Fernando Pandolfo Bortolozzo

In modern sows, litter size often exceeds the number of functional teats. Therefore, many farms retain surplus piglets within the litter. The present study evaluated the effect of cross-fostering biological litters with up to two surplus piglets relative to functional teats, allowing piglet replacement until day three of lactation. Females were selected ( n = 201) at farrowing and evenly distributed among treatments: +0 (number of piglets equal to functional teats), + 1 (one surplus piglet), and + 2 (two surplus piglets). Biological litters were formed three to 12 h after farrowing (day 0). Piglets that died or were removed (low viability) during the first three days of life were weighed and replaced. Piglets in the + 2 group tended to have lower immunocrit values than those in the + 0 group ( P = 0.06). Although the + 2 group exhibited the highest overall piglet loss rate across lactation ( P ≤ 0.01), litter sizes in the + 1 and + 2 groups were larger than those in the + 0 group ( P < 0.01). Piglets in the + 2 group also had reduced average daily gain compared with piglets in the + 0 and + 1 groups ( P < 0.01). Facial and joint injuries were more frequent in the + 1 and + 2 groups on D5 ( P < 0.01). No differences among treatments were found in udder injury scores, number of functional teats, sow body condition at weaning, daily milk production, or subsequent reproductive performance ( P ≥ 0.10). Cross-fostering litters with up to two surplus piglets increased the number of piglets weaned without impairing sow performance, although individual piglet growth and early lesions were negatively affected.

Boar seminal plasma (SP) proteins were associated with differences on sperm resistance to cooling at 17°C. However, information about seminal plasma proteins in boars classified by capacity of semen preservation and in vivo fertility remains lacking. Thus, the objective was to evaluate the SP proteome in boars classified by capacity of semen preservation and putative biomarkers for fertility. The ejaculates from high‐preservation (HP) showed higher progressive motility during all 5 days than the low‐preservation (LP) boars. There was no difference for farrowing rate between ejaculates from LP (89.7%) and HP boars (88.4%). The LP boars presented lower total piglets born (14.0 ± 0.2) than HP (14.8 ± 0.2; p < 0.01). A total of 257 proteins were identified, where 184 were present in both classes of boar, and 41 and 32 were identified only in LP and HP boars, respectively. Nine proteins were differently expressed: five were more abundant in HP (SPMI, ZPBP1, FN1, HPX, and C3) and four in LP boars (B2M, COL1A1, NKX3‐2, and MPZL1). The HP boars had an increased abundance of SP proteins related to sperm resistance and fecundation process which explains the better TPB. LP boars had a higher abundance of SP proteins associated with impaired spermatogenesis.

The rearing of large litters from hyperprolific sows is a characteristic of modern genotypes. However, these sows have body and reproductive characteristics that differentiate them from the genotypes of the past decades, making it necessary to adopt different management strategies. This review describes the main care and challenges associated with the hyperprolificity of sows during the period in which replacement gilts are selected, along with gestation, parturition, lactation, and the weaning-estrus interval. It describes the challenges that these sows’ piglets will face during the lactation period and includes some strategies adopted to develop these surplus piglets. In addition, it identifies areas where more research is needed to understand the reproductive management of modern genotypes.

Context: Mycoplasma hyopneumoniae causes enzootic pneumonia, predisposing pigs to infections with other respiratory pathogens. The main control measure is to reduce piglet exposure at lactation, which can be achieved by gilts’ acclimation prior to their entrance to the farms. One of the acclimation strategies is aerosol exposure with a positive inoculum by using a fogger. However, studies on its efficacy in gilts and their litters are lacking in the literature. Aim: The aim of this case study was to assess the efficacy fogging with a positive inoculum of M. hyopneumoniae to expose negative gilts in an acclimation program. Moreover, the infection dynamics of M. hyopneumoniae were assessed in their piglets from lactation to slaughter. Methods: The trial was performed in two phases. In Phase 1, a total of 34 and 107 gilts was selected from Farms A and B respectively, and then exposed to the inoculum through a fogger. In Phase 2, a subsample of 74 gilts from Farm B was followed to their first farrowing and 263 piglets born to those gilts were sampled from 15 to 170 days of age, and at slaughter, lung lesions were evaluated. Key results: In Phase 1, the prevalence of positive gilts at 28 days post-exposure (dpe) was 100% and 98.1% in Farms A and B respectively. In Phase 2, 10.8% of gilts remained positive at 180 dpe and 0.8% of piglets were positive at 15 days of age (day) and 28.1% at 60 days, suggesting a possible vertical transmission. Conclusion: The use of fogging with a lung homogenate positive for M. hyopneumoniae successfully acclimated negative gilts. However, it did not avoid the presence of positive gilts at farrowing and the detection of the bacterium in their progeny by polymerase chain reaction. Implications: The exposure of gilts to M. hyopneumoniae at 150 days of age was successfully achieved by fogging. However, consideration should be given to exposing replacement gilts of a younger age in order to reduce the odds of detecting positive gilts at first farrowing.

This study evaluated the effect of sperm concentration of boar semen doses, for intrauterine artificial insemination (IUAI), on semen quality and established concentration limits for their production. Twenty ejaculates from four crossbred mature PIC^® boars were collected to produce 50 mL semen doses in a split sample, reaching the following sperm concentrations: ~20, 30, 60, and 100 × 10⁶ cells/mL. Doses were produced using Androstar^® Plus, stored at 17°C, and evaluated until 120 h of storage. There was a linear decrease in sperm motility as the sperm concentration increased (p linear < .01). The concentration which no longer affected the total and progressive motility was 59 and 55 × 10⁶ cells/mL, respectively (corresponding to 71% and 62%, respectively). The pH linearly decreased as the sperm concentration increased (p < .01); yet, at 72 and 120 h, the parameter dramatically reduced in boar semen doses with 60 and 100 × 10⁶ cells/mL. The percentage of cells with intact plasma and acrosomal membranes or with high mitochondrial membrane potential was not influenced by the sperm concentration (p ≥ .15). In conclusion, sperm motility was negatively affected in highly (60 and 100 × 10⁶ cells/mL) concentrated doses. To achieve suitable sperm motility, boar semen doses may not surpass the sperm concentration of 55 × 10⁶ cells/mL. The effect of low‐concentrated boar semen doses on sperm quality still needs to be better evaluated, mainly considering the influence of extender type and thermo‐resistance conditions.