Steven M Lonergan

Iowa State University | ISU · Department of Animal Science

Calpains are cysteine proteinases responsible for many biological roles in muscle, including protein degradation, muscle growth, and myoblast fusion. Calpains are inhibited by calpastatin, an endogenous inhibitor. Other factors, such as variations in pH, ionic strength, and oxidation influence calpain activity. This study aimed to determine the ext...

Dietary phosphorous is a necessary nutrient for bone development in pigs at all stages of its growing. Deficiencies in phosphorous decrease bone mineral content (BMC) and bone mineral density (BMD) and may be a causative of lameness. However, the normal range expected in whole body (WB) and individual bones for BMC and BMD in commercial pigs has be...

Abattoir-level digital image measurement and assessments recorded during the harvest process could contribute to better estimates of the economic value of each animal and could be used as animal health and well-being assessment tools to provide information/feedback for commercial pork producers. This study evaluated the association between live ani...

Fresh pork tenderness contributes to consumer satisfaction with the eating experience. Postmortem proteolysis of proteins within and between myofibrils has been closely linked with pork tenderness development. A clear understanding of the molecular features associated with pork tenderness development will provide additional targets and open the doo...

Understanding how to control pig growth is critical during market disruptions, including foreign animal disease and harvest facility shutdowns. In times of severe market disruptions, feeding acidogenic salts such as anhydrous calcium chloride to suppress appetite is an effective way to manage pig growth. Therefore, the aim of this study was to unde...

There is a consistent and growing need for livestock and meat producers to understand the factors that affect fresh meat quality and value. New information can be used to make precise changes in management or genetic selection to improve the ability to efficiently produce the high-quality meat that customers and consumers expect. The molecular comp...

Xylose is a primary component of arabinoxylan in swine diets. As arabinoxylan is a significant component of fiber, and fiber is generally rising in practical pig diets globally, the study of arabinoxylan and xylose is of increasing interest. However, the mechanisms by which free xylose may be absorbed and the pathways impacted by xylose have yet to...

The objective of the current study was to evaluate the effects of lipid peroxidation products, malondialdehyde (MDA), hexenal, and 4-hydroxynonenal (HNE), on calpain-1 function, and liquid chromatography and tandem mass spectrometry (LC-MS/MS) identification of adducts on calpain-1. Calpain-1 activity slightly increased after incubation with 100 μM...

Unpredictable variation in quality, including fresh pork water-holding capacity, remains challenging to pork processors and customers. Defining the diverse factors that influence fresh pork water-holding capacity is necessary to make progress in refining pork quality prediction methods. The objective was to utilize liquid chromatography and mass sp...

Selection for disease resilience, which refers to the ability of an animal to maintain performance when exposed to disease, can reduce the impact of infectious diseases. However, direct selection for disease resilience is challenging because nucleus herds must maintain a high health status. A possible solution is indirect selection on indicators of...

Tenderization of fresh, intact meat is typically dependent on either natural aging or via the application of exogenous enzymes. Tenderization via natural aging (holding meat under refrigerated temperatures for several days/weeks) is done by the actions of enzymes normally occurring in living muscle. These enzymes function to regulate the growth and...

The objective was to identify metabolome and proteome differences at 1 h and 1 d postmortem between longissimus thoracis (LT) muscle classified based on 6 h pH values. Twenty beef LT rib sections were sorted based on 6 h postmortem pH values into low (LpH; pH < 5.55; n = 9) and high (HpH; pH > 5.84; n = 8) pH classifications. Warner-Bratzler shear...

The objective was to define proteomic and metabolomic profiles associated with premium and poor-quality pork. Fresh pork loins (n=100) were aged 12 to 14 d postmortem before quality evaluation. Chops with a star probe values less than 4.5 kg, and a Hunter L score less than 47 were categorized as Premium (n=10). Chops with star probe values greater...

MicroRNA21 (MIR21) abundance in porcine oocytes and cumulus cells increases during in vitro maturation. The mechanism by which MIR21 regulates oocyte maturation and the effect on the developmental competence of subsequent embryos remains unclear. The objective of this study was to assess the function of MIR21 during porcine oocyte maturation and it...

The development of fresh meat quality is dictated by biochemical changes during the perimortem and postmortem period. Lipid and protein oxidation in postmortem skeletal muscle and meat products is detrimental to product quality. The mechanisms that influence lipid and protein oxidation in fresh meat remain unelucidated. Peroxiredoxins are thiol-spe...

The objective of this experiment was to identify the impact of supranutritional zinc (SUPZN) and ractopamine hydrochloride (RAC) supplementation of beef steers on postmortem protein degradation and tenderness development of extended (>14 d) aged steaks. It was hypothesized that RAC and SUPZN supplementation would influence meat quality development...

Iowa State University (ISU) offers undergraduate certificates to demonstrate completion of a curriculum in a specialized area across various disciplines. The certificate has the significant benefit of allowing students to customize their curriculum and document the completion of an approved course of study. A Dairy Cattle Production Management Cert...

The objective of this study was to determine the extent that myoglobin and beef color are associated with calpain-1 concentration and tenderness. Longissimus lumborum (LL) samples from the left side of Holstein beef carcasses (n = 31) were collected immediately post-evisceration for 0 h analyses. At 48 h postmortem six steaks were being removed fro...

Advancements in technology and analytical methods enable researchers to explore the biochemical events that cause variation in meat quality. Among those, western blot techniques have been successfully used in identifying and quantifying the key proteins that have critical functions in the development of meat quality. Housekeeping proteins, like β-A...

Iowa State University (ISU) offers undergraduate certificates to demonstrate completion of a focused study in a specialized area across a variety of disciplines. The certificate has the significant benefit of allowing students to customize their curriculum and document an approved course of study. A Swine Production Management Certificate is now of...

owa State University (ISU) offers undergraduate certificates to demonstrate completion of a focused study in a specialized area across a variety of disciplines. The certificate has the significant benefit of allowing students to customize their curriculum and document completion of an approved course of study. A Beef Cattle Production Management Ce...

Iowa State University offers undergraduate certificates to demonstrate completion of a focused study in a specialized area. The certificate has the significant benefit of allowing students to customize their curriculum and document an approved course of study. An Equine Science and Management Certificate is offered within the Animal Science Departm...

Iowa State University (ISU) offers undergraduate certificates to allow students to customize their curriculum and demonstrate completion of focused study in a specialized area across a variety of disciplines. The Poultry Production Management Certificate is offered within the Animal Science Department at ISU and integrates technical topics in anima...

Mechanically separated chicken (MSC) from 2 different separation methods (MSC1, Beehive separator, aged bones [Provisur Technologies, Mokena, IL]; MSC2, Poss separator, fresh bones [Poss Design Limited, Oakville, Ontario, Canada]) and chicken breast trim (CBT) were used as raw materials in frankfurters. Texture, color, and lipid oxidation were meas...

Fresh meat quality is adversely affected by protein oxidation. However, a fundamental understanding of the diverse factors that influence protein oxidation in postmortem muscle remains elusive. Peroxiredoxin-2 (Prdx2), an antioxidant protein, is more abundant in tough meat based on instrumental tenderness; however, the role of Prdx2 in postmortem s...

This study’s objective was to determine the impact of a dual respiratory and enteric bacterial health challenge on the antioxidant protein peroxiredoxin-2 (Prdx-2) profile and protein oxidation in the skeletal muscle of pigs from 2 lines that were divergently selected for residual feed intake (RFI). The hypotheses were that (1) differences exist in...

This study's objectives were to identify how subtle differences in ultimate pH relate to differences in pork quality and to understand how early-postmortem glycolysis contributes to variation in ultimate pH. The hypothesis was that elements in early-postmortem longissimus thoracis et lumborum proteome and metabolome could be used to predict quality...

Although pork producers typically aim to optimize growth rates, occasionally it is necessary to slow growth, such as when harvest facility capacity is limited. In finishing pigs, numerous dietary strategies can be used to slow growth so pigs are at optimal slaughter body weights when harvest facility capacity and/or access is restored. However, the...

The objective of this study evaluated the accuracy and repeatability when determining cull sow body condition scores (BCS) evaluated by scorers utilizing digital images. Participants (n=6) were selected based on previous BCS scoring on live sows. Group standards were established utilizing the scores from two participants with extensive experience B...

The study objectives were to determine the extent to which the sarcoplasmic proteome explains variations in aged pork loin star probe value. Pork loins (n=12) were categorized by differences in star probe at 21 d post mortem from a larger set of loins. Loins were categorized into low star probe (LSP) group (n=6; star probe<5.80 kg) and high star pr...

Mechanically separated chicken (MSC) was obtained by two different separation methods (MSC1, Beehive separator, 3–5 d-old bones; MSC2, Poss separator, fresh bones) and compared to chicken breast trim (CBT). Rheological attributes of myofibrillar protein solutions during thermal gelation and cooling were evaluated. All sources exhibited gelation wit...

Three chops from 20 pork carcasses were aged for 1, 8, and 21 days. Electrospray ionization-tandem mass spectrometry was used to comprehensively analyze profiles of phospholipids from each sample (n = 60). Total phospholipid quantity decreased 4-folds (P < .01) from 1 to 21 days of aging in pork loins. Phosphatidylinositol (PI) and phosphatidylseri...

Mechanically separated chicken (MSC) obtained from two different commercial mechanical separation processes was compared to commercial chicken breast trim. Rheological analyses showed that the gentler mechanical separation process resulted in material with better thermal gelation properties than the more aggressive process, which could result in a...

Objectives Previous research revealed a relationship between meat color and beef tenderness and indicated that myoglobin can inhibit calpain-1 in solution. The objective of this study was to determine the extent to which myoglobin and beef color are associated with calpain activity and beef tenderness.Materials and Methods Beef Longissimus dorsi sa...

Objectives It is well established that fresh meat shelf-life deteriorates during aging process. We hypothesize that part of the shelf-life reduction is due to membrane phospholipid deterioration through phospholipase activity and/or phospholipid oxidation during aging. Therefore, the objective of this study was to characterize the modifications/det...

Objectives Growth promoting technologies such as the β agonist ractopamine hydrochloride (RAC) and nutritional practices such as increased zinc (ZN) supplementation have potential to positively impact beef cattle growth. However, the impact of these strategies (RAC and ZN) on meat quality is unclear. The objective of this experiment was to determin...

Objectives Postmortem aging of fresh pork loins improves tenderness through protein degradation. Sarcomere length (SL) of postmortem muscle can vary between animals, and this could impact access and efficacy of proteinases to degrade proteins within, but not outside of the myofibril. The relationship between SL and protein degradation is not well d...

The objective of this study was to determine the influence of a dual respiratory and enteric pathogen challenge on growth performance, carcass composition, and pork quality of high and low feed efficient pigs. Pigs divergently selected for low and high residual feed intake (RFI, ~ 68 kg) from the 11th generation of Iowa State University RFI project...

The objective was to investigate the effects of blast chilling on pork quality in cuts from the Longissimus thoracic et lumborum (LM), Psoas major (PM), Semimembranosus (SM; both superficial [SMS] and deep [SMD] portions) and the Triceps brachii (TB). Forty carcasses (10 carcasses per replication) were split and sides were assigned to either blast...

The objectives were to determine 1) the interaction between aging duration and post-aging freezing on pork loin quality attributes and 2) the relationship between pork loin star probe (SP) and Warner-Bratzler shear force (WBS). Loins from 20 carcasses were collected 1 d postmortem. Chops (n = 9; 2.54-cm thick) were fabricated from each loin and vac...

Porcine reproductive and respiratory syndrome (PRRS) virus is one of the most economically significant pig pathogens worldwide. The virus infects pigs at all production stages and significantly reduces the tissue accretion of growing pigs. However, the metabolic explanation for these reductions in tissue accretion remain poorly defined. Additionall...

Porcine reproductive and respiratory syndrome (PRRS) virus is one of the most economically significant pig pathogens worldwide. However, the metabolic explanation for reductions in tissue accretion observed in growing pigs remains poorly defined. Additionally, PRRS virus challenge is often accompanied by reduced feed intake, making it difficult to...

Lawsoniaintracellularis (LI) and Mycoplasma hyopneumoniae (Mh) are two globally distributed pathogens that cause significant morbidity and mortality in grow-finish pigs. However, mechanisms that reduce growth and feed efficiency during LI and Mh infection are poorly defined. We hypothesized that reductions in performance are partially due to declin...

The aim of this study was to determine the extent to which calpastatin (CASN)variants (based on two chromatographic peaks; CASN-P1 and CASN-P2)explain variation in μ-calpain autolysis, protein degradation, and changes in the sarcoplasmic proteome observed during postmortem aging of beef. The Longissimus lumborum (LL)and Triceps brachii (TB)muscles...

Understanding skeletal muscle growth is paramount to the efforts of the industry in improving livestock production systems to efficiently produce meat. Extensive work has been done over the years to develop technologies and to improve genetics and nutritional inputs to enable livestock to grow more rapidly and to produce ever larger carcasses. With...

Feed efficiency is simply defined as the ratio between growth and feed intake. However, defining the integration of genetic and environmental factors that alter molecular and physiological aspects of growth, appetite, or a combination thereof is quite complex and remains elusive. In livestock such as pigs, limited resources (i.e. nutrients and ener...

Heat stress (HS) accounts for over $900 million loss annually in the U.S. swine industry resulting from slower growth rates, reduced feed efficiency and poor reproduction. Pigs with increased feed efficiency have lower basal metabolic rates and reduced metabolic heat production. Therefore, genetic selection for improved feed efficiency may reduce s...

The objective of this study was to identify the S-nitrosylated proteins in aging samples of pork longissimus thoracis muscle (aged 0 and 3 d) and to study the effects of exogenous S-nitrosoglutathione (GSNO, concentration at 10 and 100 μM) treatments of aged 0 d sample. After validating modified biotin switch method, the samples were labeled with t...

Respiratory and enteric pathogens such as Mycoplasma hyopneumoniae (Mh) and Lawsonia intracellularis (LI) reduce lean accretion and feed efficiency (FE) in growing pigs. However, the metabolic mechanism by which this occurs is still unknown. Therefore, the primary aim of this study was to examine the metabolic adaptation of pigs presented with a du...

Postmortem aging is a value-adding process and has been extensively practiced by the global meat industry for years. The rate and extent of aging impacts on meat quality characteristics are greatly affected by various biochemical/physiological changes occurring during the pre-rigor phase through post-rigor aging processes. This should also mean tha...

Heat stress (HS) negatively impacts several swine production variables, including carcass fat quality and quantity. Pigs reared in HS have more adipose tissue than energetically predicted, explainable, in part, by HS-induced hyperinsulinemia. Study objectives were to evaluate insulin’s role in altering fat characteristics during HS via feeding insu...

Feed efficiency (FE) is a valuable trait, yet how genetic selection for enhanced FE affects other processes such as response to disease is unknown. Disease from endemic respiratory and enteric pathogens such as Mycoplasma hyopneumoniae (Mh) and Lawsonia intracellularis (LI) are common in swine production. Therefore, the aim of this study was to exa...

Porcine epidemic diarrhea virus (PEDV) infects enterocytes and in nursery pigs, results in diarrhea, anorexia, and reduced performance. Therefore, the objective of this study was to determine how PEDV infection influenced growth performance and repartitioning of amino acids and energy in nursery pigs. A total of 32 barrows and gilts, approximately...

Heat stress (HS) is one of the costliest issues in the U.S. pork industry. Aims of the present study were to determine the consequences of repeated exposure to HS on growth performance, and the effects of a high fiber diet, the genetic potential for high lean tissue accretion, and the genetic potential for residual feed intake (RFI) on resilience t...

Heat stress (HS) is an important topic in the swine industry, costing hundreds of millions of dollars in economic losses annually, figures that could easily rise in light of global climate change. Muscle biology during HS is particularly important given skeletal muscle’s large proportion to the body and its ultimate conversion to meat. Here we repo...

This review reports the pork quality attributes, Warner-Bratzler Shear Force, Slice Shear Force, Star Probe, pH, marbling, color (Minolta L*/L or Hunter L*/L), and sensory tenderness evaluation, in control groups used in comparative nutrition experiments over the past 20 yr. The original aim of this study was to evaluate if changes in pork quality...

The extent to which selection for improved lean accretion and feed efficiency affects livestock behavior and response to stress is not well understood. The objective of this experiment was to examine the behavioral metric correlations and growth performance of barrows divergently selected for residual feed intake (RFI). A human approach test (HAT)...