Helen M Golder

Helen M Golder
Scibus, Camden, NSW, Australia

Bachelor of Agricultural Science (Hons. Ani. Sci), PhD

About

64
Publications
19,621
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912
Citations
Introduction
My PhD was on 'Increasing the understandings of ruminal acidosis in dairy cattle'. Im interested in dairy nutrition, rumen microbiology and carbohydrate metabolism.
Additional affiliations
July 2012 - January 2014
The University of Sydney
Position
  • Lecturer
March 2010 - December 2013
SBScibus/University of Sydney
Position
  • PhD Student
March 2010 - present
SBScibus
Position
  • Researcher
Education
March 2010 - December 2014
The University of Sydney
Field of study
  • Veterinary Science
February 2009 - December 2009
February 2006 - December 2008

Publications

Publications (64)
Conference Paper
Full-text available
Rumen acidosis is an important nutritional disorder of ruminants whose pathogenesis still remains unclear. The objectives of this paper are to describe rumen conditions in a heifer (identification number 1250) with clinical signs consistent with rumen acidosis and to compare them with those of other heifers in her cohort. A cohort of eight Holstein...
Article
Full-text available
We evaluated the effect of feed additives on the risk of ruminal acidosis in Holstein heifers (n = 40) fed starch and fructose in a challenge study. Heifers were randomly allocated to feed additive groups (n = 8 heifers/group): (1) control (no additives); (2) virginiamycin (VM); (3) monensin + tylosin (MT); (4) monensin + live yeast (MLY); and (5)...
Article
Full-text available
Ruminal endotoxin and plasma oxidative stress biomarker concentrations were studied in dairy heifers challenged with grain, fructose, and histidine in a partial factorial study. Holstein-Friesian heifers [n = 30; average body weight (BW) of 359.3 ± 47.3 kg] were randomly allocated to 5 treatment groups: (1) control (no grain); (2) grain [crushed tr...
Article
Full-text available
Our objective was to evaluate a near-infrared reflectance spectroscopy (NIRS) used in the feed industry to estimate the potential for grains to increase the risk of ruminal acidosis. The existing NIRS calibration was developed from in sacco and in vitro measures in cattle and grain chemical composition measurements. To evaluate the existing model,...
Article
Full-text available
The effects of grain, fructose, and histidine on ruminal pH and fermentation products were studied in dairy cattle during an induced subacute acidosis protocol. Thirty Holstein heifers were randomly allocated to 5 treatment groups: (1) control (no grain); (2) grain [fed at a crushed triticale dry matter intake (DMI) of 1.2% of body weight (BW)]; (3...
Article
Body condition scoring (BCS) and body weight (BW) are observations associated with labile tissue reserves, health, and reproduction efficiency of dairy cows. The effect of parity (1 through to ≥5) and feeding system (pasture-based and TMR) on BCS and BW were evaluated utilizing raw data sets from 16 retrospective studies that totaled 24,807 Holstei...
Article
Full-text available
Probiotics are widely used in commercial shrimp aquaculture, but responses are variable. The objectives of this study were to quantitatively review using meta-analysis the production, survival, and immune responses of Macrobrachium rosenbergii to probiotics and to identify sources of residual variation. A total of 58 comparisons from 16 experiments...
Article
Full-text available
Objectives of analyses conducted were to quantitatively review using meta-analysis the production, survival, and immune responses of shrimp to probiotics, and to identify sources of residual variation. A total of 277 comparisons from 89 experiments were included in the final meta-analyses. Data were analysed as 3 databases on interventions with: (1...
Article
Full-text available
There has been considerable interest in the use of red seaweed, and in particular Asparagopsis taxiformis , to increase production of cattle and to reduce greenhouse gas emissions. We hypothesized that feeding seaweed or seaweed derived products would increase beef or dairy cattle performance as indicated by average daily gain (ADG), feed efficienc...
Article
Full-text available
The objective of this clinical trial was to evaluate the effectiveness of probiotic, prebiotic, and synbiotic supplementation on average daily weight gain (ADG), duration of diarrhea, age at incidence of diarrhea, fecal shedding of Cryptosporidium oocysts, enteric pathogens, and the odds of pneumonia in preweaning dairy heifer calves on a commercia...
Preprint
Full-text available
There has been considerable interest in the use of red seaweed, and in particular Asparagopsis taxiformis, to increase production of cattle and to reduce greenhouse gas emissions. We hypothesized that feeding seaweed or seaweed derived products would increase beef or dairy cattle performance as indicated by average daily gain (ADG), feed efficiency...
Article
Full-text available
We hypothesized that feeding 25-hydroxyvitamin D3 [25-(OH)D3] during lactation and prepartum in conjunction with negative dietary cation-anion difference diets would improve milk production, increase the probability of pregnancy, and reduce the incidence of postcalving diseases. Cows from 4 dairies with prepartum transition diets negative in dietar...
Article
Full-text available
Objective Our objectives were to evaluate milk production and constituent responses to changes in the diet for pens of cows over time and whether differences in response were attributable to fibrolytic enzymes and dairy. Materials and Methods A multiherd trial used 7,507 cows in 8 control and enzyme-treated (750 mL/t of DM feed) replicates (16 pen...
Chapter
Acidosis is a continuum of conditions of varying severity reflecting the challenge of safely sequestering hydrogen that accumulates from carbohydrate fermentation. Laminitis is aseptic inflammation, ischemia, and degeneration of laminae of the hooves. Laminitis may be caused directly and indirectly by acidosis or occur independently. Proper and reg...
Conference Paper
Full-text available
Acidosis is a much more complex condition than simply reflected in a drop in ruminal pH. Acidosis is increased by diets higher in starch and sugars and lower in fiber and is reflected in increases in propionate and valerate concentrations and reduced ammonia concentrations and rumen pH. While the clinical expression of acidosis may be influenced by...
Article
Full-text available
Our objectives were to characterize responses in the field to a mix of fibrolytic enzymes using large commercial dairy herds and sufficient study power to evaluate milk production and reproductive responses to an enzyme treatment started during the precalving period. We hypothesized that the use of the enzyme treatment would increase milk productio...
Article
Full-text available
The objectives were to use meta-analytic methods to determine the effects of changes in dietary cation-anion difference (DCAD) prepartum on productive performance and health of dairy cows. The literature was systematically reviewed, searching randomized experiments with transition cows that manipulated the prepartum DCAD or experiments with acidoge...
Article
Prepartum diets influence cow performance for weeks to months postpartum. This observation leads to questions about milk yield and physiological and health responses to diets with negative dietary cation-anion difference (DCAD). Further, responses to increased intake of a diet with lower DCAD (Eq/d) have not been explored using meta-analysis. Our o...
Article
Full-text available
Prepartum diets influence cow performance for weeks to months postpartum. This observation leads to questions about milk yield and physiological and health responses to diets with negative dietary cation-anion difference (DCAD). Further, responses to increased intake of a diet with lower DCAD (Eq/d) have not been explored using meta-analysis. Our o...
Article
Full-text available
Due to their high energy requirements, high-yielding dairy cows receive high-grain diets. This commonly jeopardises their gastrointestinal health by causing subacute ruminal acidosis (SARA) and hindgut acidosis. These disorders can disrupt nutrient utilisations, impair the functionalities of gastrointestinal microbiota, and reduce the absorptive an...
Article
Full-text available
Background Benefits of hormonal growth promotants (HGP) include production efficiency, profit, and reduced environmental effects for beef cattle. Questions remain about effects of HGP on beef quality, particularly on measures of toughness such as Warner-Bratzler shear force (WBSF), tenderness, and other taste-panel attributes of beef. Objective To...
Article
Full-text available
Grain-based concentrate (GBC) supplement is of high cost to dairy farmers as a feed source as opposed to grazed pasture. Milk production response to GBC is affected by the composition and nutritive value of the remainder of the diet, animal factors, and interactions between forage type and level of GBC. In grazing systems, dairy cattle encounter co...
Article
Full-text available
Dairy heifers were subjected to a non-life-threatening challenge designed to induce ruminal acidosis by feeding grain and sugar. Large among animal variation in clinical signs of acidosis, rumen metabolite concentrations, and the rumen microbiome occurred. This exploratory study investigates sources of the variation by examining associations betwee...
Article
Full-text available
The study of Vitamin D in cattle has often focussed on its role in calcium and mineral metabolism. However, there is evidence of a wider role for Vitamin D in bone and energy metabolism. Two studies were conducted to explore relationships between calcidiol supplementation, blood minerals and metabolites in mid-lactation dairy cows. In Experiment 1,...
Article
Full-text available
CASE HISTORY: A herd of Holstein, Jersey, or Holstein-Jersey cross lactating cattle of mixed ages presented with a sudden drop in milk yield in 94/678 cows on 3 October 2014 (Day 0). The herd was located in Gretna in the Derwent Valley (Tasmania, Australia) and had been grazing dryland pasture. CLINICAL FINDINGS: On Day 0 the cows variably showed r...
Article
Full-text available
The objective of this study was to determine the efficacy of an internal teat sealant (TS; Teatseal; Zoetis Australia, Silverwater, NSW, Australia), when used in combination with antibiotic dry-cow therapy (ADCT) administered at dry-off, on milk individual somatic cell count (ISCC), milk production and components, and the incidence of clinical and...
Article
Full-text available
The effects of lasalocid on rumen measures, beef and dairy performance, and carcass traits were evaluated using meta-analysis. Meta-regression was used to investigate sources of heterogeneity. Ten studies (20 comparisons) were used in the meta-analysis on rumen measures. Lasalocid increased total VFA and ammonia concentrations by 6.46 and 1.44 m, r...
Article
Full-text available
The effects of lasalocid on rumen measures, beef and dairy performance, and carcass traits were evaluated using meta-analysis. Meta-regression was used to investigate sources of heterogeneity. Ten studies (20 comparisons) were used in the meta-analysis on rumen measures. Lasalocid increased total VFA and ammonia concentrations by 6.46 and 1.44 mM,...
Article
Full-text available
The objective of this study was to investigate the effect of ruminal mechanical stimulating brushes (RMS brush) on rumen fermentation and plasma oxidative stress and subsequent milk production in early lactation dairy cattle in the Australian spring and summer. Two hundred pasture-fed Holstein, Jersey, and Holstein × Jersey multiparous cows were en...
Conference Paper
This study determined the impact of varying proportions of grain-based concentrate (GBC) allocation and ryegrass pasture sward on herbage and DM intake and milk production. Ninety cows were allocated to two consistent (fresh-fresh and depleted-depleted) and two inconsistent (fresh-depleted and depleted-fresh) treatments of ryegrass pasture with thr...
Conference Paper
Dairy cows progressively deplete a pasture sward in successive layers, and these layers vary in their chemical composition. As the milking order of dairy cows is relatively consistent, the objective of this study was to determine the effects of milking order on the quality and quantity of pasture accessed by dairy cows. Two experiments were conduct...
Article
Full-text available
Achieving optimal rumen function requires an understanding of feeds and systems of nutritional evaluation. Key influences on optimal function include achieving good dry matter intake. The function of feeds in the rumen depends on other factors including chemical composition, rate of passage, degradation rate of the feed, availability of other subst...
Article
Full-text available
Late-lactation Holstein cows (n = 144) that were offered 15 kg dry matter (DM)/cow per day of perennial ryegrass to graze were randomized into 24 groups of 6. Each group contained a fistulated cow and groups were allocated to 1 of 3 feeding strategies: (1) control (10 groups): cows were fed crushed wheat grain twice daily in the milking parlor and...
Article
Full-text available
Rumen and blood biochemical profiles were monitored in 8 Holstein heifers exposed to a carbohydrate feeding challenge. One of the heifers had clinical signs consistent with acute ruminal acidosis on the day of, and subsequent to, the challenge. Within 24 h of challenge, 6 of 7 rumen volatile fatty acids measured were not detectable in this heifer a...
Article
Full-text available
Ruminal bacterial community composition (BCC) and its associations with ruminal fermentation measures were studied in dairy heifers challenged with combinations of grain, fructose, and histidine in a partial factorial study. Holstein-Friesian heifers (n = 30) were randomly allocated to 5 triticale grain-based treatment groups: (1) control (no grain...
Conference Paper
Full-text available
Ruminal acidosis is an important nutritional disorder of ruminants induced by large amounts of readily fermentable carbohydrates. We hypothesized that feed additives would reduce acidosis risk by perturbing the rumen during a substantial challenge with starch and fructose. Holstein heifers (n = 40) were allocated to 5 groups: (1) control (no addit...
Conference Paper
Full-text available
We hypothesized that distinct bacterial communities would develop among starch, fructose and/or histidine fed heifers during a single non-life threatening but substantial challenge. Holstein heifers (n = 30) were assigned to 5 grain-based groups: (1) control (no grain); (2) grain [fed at a dry matter intake (DMI) of 1.2% of bodyweight (BW)]; (3) gr...
Conference Paper
Full-text available
We hypothesized that feed additive(s) would reduce acidosis risk during a non-life threatening but substantial challenge with starch and fructose. Holstein heifers (n = 40) were allocated to 5 groups: (1) control (no additives); (2) virginiamycin (10 g/hd/d:VM); (3) monensin (2.2 g/hd/d) + tylosin (0.44 g/hd/d:MT); (4) monensin (2.5 g/hd/d) + yeast...
Conference Paper
Full-text available
We hypothesized that distinct bacterial communities would result from different feeding strategies. Twenty four rumen fistulated, lactating Holstein cows in a prospective cohort study grazed pasture that provided approximately 8 kg DM/cow per d and were offered one of 3 diets: 1) Control (10 cows); 2) partial mixed ration (PMR; 10 cows); or 3) PMR...
Conference Paper
Full-text available
Twenty four rumen fistulated lactating Holstein cows were fed 8, 10, 12, 14 and 16 kg/hd/d of concentrate with either a control diet or partial mixed ration (PMR). These were used to validate an existing acidosis model based on ruminal pH, volatile fatty acid (VFA), ammonia and lactate measures. Controls were fed rolled wheat grain twice a day at m...
Conference Paper
Full-text available
The lack of consistent techniques to diagnose ruminal acidosis is a major challenge for management of dairy and feedlot cattle. Developing better diagnostic tools will help farmers and their advisors identify cows and herds at risk of acidosis. It is important to validate the model that Bramley et al. (2008) developed to define ruminal acidosis usi...
Article
Full-text available
The objectives of this study were to critically review randomized controlled trials, and quantify, using meta-analysis and meta-regression, the effects of supplementation with fats on milk production and components by dairy cows. We reviewed 59 papers, of which 38 (containing 86 comparisons) met eligibility criteria. Five groups of fats were evalua...
Technical Report
Full-text available
This project provides evidence that progress in improving liveweight gains of cattle has been limited since the 1950’s. Currently used interventions that provide increased weight gain include minerals, ionophores, non-protein nitrogen, protein meals and Leucaena. There is a lack of knowledge of integrated effects of supplementary feeding strategies...
Conference Paper
Full-text available
Introduction: The effects of subacute acidosis on oxidative stress and inflammatory response are relatively unknown. The subacute acidosis protocol used in this study is capable of significantly decreasing rumen pH and altering rumen fermentation products. The greatest effects on rumen fermentation were observed in treatment groups containing fruct...
Article
Full-text available
1. This study investigated the effect of Eimeria spp./Clostridium perfringens induced necrotic enteritis and traditional antibiotic preventatives on intestinal micro-architecture and mucin profile. 2. A total of 600 Cobb 500 broiler chickens were randomly assigned to the following three groups: (i) unchallenged, (ii) challenged, and (iii) zinc baci...
Conference Paper
Full-text available
We examined the effects of grain, fructose and histidine on oxidative stress and inflammatory response in dairy cattle during an induced subacute acidosis (SARA) protocol. Thirty Holstein-Friesian heifers were randomly allocated into 5 groups; 1. Control (no grain), 2. Grain (1.2% liveweight (LW) rolled triticale)(GR), 3. Grain (0.8% LW) + fructose...
Conference Paper
Full-text available
This study investigated the effects of grain, fructose and histidine on ruminal pH and fermentation products in dairy cattle. Thirty Holstein heifers were randomly allocated into 5 treatments; i) Control (no grain), ii) Grain (1.2% liveweight (LW) rolled triticale)(GR), iii) Grain (0.8% LW) + fructose (0.4% LW)(FR), iv) GR + histidine (6g/hd) and v...