Seasonal changes of nuclear DNA fragmentation in boar spermatozoa in Spain

There are numerous cases when conventional spermiogram parameters are all within an acceptable range but boar subfertility persists. The total sperm nuclear DNA fragmentation index (tDFI) is a trait related to fertility and prolificacy problems that is not routinely evaluated in commercial AI boars. The aim of this research was to study the effect of the photoperiod, season and reproductive age of the boar on tDFI (measured by SCSA) of 1279 ejaculates from 372 different boars belonging to 6 different breeds located in 6 AI studs in Spain. tDFI data ranged from 0.018% to 20.1%. Although there was a significant single boar effect in the tDFI occurrence, a negative correlation between the tDFI and the age of the boar was found (p < 0.001). tDFI would decrease due to aging of the boar 0.66% each year old within the observed age range. After including age as a covariate in the ANCOVA, no differences were found in tDFI between photoperiods when the sperm collection date was evaluated. However, when the date of the production of semen in the testis was evaluated, the total percentage of spermatozoa with fragmented nuclear DNA was 1.46% higher in the increasing photoperiod in comparison to the decreasing photoperiod (p < 0.0001). On the other hand, for both dates, the lowest tDFI values corresponded to minimum day length for decreasing photoperiod phase (autumn), while the highest tDFI values were found in summer (maximum day length for decreasing photoperiod phase)

Immunocastration in gilts: a preliminary study of the effect of the second dose administration time on growth, reproductive tract development, and carcass and meat quality

Increasing fatness and avoiding puberty are desirable in gilts intended for high-quality dry-cured ham production. A total of 48 Duroc x (Landrace x Large White) females of 26.5 ± 3.70 kg body weight (BW) were used to evaluate the impact of immunocastration and to find the optimum application time of the second dose for immunocastration on growth; sex hormones; reproductive tract development; and carcass, meat, and fat quality. Gilts were allocated to four experimental treatments (n = 12): control (entire gilts, EG) and immunocastrated gilts (IG), providing the second dose at 12, 9, or 7 weeks before slaughter (with approximately 60, 75, or 90 kg BW, respectively). Mean slaughter BW was 125 kg. Immunocastrated gilts had lighter reproductive tracts and greater fat thickness than EG. Fat from IG was more saturated and less polyunsaturated than that from EG. Numerically, gilts immunocastrated 9 and 12 weeks before slaughter presented higher fatness than those immunocastrated 7 weeks before slaughter. In conclusion, immunocastration is a good strategy to improve the fatness of gilts destined to dry-cured ham elaboration, with the optimum time for the second dose application seemingly between 9 and 12 weeks before slaughter

Determination of puberty in gilts: contrast of diagnostic methods

Background Early onset of a gilt´s puberty is needed for adequate economic performance in farms, because it indicates her reproductive performance and longevity. Therefore, an effective diagnosis is needed. Our purpose was to compare different procedures (external characteristics, blood progesterone analysis and ultrasonography diagnosis) to detect puberty in 70 gilts (Topigs TN70; 240 days old) on farm conditions. Postmortem examination was the standard reference. Multiple logistic regression analysis was used to identify which combination of independent variables (predictors) best predicts the status of gilts. Results Puberty (46/70 gilts; 65.71%) was characterized by the presence of follicles larger than 6 mm, corpus albicans, corpus rubrum, and corpus luteum (postmortem examination). Vaginal length, body condition, backfat, carcass weight and progesterone blood concentration were significantly higher in pubertal than prepubertal gilts (P < 0.05). Two types of ultrasonography equipment (DELTA and W3) were compared and performed by the same senior technician (V1). The results obtained by two technicians with different levels of experience (V1 and V2, a junior technician) using W3 were also compared. Ultrasonography provided better results than other diagnostic techniques, although the effectiveness of the ultrasonography changed with technological improvements and with increased expertise of technicians. The most accurate results were found by V1/DELTA (Nagelkerke´s R2 = 0.846; Sensitivity = 0.956; Specificity = 0.958; Positive predictive value = 0.978; Negative predictive value = 0.920; Area under ROC curve = 0.957). Results using the W3 equipment could be improved when used in conjunction with vaginal length (V1; Nagelkerke´s R2 = 0.834; Sensitivity = 0.933; Specificity = 0.958; Positive predictive value = 0.977; Negative predictive value = 0.885; Area under ROC curve = 0.972) or progesterone concentration (V2; Nagelkerke´s R2 = 0.780; Sensitivity = 0.955; Specificity = 0.826; Positive predictive value = 0.915; Negative predictive value = 0.905; Area under ROC curve = 0.970). Conclusions Ultrasonography provided better results than other diagnostic techniques. The effectiveness of the ultrasonography changes with technological improvements and with increased expertise of technicians. Results using the W3 equipment could be improved when used along with vaginal length (V1) or progesterone concentration (V2). Accuracy parameters are a guide to choose puberty diagnosis, but the farms must also evaluate effect on gilts, ease and cost of administration

Efecto del limado de los dientes de aguja en lechones sobre el rendimiento al destete

La presencia de dientes de aguja es una preocupación importante para el bienestar y el rendimiento de los lechones al destete. El objetivo del estudio fue comparar el rendimiento de los lechones cuando se liman los dientes, considerando la paridad de la cerda. Para ello se analizaron 1.798 lechones de genética Hypor [cerdas Landrace x Large White cruzadas con machos German Pietrain]; 162 camadas fueron asignadas aleatoriamente a los grupos control (C: 871 lechones) o tratado (T: 915 lechones). No se detectó un efecto significativo del sexo en peso al destete (PD; P = 0, 390), ganancia media diaria (GMD; P = 0, 375) ni tiempo hasta el destete (TD; P = 0, 785). Se detectaron efectos significativos de la interacción grupo x paridad de la cerda (G x PC) sobre PD ( P 0, 05). El limado de dientes mejor ó la tasa de crecimiento hasta el destete en lechones de primíparas y cerdas de 2-6 partos, pero esta técnica no sería recomendable para lechones de cerdas maduras. The presence of needle teeth is an important issue for piglet welfare and performance. The objective of this study was to compare teeth grinding versus intact teeth in terms of piglet weaning performance, taking into account the sow''s parity. A number of 1, 798 piglets from Hypor Genetics [(Landrace x Large White sows) x German Pietrain boards] were studied; 162 litters were randomly assigned to the control (C: 871 piglets) or treated group (T: 915 piglets). Sex had no significant effects on wean weight (WW; P = 0.390), average daily gain (ADG; P = 0.375) and time of weaning (TW; P = 0.785). Significant interactive effects group x sow''s parity (GxSP) were observed for WW (P 0.05). Grinding improved growth until weaning of piglets from primiparous and parity 2-6 sows, but the use of this technique would not be advisable for piglets from mature sows