Relative bioavailability of l-lysine sulfate is equivalent to that of l-lysine HCl for nursery piglets.

Supplementary l-lysine sources include l-lysine HCl and l-lysine sulfate. l-Lysine sulfate contains at least 50% l-Lys and other components as residues from the fermentation process, other amino acids, and other organic and inorganic substances, being an alternative to l-Lys HCl. The aim of this study was to evaluate the relative bioavailability (RBV) of l-Lys sulfate in comparison with l-Lys HCl and its effects on performance, blood parameters, intestinal functionality, and the apparent total tract digestibility in nursery piglets. A total of 168 female piglets (DB90 × PIC337), weaned at 22 d (BW = 6.29 ± 0.41 kg), were distributed in seven dietary treatments and eight replicates, with three pigs per pen. The experimental period of 42 d was divided into two phases (phase 1, days 0-21; phase 2, days 21 to 42). The basal diet (CON) was lysine-deficient formulated to meet 73% of standardized ileal digestible Lys requirements. For the other diets, the CON was supplemented with three levels (80%, 90%, and 100% of standardized ileal digestible Lys requirements) of l-Lys sulfate (70% l-Lys) or l-Lys HCl (79% l-Lys). There were no significant differences (P > 0.05) in the performance and concentrations of plasma urea and creatinine between the l-Lys sources. The RBV of l-Lys sulfate relative to l-Lys HCl was 106%, 119%, and 117% for effects on ADG, G:F, and plasma urea, respectively. Lys deficiency resulted in a greater (P < 0.05) incidence of diarrhea, while pigs supplemented with Lys sulfate or Lys HCl showed greater (P < 0.05) villus height in the jejunum when compared to those receiving the CON. Diets supplemented with l-Lys sulfate had greater (P < 0.05) apparent total tract digestibility of dry matter, gross energy, and crude protein. In conclusion, the RBV of l-Lys sulfate for effects on ADG, G:F, and plasma urea is equivalent to that of l-Lys HCl for nursery piglets.

Effects of maternal artificial vocalization on hyperprolific lactating sows and piglets behavior.

The objective of this trial was to evaluate the behavioral patterns and performance of lactating sows and their litters under the effect of artificial vocalization. Twenty-eight sows and their litters were distributed in a completely randomized design in a 2x2 factorial scheme (artificial vocalization x lactation week). The behavior of the animals was monitored during 24 hours on the 7th and 15th days of lactation, analyzing the number, interval, and frequency of nursings. The body condition and performance of the sows were also evaluated. Artificial vocalization promoted higher frequencies of eating for sow and nursing for piglets (P <0.05), increased inactive sow behavior (P <0.05), and reduced sow alert in activity (P <0.05). The number and duration of suckling sessions at the 15thday of lactation were reduced (P <0.05). The use of artificial vocalization did not affect the body condition or milk production of the lactating sows, or the performance of the litter during lactation (P> 0.05). The use of maternal artificial vocalization during lactation of sows promoted greater lactation efficiency and longer rest time, favoring the sows' welfare.