• Title, Summary, Keyword: Dormant native range

Search Result 2, Processing Time 0.038 seconds

Effect of stocker management program on beef cattle skeletal muscle growth characteristics, satellite cell activity, and paracrine signaling impact on preadipocyte differentiation

  • Vaughn, Mathew A.;Lancaster, Phillip A.;Roden, Kelly C.;Sharman, Evin D.;Krehbiel, Clinton R.;Horn, Gerald W.;Starkey, Jessica D.
    • Journal of Animal Science and Technology
    • /
    • v.61 no.5
    • /
    • pp.260-271
    • /
    • 2019
  • The objective of this study was to determine the effect of different stocker management programs on skeletal muscle development and growth characteristics, satellite cell (SC) activity in growing-finishing beef cattle as well as the effects of SC-conditioned media on preadipocyte gene expression and differentiation. Fall-weaned Angus steers (n = 76; $258{\pm}28kg$) were randomly assigned to 1 of 4 stocker production systems: 1) grazing dormant native range (NR) supplemented with a 40% CP cottonseed meal-based supplement ($1.02kg{\cdot}steer^{-1}{\cdot}d^{-1}$) followed by long-season summer grazing (CON, 0.46 kg/d); 2) grazing dormant NR supplemented with a ground corn and soybean meal-based supplement fed at 1% of BW followed by short-season summer grazing (CORN, 0.61 kg/d); 3) grazing winter wheat pasture (WP) at high stocking density (3.21 steers/ha) to achieve a moderate rate of gain (LGWP, 0.83 kg/d); and 4) grazing winter WP at low stocking density (0.99 steers/ha) to achieve a high rate of gain (HGWP, 1.29 kg/d). At the end of the stocker (intermediate harvest, IH) and finishing (final harvest, FH) phases, 4 steers / treatment were harvested and longissimus muscles (LM) sampled for cryohistological immunofluorescence analysis and SC culture assays. At IH, WP steers had greater LM fiber cross-sectional area than NR steers; however, at FH, the opposite was observed (p < 0.0001). At IH, CORN steers had the lowest Myf-5+:Pax7+ SC density (p = 0.020), while LGWP steers had the most Pax7+ SC (p = 0.043). At FH, CON steers had the highest LM capillary density (p = 0.003) and their cultured SC differentiated more readily than all other treatments (p = 0.017). At FH, Pax7 mRNA was more abundant in 14 d-old SC cultures from HGWP cattle (p = 0.03). Preadipocytes exposed to culture media from proliferating SC cultures from WP cattle isolated at FH had more $PPAR{\gamma}$ (p = 0.037) and less FABP4 (p = 0.030) mRNA expression compared with NR cattle. These data suggest that different stocker management strategies can impact skeletal muscle growth, SC function, and potentially impact marbling development in growing-finishing beef cattle.

NUTRITIVE EVALUATION OF FOURWING SALTBUSH IN GROWTH AND DIGESTIBILITY TRIALS WITH HARNAI LAMBS IN UPLAND BALOCHISTAN

  • Rehman, Atiq-ur;Rafique, Shahid;Ali, Amanat;Munir, M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.3 no.4
    • /
    • pp.299-303
    • /
    • 1990
  • Twenty-four Harnai lambs 6 to 7 month old, weighing $16{\pm}2kg$ were used in a completely randomized design in growth and digestibility trials to study fourwing saltbush ratio supplemented with cotton seed cake. The animal were divided at random into three groups of 8 animals each. Three iso-nitrogenous (10.5% CP) experimental rations (1, 2 and 3) containing wheat straw + lucerne hay (24:76); fourwing saltbush (Atriplex canescens) + cotton seed cake (71:29); and wheat straw + cottonseed cake (41:59); respectively, were allotted to each group randomly. All the animals were taken out for grazing in a dormant native range for about 3 hours in the afternoon during the growth trial. The growth trial lasted for 8 weeks followed by a digestibility trial. At the end of 8 weeks lambs on ration 3 had gained significantly (p<0.10) more weight compared to those on rations 1 and 2 which maintained their body weight. The crude protein digestibility of the fourwing saltbush based ration was comparable with the other two treatments (71 vs 70 and 71%). However, the digestibility of dry matter (41%), acid detergent fibre (13%) and neutral detergent fibre (22%) of this ration was significantly lower (p<0.10) than the other two diets. The results suggest that lambs can be maintained on fourwing saltbush during winter without significant loss in body weight with 30% extra protein concentrate supplementation.