Use of electromyography to detect muscle exhaustion in finishing barrows fed ractopamine HCl1

The objective of this study was to examine the effect of nicotinamide riboside (NR) on pectoralis major muscle (PM) development and growth. Fertilized Cobb 500 broiler eggs (N = 156; average weight of 70.3 g) were ordered by weight and within each 4 egg strata eggs were randomly assigned to treatments within a 2 × 2 factorial arrangement. Factor 1 consisted of NR treatment with eggs receiving 0 or 250 mM NR. Factor 2 consisted of injection location, with treatments injected into either the yolk sac or albumen. Eggs were incubated at a temperature of 37°C and a relative humidity of 40 ± 2% for the first 18 d of incubation and humidity was increased to 60 ± 2°C for the final 3 d. On d 10 of incubation, eggs were injected in their designated location with 100 μL of 0.9% sterile saline containing the assigned NR dose. Chicks were hatched, euthanized, and morphometric measurements of the body and left PM were collected. The left PM was also analyzed for muscle fiber cross-sectional area (CSA) and density. There were no treatment × location or main effects for all body morphometric measurements (P > 0.07), except chest width of chicks from eggs injected in the yolk were wider (P = 0.01) than chicks from eggs injected in the albumen. There were only treatment × location interactions for PM weight and length (P < 0.01). When NR was injected into the albumen, PM weight did not differ (P = 0.09); however, when NR was injected into the yolk sac, PM weight increased (P < 0.01). When NR was injected into both locations, PM length increased (P < 0.01), but increased to a greater extent when NR was injected into the yolk sac. There were treatment main effects for PM width and depth (P < 0.01), with NR injected chicks having PM with greater width and depth. There were no treatment × location or main effects for PM fiber CSA (P > 0.06). There was a treatment × location interaction (P < 0.01) for fiber density. When NR was injected into the albumen, fiber density did not differ (P = 0.09); however, when NR was injected into the yolk sac, fiber density increased (P < 0.01). Injecting NR into the yolk sac of the developing embryo at d 10 of incubation increased PM development which was due to an increase in muscle density.

Section: Resultsmentioning

confidence: 99%

“…The methods of Noel et al (2016) were followed for immunohistochemistry with modifications. The PM was removed from the tongue depressor, embedded in tissue embedding media (Fisher Scientific), cooled with isopentane chilled liquid nitrogen, and stored at −80 °C until cryosectioning.…”

Section: Methodsmentioning

confidence: 99%

In ovo feeding of nicotinamide riboside affects broiler pectoralis major muscle development1,2

Gonzalez

Jackson²

2020

“…Two cryosections, 10 μm thick, per slide were collected on 1 (birth sections) or 2 (wean sections) frost-resistant slides (Fisher Scientific). The methods of Noel et al (2016) were followed for fiber type immunohistochemistry with modifications.…”

Section: Methodsmentioning

confidence: 99%

“…When analyzing muscle fibers of pigs harvested at weaning, fibers that stained exclusively positive for BA-D5, SC-71, and BF-F3 were labeled type I, type IIA, and type IIB, respectively. Fibers that stained positive for both SC-71 and BF-F3 were labeled as type IIX fibers ( Noel et al, 2016 ). The periphery of all muscle fibers was identified with α-dystrophin, Hoechst 33342 dye identified all nuclei and Pax7 identified satellite cells for all cryosections.…”

Section: Methodsmentioning

confidence: 99%

The effects of maternal dietary supplementation of cholecalciferol (vitamin D3) and 25(OH)D3 on sow and progeny performance1

Thayer

Nelssen

Langemeier

et al. 2019

Abstract A total of 69 sows (DNA Line 200 × 400) and their progeny were used to determine if feeding a combination of vitamin D3 and 25(OH)D3 influences neonatal and sow vitamin D status, muscle fiber morphometrics at birth and weaning, and subsequent growth performance. Within 3 d of breeding, sows were allotted to one of three dietary treatments fortified with 1,500 IU/kg vitamin D3 (CON), 500 IU/kg vitamin D3 + 25 μg/kg 25(OH)D3 (DL), or 1,500 IU/kg vitamin D3 + 50 μg/kg 25(OH)D3 (DH). When pigs were sacrificed at birth, there were no treatment effects for all fiber morphometric measures (P > 0.170), except primary fiber number and the ratio of secondary to primary muscle fibers (P < 0.016). Pigs from CON fed sows had fewer primary fibers than pigs from sows fed the DH treatment (P = 0.014), with pigs from sows fed DL treatment not differing from either (P > 0.104). Pigs from CON and DL fed sows had a greater secondary to primary muscle fiber ratio compared to pigs from DH sows (P < 0.022) but did not differ from each other (P = 0.994). There were treatment × time interactions for all sow and pig serum metabolites (P < 0.001). Therefore, treatment means were compared within the time period. At all time periods, sow serum 25(OH)D3 concentrations differed for all treatments with the magnitude of difference largest at weaning (P < 0.011), where serum 25(OH)D3 concentration was always the greatest when sows were fed the DH diet. At birth, piglets from DH fed sows had greater serum 25(OH)D3 concentrations than piglets from sows fed the DL treatment (P = 0.003), with piglets from sows fed CON treatment not differing from either (P > 0.061). At weaning, serum concentrations of 25(OH)D3 in piglets from all sow treatments were different (P < 0.001), with the greatest concentration in piglets from DH sows, followed by CON, and followed by DL. There were no treatment × time interactions for any of the metabolites measured in milk and no treatment or time main effects for 24,25(OH)2D3 concentration (P > 0.068). Colostrum collected within 12 h of parturition contained less (P = 0.001) 25(OH)D3 than milk collected on day 21 of lactation. Regardless of time, concentrations of 25(OH)D3 in milk were different (P < 0.030), with the largest 25(OH)D3 concentration from DH fed sows, followed by DL, and then CON. In conclusion, combining vitamin D3 and 25(OH)D3 in the maternal diet improves the vitamin D status of the dam and progeny and it increases primary muscle fiber number at birth.

“…As previously mentioned, the studies by Miller (unpublished data) and Ivers (unpublished data, Study #1) evaluated the effects of 20 mg/kg of RAC and handling methods and reported that the effects of RAC dose on fatigued pigs is dependent on handling methods. More recently, Noel et al (2016) found that barrows fed 10 vs. 0 mg/kg RAC reached subjective exhaustion earlier and covered less distance in a circular track when continuously handled during a performance test. Peterson et al (2015) reported that feeding RAC at 7.5 mg/kg resulted in a higher rate of non-ambulatory pigs than 0 and 5 mg/kg of RAC.…”

Section: Resultsmentioning

confidence: 99%

Review: Effects of Ractopamine Hydrochloride (Paylean) on welfare indicators for market weight pigs1

Ritter

Johnson

Benjamin

et al. 2017

This review summarizes the effects of ractopamine hydrochloride (RAC) dose (5, 7.5, 10, and 20 mg/kg) on market weight pig welfare indicators. Ractopamine hydrochloride (trade name Paylean) is a β-adrenergic agonist that was initially approved in the U.S. in 1999 at doses of 5 to 20 mg/kg to improve feed efficiency and carcass leanness. However, anecdotal reports suggested that RAC increased the rate of non-ambulatory (fatigued and injured) pigs at U.S. packing plants. This led to the addition of a caution statement to the Paylean label, and a series of research studies investigating the effects of RAC on pig welfare. Early research indicated that: (1) regardless of RAC administration, fatigued (non-ambulatory, non-injured) pigs are in a state of metabolic acidosis; (2) aggressive handling increases stress responsiveness at 20 mg/kg RAC, while 5 mg/kg reduces stress responsiveness to aggressive handling. Given this information, dosage range for Paylean was changed in 2006 to 5 to 10 mg/kg in market weight pigs. Subsequent research on RAC demonstrated that: (1) RAC has minimal effects on mortality, lameness, and home pen behavior; (2) RAC fed pigs demonstrated inconsistent prevalence and intensity of aggressive behaviors; (3) RAC fed pigs may be more difficult to handle at doses above 5 mg/kg; and (4) RAC fed pigs may have increased stress responsiveness and higher rates of non-ambulatory pigs when subjected to aggressive handling, especially when 20 mg/kg of RAC is fed.