Effect of growth-promoting technologies on Longissimus lumborum muscle fiber morphometrics, collagen solubility, and cooked meat tenderness

Citation: Ebarb, S. M., Drouillard, J. S., Maddock-Carlin, K. R., Phelps, K. J., Vaughn, M. A., Burnett, D. D., . . . Gonzalez, J. M. (2016). Effect of growth-promoting technologies on Longissimus lumborum muscle fiber morphometrics, collagen solubility, and cooked meat tenderness. Journal of Animal Science, 94(2), 869-881. doi:10.2527/jas2015-9888The objective of the study was to examine the effect of growth-promoting technologies (GP) on Longissimus lumborum steak tenderness, muscle fiber cross-sectional area (CSA), and collagen solubility. Crossbred feedlot heifers (n = 33; initial BW 464 +/- 6 kg) were blocked by BW and assigned to 1 of 3 treatments: no GP (CON; n = 11); implant, no zilpaterol hydrochloride (IMP; n = 11); implant and zilpaterol hydrochloride (COMBO; n = 11). Heifers assigned to receive an implant were administered Component TE-200 on d 0 of the study, and the COMBO group received 8.3 mg/kg DM of zilpaterol hydrochloride for the final 21 d of feeding with a 3 d withdrawal period. Following harvest, strip loins were collected and fabricated into 4 roasts and aged for 3, 14, 21, or 35 d postmortem. Fiber type was determined by immunohistochemistry. After aging, objective tenderness and collagen solubility were measured. There was a treatment x day of aging (DOA) interaction for Warner-Bratzler shear force (WBSF; P 0.31). Soluble collagen amount tended to be affected (P = 0.06) by a treatment x DOA interaction which was due to COMBO muscle having more soluble collagen than the other 2 treatments on d 21 of aging (P < 0.02). Correlation analysis indicated that type I, IIA, and IIX fiber CSA are positively correlated with WBSF at d 3 and 14 of aging (P < 0.01), but only type IIX fibers are correlated at d 21 and 35 of aging (P < 0.03). At these time periods, total and insoluble collagen became positively correlated with WBSF (P < 0.01). This would indicate that relationship between muscle fiber CSA and WBSF decreases during postmortem aging, while the association between WBSF and collagen characteristics strengthens. The use of GP negatively impacted meat tenderness primarily through increased muscle fiber CSA and not through altering collagen solubility

Effects of anabolic implants and ractopamine-HCl on muscle fiber morphometrics, collagen solubility, and tenderness of beef longissimus lumborum steaks

Citation: Ebarb, S. M., Phelps, K. J., Drouillard, J. S., Maddock-Carlin, K. R., Vaughn, M. A., Burnett, D. D., . . . Gonzalez, J. M. (2017). Effects of anabolic implants and ractopamine-HCl on muscle fiber morphometrics, collagen solubility, and tenderness of beef longissimus lumborum steaks. Journal of Animal Science, 95(3), 1219-1231. doi:10.2527/jas2016.1263The objective of this study was to examine the effects of growth-promoting technologies (GP) and postmortem aging on longissimus lumborum muscle fiber cross-sectional area (CSA), collagen solubility, and their relationship to meat tenderness. Two groups of black-hided crossbred feedlot heifers (group 1: n = 33, initial BW 430 +/- 7 kg; group 2: n = 32, initial BW 466 +/- 7 kg) were blocked by BW and assigned to 1 of 3 treatments consisting of: no implant and no ractopamine hydrochloride (CON; n = 21); implant, no ractopamine hydrochloride (IMP; n = 22); implant and ractopamine hydrochloride (COMBO; n = 22). Heifers that received an implant were administered an implant containing 200 mg trenbolone acetate and 20 mg estradiol on d 0 of the study, and heifers in the COMBO group received 400 mg.head(-1).d(-1) of ractopamine hydrochloride for 28 (Group 1) or 29 d (Group 2) at the end of 90-(Group 1) or 106-d (Group 2) feeding period. Following harvest, strip loins were collected and further fabricated into 5 roasts for postmortem aging (DOA) periods of 2, 7, 14, 21, or 35 d. After aging, Warner-Bratzler shear force (WBSF), muscle fiber CSA, and collagen solubility were measured. There was no treatment x DOA interaction for WBSF (P = 0.86), but treatment and DOA impacted WBSF (P 0.33). Collagen amounts were not impacted by GP treatment (P > 0.72), but DOA increased the concentration of soluble collagen (P = 0.04). Fiber CSA of all fiber types were positively correlated (P < 0.05; r = 0.21 to 0.28) with WBSF only on d 2 of aging, while soluble collagen amount tended to negatively correlate with WBSF on d 7 and 14 of aging (P < 0.10; r = -0.24 and -0.23, respectively). Administration of GP during heifer finishing resulted in greater steak WBSF over 35 d of aging, which was not due to collagen characteristics and only minimally affected by fiber CSA

Effects of Maternal Nutritional Plane and Selenium Supply on Cellularity Estimates of Neonatal Lamb Jejunal Mucosa, Heart, and Skeletal Muscle

Objectives were to investigate the effects of maternal nutrition and Se supply during gestation on lamb jejunal mucosa, heart, and skeletal muscle RNA, DNA, and protein. Rambouillet ewe lambs (n = 84) were allotted to a 2 x 3 factorial design including dietary factors of Se [adequate Se (ASe; 11.5 μg/kg BW) or high Se (HSe; 77.0 μg/kg BW)] and nutritional plane [60% (RES), 100% (CON), or 140% (HIGH)]. At breeding Se treatments were initiated followed by nutritional treatments on d 40 of gestation. At birth, lambs (n = 13, 14, 14, 12, 13, and 15 for ASe-RES, ASe-CON, ASe-HIGH, HSe-RES, HSe-CON, and HSe-HIGH, respectively) were removed from ewes before nursing, placed in a common pen, and group fed until necropsy at 20.6 ± 0.9 d of age. Maternal nutritional plane affected (P ≤ 0.07) offspring jejunal mucosal scrape concentration (mg/g) and total content (mg) of DNA where RES was least, HIGH greatest, and CON intermediate. Plane of nutrition also affected (P = 0.07) right ventricle DNA content where RES (189.8 ± 11.8 mg) was least, HIGH (208.2 ± 11.2 mg) intermediate, and CON (227.7 ± 11.3 mg) greatest. Maternal Se supplementation decreased (P = 0.08) left ventricle protein:DNA in offspring. For lamb right ventricle, RNA concentration was greatest (P = 0.05) for ASe-RES and least for HSe-RES with all other treatments intermediate. However when lamb right ventricle RNA was expressed as total content, HSe-RES was least (P = 0.02), ASe-HIGH intermediate, and all other treatments were greater. When RNA:DNA was calculated in right ventricle, ASe-RES and HSe-HIGH were greatest (P = 0.02), ASe-CON intermediate, and ASe-HIGH, HSe- RES, and HSe-CON least. Skeletal muscle RNA concentration and RNA:DNA were least (P \u3c 0.05) for ASe-HIGH, intermediate for HSe-RES and HSe-CON, and greatest for ASe-RES, ASe-CON, and HSe-HIGH. These data indicate cellularity estimates have tissue specific responses to maternal nutritional plane and Se supply

Nutritional plane and selenium supply during gestation affect yield and nutrient composition of colostrum and milk in primiparous ewes

The objectives were to investigate effects of nutritional plane and Se supply during gestation on yield and nutrient composition of colostrum and milk in first parity ewes. Rambouillet ewe lambs (n = 84, age = 240 ± 17 d, BW = 52.1 ± 6.2 kg) were allocated to 6 treatments in a 2 × 3 factorial array. Factors included Se [adequate Se (ASe, 11.5 µg/ kg of BW) or high Se (HSe, 77.0 µg/kg of BW)] initiated at breeding, and nutritional plane [60 (RES), 100 (CON), or 140% (HIH) of requirements] initiated at d 40 of gestation. Ewes were fed individually from d 40, and lambs were removed at parturition. Colostrum was milked from all ewes at 3 h postpartum, and one-half of the ewes (n = 42) were transitioned to a common diet meeting lactation requirements and mechanically milked for 20 d. Colostrum yield was greater (P = 0.02) for HSe ewes than ASe, whereas CON had greater (P \u3c 0.05) colostrum yield than RES and HIH. Colostrum Se (%) was greater (P \u3c 0.01) for HSe than ASe. Colostrum from ewes fed HSe had less (P = 0.03) butterfat (%), but greater (P ≤ 0.05) total butterfat, solids-notfat, lactose, protein, milk urea N, and Se than ASe. Colostrum from HIH ewes had greater (P ≤ 0.02) solids- not-fat (%) than RES, whereas RES had greater (P ≤ 0.04) butterfat (%) than CON and HIH. Colostrum from ewes fed the CON diet had greater (P = 0.01) total butterfat than HIH. Total solids-not-fat, lactose, and protein were greater (P \u3c 0.05) in colostrum from CON than RES and HIH. Ewes fed HSe had greater (P \u3c 0.01) milk yield (g/d and mL/d) than ASe, and CON and HIH had greater (P \u3c 0.01) yield than RES. Milk protein (%) was greater (P ≤ 0.01) in RES compared with CON or HIH. Ewes fed HSe had greater (P \u3c 0.01) milk Se (µg/g and mg/d) than ASe on each sampling day. Milk from CON and HIH ewes had greater (P \u3c 0.01) total solids-not-fat, lactose, protein, and milk urea N than RES. Total Se was greater (P = 0.02) in milk from ewes fed the CON diet compared with RES. Somatic cell count and total somatic cells were greater (P ≤ 0.05) in milk from CON than RES. A cubic effect of day (P ≥ 0.01) was observed for milk yield (g and mL). Butterfat, solids-not-fat, lactose, milk urea N, and Se concentration responded quadratically (P ≤ 0.01) to day. Protein (%), total butterfat, and total Se, and somatic cells (cells/mL and cells/d) decreased linearly (P \u3c 0.01) with day. Results indicate that gestational nutrition affects colostrum and milk yield and nutrient content, even when lactational nutrient requirements are met

The federal arbitration system and Australian economic performance

Has the Federal arbitration system been a facilitator, a barrier or irrelevant in the twentieth century growth record of Australia? To consider this question, the present review considers the role of wage setting institutions in the growth process. It then goes on to consider the contribution of the arbitration system to Australian economic performance. A number of criteria will be addressed, including inflation, unemployment, allocation of labour, productivity growth and responsiveness to economic shocks. The evidence is inconclusive in terms of a direct relationship between the wage setting decisions of the arbitration system and macroeconomic performance. Nevertheless, there are important institutional features of the arbitration system that are important in shaping the growth path of the Australian economy over the past century