Disentangling Litter Size and Farrowing Duration Effects on Piglet Stillbirth, Acid-Base Blood Parameters and Pre-Weaning Mortality

The current study evaluated interactions between farrowing duration and litter size on the level of asphyxia, vitality, percentage of stillbirth, and pre-weaning mortality of piglets. Farrowing duration was measured in 159 crossbred gilts and sows (Yorkshire × Dutch Landrace). Litter size ranged between 12 and 21 piglets. Blood acid–base parameters in umbilical cord blood and vitality scores of piglets were determined immediately after birth. Number of piglets born alive and stillborn as well as individual piglet weights at birth were recorded. Pre-weaning mortality (excluding stillbirth) was determined throughout lactation. Litter size as well as farrowing duration were categorized to evaluate the interaction between the two. There tended to be an interaction between litter size and farrowing duration for pre-weaning mortality (p = 0.10). In small litters (12–15 piglets), a prolonged farrowing duration (>250 min) tended to increase pre-weaning mortality compared with a short (<150 min) and medium farrowing duration (150–250 min), while for large litters (19–21 piglets), a medium to long farrowing duration tended to decrease pre-weaning mortality. No other interactions between litter size and farrowing duration were found. Piglets within large litters showed a higher umbilical cord lactate level (p < 0.01), lower average vitality score (p = 0.01), and a higher stillborn percentage (p < 0.01) compared with piglets within medium size (16–18 piglets) and small litters. Each additional piglet born to a litter linearly decreased average piglet birth weight (17.6 g, p < 0.01), increased farrowing duration (11 min, p < 0.01), and increased stillbirth (0.5%, p = 0.04). A medium farrowing duration resulted in a lower stillborn percentage compared with a short or prolonged farrowing duration, suggesting that farrowing duration might have an optimum. When analyzed linearly, stillborn percentage increased with 1.85% per every 100 min (p < 0.01) of farrowing duration. It can be concluded that both litter size and farrowing duration affect stillborn percentage, but independent from each other. However, these two factors tended to interact regarding pre-weaning mortality, suggesting that setting a certain threshold for maximal farrowing duration should be taken with care, because this appears to depend on litter size.

Use of repopulation for optimizing sow reproductive performance and piglet loss

The objective of this study was to analyse sow reproductive performance and piglet loss from birth to weaning before and after repopulation of a selected farm. The observation was carried out on a productive sow farm; 160 sows were included in the experiment. Before repopulation, 80 sows from the 1st to the 5th litter were evaluated. The original population of sows was removed. Repopulated (newly stocked) group consisted of 80 gilts at the 1st litter. Newly delivered gilts with a status of minimum disease were placed into a decontaminated stable with a strict batch, black and white breeding system with stringent hygienic provisions. The piglets were weaned at the mean age of 28 ± 3 days. A very highly significant difference (P ≤ 0.001) in favour of the repopulated group of sows was found in the evaluation of the total number of piglets, the number of live-born piglets and the number of stillborn piglets in %; a significant difference (P ≤ 0.05) in favour of the repopulated group of sows was found in the number of stillborn piglets. In reared piglets and losses of piglets, both in numbers and percentage, a highly significant difference (P ≤ 0.001) was found in favour of the repopulated group. This study brings important information on the benefits of repopulation pig breeding.

Effects of subcutaneous administration of caffeine on the physiometabolic profile of low-birthweight neonate piglets

Caffeine administration has been used to stimulate respiration and reverse metabolic alterations in high-birthweight piglets that suffer neonatal asphyxia. However, its effect has not been evaluated on low-birthweight neonates. This study determined the effect of subcutaneously administering caffeine on the physiometabolic profile of neonate piglets with low birthweight and neonatal asphyxia. A 35-mg subcutaneous dose of caffeine, or an equivalent placebo, was randomly administered at 0 and 24 h to neonate piglets (n = 120) diagnosed with intrapartum asphyxia and classified as low-(LW) or high weight (HW) in a 2 by 2 experimental design. Blood samples were obtained at 0, 2 and 24 h postpartum. At 2 h, blood glucose concentrations diminished in the animals in both groups that were treated with caffeine (P < 0.005). Of those animals, only the ones in HW showed increased glucose concentrations by 24 h. At 0 h, group LW exhibited the highest levels of pCO2 (P < 0.005). In contrast, from 2 to 24 h only the neonates in group HW treated with caffeine reached the levels of pCO2 and pO2 characteristic of non-asphyxiated piglets. At the conclusion of the experiment, the weight of the piglets in group LW that were treated with caffeine was less than that of those that received the placebo. In contrast, the weight of the piglets in group HW that were treated with caffeine was 19% higher than that of those which received the placebo (P < 0.005). In this study, administering two doses of 35 mg of caffeine to LW neonate piglets significantly accelerated their energy expenditure, thus reducing their weight gain at 8 days of life; in contrast, the physiometabolic profile of the HW neonate piglets improved and they showed greater weight gain.