labrador Retriever, Great Dane and Jack Russell, Bernese Mountain Dog, Pug and at least with shorter gestation duration and high probability of having cesarean delivery are Bull Terrier and English Bulldog. This information is clinically important in attempting to predict the whelping day and prepare a cesarean section. The importance for breeders lies in genetic improvement of the breed.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».