Effect of Lysine-Fermentation By-Product on Urine pH and Total Effect of Lysine-Fermentation By-Product on Urine pH and Total Urine Bacteria Count in Lactating Sows Urine Bacteria Count in Lactating Sows

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Introduction
The dietary electrolyte balance (dEB) in swine diets can be altered by including acidifiers.A reduction in pH within the GI tract can decrease the development of bacteria Swine Day 2018 and potentially improve pre-weaning mortality. 4Lowering pH also allows sows to mobilize calcium to be used during muscle contractions in farrowing, thus reducing stillbirths.Additionally, lowering the pH of the urine may also help to reduce urinary tract infections. 5Most previous research utilizes protected calcium chloride products or inorganic acidifiers to lower urine pH. 3 This particular by-product from the fermentation of crystalline lysine (Ajinomoto Heartland Inc., Chicago, IL) has a high sulfur content.Because sulfur is an anion, it has the ability to decrease the dEB of the diet.However, this fermentation by-product has never been evaluated in lactating sows.Therefore, the objective of this study was to determine the effect of including the lysine-fermentation by-product in sow diets on urine pH and bacteria concentrations.

Procedures
A total of 27 sows were moved into the farrowing house on d 110 of gestation and allotted by BW and parity to 1 of 2 dietary treatments.Dietary treatments included a control (corn-soybean meal lactation diet) or the control diet that was acidified with the addition of 1.75% (as-fed basis) of lysine-fermentation by-product (Table 1).Corn was replaced by the lysine-fermentation by-product to achieve the treatment diet (Table 2).The dietary electrolyte balance was calculated using the following equation: dEB ={[(Na/23) + (K/39.1)]-[(Cl/35.5)+ (S/16)]} × 10,000.The calculated dEB was 95.9 and -23.7 mEg/kg for the control and lysine-fermentation by-product diets, respectively.Dietary treatments were manufactured at the Kansas State University O.H. Kruse Feed Mill in Manhattan, KS.During bagging of the experimental diets, feed samples were collected from every fifth bag (50 lb), and these samples were pooled and used for nutrient analysis.Duplicate composite samples per dietary treatment were analyzed at a commercial laboratory (Ward Laboratories, Kearney, NE) for dry matter (DM), crude protein (CP), crude fiber, Ca, P, K, S, Cl, Na, and Mg.
From d 110 of gestation until farrowing, sows were fed 6 lb/d of their respective diets.After farrowing, sows were allowed ad libitum access to their respective diets.Sows were fed the lysine-fermentation by-product diet until d 10 of lactation, at which point they were switched to the control diet for the remainder of the lactation period.
Urine samples (40 mL) were collected by free-catch in the middle of urination, at d 110 of gestation (pre-treatment) farrowing, d 10 of lactation and at weaning using a 50 mL plastic cup.All samples were measured for pH using a pH meter (Accumet Portable AP62 pH/mV meter, Fisher Scientific, Hampton, NH) and 4 mL of subsampled urine was sent to a commercial laboratory (Microbial Research Inc., Fort Collins, CO) for analysis of a total aerobic bacteria count.
On the day of birth, piglets were weighed and cross-fostered within treatment in an attempt to equalize litter size.Individual sow feed intake measurements were collected by recording the amount of feed provided to each sow and recording feed remaining in the feeder.Litter characteristics were measured on all sows, including stillborn and mummified fetuses, and pre-weaning mortality.

Statistical Analysis
A repeated measures statement, with random effect of block, was used for analyzing urine pH and total aerobic bacteria counts (log transformed).Results were considered significant at P ≤ 0.05, and marginally significant at 0.05 ≤ P ≤ 0.10.Data were analyzed using the GLIMMIX procedure of SAS (Version 9.4, SAS Institute Inc., Cary, NC).

Chemical Analysis
Chemical analysis of DM, CP, crude fiber, P, K, and Na in diets were similar to formulated values (Table 3).Chemical analysis of Ca, S, and Cl differed from formulated values in both diets; however, the analyzed values were different by a similar percentage in both diets.Thus, a new dEB was calculated based on the chemical analysis.The dEB values after analysis were approximately 50 mEq/kg lower than formulated, but with similar magnitude of difference between treatments.The dEB was based on analyzed values of 51.5 and -76.2 mEq/kg for the control diet and diet containing the lysinefermentation by-product, respectively.

Urine Analysis
For analysis of urine pH, as expected, there was no evidence for difference in urine pH (P > 0.05) between dietary treatments at d 110 of gestation; however, at farrowing and d 10 of lactation, there was a reduction (P = 0.001) in urine pH in sows fed the lysinefermentation by-product compared to sows fed the control diet.By weaning (d 19) there was no evidence for differences in urine pH observed among the dietary treatments.For urine bacteria concentrations, there was no evidence for treatment difference (P > 0.05) in total bacteria count at any measured time point (Table 5).

Observational Data
Because there were not enough sows per treatment to determine the influence of the fermentation by-product on sow performance, means are provided for observational purposes.The average sow parity was 2.2 with a range of 1 to 4. Average daily feed intake was 13.4 lb for sows fed the control diet and 13.8 lb for sows fed the lysinefermentation by-product diet.Average total born was 16.2 pigs, with 89% (14.4) born alive, 6% stillborn and 5% mummified fetuses.The average number of pigs weaned per litter was 12.7, with weaning occurring on day 19 (± 2 d) of age.
In conclusion, feeding the lysine-fermentation by-product in diets for sows reduced urine pH during the treatment period, but did not affect total bacteria count in the urine.This proof of concept study supported the hypothesis that the lysine-fermentation by-product would reduce sow urine pH and could possibly be used as an ingredient to influence dEB of diets fed to sows.

2
Lysine-fermentation by-product is from the manufacturing of crystalline lysine and added to the diet at 1.75% (as-fed).Sows were fed the lysine-fermentation by-product diet from d 111 of gestation until d 10 of lactation, then control diet from d 10 of lactation to weaning.day interaction was observed, where sows on the control treatment had no change in pH over time.However, sows on the lysine-fermentation by-product treatment had lower pH on the day of farrowing and d 10 of lactation compared to d 110 of gestation and d of weaning.Swine Day 2018

Table 4 .
Effects of lysine-fermentation by-product in lactation on sow urine pH1,4 1A total of 27 mixed parity females were used in a lactation study.Sows were allotted to treatment based on d 110 BW and parity.Sows consumed 6 lb/d from d 111 of gestation until farrowing.

Table 5 .
Effects of lysine-fermentation by-product in lactation on total bacteria count (CFU/ml log 10 ) in urine 1,2 27 mixed parity females were used in a lactation study.Sows were allotted to treatment based on d 110 BW and parity.Sows consumed 6 lb/d from d 111 of gestation until farrowing.Log counts were analyzed using pre-planned contrast statements to test for treatment, day, and treatment × day interactions.No evidence for difference was detected. 2