Plane of nutrition during gestation affects reproductive performance and retention rate of hyperprolific sows under commercial conditions.

Defining a maternal plane of nutrition during gestation is pivotal for improving sow productivity and the cost-effectiveness of feeding. The benefits of increasing the amount of feed during late gestation have been controversial. The objective of this study was to investigate the effects of different planes of nutrition during gestation on reproductive performance of hyperprolific sows and pre-weaning litter performance. One hundred and thirty-five gestating sows were randomly assigned to one of three planes of nutrition throughout parities three and four (P4), as follows: Req - plane designed to meet requirements of prolific sows (2.3 kg per day from day 1 to 21; 1.8 kg per day from day 22 to 75; 2.3 kg per day from day 76 to farrowing); Bump - plane designed as the Req, with increased feed intake during late gestation (3.0 kg per day from day 91 to farrowing); and Maintenance - plane designed to closely meet maintenance requirements of sows (1.8 kg per day from day 1 to farrowing). All treatments were fed the same gestation diet (2.50MCal NE/kg; 0.67% SID Lysine; 15.17% CP). Sow biometrical parameters at farrowing and at weaning, and litter characteristics were recorded. Also, blood samples were collected for pre- and post-prandial serum glucose and plasma insulin, as well as triglycerides, calcium, and phosphorus analyses. Culling, stratified by cause, and retention rates were recorded in all treatments for each parity. Over two parities, Bump sows had higher weight gain and, at P4, had a higher number of piglets born alive (P < 0.05). Bump sows lost more weight between the end of gestation and weaning over two parities (P < 0.05). Maintenance sows showed reduced body condition score with a higher percentage of piglets removed throughout lactation (due to inappetence and inability to reach the udder) at P4 (P = 0.03). Pre- and post-prandial glucose levels were higher in Bump sows, as well as post-prandial insulin and phosphorus levels at P4 (P < 0.05). Bump sows also showed increased plasma triglycerides compared to the other treatments (P = 0.03). Retention rate was reduced in Maintenance compared to Bump and Req sows at parity 5 (P = 0.02). Taken together, our results indicate that higher feed intake allowance during late gestation may improve the sow's nutritional status triggering positive results on litter size of hyperprolific sows (e.g., more than 17 total born). However, body condition score must be carefully evaluated to prevent excessive weight gain during successive parities.

The Effect of Oxidative Stress on Thawed Bulk-Sorted Red Deer Sperm.

The aims of this study were to assess the effects of the sex-sorting process on post-thaw sperm quality as well as on induced oxidative stress damage (H2 O2 0 mm = H000; H2 O2 50 mm = H050; H2 O2 100 mm = H100) and the protective action of reduced glutathione (GSH) and Trolox, when comparing sorted (BSS) and non-sorted (NS) red deer spermatozoa incubated at 37°C. Sperm samples from three stags were collected by electroejaculation and frozen. Immediately after thawing, sperm motility was higher (p < 0.05) for NS (59% ± 3.3) than BSS (36.9% ± 5.8) sperm. Furthermore, the percentage of apoptotic sperm was higher (p < 0.05) for BSS (21.6% ± 5.0) than NS sperm (14.6% ± 1.2). The presence of H2 O2 increased DNA damage in NS (H000 = 4.1% ± 0.9; H050 = 9.3% ± 0.7; and H100 = 10.9% ± 2.3), but not in BSS sperm. However, in the presence of oxidant, GSH addition improved (p < 0.05) sperm motility in both groups of sperm samples as compared to their controls (NS: 44.5 ± 4.8 vs 21.1 ± 3.9 and BSS: 33.3 ± 8.1 vs 8.9 ± 1.8). These results demonstrate that the sperm-sorting process induces sublethal effects, albeit selecting a sperm population with a chromatin more resistant to oxidative stress than that in non-sorted sperm. Moreover, addition of GSH at 1 mm may be a good choice for maintaining the quality of stressed sperm samples, unlike Trolox, which inhibited sperm motility.

The activity of paraoxonase type 1 (PON-1) in boar seminal plasma and its relationship with sperm quality, functionality, and in vivo fertility.

Paraoxonase 1 (PON-1) is a hydrolytic enzyme present in body fluids, capable of protecting cells against oxidative stress. The hypothesis was hereby to test that PON-1, present in seminal plasma (SP), acts protecting boar spermatozoa when showing a reasonable high activity in the ejaculate. SP-PON-1 activity differed (p < 0.001) among boars (from 0.10 to 0.29 IU/mL). Intra-boar variability was also observed (p < 0.05), but only in two of the 15 boars. SP-PON-1 activity differed among ejaculate portions, showing the spermatozoa-peak portion of spermatozoa-rich ejaculate fraction the highest levels (0.35 ± 0.03 IU/mL, ranging from 0.12 to 0.69) and the post-sperm ejaculate fraction the lowest levels (0.12 ± 0.01 IU/mL, ranging from 0.03 to 0.21). SP-PON-1 activity was positively correlated with the percentage of spermatozoa with rapid and progressive movement (p < 0.01) and negatively correlated with the generation of intracellular reactive oxygen species (p < 0.01) in semen samples after 72 h of liquid storage. SP-PON-1 activity was highest (p < 0.01) in boars with highest farrowing rates. In conclusion, SP-PON-1 activity differed among boars and ejaculate fractions/portions. SP-PON-1 activity was positively correlated with sperm quality and functionality of liquid-stored semen samples and it evidenced a positive association with in vivo fertility.

Efeito da porção do ejaculado e do método de resfriamento sobre as características físicas do sêmen suíno / Effect of ejaculate portion and conservation method on the physical characteristics of boar semen

Duas porções do ejaculado suíno - primeiros 15mL da fração espermática rica (P1) e o restante do ejaculado (P2) - foram coletadas semanalmente de cinco varrões e submetidas a dois protocolos de resfriamento, diluição no diluidor MR-A® e conservação a 17°C (T1) ou no diluidor glicina-gema de ovo e conservação a 5°C (T2). As doses foram avaliadas no que se refere à motilidade, ao vigor e à morfologia espermáticas no sêmen a fresco e em diferentes tempos de estocagem. Todos os tratamentos mantiveram uma motilidade aceitável, superior a 50 por cento, nas primeiras 24 horas de armazenamento. O grupo P2T2 manteve uma motilidade similar (P>0,05) ao longo de todo o período de resfriamento (72 horas), sendo inclusive superior aos demais neste período, enquanto os outros tratamentos apresentaram uma redução da motilidade no decorrer do tempo de armazenamento. Com relação às características morfológicas do sêmen, não se observaram diferenças (P>0,05) quanto às porcentagens de espermatozoides normais entre as duas frações do ejaculado fresco. Ainda, todos os tratamentos mantiveram-se dentro dos limites aceitáveis, independentemente do tempo de armazenamento. A P1 parece ser mais adequada à produção de doses para o transporte em virtude de seu pequeno volume e alta concentração, enquanto o restante do ejaculado (P2) pode ser utilizado com eficiência dentro da própria granja.

Two portions of boar ejaculate - first 15mL of the sperm rich fraction (P1) and the rest of the ejaculate (P2) - were collected weekly from 5 mature boars and submitted to two cooling methods, extended in MR-A® and cooled at 17°C (T1) or extended in glycine-egg yolk and cooled at 5°C (T2). Spermatozoa motility, vigor, and morphological characteristics were evaluated immediately after collection and in different storage times. All treatments kept an acceptable motility, higher than 50 percent, in the first 24h of storage. The P2T2 maintained a similar motility (P>0.05) throughout the cooling storage (72h) and was superior in that period, while the other treatments presented a decrease in motility related to time. There was no difference between the two portions regarding the total number of normal spermatozoa in the fresh semen (P>0.05). All treatments showed morphological abnormalities within the acceptable thresholds, irrespectively of the storage time. Thus, due to low volume and high concentration, P1 seems to be more adequate for sperm dose transportation. Furthermore, this methodology will allow the development of new proposals concerning the transportation of swine semen, while the rest of the ejaculate could be used in farm routines to produce conventional liquid semen doses.