The effects of feeding sows at onset of farrowing supplemental energy (blend of carbohydrates and glycerol) on farrowing kinetics and piglet vitality.

Delivering piglets is one of the most energy-demanding activities sows undergo in their lifetime. Sows can have myometrial contractions from 2 to 12 h before the first piglet is expelled as well as a nest-building behavior. Thus, when the first piglet is delivered, the female has already used part of her energy supply. When the sow gets exhausted due to lack of energy, the farrowing process can be interrupted, causing damage to the viability and vitality of the piglets. In the present study, we evaluated the effects of feeding sows an energy supplement at the onset of farrowing on farrowing kinetics and piglet vitality. The energy supplement consisted of a blend of carbohydrates and glycerol which provides 439 kJ of metabolizable energy per kg of metabolic weight. A total of 180 sows were used. At the onset of farrowing, sows were assigned to one of the following treatments: sows that were not supplied energy at the onset of farrowing, serving as controls (CON, n = 85); sows fed the energy supplement at the onset of farrowing (ESP, n = 95). Farrowing kinetics, blood glucose concentration, and piglet vitality were recorded for each sow. Blood glucose concentration was assessed by puncturing the auricular vein and using a portable glucometer at four different time points: after the birth of the 1st piglet (T0), and at 20 (T20), 40 (T40), 80 (T80), and 180 (T180) min after the birth of the 1st piglet. The vitality of the 1st, 6th, 12th, 17th, and 20th piglet born was evaluated using the Apgar score. Piglet birth weight and average colostrum intake were measured. The farrowing duration was 20 min shorter (P < 0.05) for ESP sows in comparison with CON sows. Sows from ESP treatment had higher (P ≤ 0.05) blood glucose concentration at T20 and T40 compared to the CON sows. The inter-piglet birth interval was shortened (P < 0.05) by 14 min between the 1st and 2nd piglet for the ESP treatment. The 17th and 20th piglets born from ESP sows had higher (P < 0.05) Apgar score compared to piglets of the same birth order from CON sows. Colostrum intake was higher (P < 0.01) for piglets born from ESP sows. Litter growth performance did not differ (P > 0.05). In conclusion, feeding a blend of carbohydrates and glycerol as an energy supplement for farrowing sows improved farrowing kinetics and piglet vitality score.

Supplying sows energy on the expected day of farrowing improves farrowing kinetics and newborn piglet performance in the first 24 h after birth.

The farrowing process is one of the most energy-demanding activities for the modern hyperprolific sow. This study evaluated the effects of supply of energy on the expected date of farrowing on the farrowing kinetics and piglets' performance during the first 24 h after birth. A total of 80 sows were used. The sows and their respective litters were considered as the experimental unit. On the expected day of farrowing, the sows were allocated to one of the following groups: sows that did not have access to feed from farrowing induction until the end of the farrowing process (CON, n = 40); sows fed 500 g of energetic supplement, which consisted of 250 g of the basal lactation diet plus 250 g of cane sugar, 18 h after farrowing induction (SUP, n = 40). The farrowing duration, farrowing assistance, birth interval, number of total born, stillborn and mummified piglets were recorded for each sow. Piglets were weighed individually at birth and 24 h later. The interval from birth to first suckle was evaluated individually for each piglet in 16 randomly selected litters (eight litters per treatment group). Blood glucose concentrations of six sows were measured shortly after expulsion of the first piglet. Farrowing duration, farrowing assistance and stillborn rate tended to be greater (P = 0.06, P = 0.09 and P = 0.07, respectively) in sows from the CON group compared to sows from the SUP group. However, there was no difference (P > 0.05) between the groups for birth interval. Colostrum intake was greater (P < 0.05) for piglets from the SUP group compared to piglets from the CON group. Additionally, BW gain of the piglets suckling the SUP group was greater (P < 0.05) than those suckling the CON group at 24 h after birth. The blood glucose concentrations during the expulsive stage of farrowing were greater (P < 0.05) in the SUP group than for sows from the CON group. In conclusion, supplying modern hyperprolific sows energy on the expected day of farrowing is a valuable nutritional intervention to improve the farrowing kinetics and piglets' performance in early life.

Effects of oestrous synchronization with altrenogest in gilts on endometrial and embryonic characteristics.

The use of altrenogest (ALT) supplementation for oestrous synchronization improves subsequent reproductive performance of gilts and sows. However, the causes of this improvement in reproductive performance after ALT treatment are not fully/clearly understood. The objective of this study was to evaluate the effects of ALT supplementation for oestrous synchronization in gilts on the endometrial glands and embryonic development characteristics at 28 days of pregnancy. Pregnant gilts were divided into two experimental treatments: Control (did not receive ALT; n = 9 gilts) and ALT (ALT feeding at 20 mg/day for 18 days; n = 9 gilts). At 28 days of pregnancy, six gilts from each treatment were slaughtered, and reproductive tracts were immediately evaluated. There was no statistical difference (P > 0.05) between treatments regarding ovulation rate, number of embryos, number of vital embryos and number of non-vital embryos. Embryo weight, length and embryonic vesicle weight were lower in ALT treatment compared with Control (P < 0.01), and it was lower in the cervical uterine region compared with apex uterine region, respectively (P < 0.05). Higher values of gland duct area, gland duct perimeter, percentage of the glandular area and total endometrial area were observed in ALT treatment compared with Control (P < 0.05). The use of ALT during 18 days for oestrous synchronization in gilts increased the gland duct area, perimeter and total endometrial area but did not increase the embryo number and embryo size at day 28 of pregnancy.

Supplemental progesterone during early pregnancy exerts divergent responses on embryonic characteristics in sows and gilts.

Progesterone (P4) plays a key role in pregnancy establishment and maintenance; during early pregnancy, P4 stimulates the production and release of uterine secretions necessary for conceptus growth prior to implantation; therefore, exogenous P4 supplementation may improve embryo development. This study evaluated the effects of supplementation during early pregnancy with long-acting injectable progesterone or altrenogest on embryonic characteristics of sows and gilts. Thus, a total of 32 sows and 16 gilts were used. On day 6 of pregnancy sows and gilts were allocated to one of the following groups: non-supplemented; supplemented with 20 mg of altrenogest, orally, from days 6 to 12 of pregnancy; supplemented with 2.15 mg/kg of long-acting injectable progesterone on day 6 of pregnancy. Animals were killed on day 28 of pregnancy, and ovulation rate, embryo survival, embryo weight, crown-to-rump length, uterine glandular epithelium and endometrial vascularization were assessed. Treatments had no effect on pregnancy rate, embryo survival or endometrial vascular density (P > 0.05). Non-supplemented gilts presented larger and heavier embryos compared to gilts from supplemented groups (P < 0.05). Sows in the altrenogest group presented larger and heavier embryos compared to non-supplemented sows and sows supplemented with long-acting injectable progesterone. In conclusion, supplementation of sows and gilts with progestagen from day 6 of pregnancy can be used as a means to improve embryo survival without deleterious effects.

Dietary ractopamine supplementation of pregnant sows: what are the impacts on the neonate?

The use of additives such as ractopamine (Rac) in pregnant sows during early-mid pregnancy is an alternative to increase foetal and progeny growth and development. However, Rac supplementation in finishing pigs can lead to behavioural and physiological changes similar to the typical stress responses. The objective of this study was to evaluate the effects of dietary supplementation with Rac in pregnant sows from day 25 to 50 of gestation (pre-hyperplastic stage) on piglet's vitality, blood parameters, number, diameter and perimeter of muscle fibres in semitendinosus muscle and developmental characteristics of piglets at birth to weaning. Forty-one hybrid sows were divided into three dietary treatments: (1) control diet without Rac (control), (2) addition of 10 mg/kg of Rac (Rac10) and (3) addition of 20 mg/kg of Rac (Rac20). Higher numbers of low-vitality piglets (P<0.05) were observed in Rac-fed sows, regardless of dose, compared with the control group. Very low-density lipoprotein levels were lower in the Rac10 group when compared with the Rac20 group at day 21. Haematocrit was greater, and the mean corpuscular haemoglobin concentration was lower in piglets from Rac-fed sows. No significant statistical differences were detected regarding piglets body weight, average daily gain, blood gasometry, complete blood count and muscle fibre measurements in semitendinosus muscle. The use of Rac in pregnant sows reduced the vitality parameters of piglets but did not improve the performance from birth until weaning and did not negatively influence the haematological parameter and lipid metabolism.

Seminal plasma arising from the whole boar sperm-rich fraction increases the stability of sperm membrane after thawing.

Boar spermatozoa arising from the sperm-rich ejaculate fraction are reported to have a more stable plasma membrane and are more resistant to cold shock and premature acrosome reaction than spermatozoa from the whole ejaculate. Furthermore, seminal plasma (SP) can increase the cryotolerance of boar spermatozoa, and in other domestic species, it has the ability to reverse cryopreservation damage. This study aimed to evaluate the effects of boar SP arising from the whole sperm-rich ejaculate fraction (SP-SRF) on the integrity, stability, and peroxidation of sperm membranes after thawing. Each ejaculate ( = 24) was divided among 4 treatments: control (CT), centrifuged and suspended in autologous SP-SRF (CS), centrifuged with withdrawn SP-SRF (CW), and post-thawed SP arising from the whole sperm-rich fraction addition to CW (CWSP). After thawing, all treatments were incubated for 5, 60, and 120 min and were analyzed for membrane integrity, fluidity, and peroxidation by flow cytometer. The absence of SP-SRF increased the lipid disorder ( < 0.05) but had no effect on lipid peroxidation ( > 0.05) or membrane integrity ( > 0.05). However, the increase in lipid disorder by withdrawal of SP-SRF was reversed by SP-SRF addition ( < 0.05) to the post-thawing medium, whereas plasma and acrosomal membrane integrity ( > 0.05) and lipid peroxidation ( > 0.05) were unchanged. In conclusion, despite the centrifugation effects, the addition of SP arising from the whole sperm-rich fraction to post-thawed boar semen decreased sperm lipid disorder without an influence of the sperm membrane integrity and peroxidation.

Gonadotropin-induced puberty does not impair reproductive performance of gilts over three parities.

The aim of this study was to evaluate the reproductive performance of three parities of gilts treated or not treated with gonadotropin to induce puberty. Sixty gilts received 600 IU of equine chorionic gonadotropin (eCG) followed by 2.5 mg of porcine luteinizing hormone (LH) 72 h later. Fifty-nine other gilts were exposed only to a mature boar for 15 min twice daily. Artificial insemination (AI) was performed at 0, 12 and 24 h after the detection of oestrus, and gestation was confirmed by ultrasound after 35 days. Sows were inseminated at the first post-weaning oestrus. The total numbers of piglets born, piglets born alive, stillborn, mummified foetuses, as well as pregnancy and farrowing rates were evaluated for each of the three parities. Culling rates, farrowing intervals and weaning-to-oestrous intervals (WEI) were also analysed. Mean age at puberty and oestrous manifestation were not significantly different between treatments (p = 0.0639; 179.20 ± 17.52 compared with 173.96 ± 16.94, 91.66% compared with 94.92%) across the experimental period. However, females that underwent puberty induction showed modest increases both in the number of total pigs born and in the number of piglets born alive. In conclusion, puberty induction through exogenous gonadotropin administration in field conditions did not induce a more concentrated first oestrous manifestation, but trended to a modest increase in the number of pigs born alive in the first parity and a reduced culling rate during the first gestation.