Rumen in vitro techniques for the investigation of rumen probiosis. Jerry Hughes Memorial Scholarship for 1991

Author(s):  
J.A. Huntington

Recent research has shown that supplemention of beef cattle diets with small quantities (10-20 g/d) of yeast culture can lead to increased liveweight gain and improved feed conversion efficiency (Hughes 1988, Edwards 1991). Supplementation of dairy cow diets has led to reduced weight loss in early lactation, increased milk yield and an improved milk composition (Williams et al 1989). Improved animal performance has usually been associated with increased dry matter intake. The precise mode of action of yeast culture in ruminants is, as yet, unknown. There is evidence that yeast culture increases cellulolytic (Harrison et al 1988) and total rumen bacterial numbers (Edwards 1991). This may lead to increased rates of fibre digestion and increased microbial protein production. A number of in sacco studies have shown increased degradation of substrates at rumen incubation times of 24 hours or less (Williams 1989, Chademana and Offer 1990).

1995 ◽  
Vol 1995 ◽  
pp. 123-123
Author(s):  
H. Khalili ◽  
P. Huhtanen ◽  
S. Jaakkola ◽  
T. Varvikko

Enhanced cellulolytic activity in the rumen and improved balance between amino acids and energy have been suggested to increase silage dry matter intake in cows given high quality protein supplements. The objective of this study was to investigate the effects of casein infused continuously into the rumen, duodenum or both on forage intake, milk yield, milk composition and microbial protein production.


1991 ◽  
Vol 52 (3) ◽  
pp. 407-420 ◽  
Author(s):  
A. J. Rook ◽  
M. Gill ◽  
R. D. Willink ◽  
S. J. Lister

ABSTRACTData for individually recorded silage dry-matter intake (SDMI), concentrate dry-matter intake (CDMI), live weight, milk yield and milk composition of lactating dairy cows offered silage ad libitum and concentrates on a flat-rate basis, together with data for silage composition from experiments conducted at four sites, were used to obtain simple and multiple regressions of SDMI on other variables.Simple regressions showed that the most important variables affecting SDMI were, in order of importance: silage ammonia nitrogen, fat yield, CDMI, silage digestible organic matter concentration (DOMD) and live weight. The best multiple regression for the mean SDMI over weeks 4 to 13 of lactation accounted for proportionately 0·649 of the variation. Examination of week by week data for weeks 3 to 20 of lactation showed that two models for early and mid lactation were required to give a reasonable pattern of residual variances. These models accounted for 0·627 and 0·581 of the variation respectively. It was necessary to fit time effects explicitly in early lactation. Live weight was best represented by fitting post-calving live weight and deviations from post-calving live weight separately. A number of models requiring fewer input variables were also obtained to allow for use in situations where the full range of measurements is not made.The new models were tested using independent data from three sites. They performed better than a number of previously published models but the best model still gave a prediction error of proportionately 0·17 about the mean actual silage intake in early lactation and 015 in late lactation.The results suggest that there is little to be gained from further refinement of the functional form of the models and that the construction of a number of models for specific food and management situations is preferable to the use of global models.


2020 ◽  
Vol 41 (3) ◽  
pp. 1017
Author(s):  
Alberto Magno Fernandes ◽  
Tadeu Silva Oliveira ◽  
Alisson Rodrigues Jordão ◽  
Domingos Sávio Campos Paciullo ◽  
Danielle Ferreira Baffa ◽  
...  

The objective of this work was to evaluate the supply, morphological and chemical composition of forage, performance and milk composition of crossbred cows managed in Megathyrsus maximus cv. Tanzania in intermittent grazing system with fixed and variable defoliation intervals according to the interception of 95% of photosynthetically active radiation by the canopy. The experimental design was a randomized complete block design with two treatments and two area replications. In each grazing cycle the supply, morphological composition, forage nutritive value, dry matter intake, milk production and composition were determined. The experimental area was 4.0 hectares, divided into two blocks of 2 hectares. Each block was subdivided into 22 pickets (11 for each treatment) totaling 44 pickets with an area of 909 m2 each. Significant differences (P < 0.05) were observed for leaf blade content, in vitro digestibility of dry matter and forage crude protein, dry matter intake, individual and area milk production and lactose content milk, being the highest values found in the pastures managed with variable defoliation interval. Thus, the defoliation interval defined by the 95% interception of the photosynthetically luminosity leads to higher leaf blade proportions in the forage canopy, resulting in higher individual milk yield and per unit area, but with a loss of protein and total solids contents of milk.


2017 ◽  
Vol 9 (3) ◽  
pp. 226
Author(s):  
Dheynne Alves Vieira ◽  
Andréia Santos Cezário ◽  
Wallacy Barbacena Rosa dos Santos ◽  
Jeferson Corrêa Ribeiro ◽  
Tiago Neves Pereira Valente ◽  
...  

The aim of this study was to evaluate the performance of crossbred Holstein × Zebu steers fed on the diets containing sugarcane in natura or ensiled with two levels of concentrate (30% and 70%). A total of 32 males of 394 kg of body weight were used in a completely randomized experimental design with four treatments and seven repetitions. The animals reported a high dry matter intake (DMI) (P < 0.05) when fed on the high concentrate levels. The increase in concentrate levels resulted in an approximately 25% to 60% higher DMI as compared to the lowest level offered by silage-based diets and sugarcane in natura. The highest apparent digestibility coefficients of dry matter were observed in the diets based on sugarcane in natura (P < 0.05). The sugarcane based diets also affected (P > 0.05) the digestibility of organic matter, neutral detergent fiber, crude protein, ether extract, and non-fiber carbohydrates. There were no differences (P > 0.05) between the diets for average daily weight gain, carcass dressing, carcass gain, and feed conversion. The diets based on sugarcane in nature or ensiled with 30% and 70% concentrates do not influence the performance of crossbred Holstein × Zebu cattle.


1983 ◽  
Vol 63 (1) ◽  
pp. 155-162 ◽  
Author(s):  
L. KUNG Jr. ◽  
B. W. JESSE ◽  
J. W. THOMAS ◽  
J. T. HUBER ◽  
R. S. EMERY

Whole barley was treated with sodium hydroxide (NaOH) in laboratory trials. Dry matter disappearance from nylon bags in the rumen of whole barley treated with 2.5, 3.5, or 4.9% NaOH for 30 h was 59.6, 72.4, and 93.0%, respectively, compared with 82.2% for untreated ground barley. In a subsequent lactation trial, 24 Holstein cows (eight per treatment) were fed high moisture ground ear corn, high moisture rolled barley or high moisture whole barley treated with 3.5% NaOH. Milk persistencies tended to be greater for cows fed high moisture rolled barley, next for ground ear corn and least for NaOH-treated barley. Milk composition was similar for all treatments. Dry matter intake was greatest for cows fed ground ear corn and lower for those fed the barley diets. Alpha-linked glucose and pH of feces were similar for cows fed ground ear corn and high moisture rolled barley diets, but fecal pH was lower and alpha-linked glucose concentrations three times greater for NaOH-treated barley. Digestibility percents of dry matter, acid detergent fiber and nitrogen were 61.4, 25.3, 64.7 for ground ear corn; 64.4, 38.0, 67.1 for high moisture rolled barley; and 56.8, 43.2, 54.8 for NaOH-treated barley, respectively. Rumen grain turnover estimated by excretion of ytterbium in feces was greatest for NaOH-treated barley (9.09%/h), intermediate for ground ear corn (6.10%/h) and lowest for high moisture rolled barley (4.93%/h). Key words: Dairy, sodium hydroxide, high moisture grains


2017 ◽  
Vol 57 (4) ◽  
pp. 627 ◽  
Author(s):  
J. I. Velazco ◽  
R. M. Herd ◽  
D. J. Cottle ◽  
R. S. Hegarty

As daily methane production (DMP; g CH4/day) is strongly correlated with dry matter intake (DMI), the breeding of cattle that require less feed to achieve a desired rate of average daily gain (ADG) by selection for a low residual feed intake (RFI) can be expected to reduce DMP and also emission intensity (EI; g CH4/kg ADG). An experiment was conducted to compare DMP and EI of Angus cattle genetically divergent for RFI and 400-day weight (400dWT). In a 6-week grazing study, 64 yearling-age cattle (30 steers, 34 heifers) were grazed on temperate pastures, with heifers and steers grazing separate paddocks. Liveweight (LW) was monitored weekly and DMP of individual cattle was measured by a GreenFeed emission monitoring unit in each paddock. Thirty-nine of the possible 64 animals had emission data recorded for 15 or more days, and only data for these animals were analysed. For these cattle, regression against their mid-parent estimated breeding value (EBV) for post-weaning RFI (RFI-EBV) showed that a lower RFI-EBV was associated with higher LW at the start of experiment. Predicted dry matter intake (pDMI), predicted DMP (pDMP) and measured DMP (mDMP) were all negatively correlated with RFI-EBV (P < 0.05), whereas ADG, EI, predicted CH4 yield (pMY; g CH4/kg DMI) were not correlated with RFI-EBV (P > 0.1). Daily CH4 production was positively correlated with animal LW and ADG (P < 0.05). The associations between ADG and its dependent traits EI and pMY and predicted feed conversion ratio (kg pDMI/kg ADG) were strongly negative (r = –0.82, –0.57 and –0.85, P < 0.001) implying that faster daily growth by cattle was accompanied by lower EI, MY and feed conversion ratio. These results show that cattle genetically divergent for RFI do not necessarily differ in ADG, EI or pMY on pasture and that, if heavier, cattle with lower RFI-EBV can actually have higher DMP while grazing moderate quality pastures.


2021 ◽  
Vol 51 (11) ◽  
Author(s):  
Fernando Carcelén Cáceres ◽  
Felipe San Martín Howard ◽  
Miguel Ara Gómez ◽  
Sandra Bezada Quintana ◽  
Ana Asencios Méndez ◽  
...  

ABSTRACT: This study evaluated the effect of the three inulin levels (0.1%, 0.2%, 0.4%) supplemented as a substitute for an antibiotic growth promoter (AGP, zinc bacitracin) and control in guinea pigs raised for human consumption. Fifty 14-day-old male guinea pigs were used. Productive parameters (weight gain, total dry matter intake, and feed conversion ratio (FCR)) and intestinal morphology of the duodenum, jejunum, and ileum at slaughter (70 days of age) were evaluated. An inverse relationship was observed between inulin levels and FCR (linear effect; P = 0.006). There was no statistically significant effect of the treatments on total dry matter intake and weight gain (P > 0.05). A linear effect of the inulin level on the villi’s length (VL), villi’s width (VW), and length/depth ratio (VL/DC) in the duodenum; VW in the jejunum; and VL in the ileum (P <0 .05) was reported. In conclusion, a linear effect of the increasing doses of inulin was found on the FCR and the morphological parameters of the duodenum’s integrity, and no differences in the effects of the inulin added to the diet and the treatment with AGP were found.


1995 ◽  
Vol 1995 ◽  
pp. 113-113
Author(s):  
D M Harris ◽  
A Barlet ◽  
A T Chamberlain

The pressure transducer technique has been proposed as a method of evaluating feed degradation characteristics (Theodorou, 1993) and it has been shown to predict the in vivo and in sacco degradability of forages (Blummel and Orskov, 1993). However the original technique requires rumen liquor and hence access to surgically prepared animals. Faecal material is generally easier to obtain and this work assessed it's suitability as an alternative source of microbes.Rumen liquor (R) and faeces (F) were collected simultaneously from a rumenally fistulated lactating dairy cow. R was mixed 1:1 with modified van Soest medium and F 1:2 to obtain similar dry matter contents. Homogenised strained 20 ml aliquats were inoculated into vented 250 ml bottles containing 180 ml of modified van Soest medium and 1.5g DM of a 7:3 mixture of milled air dried grass silage and 180 g CP / kg DM concentrates. The 7:3 ratio of silage and concentrates was chosen to reflect the diet the donor cow was consuming.


2020 ◽  
Vol 158 (1-2) ◽  
pp. 150-158 ◽  
Author(s):  
B. C. Silva ◽  
M. V. C. Pacheco ◽  
L. A. Godoi ◽  
F. A. S. Silva ◽  
D. Zanetti ◽  
...  

AbstractAn experiment was conducted to evaluate: (1) the effects of ensiling maize or sorghum grains after reconstitution on readily soluble fraction (a), potentially degradable fraction in the rumen (b) and rate constant for degradation of b (c) of dry matter (DM), organic matter (OM) and starch (STA); and (2) an appropriate incubation time for in situ or in vitro procedures to estimate in vivo digestibility. Four rumen-cannulated Nellore bulls (body weight = 262 ± 19.6 kg) distributed in a 4 × 4 Latin square were used. Diets were based on dry ground maize (DGM); or dry ground sorghum (DGS); or reconstituted ground maize silage; or reconstituted ground sorghum silage. In vitro and in situ incubations of the individual grains and diets were simultaneously performed with in vivo digestibility. In general, reconstituted grains and diets based on reconstituted grains presented greater (P < 0.05) fraction a and lower (P < 0.05) fraction b of DM, OM and STA compared to dry grains and diets based on dry grain. However, the magnitude of response of the reconstitution and ensiling process on DM and OM degradability parameter was greater for maize than that for sorghum. Moreover, no differences (P > 0.05) were observed between DGM- and DGS-based diets for c estimates. The results suggest that the reconstitution process promotes grains protein matrix breakdown increasing STA availability. The incubation times required for in vivo digestibility estimations of DM, OM and STA are 24 h for in situ and 36 h for in vitro procedures.


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