Increased dietary protein for lactating sows affects body composition, blood metabolites and milk production.

Hyper-prolific sows nurse more piglets than less productive sows, putting a high demand on the nutrient supply for milk production. In addition, the high production level can increase mobilization from body tissues. The effect of increased dietary protein (104, 113, 121, 129, 139 and 150 g standardized ileal digestible (SID) CP/kg) on sow body composition, milk production and plasma metabolite concentrations was investigated from litter standardization (day 2) until weaning (day 24). Sow body composition was determined using the deuterium oxide dilution technique on days 3 and 24 postpartum. Blood samples were collected weekly, and milk samples were obtained on days 3, 10 and 17 of lactation. Litter average daily gain (ADG) peaked at 135 g SID CP/kg (P < 0.001). Sow BW and back fat loss reached a breakpoint at 143 and 127 g SID CP/kg (P < 0.001). Milk fat increased linearly with increasing dietary SID CP (P < 0.05), and milk lactose decreased until a breakpoint at 124 g SID CP/kg and 5.3% (P < 0.001) on day 17. The concentration of milk protein on day 17 increased until a breakpoint at 136 g SID CP/kg (5.0%; P < 0.001). The loss of body protein from day 3 until weaning decreased with increased dietary SID CP until it reached a breakpoint at 128 g SID CP/kg (P < 0.001). The body ash loss declined linearly with increasing dietary SID CP (P < 0.01), and the change in body fat was unaffected by dietary treatment (P=0.41). In early lactation (day 3 + day 10), plasma urea N (PUN) increased linearly after the breakpoint at 139 g SID CP/kg at a concentration of 3.8 mmol/l, and in late lactation (day 17 + day 24), PUN increased linearly after a breakpoint at 133 g SID CP/kg (P < 0.001) at a concentration of 4.5 mmol/l. In conclusion, the SID CP requirement for sows was estimated to 135 g/kg based on litter ADG, and this was supported by the breakpoints of other response variables within the interval 124 to 143 g/kg.

Amino acid digestibility by weanling pigs of processed ingredients originating from soybeans, 00-rapeseeds, or a fermented mixture of plant ingredients.

An experiment was conducted to determine the apparent ileal digestibility (AID) and the standardized ileal digestibility (SID) of CP and AA in 4 sources of processed soybean products, in conventional dehulled soybean meal (SBM-CV), in conventional 00-rapeseed expellers (RSE), and in a fermented coproduct mixture (FCM) that contained rapeseed meal, wheat, soy molasses, and potato peel fed to weanling pigs. The 4 processed soybean products included 2 sources of enzyme-treated soybean meal (ESBM-1 and ESBM-2), extruded soybean meal, and soy protein concentrate (SPC). Twenty-seven weanling barrows (9.29 ± 0.58 kg initial BW) were surgically equipped with a T-cannula in the distal ileum. Pigs were randomly allotted to three 9 × 5 Youden squares with 9 pigs and five 7-d periods in each square. Seven cornstarch-based diets were prepared using each of the protein sources as the sole source of CP and AA. A N-free diet was prepared to calculate basal endogenous losses of CP and AA, and this diet was fed to 2 groups of pigs, which resulted in a total of 9 dietary treatments. Results indicate that the SID of CP was greater ( < 0.05) in ESBM-1 than in SPC, RSE, or FCM. The SID of Arg, His, Ile, Leu, Met, and Phe were greater ( < 0.05) in ESBM-1 than in SPC, and the SID of Lys was greater ( < 0.05) in SBM-CV than in ESBM-2. The SID of Thr, Trp, Val, and total indispensable AA were not different among the soybean products, but the SID of total dispensable AA in ESBM-1 was greater ( < 0.05) than in SPC. Therefore, the SID of total AA was greater ( < 0.05) in ESBM-1 than in SPC, but no other differences were observed among soybean meal (SBM) products. The SID of most AA in RSE and the SID of all AA in FCM were less ( < 0.05) than in all the SBM products, but the SID of all AA in RSE were greater ( < 0.05) than in FCM. Results of this research indicate that although processing of SBM results in increased concentration of CP, processing may also reduce the digestibility of AA, which is likely due to heat damage during processing. There are, however, differences among processed soy products, with some products having greater SID of AA than others. Results also indicate that fermentation of a mixture of rapeseed meal, wheat, and relatively low quality coproducts does not result in SID values that are similar to those of unfermented 00-rapeseed expellers or soybean products.

Sows with high milk production had both a high feed intake and high body mobilization.

Selection for increased litter size have generated hyper-prolific sows that nurses large litters, however limited knowledge is available regarding the connection between milk production, feed intake and body mobilization of these modern sows. The aim of the current study was to determine what characterized sows with high milk production and nursing large litters, differences between sows of different parities and effects of lactational performance on next reproductive cycle. In total 565 sows (parity 1 to 4) were studied from 7 days before farrowing until weaning. On day 2 postpartum litters were standardized to 14 piglets. Weight and back fat thickness of sows were measured at day 7 prepartum, day 2 postpartum and at weaning. Litters were weighed at day 2 and at weaning. Pearson correlation coefficients between variables were calculated and regression models were developed. The average daily feed intake (ADFI) of the sows was 6.1±1.1 kg/day, average daily gain (ADG) of the litter was 2.92±0.53 kg/day and sows weaned 13.0±1.1 piglets. First parity sows generally had a lower ADFI and milk production and a decrease in total born piglets in next litter compared with parity 2 to 4 sows, which could be explained by a relatively higher proportion of their body reserves being mobilized compared with multiparous sows. The ADG of the litter was positively related by ADFI of the sows, litter size and BW loss and increasing the ADFI with 1 kg/day throughout lactation likely increased the ADG of the litter with 220 to 440 g/day in parity 1 to 4, respectively. Increasing the ADFI by 1 kg/day reduced the BW loss with 6.6 to 13.9 kg of parity 1 to 4 sows, respectively, during lactation, whereas increasing the average milk yield with 1 kg/day raised the BW loss with 4.3 to 21.0 kg of the four parities during lactation. The number of total born piglets in the next litter was positively related to the number of piglets born in the previous litter. In conclusion, both a high feed intake and a high mobilization of body reserves was a prerequisite for a high milk production. The sows might be very close to the physical limit of what they can ingest and future research should therefore, focus on optimizing the dietary energy and nutrient concentrations of diets for lactating hyper-prolific sows and herein distinguish between primiparous and multiparous sows.

Impact of fat source and dietary fibers on feed intake, plasma metabolites, litter gain and the yield and composition of milk in sows.

Sow lactation diets often include fat sources without considering the impact on digestion, metabolism and performance. Fiber ingredients may reduce feed intake and are often completely excluded from lactation diets, although locally available ingredients may be cost-efficient alternatives to partly replace cereals in lactation diets. Thus, a standard lactation diet low in dietary fiber, and two high-fiber diets based on sugar beet pulp (SBP) or alfalfa meal (ALF) were formulated. The SBP diet was high in soluble non-starch polysaccharides (NSP), whereas ALF being high in insoluble NSP. Each diet was divided in three portions and combined with 3% soybean oil (SOYO), palm fatty acid distillate (PFAD), or glycerol trioctanoate (C8TG) as the dietary fat source. Equal amounts of metabolizable energy were fed to 36 second parity sows from day 105 of gestation and throughout lactation to study the impact on feed intake, plasma metabolites, milk production and litter performance. Backfat thickness and BW of sows were recorded on days 3, 17 and 28 of lactation; blood was sampled on days 3 and 17; milk samples were obtained on days 3, 10, 17 and 24 of lactation; and piglets were weighed on days 2, 7, 14, 21 and 28 of lactation. Litter gain and milk yield during late lactation were greater in sows fed C8TG or SOYO than in sows fed PFAD (P=0.05), whereas loss of BW (P=0.60) and backfat (P=0.70) was unaffected by fat source. Milk protein on days 3 and 10 of lactation were lower in C8TG and SOYO sows, than in PFAD sows (P<0.05). The lowest concentration of plasma lactate on day 3 (P<0.05) and plasma acetate on day 17 (P<0.05) was observed in C8TG sows. Milk yield was unaffected by fiber treatment (P=0.43), whereas milk protein concentration was lowest in ALF sows (P<0.05). Feed intake tended to be lower (P=0.09), and litter gain during the 3rd week of lactation was decreased (P<0.05) in SBP sows. In conclusion, performance was enhanced in SOYO and C8TG compared with PFAD sows, possibly associated with reduced energy intake in PFAD-fed sows. Furthermore, the SBP diet seemed to impair feed intake and litter gain at peak lactation, suggesting that effects of the dietary fiber fraction on energy intake determines the potential inclusion level of fiber-rich ingredients.

Dietary supplement rich in fiber fed to late gestating sows during transition reduces rate of stillborn piglets.

The beneficial effects of dietary fiber (DF) from a behavioral and welfare perspective have been thoroughly studied. However, data on the effects of DF on reproductive performance are scarce. Therefore, the aim of this study was to investigate the impact of increased DF supply during the last 2 wk of gestation on stillbirth rate, preweaning mortality, and total piglet mortality. A total of 644 sows were selected for the experiment from a commercial farm, and the sows were inseminated in weekly batches. Sows in the control group ( = 310) were fed according to the normal feeding strategy of the farm with a gestation diet until 1 wk before expected farrowing, then a transition diet until d 5 of lactation, and then a lactation diet until weaning. Sows in the treatment group ( = 334) were fed as the control group except that 280 g/d of the gestation diet (from d 102 to 108 of gestation) and 570 g/d of the transition diet (from d 109 of gestation until farrowing) was daily replaced with 350 and 700 g/d, respectively, of a DF-rich supplement. Both groups received isocaloric diets on a NE basis. The numbers of live-born and stillborn piglets as well as mortality of live-born piglets with presumed causes of death were recorded. The supplemented DF reduced the proportion of stillborn piglets from 8.8 to 6.6% ( < 0.001) and mortality of total born piglets from 22.3 to 19.9% ( = 0.004) but had no impact on preweaning mortality of the piglets ( = 0.21). Moreover, supplemented DF reduced the proportion of death due to poor viability ( < 0.001; 2.8 vs. 1.5% in the control and treatment groups, respectively) and prevalence of piglet diarrhea ( = 0.004; 0.7 vs. 0.3% in the control and treatment groups, respectively). Crushing, low birth weight, and poor viability were the top 3 contributors to preweaning mortality of live-born piglets, in descending order. In conclusion, the supplemented DF reduced the proportion of stillborn piglets and total piglet mortality as well as mortality due to poor viability and piglet diarrhea in lactation.

Reproductive performance of "nurse sows" in Danish piggeries.

The use of nurse sows in Danish piggeries is common practice because of large litter sizes; however, the effect of being selected as a nurse sow on subsequent reproductive performance is unknown. Therefore, the aim of this study was to quantify a nurse sow's reproductive performance in the subsequent litter. Nurse sows were defined as sows weaning their own litter at least 18 days postpartum and thereafter nursing another litter (nurse litter) before service. Data (2012-2013) from 20 piggeries with more than 14.5 live born piglets per litter and a stable distribution of sows among parities over time were selected. Records from 79,864 litters were obtained and analyzed using mixed linear and logistic regression models. The average lactation lengths were 40.3 days for nurse sows and 27.8 days for non-nurse (normal) sows. Nurse sows weaned on average 12.4 piglets and subsequently 11.5 nurse piglets, whereas non-nurse weaned 11.7 piglets in their single weaning. There was no difference in re-service rate between nurse and non-nurse sows in the subsequent reproductive cycle. Subsequent litter size in the next reproductive cycle was higher for nurse sows than that for non-nurse sows (18.69 vs. 18.11 total born piglets; P < 0.001). Nurse sows were of a slightly lower parity than non-nurse sows (3.12 vs. 3.27, P < 0.001), and nurse sows had an increased weaning to estrus interval compared to non-nurse sows (4.23 vs. 4.19 days, P < 0.001). The results indicate that nurse sows were selected among sows nursing large litters and could therefore suggest that these sows represent the best percentile of sows in a given piggery. In conclusion, this survey indicated no negative effects of being selected as a nurse sow on the subsequent reproductive performance. On the contrary, nurse sows gave birth to more piglets compared to non-nurse sows in their subsequent litter.

The effect of increasing the dietary valine-to-lysine ratio on sow metabolism, milk production, and litter growth.

A study was conducted to investigate the effect of increasing the dietary valine-to-lysine ratio (Val:Lys) for lactating sows weaning more than 12 piglets. Five hundred fifty-eight sows (parity 1 to 4) were allotted to 6 dietary treatments from 2 d postpartum, when litters were standardized to 14 piglets. Diets were analyzed to have a total dietary Val:Lys of 0.84, 0.86, 0.88, 0.90, 0.95, or 0.99:1. On all 558 sows, BW, back fat thickness (BF), and litter weight were registered at d 108 of gestation and d 2 and 25 (weaning) postpartum. On a subsample of 72 sows, additional measurements were made: sow BW and BF were measured on d 17 and litter weight was measured on d 10 and 17, and blood and urine samples were collected weekly. The litter size at weaning was not affected by the dietary Val:Lys ( = 0.23) and, on average, the sows weaned 13.0 ± 1.1 piglets. Average daily gain of the litter (2.93 ± 0.53 kg/d; = 0.84), litter weight at weaning ( = 0.67), the average milk yield (11.3 ± 1.4 kg/d; = 0.49), and milk contents of fat ( = 0.57), protein ( = 0.18), and lactose ( = 0.20) were not affected by the dietary Val:Lys. Increasing the dietary Val:Lys increased the milk concentration of Val ( < 0.05) and Ile ( < 0.01). The change in sow BW and BF were similar for all sows from d 2 to 17, d 17 to 25, and d 2 to 25 ( > 0.05). During lactation, sows, on average, had a BW and back fat loss of 22.1 ± 12.7 kg and 2.9 ± 1.7 mm, respectively. Plasma concentrations of glucose ( = 0.26), lactate ( = 0.95), urea N ( = 0.84), NEFA ( = 0.24), and creatinine ( = 0.42); urine concentration of creatinine ( = 0.57); and concentrations of AA in whole blood ( > 0.05) were not affected by the dietary Val:Lys. In conclusion, there was no effect of increasing the total dietary Val:Lys above 0.84:1 on sow metabolism and litter performance during lactation.