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A total of 1,156 PIC 800-sired pigs (12.4 kg BW) were used in a 27-day experiment to estimate the SID lysine requirement of pigs ranging from 12.4 to 31.3 kg BW. Forty-eight pens of mixed sex pigs were used. Pens were blocked by location within the barn, with barrow and gilt numbers in pens kept consistent within block. Pens were allotted to one of five dietary treatments in a randomized design with 9 to 10 replicate pens (10 pens for treatments 1, 3, 5 and 9 pens for treatments 2, 4) per treatment. Dietary SID lysine concentrations evaluated were 1.12, 1.19, 1.26, 1.33, and 1.40%. Diets were corn-soybean meal-based and formulated to equal NE concentrations across treatment. Data were analyzed using a general linear model. Orthogonal contrasts with coefficients for equally spaced treatments were used to analyze for linear and quadratic effects. For significant quadratic effects, breakpoint analysis was conducted (two slope regression or quadratic broken line analysis) using nonlinear regression analysis to estimate for SID lysine requirement. A linear (P < 0.05) response was observed for BW to increase as SID lysine level in the diet increased. Increasing SID lysine increased average daily gain (ADG) quadratically (P = 0.05) with a plateau observed above 1.357% SID Lys. Additionally, increased SID lysine yielded a quadratic effect on G:F (P < 0.05) with a plateau above 1.327% SID lysine. There was a quadratic response (P < 0.05) observed for cost of gain (COG), with no benefit to COG when feeding above 1.201% SID lysine. However, there was a linear response (P < 0.05) observed for return over feed cost (ROFC) as SID lysine increased due to increased BW. There was no effect of SID lysine level fed on feed intake or mortality and morbidity. These data indicate that the estimated SID lysine requirement for PIC 800-sired pigs ranging from 12.4 to 31.3 kg to be 1.327 and 1.357 for optimal feed efficiency and ADG, respectively. [ABSTRACT FROM AUTHOR]

A total of 1,125 pigs (31.4 kg BW) of DNA genetics were used in a 109-d experiment to evaluate the effect of SID Lys feeding curve of pigs from 31.4 to 133.3 kg BW. Forty-five pens of mixed sex pigs were used. Pens were blocked by location within the barn with barrow and gilt numbers in pens kept consistent within block. Pens were allotted to one of five dietary treatments in a randomized complete block design with 9 replicate pens per treatment. Dietary SID lysine concentrations were evaluated on a curve (corresponding to 90, 95, 100, 105, and 110% of the DNA Genetics SID lysine recommendations) using a 6-phase feeding program throughout the experimental period. The 100% curve concentrations used were 1.16% for phase 1 (31.4 - 47.5 kg), 1.02% for phase 2 (47.5 - 64.4 kg), 0.92% for phase 3 (64.4 - 81.8 kg), 0.79% for phase 4 (81.8 - 98.9 kg), 0.72% for phase 5 (98.9 - 117.1 kg), and 0.65% for phase 6 (117.1 - 133.3 kg). Diets were corn-soybean meal-DDGS-based and formulated for equal NE concentrations across treatment within diet phase. Data were analyzed using a general linear model. Orthogonal contrasts with coefficients for equally spaced treatments were used to analyze for linear and quadratic effects. A linear (P < 0.05) increase was observed for BW, average daily gain, and G:F as SID lysine level in the diet increased. There was a linear increase observed (P < 0.05) for lysine intake (g/d and g per lb. gain) as SID lysine level of the diet increased. While no difference (P > 0.10) was observed for NE intake, caloric efficiency improved linearly (P < 0.05) as lysine level in the diet increased. Furthermore, return over feed cost improved linearly (P < 0.05) as dietary SID lysine level increased. There was no effect of SID lysine level fed on mortality and morbidity. A linear response (P < 0.05) for hot carcass weight and loin depth was observed as SID lysine level increased. Additionally, a quadratic response was observed (P < 0.05) for fat depth and percent lean as SID lysine level increased. These data indicate the SID lysine level that optimized growth and carcass measurements for DNA pigs ranging from 31.4 to 133.3 kg to be above the 105% curve, corresponding to 1.22, 1.071, 0.966, 0.83, 0.756, and 0.683 for diet phases 1 through 6, respectively. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to evaluate the effect of feeding Microfused Essential Oil Technology (MEOT, Ralco Nutrition, Inc.) to mature boars on their semen production and semen quality biomarkers. In Experiment 1, boars (n = 21) housed at a commercial boar stud were fed MEOT in their diet. These boars were collected in their normal collection routine of twice per week. Total motile sperm count was measured for each collection over a 10-month period (December to September). A baseline motile sperm count was determined for each boar during the 2 months before the beginning of the MEOT feeding in February. Repeated measures analysis was conducted to evaluate the effects of sperm production over time. Feeding MEOT to boars resulted in greater motile sperm count (P < 0.0001) and greater (P < 0.0001) economic revenue per collection. In Exp. 2, the objective was to determine if the increased semen production measured had any impact on semen quality biomarkers. Semen samples were collected from the same boar stud used in Exp. 1 after MEOT feeding. Control samples were collected from a boar stud using similar boar genotypes, environmental condition, semen extender, and time from collection. One 75 mL extended semen dose from 8 to 10 boars across 3 weeks was collected and sent to the laboratory for semen quality analysis. The traits and biomarkers that were analyzed for each sample included morphology, zinc signature, plasma membrane integrity (detected by propidium iodide; PI), lectin PNA acrosome health, lectin LCA membrane health, reactive oxygen species status (ROS; detected by H2DCFDA), aggresome (AGG), and DNA fragmentation (dected by acridine orange). No differences in morphology (P > 0.05) were detected. For the MEOT-fed boars, a greater portion (P < 0.001) of the sperm population was in the zinc signature 2 category indicating more live, non-capacitated sperm and a lesser portion (P < 0.0003) in the zinc signature 4 category indicating less dead, fully capacitated sperm. In addition, for PI, a greater portion (P < 0.03) of the sperm were live with good plasma membrane integrity for boars fed MEOT versus the controls. A greater portion of the sperm from the MEOT-fed boars had better acrosome integrity (P < 0.001) as well as tail membrane health (P < 0.01). No differences (P > 0.05) were observed for ROS. Semen from MEOT-fed boars had less AGG misfolded proteins (P < 0.0001) and a tendency (P < 0.07) for less DNA fragmentation. These data indicate that feeding MEOT to boars resulted in greater motile sperm production and that did not result in a negative impact on semen quality with many semen biomarkers being improved in MEOT-fed boars. [ABSTRACT FROM AUTHOR]

A total of 1,000 Genesus (Oakville, Manitoba, Canada) genetics pigs (51.8 kg body weight) were used to estimate the standardized ileal digestible (SID) lysine requirement by dietary phase. Pigs were penned by sex at 25 pigs per pen. Pens were allotted to one of five dietary treatments in a completely randomized design with eight replicate pens (four barrow, four gilt) per treatment. Growth performance was evaluated in four independent phases in which pens were re-allotted to dietary treatment between phases. Dietary SID Lys concentrations evaluated were 0.78, 0.88, 0.98, 1.08, and 1.18% for phase 1, 0.68, 0.77, 0.86, 0.95, and 1.04% for phase 2, 0.60, 0.67, 0.75, 0.83 and 0.90% for phase 3, and 0.53, 0.60, 0.67, 0.74, and 0.81% for phase 4. Diets were formulated to be isoenergetic within each phase. During phase 1 (52-64 kg), average daily gain (ADG) and gain to feed ratio (G:F) increased (P < 0.01) quadratically with increasing SID Lys. Breakpoint analysis estimated the SID Lys requirement for ADG and G:F for phase 1 at 0.99 and 1.02%, respectively. During phase 2 (64-82 kg), ADG increased (P < 0.10) quadratically as dietary SID Lys increased with a plateau observed above 0.86% SID Lys. Gain:feed increased linearly (P < 0.01) with increasing SID Lys. During phase 3 (82-97 kg) cost of gain was a quadratic response (P < 0.10) with the breakpoint being at 0.76% SID Lys. During phase 4 (97-131 kg), a linear response (P < 0.02) in G:F was observed with increasing SID Lys but with no improvement above 0.67% SID Lys. These data indicate the SID lysine requirement for Genesus finishing pigs to be approximately 0.99% (23.0 g/d) for 52-64 kg, 0.86% (21.9 g/d) for 64-82 kg, 0.76% (20.2 g/d) for 82-97 kg, and 0.67% (21.6 g/d) 97-131 kg. [ABSTRACT FROM AUTHOR]