97 Awardee Talk: Feeding Essential Fatty Acids to Late-gestating Beef Cows Optimizes Performance and Health Responses of the Offspring

Option 1, Fetal Programming Only: Non-lactating, pregnant, multiparous Angus × Hereford cows (n = 104) were ranked by pregnancy sire (1 of 2 sires), body weight (BW), and body condition score (BCS) on d -15 of the experiment (d 180 of gestation). Cows were then assigned to receive: (1) 195 g/cow daily of CSSO (n = 52) or 2) 170 g/cow daily of CON (n = 52). Cows received treatments individually from d 0 to calving. Calves were weaned on d 290 of the experiment, preconditioned for 35 d, and placed in a feedyard until slaughter (d 514). Cows receiving CSSO and their calves had greater (P < 0.01) plasma concentrations ω-6 PUFA compared with CON after calving. Colostrum IgG and calf plasma IgG concentrations 24 h after birth were greater (P ≤ 0.02) in CSSO vs. CON cattle. Calves from CSSO cows had greater (P ≤ 0.05) expression of adipogenic and myogenic genes in the longissimus muscle compared with CON. No treatments differences in birth BW, weaning BW, and final preconditioning BW were noted (P ≥ 0.36). Average daily gain and final BW in the feedyard were greater (P ≤ 0.05) in steers from CSSO cows compared with CON. The incidence of calves diagnosed with BRD that required a second antimicrobial treatment was less (P = 0.03) in calves from CSSO cows, resulting in reduced (P = 0.05) need of treatments to regain health compared with CON. Upon slaughter, LM area was greater (P = 0.03) in calves from CSSO cows compared with CON. Collectively, these results are indicative of programming effects on postnatal offspring growth and health resultant from CSSO supplementation to late-gestating cows. Hence, supplementing CSSO to beef cows during pregnancy might be a feasible alternative to optimize offspring productivity and welfare. Option 2, Fetal Programming and Fat Tubs: Two experiments were conducted to evaluate: (1) effects of calcium salts of soybean oil (CSSO) supplementation to late gestating beef cows on the performance of the offspring; (2) the viability of utilizing low-moisture molasses-based blocks (LMB) as a delivery method for CSSO supplementation. In experiment 1, non-lactating, pregnant, multiparous Angus × Hereford cows were assigned to receive: (1) 195 g/cow daily of CSSO (n = 52) or (2) 170 g/cow daily of CON (n = 52) from d 195 of gestation until calving. CSSO cattle had greater (P < 0.01) plasma concentrations ω-6 PUFA; greater (P ≤ 0.02) colostrum and calf plasma IgG concentrations; greater (P ≤ 0.05) expression of adipogenic and myogenic genes in the longissimus muscle (LM); required fewer microbial treatments for BRD (P = 0.05) and had greater LM area compared to CON cohorts. In experiment 2, non-lactating, non-pregnant, multiparous beef cows were allocated to 1 of 9 pens (n = 9 pens; 4 cows/pen) and each pen was assigned to receive: 1) NOSUPP, hay only diet; 2) LMB, self-fed LMB supplement containing 24.7% DM CSSO; 3) CONC, hand-fed supplement identical to LMB. The design was a replicated 3 x 2 Latin square with 2 periods of 42 d, and a 21-d washout interval. Supplement DM intake did not differ (P = 0.39) between LMB and CONC cows from d 14 to 42 as designed, despite a greater variation in daily intake of LMB vs. CONC (treatment × day interaction; P < 0.01). No treatments effects were noted (P ≥ 0.40) for hay intake, BCS, and BW. From d 14 to 42, plasma concentrations of, ω-6 PUFA (P < 0.01) in CONC and LMB vs. NOSUPP cows. Hence, the use of self-fed LMB appears to be a valid strategy to provide CSSO to forage-fed beef cattle.

208 MicroRNA Expression in Longissimus Muscle Biopsies During Feedlot Finishing of Angus Steers

Intramuscular fat or marbling (IMF) is highly desired in beef products due to its ability to improve carcass value. Studies indicate that finishing cattle on high concentrate diets increase marbling deposition over time-on-feed (TOF). Angus-cross steers (n = 7; 433 + 17 kg) were individually fed a high concentrate diet for a period of 124 d. Steers were weighed and ultrasounded every 30 d on feed. Longissimus muscle biopsies were taken between the 11th and 13th rib on alternating sides at d 0, 90, and 124. RNA was extracted from the biopsy samples and subjected to microRNA (miRNA) sequencing and qPCR for mRNA expression of key lipogenic genes. Data were analyzed with time-on-feed in the model. ADG was increased between d30 and d90 (P < 0.05). The feed conversion ratio was lowest during d0 to d60 and increased from d90 to d124 (P < 0.05). Fat thickness increased (P < 0.05) between 90 to 124 d. Ultrasound intramuscular fat percentage increased (P < 0.05) between 60 and 90 d. miRNA sequencing results showed that mir-122 was differentially expressed from d0 to d90 (6.72 log fold change; P = 0.0048) and from d0 to 124 (3.83 log fold change; P = 0.026). Several miRNA were down regulated (> 2 log fold change; P < 0.05) during TOF, which included miR-2411, -449a, -1197, -323, and -485. Relative expression of key lipogenic genes, stearoyl Co-A desaturase (SCD-1) and fatty acid synthase, were up-regulated (P < 0.05) between d90 and 124 d. These results show that miR-122 appears to be a novel miRNA associated with marbling deposition and lipid metabolism.

PSVIII-23 Mycotoxin exposure on fetal skeletal muscle fiber hypertrophy and miRNA transcriptome

The objective of this study was to evaluate the miRNA transcriptome and muscle fiber characteristics of lambs from ewes consuming endophyte-infected tall fescue (E+) seed during two stages of gestation at two animal ages. Pregnant Suffolk ewes (yr 1 n = 36; yr 2 n = 60) were randomly assigned to one of two gestational treatments: E+ seed (1.77 mg/hd/d of ergovaline/ergovalinine) during mid- (gd 35 - 85; MID) or late-gestation (gd 86 – 133/parturition; LATE). Longissimus muscle samples (n = 3/E+ treatment/time) were collected from fetuses on gd 133 (FETAL; expt. 1) or from wethers after finishing to market weight (MKT; expt. 2) from ewes from MID and LATE E+ treatments. Data were analyzed as a 2 x 2 factorial with E+ treatment (MID or LATE), time (FETAL or MKT), and the two-way interaction in the model. Exposure to E+ fescue seed during LATE gestation reduced (P = 0.03) cross-sectional area of Type II muscle fibers at MKT but not at FETAL. Cross-sectional area of Type II muscle fibers were larger (P < 0.05) at MKT than FETAL. Animal age influenced miRNA expression with 120 miRNA differentially expressed. miRNA-22-3p and -29a were down regulated (P < 0.001; > -5 log fold change) with animal age; whereas miR-3958-3p, -410-3p, -299-5p and -487b-3p (P < 0.0001; > 3 log fold change) were up-regulated. Exposure to E+ during MID or LATE gestation did not alter miRNA expression. Muscle fiber hypertrophy increased from FETAL to MKT age altered the expression of miRNA in longissimus muscle.

PSII-B-26 Comparison of Suffolk and Texel sired lamb growth and satellite cell proliferation in the early postnatal period

Suffolk ewes (n = 26) were blocked by body condition and weight, and randomly divided into two breeding groups (n = 13/group). One group was bred to a Texel ram and the other to a Suffolk ram. Ewes were confirmed pregnant by ultrasound and went to term. Male lambs (n = 4/sire/time) were harvested on d 2, 14, and 203 of age for muscle characterization and satellite cell isolation. From d 2 to 14, body weight increased (P < 0.01) by 80%, weight of the longissimus increased by 160%, and longissimus muscle area increased by 100%. Between d 14 and 203 lamb weight and weight of the longissimus increased by 350%, while longissimus area only increased by 100%. Sire breed did not alter lamb weight or weight of the longissimus (P > 0.10). Longissimus muscle area tended (P < 0.10) to be increased for Texel sired lambs when compared to Suffolk sired lambs. The total number of satellite cells isolated were not different by sire breed but did differ by animal age (P < 0.01). Satellite cell populations per gram of tissue increased between d 2 and 14 and decreased from d 14 to 203. Due to the large changes in growth from d2 to 14, satellite cell proliferation was examined at d 2 of age. Satellite cell proliferation capacity was altered by sire breed at d 2 of age potentially contributing to the increased longissimus muscle area. Advancing animal age and development alters satellite cell population numbers and potentially supports a high capacity for growth.

PSXIII-16 Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: physiological and productive responses of cows and their offspring until weaning

Pregnant, non-lactating beef cows (n = 190; 117 ± 2.2 d of gestation; d 0) were assigned to receive: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4, Zinpro; n = 95). From d 0 to calving, cows were maintained in a single pasture and individually offered treatments three times weekly. Cow BW and BCS were recorded on d -30, d 97, upon calving, and at weaning and liver biopsies performed in 30 cows/treatment. Milk production was estimated at 42 ± 0.5 d postpartum via weigh-suckle-weigh (WSW). Liver and longissimus muscle (LM) biopsies were performed in 30 calves/treatment upon calving and 24 h later, at WSW, and at weaning. No treatment effects were detected (P ≥ 0.49) for cow BCS, despite AAC cows having greater (P = 0.04) BW on d 97. Liver Co (P < 0.01) concentrations were greater for AAC compared to INR cows, and liver concentrations of Cu were greater (P = 0.02) for INR compared to AAC cows on d 97. Upon calving, INR cows had greater (P ≤ 0.01) liver Cu and Zn concentrations compared to AAC cows. Cows receiving AAC had greater (P = 0.04) hepatic mRNA expression of metallothionein 1A at calving, and their calves had greater (P = 0.04) hepatic mRNA expression of superoxide dismutase at weaning. Milk production did not differ between AAC and INR cows (P = 0.70). No treatment effects were detected (P ≥ 0.29) for mRNA expression of LM genes in calves at birth and weaning. Calf birth and weaning BW were similar (P ≥ 0.19) between treatments. Hence, supplementing AAC or INR to beef cows during the last 5 mo of gestation yielded similar cow-calf productive responses until weaning.

Lipid Metabolism Gene Expression And Cellularity of Intramuscular Adipocytes Within The Longissimus Muscle of Angus- And Wagyu-Sired Cattle When Raised To A Similar Age or Body Weight

Background: This study investigates intramuscular (IM) adipocyte development and growth in the Longissimus muscle (LM) between Wagyu- and Angus-sired steers compared at a similar age and days on feed (DOF) endpoint or similar body weight (BW) endpoint by measuring IM adipocyte cell area and lipid metabolism gene expression. Methods: Angus-sired steers (AN, n=6) were compared with steers from two different Wagyu sires, selected for either growth or marbling, to be compared at a similar DOF (WA-GD, n=5 and WA-MD, n=5) in experiment 1 or BW (WA-GB, n=4 and WA-MB, n=5) in experiment 2, respectively. Results: In experiment 1, WA-MD steers had a greater percentage of IM fat in the LM compared with AN and WA-GD steers. In experiment 2, WA-MB steers had a greater percentage of IM fat in the LM compared with AN and WA-GB steers. The distribution of IM adipocyte area was unimodal at all biopsy collections, with IM adipocyte area becoming progressively larger as cattle age and BW increased (P≤0.01). Peroxisome proliferator activated receptor delta (PPARd) was upregulated earlier for WA-MD and WA-MB cattle compared with other steers at a similar age and BW (P≤0.02; treatment×biopsy interaction). An earlier upregulation of PPARd is believed to have then upregulated peroxisome proliferator activated receptor gamma (PPARg) at a lesser BW for WA-MB steers (P=0.09; treatment×biopsy interaction), while WA-MD steers had a greater (P≤0.04) overall mean PPARg expression compared with other steers. Glycerol-3-phosphate acyltransferase, lipin 1, and hormone sensitive lipase demonstrated expression patterns similar to PPARg and PPARd or CCAAT enhancer binding protein beta, which emphasizes their importance in marbling development and growth. Additionally, WA-MD and WA-MB steers often had a greater early expression of fatty acid transporters (fatty acid transport protein 1; P<0.02; treatment×biopsy interaction) and binding proteins (fatty acid binding protein 4) compared with other steers. With many lipolytic genes upregulated at harvest, acetyl-CoA carboxylase beta may be inhibiting fatty acid oxidation in the LM to allow greater IM fat accumulation.Conclusions: Cattle with a greater marbling propensity appear to upregulate adipogenesis at a lesser maturity through PPARd, PPARg, and possibly adipogenic regulating compounds in lysophosphatidic acid and diacylglycerol.

SINE Insertion in 5’ Flanking of IGFBP3 May Associated With Gene Expression and Phenotypic Variations

Background: Insulin-like growth factor binding proteins (IGFBPs), specifically binding to IGF1 and IGF2, play an important role in regulating physiological functions of insulin-like growth factors (IGFs). IGFBPs have been considered important candidate genes for economic traits due to their involvement in physiological processes related to growth and development. However, most of the current studies on genetic markers of IGFBPs have focused on SNPs, and large fragment insertion mutations such as retrotransposons have rarely been considered. In this paper, we screened the porcine IGFBP genes (IGFBP1-8) for retrotransposon insertion polymorphisms (RIPs) using bioinformatics prediction combined with the PCR-based amplification. Furthermore, for two linked RIPs their population distribution and impact on promoter activity and phenotype were further evaluated.Results: Screening of IGFBPs identified RIPs in IGFBP1-5 and IGFBP7. In total twelve predicted RIPs were confirmed by PCR. These RIPs were detected in different breeds with an uneven distribution among them. By linkage genetic analysis and PCR verification, IGFBP3-1-RIP and IGFBP3-2-RIP are completely linked, showing only three genotypes, SINE+/+/LINE-/-, SINE-/-/LINE+/+ and SINE+/-/LINE-/+. The age of 100 kg body weight and longissimus muscle thickness of Large white individuals of SINE+/+/LINE-/-genotype were significantly (P<0.05) higher than those of SINE+/-/LINE+/- genotype and SINE-/-/LINE+/+ genotype. However, the longissimus muscle thickness and corrected backfat thickness of SINE+/+/LINE-/- individuals were significantly (P<0.05) thinner than those of SINE+/+/LINE-/- genotype. The expression of the IGFBP3 gene in liver, leg muscles and backfat of 30-day Sujiang piglets with SINE+/+/LINE-/- genotype were significantly higher (P<0.05) than those with SINE-/-/LINE+/+ genotype by the real-time quantitative polymerase chain reaction (qPCR). Further study was conducted to confirm the effect of SINE and LINE insertion on the promoter activity of IGFBP3. First, the core promoter region of the IGFBP3 gene was identified locating within 482bp upstream of ATG by using the dual-luciferase activity assay. Then SINE and LINE were combined with 482bp fragment to construct a recombinant vector respectively based on the PGL3-Promoter-Enhancer. The recombinant vector was transfected into C2C12, 3T3-L1, and Hela cells. The detection of the dual-luciferase reporter gene revealed that only SINE insertion was significantly increased (P<0.05) promoter activity of the IGFBP3 gene, indicating that the SINE may act as an enhancer to regulate the promoter activity of the IGFBP3 gene. Conclusions: Overall, this study identified 12 RIPs in IGFBP gene clusters, which provided useful markers for genetic analysis of pig populations. Furthermore, based on the dual-luciferase activity assay in cells and association analysis, the linked genetic variations generated by SINE and LINE insertions in 5’ flanking of IGFBP3 may associated with variations of gene expression and phenotype.