Effect of different feeding strategies and dietary fiber levels on energy and protein retention in gestating sows.

The aim of the study was to investigate whether increased inclusion of sugar beet pulp (SBP) alters retention of fat, protein, and energy when backfat (BF) is restored in early- and mid-gestation. In total, 46 sows were fed one of four dietary treatments with increasing inclusion of SBP providing dietary fiber (DF) levels of 119, 152, 185, and 217 g/kg; sows were assigned to one of three feeding strategies (FS; high, medium, and low) depending on BF thickness at mating and again at day 30 for the following month. On days 0, 30, 60, and 108, body weight (BW) and BF thickness were measured and body pools of protein and fat were estimated using the deuterium oxide technique. On days 30 and 60, urine, feces, and blood samples were collected to quantify metabolites, energy, and nitrogen (N) balances. On days 15 and 45, heart rate was recorded to estimate heat energy. At farrowing, total born and weight of the litter were recorded. In early gestation, BW gain (P < 0.01) and body protein retention increased (P < 0.05) with increasing fiber inclusion, while body fat retention increased numerically by 59%. The increase in BF was greatest for sows fed the high FS, intermediate when fed the medium strategy, and negligible for sows fed the lowest FS (P < 0.001). Nitrogen intake, N loss in feces, and N balance increased linearly, whereas N loss in urine tended to decrease with increasing inclusion of fibers in early gestation. Concomitantly, fecal energy output and energy lost as methane increased linearly (P < 0.001), while energy output in urine declined linearly. Total metabolizable energy (ME) intake therefore increased from 36.5 MJ ME/d in the low fiber group to 38.5 MJ ME/d in the high fiber group (P < 0.01). Changing the ME towards more ketogenic energy was expected to favor fat retention rather than protein retention. However, due to increased intake of ME and increased N efficiency with increasing fiber inclusion, the sows gained more weight and protein with increasing fiber inclusion. In conclusion, increased feed intake improved both fat and protein retention, whereas increased DF intake increased protein retention.

Feeding sows sugar beet pulp (SBP) has many known benefits, for example, increased satiety and high fermentability. This study investigates the ability of the sow to utilize energy for fat retention when replacing part of starch with dietary fiber. After a demanding lactation, sows need to restore body fat, and concomitantly avoid excessive protein retention, which will increase energy demand for maintenance and risk of locomotory problems. The hypothesis in this study is that energy from fermented fibers is more efficient for fat retention than dietary starch. In the study, sows had numerically greater fat retention when fed high concentrations of fiber from SBP, but concomitantly sows unintendedly also increased their protein retention, which in turn substantially increased their body weight. Sows were allocated to one of three feeding strategies depending on their body condition score (lean, medium, or fat) in early gestation, and backfat was efficiently restored in most sows within a month. In conclusion, although gestating sows have a high capability to utilize energy from fermentable fiber, they are disposed to protein over fat retention. These aspects need to be addressed in the nutrition of modern genotype sows.

Influence of fiber-rich coproducts on nutrient and energy digestibility and utilization in sows.

Coproducts from the food and agricultural industries can potentially be used to replace concentrated high-value grain crops in diets for sows. The coproducts are typically high in fiber and with diverse composition. Energy digestibility and utilization are generally high in sows fed fiber-rich feedstuff, but nitrogen digestion and utilization may be compromised. The purpose of this study was to quantify the apparent total tract digestibility (ATTD) of nutrients and utilization of energy and nitrogen in empty nonlactating sows fed with six different fiber-rich coproducts (FRCP). Brewers spent grain (BSG), pea hull (PH), potato pulp (PP), pectin residue (PR), sugar beet pulp (SBP), and seed residue (SR) were mixed into a basal diet (BD) with as high an inclusion level as possible, or the BD was fed solely to eight empty sows in a Youden square incomplete cross-over design. The collection period consisted of a total collection period of 5 d, of which 2 d were in a respiration chamber. The sows had a gross energy (GE) intake between 28.5 and 42.3 MJ/d; greatest for the PH fed sows and lowest for the PP fed sows. The ATTD of dry matter, organic matter, GE, and N did not differ among the BD and the PH and SBP fed sows, while the ATTDs of all nutrients and energy were intermediate for PR and BSG lowest in SR fed sows (P < 0.01). The differences were caused by variation in digestible and metabolizable energy content of the FRCP ingredients, which was lowest for SR, intermediate for PR followed by BSG and greatest for SBP, PP, and PH (P < 0.001). Total heat production (HP) did not differ among treatments but the nonactivity related HP was highest in SR fed sows and lowest in PH and SBP fed sows (P < 0.05). Retention of energy was greatest following the PH and BD (7.42 and 2.19 MJ/d, respectively), intermediate for PP, SBP, and BSG fed sows (-0.22 to -0.69 MJ/d) and lowest for the PR and SR fed sows (-4.26 and -6.17 MJ/d, respectively; P < 0.001). From a sow feeding perspective, SBP and PH have the potential to partly replace high-value grain crops due to high ATTD of all nutrients and because sows can efficiently utilize energy and protein. In contrast, SR and PR show low ATTD of nutrients and energy, thereby compromising the nutritive value. PP and BSG also have the potential to be included in sow diets, but caution should be taken because of compromised N utilization and thereby increased environmental impact.

Coproducts from the food and agricultural industries have the potential to partly substitute grain in diets for empty nonlactating sows. Many coproducts are high in fiber and with diverse fiber composition. Some being easily fermented, while others are more resistant to fermentation giving rise to a large variation in the total tract digestibility and utilization of nutrients and energy. How well fiber-rich coproducts are digested and utilized is poorly understood in sows, but it is important to ensure an optimal energy and protein composition of the feed depending on the physiological stage of the sow. This study aimed to increase knowledge on the digestibility and utilization of six fiber-rich coproducts potentially to be included in the sow's feed. We found pea hulls and sugar beet pulp suitable as grain replacers due to their high total tract digestibility and no negative effects on energy and protein utilization. Potato pulp and brewers spent grain were also well suited. However, caution should be taken in balancing diets because of increased fecal and urine nitrogen output, which will increase environmental impact. Seed and pectin residues primarily serve as gut fill.

Influence of four fiber-rich supplements on digestibility of energy and nutrients and utilization of energy and nitrogen in early and mid-gestating sows.

The digestibility of energy and nutrients in fiber-rich diets depends greatly on the fiber source but most data are from studies with growing pigs. The purpose of this study was to investigate the apparent total tract digestibility (ATTD) of nutrients in different fiber-rich diets and to quantify whole-body metabolism and utilization of energy and nitrogen (N) in gestating sows. Four fiber-rich diets based on sugar beet pulp (SBP), soy hulls (SH), palm kernel expellers (PKE), or a mixed fiber (MF) were formulated, with an average daily intake of total fiber (TF) of 471, 507, 651, and 437 g/d, respectively. A total of 48 multiparous sows were stratified by body weight at mating (day 0) and assigned to one of the four diets throughout gestation. Body weight and backfat were measured, and body pools of fat and protein were estimated using the deuterium oxide dilution technique at days 0, 30, and 60. On days 30 and 60, urine and fecal grab samples were obtained. On days 15 and 45, heart rate was measured to estimate total heat production. The ATTD of nutrients differed across treatments (P < 0.001), while in vivo organic matter digestibility deviated with up to ±3.3% units from in vitro enzyme digestibility of organic matter. The ATTD of energy was highly negatively correlated with intake of lignin (P < 0.001), while ATTD of N was highest (negatively) correlated (P < 0.001) with intake of insoluble non-starch polysaccharides (NSP). The ATTD of all nutrients except NSP was lowest in PKE-fed sows and highest, except for N, in sows fed the SBP diet. The ATTD of N was highest in the MF-fed sows and ATTD of NSP was lowest in the MF-fed sows. Sows lost most energy as heat (53% to 72% of gross energy intake), followed by energy in feces (15% to 17%), urine (3% to 4%), and methane (0.5% to 0.9%). Energy for maintenance accounted for the majority of the heat production and the total energy retention was lowest and highest in the SBP- and PKE-fed sows, with a retention of 3.3 and 13.3 MJ/d, respectively (P < 0.001). Sows lost most N through urine, the lowest and highest N loss (relative to intake) was observed in SH- and SBP-fed sows (50% to 63%, respectively), while 14% to 26% was retained as body protein. In conclusion, the fiber-rich diets were utilized efficiently by gestating sows with respect to energy with ATTD values above 82% in all four fiber-rich diets, whereas the high TF content in the diets compromised the N utilization in gestating sows.

How much energy and nutrients a pig can use from the feed depends greatly on the feed ingredients, feed level, and the physiological stage of the animal. Fibers are of great interest because they can improve health and welfare of pigs and co-products from the food and agriculture industries are among the most interesting. The ability to degrade different fiber sources and utilize energy and nutrients are poorly understood in gestating sows, but highly important when formulating the feed composition. The hypothesis was that sugar beet pulp was superior to the other three fiber-rich sources investigated: soy hulls, palm kernel expellers, or a mix of fibers, with respect to intake and utilization of energy and nutrients. We did not find sugar beet pulp to be particularly superior with respect to energy (fermentation or utilization), whereas utilization of nitrogen was highest for sugar beet pulp but compromised in the three other diets depending on fiber sources.

Increased feed supply and dietary fiber from sugar beet pulp improved energy retention in gestating sows.

The aim of the study was to investigate whether increased inclusion of sugar beet pulp (SBP) alters retention of fat, protein, and energy when backfat (BF) is restored in early- and mid-gestation. In total, 46 sows were fed one of four treatments with increasing inclusion of SBP with dietary fiber (DF) levels of 119, 152, 185, and 217 g/kg; sows were assigned to one of three feeding strategies (FS; high, medium, and low) depending on BF thickness at mating and again at day 30 for the following month. On days 0, 30, 60, and 108, body weight (BW) and BF thickness were measured, and body pools of protein and fat were estimated using the deuterium technique. On days 30 and 60, urine, feces, and blood samples were collected to quantify metabolites, energy, and N balances. On days 15 and 45, heart rates were recorded to estimate the heat production. At farrowing, total born and weight of the litter were recorded. In early gestation, BW gain (P < 0.01) and body protein retention increased (P < 0.05) with increasing fiber inclusion, while body fat retention increased numerically by 59%. Increase in BF was the greatest for sows fed the high FS, intermediate when fed the medium strategy, and negligible for sows fed the lowest FS. N intake, N loss in feces, and N balance increased linearly, whereas N loss in urine tended to decrease with increasing inclusion of fibers in early gestation. Concomitantly, fecal energy output and energy lost as methane increased linearly (P < 0.001), while energy output in urine declined linearly, and total metabolizable energy intake, therefore, increased from 40.5 MJ ME/d in the low-fiber group to 43.5 mega joule (MJ) metabolizable energy (ME)/d in the high-fiber group (P < 0.001). Changing the metabolizable energy toward more ketogenic energy was expected to favor fat retention rather than protein retention. However, due to increased intake of metabolizable energy and increased N efficiency with increasing fiber inclusion, the sows gained more weight and protein with increasing fiber inclusion. In conclusion, increased feed intake improved both fat and protein retention, whereas increased DF concentration increased protein retention.

Feeding sows sugar beet pulp (SBP) has many known benefits, for example, increased satiety, and it is a highly fermentable fiber source for sows. This study investigates how efficient sows utilize energy for fat and protein retention in response to increased SBP inclusion in the diet. After a demanding lactation, sows need to restore body fat and concomitantly avoid excessive protein retention, which increases energy demand for maintenance and risk of locomotory problems. The hypothesis in this study was that energy from fermented fibers is more efficient for fat retention than dietary starch. In the study, sows had numerically greater fat retention when fed high concentrations of fiber from SBP, but, concomitantly, sows unintendedly also increased their protein retention, which in turn increased substantially their live weight. Sows were fed one of three feeding strategies depending on the body condition score (lean, medium, or fat) in early gestation, and backfat was efficiently restored in most sows within a month. To conclude, gestating sows have a high capability to utilize energy from fermented fiber, but sows prefer to retain protein rather than fat, which needs to be addressed in the nutrition of modern genotype sows.