Backfat Thickness at Pre-Farrowing: Indicators of Sow Reproductive Performance, Milk Yield, and Piglet Birth Weight in Smart Farm-Based Systems

Abstract

The importance of backfat thickness in sows lies in its correlation with nutritional status, reproductive performance, and overall health. Identifying the optimum backfat thickness is crucial for determining the ideal energy reserves needed to support successful reproduction and lactation. This research aimed to determine optimal backfat thickness (BFT) of sows in relation to reproductive and lactation performance. In this study, 32 lactating sows were housed in a controlled environment and assigned to four groups based on their BFT before farrowing: <17.00 mm, 17.00–17.99 mm, 18.00–18.99 mm, and ≥19.00 mm. The data were analyzed with One-way analysis of variance, and the association between backfat thickness and sow reproductive performance was examined through Spearman’s correlation analysis using SAS software. The results revealed no significant difference between the groups in total born, total born alive, and litter size weaned, but the piglets’ survival rate during the lactation period is lower from sows with BFT < 17.00. Moreover, piglet birth weight and body weight at Day 3 were significantly lower in sows with BFT < 17.00 mm. The BFT of sows at weaning showed significant differences among the groups associated with the backfat thickness before farrowing. No significant difference was found in the duration of farrowing. The return-to-estrus interval was longer in sows with <17.00 mm BFT than in those with 17.00–17.99 mm, 18.00–18.99 mm, and ≥19.00 mm backfat thickness, with estrus intervals of 7.17, 6.25, 5.31, and 5 days after weaning, respectively. Numerically, calculated milk yield (MY) is lowest in sows with BFT < 17.00, and the highest MY was obtained from sows with BFT 18.00–18.99 mm. In conclusion, sows with at least 17.00 mm BFT before farrowing are ideal for increasing the lifetime productivity of sows. This study provides valuable insights into the importance of sow management during gestation for subsequent reproductive success.

Hourly Feeding Regime of Modern Genetics Lactating Sows: Enhancing Productive Performance, Welfare, and Piglet Growth in Smart Farm-Based Systems

“…At 28 days of age, the piglets were weighed individually to measure their body weight gain and calculate the sows' milk yield based on the litters' weight gain. The total milk yield from Days 1-28 was determined by multiplying the litter size weight gain at weaning by a factor of 4.2 [11,26,28,29]. Subsequently, piglets were cross-fostered on day 3 to obtain an experimental litter size of 13-14 piglets per sow and ensure every litter had access to viable teats [11].…”

“…The total milk yield from Days 1-28 was determined by multiplying the litter size weight gain at weaning by a factor of 4.2 [11,26,28,29]. Subsequently, piglets were cross-fostered on day 3 to obtain an experimental litter size of 13-14 piglets per sow and ensure every litter had access to viable teats [11]. Piglets were cross-fostered within their groups, with the same sows' parity numbers, comparable body weights, and the average birth weight of the littermates being considered.…”

“…The pre-weaning mortality rate was determined by dividing the total number of piglets in each group by the number of piglets that died after cross-fostering [26,31]. A digital infrared thermal imaging camera (FLIR E76) with an emissivity of 0.95 was used to detect estrus starting 3 days after weaning at 09:00 and 15:00 daily [11,26,32]. The body temperature readings were taken from the sows' vulvas at a distance of 1 m. Sows were identified as being in estrus when their average body temperature was 35 • C higher than the baseline [25].…”

“…The body temperature readings were taken from the sows' vulvas at a distance of 1 m. Sows were identified as being in estrus when their average body temperature was 35 • C higher than the baseline [25]. A more detailed technique for estrus detection was described in previous studies [11,25,26,32].…”

“…In contrast, insufficient nutrient intake causes sows to mobilize body tissues to maintain milk production [9], often leading to catabolic metabolism, negatively impacting reproductive processes [10]. Studies have indicated that low feed intake and excessive backfat thickness loss during lactation can affect the reproductive performance of sows, resulting in a longer duration of the weaning-to-estrus interval and low milk yields [5,8,11]. The colostrum and milk yield of sows are vital for improving the survival rates of newborn piglets, especially in the pre-weaning stage [12].…”