Influence of Protein Supplementation on Forage Intake, in Situ Forage Disappearance, Ruminal Fermentation and Digesta Passage Rates in Steers Grazing Dormant Blue Grama Rangeland

Abstract Three 10-d collection periods (April 4 to 14, early April, EApr; April 23 to May 3, late April, LApr; May 10 to 20, 1984, mid-May, MMay) were conducted to evaluate effects of no supplement (C), .5 kg·head−1·d−1 (as-fed basis) supplemental grain (steam-flaked milo, G) or G plus 170 mg monensin·headhead−1·d−1 (M) on forage intake and digestion by 12 ruminally cannulated beef steers (four/treatment; avg initially BW = 393 kg) grazing irrigated winter wheat pasture. Ruminal pH was greater (P < .01) for M than for C or G during EApr but was not altered by treatments in LApr or MMay. Compared with C, ruminal NH3 was decreased (P < .10) by G and M (5 h after supplementation) in EApr, decreased (P < .05) by G (2h) and increased (P < .05) by M (8 h) in LApr and decreased (P < .10) by G (−1h) in MMay. Treatments had little influence on total VFA concentrations or on molar proportions of acetate and propionate. Butyrate molar proportion was decreased (P < .10) by M during EApr and LApr, but not during MMay. Monensin increased (P < .05) fluid passage rate compared with C and G in EApr but not in other periods. Particulate passage measurements did not differ (P > .10) among treatments within periods. Forage DM intake was not influenced (P > .10) by supplementation during any period. Extent of in situ forage DM disappearance was greater (P < .10) for M than for C or G during EApr (12 and 30 h of incubation) but was not different (P > .10) in LApr or MMay. Incidence of frothy bloat was decreased (P < .05) by M during EApr; this reduction may have been related to effects of M on ruminal pH, forage digestion and fluid passage.

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Influence of energy source on forage intake, digestibility, in situ forage degradation, and ruminal fermentation in beef steers fed medium-quality brome hay

Journal of Animal Science ◽

10.2527/1993.7182260x ◽

1993 ◽

Vol 71 (8) ◽

pp. 2260-2269 ◽

Cited By ~ 35

Author(s):

D. A. Carey ◽

J. S. Caton ◽

M. Biondini

Keyword(s):

Energy Source ◽

Beef Steers ◽

Ruminal Fermentation ◽

Medium Quality ◽

Forage Intake

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Effects of roughage type on particle separation, rumination, fiber mat characteristics, in situ degradation, and ruminal fermentation parameters in beef steers

Journal of Animal Science ◽

10.1093/jas/skab214 ◽

2021 ◽

Author(s):

Catherine L Lockard ◽

Caleb G Lockard ◽

Wyatt N Smith ◽

Kendall J Karr ◽

Ben P Holland ◽

...

Keyword(s):

Dry Matter ◽

Rumen Fluid ◽

Fluid Collection ◽

Latin Square ◽

Experimental Unit ◽

Beef Steers ◽

Ruminal Fermentation ◽

In Situ Degradation ◽

Fermentation Parameters

Abstract Six ruminally cannulated steers (average BW = 791 + 71 kg) were used in a replicated 3 × 3 Latin square experiment to determine the effects of roughage type on rumination, fiber mat characteristics, and rumen fermentation variables. Three roughages were included at 7% (DM basis) in a steam flaked corn-based diet; cotton burrs (CB), wheat silage (WS), or corn stalks (CS). Steers were fitted with a sensory collar to record rumination behaviors in 2-h intervals at the beginning of the experiment. Each 30-d period consisted of a 7-d of recovery, 14-d of diet adaptation, 7-d of rumination data collection (daily and bi-hourly average rumination), 1-d of rumen fluid collection, and 1-d of rumen evacuations. In situ degradation of individual roughages was determined for 4-d after period 3 evacuations. During rumen evacuations, ruminal contents were removed; the rumen fiber mat (RF) was separated from the liquid portion with a 2 mm sieve, weighed, and a subsample was dried. Data were analyzed using the MIXED procedure of SAS with steer as the experimental unit and roughage (CB, WS, and CS) as the main effect. Dry matter intake (DMI) was not different for CB and WS (P = 0.25) and greatest for steers consuming CS diet (P < 0.01). Roughage type did not influence the weight of the RF dry matter (%; DM; P = 0.92), RF weight (P = 0.69), or RF:DMI ratio (P = 0.29). Daily rumination (min/d) did not differ among roughages (P = 0.40), but min of rumination/kg of DMI was greatest for CS (18.0 min), min/kg of NDF was greatest for WS (89.8 min; P = 0.02), and min/kg of peNDF was greatest for CS (132.4 min; P < 0.01). Wheat silage had the greatest percentage of soluble DM and CB-R and CS-R (P < 0.01) had the greatest ruminal degraded DM fraction. Rumen fiber mat did not differ for roughages, although rumination min/kg of DMI and peNDF was greatest for steers consuming CS and WS. In situ degradation determined that CB-R and CS-R had the greatest percentage of ruminal degraded DM. Based on the objective of the experiment, roughage type did not influence daily rumination or fiber mat characteristics.

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THE NUTRITIONAL BALANCE OF EARLY LACTATION DAIRY COWS GRAZING IN INTENSIVE SILVOPASTORAL SYSTEMS

Ciência Animal Brasileira ◽

10.1590/1089-6891v18e-40419 ◽

2017 ◽

Vol 18 (0) ◽

Cited By ~ 1

Author(s):

Elisa Sierra Montoya ◽

Julian David Chará ◽

Rolando Barahona-Rosales

Keyword(s):

Dairy Cows ◽

Negative Energy ◽

Protein Supplementation ◽

Metabolizable Energy ◽

Early Lactation ◽

Tropical Conditions ◽

Forage Intake ◽

Daily Milk Yield ◽

To Receive ◽

Daily Milk

Abstract A study was carried out to estimate the balance of metabolizable protein (MP), metabolizable energy (ME), calcium, and phosphorus in 12 recently calved (RC) and early lactation (EL, 42 - 50 days after calving) Gyr x Holstein dairy cows grazing in a Leucaena leucocephala and Cynodon plectostachyus intensive silvopastoral system (ISS) and receiving energy and protein supplementation. Dry matter (DM) availability from the grazing paddocks, nutrients offered and their balance were estimated. On average, the available forage DM per animal.day-1 was 44.7 kg for C. plectostachyus and 11.8 kg for L. leucocephala. EL cows had greater requirements of MP, ME, and minerals than RC cows. In RC cows, ME, MP, and mineral requirements were supplied by the total diet, while EL cows exhibited a negative energy balance. For both RC and EL cows, ME was the limiting dietary factor, whereas MP and P were found to be in excess. If cows were only to receive ISS forages with no supplementation, estimated daily milk yield would be 10 and 12 litters for RC and EL cows, respectively. Under tropical conditions, based on ISS forage intake, RC and EL cows can meet most of their ME, MP, calcium, and phosphorous requirements.

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