P.H. Robinson's research while affiliated with University of California, Davis and other places

Publications (184)

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Impacts of an additional cooling event during the night on physiological and productive parameters of two breeds (B) of dairy cows under severe heat stress conditions were determined. Fifteen Holstein (H) and 15 Jersey x Holstein (JxH) cows were assigned to one of the two cooling strategies (CS), where the difference was an added 1 h cooling event...
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The amount of milk Canadian dairy farmers produce is limited to a production quota expressed in milk fat. Because milk economic value is primarily based on fat and protein, it can be advantageous to decrease the milk fat to protein ratio. Monensin sodium has been suggested to reduce milk fat proportion and outputs, but not milk protein. Publication...
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A major cause of reproductive failure in contemporary lactating dairy cows is early post-partum negative energy balance (NEB). A strategy to alleviate NEB is to reduce milk energy density by feeding supplements to suppress milk fat synthesis, which could reduce body fat mobilization to favor earlier ovulation and improved pregnancy rates. As fish o...
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A source of methane (CH4) emissions from dairy farms arefecal volatile solids (VS) produced by cattle, which is impacted by herd size, cattle type, feed intake/composition and farm management practices. Where cattle deposit fecal VS in their pen is important in this regard since that deposited on concrete, which will be handled and stored in a liqu...
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Efficient production by dairy cows depends on optimal protein nutrition. Canola meal (CM) and dried corn distillers’ grains (DDGS) have been primary protein meals on Western USA dairies for >10 years, but a lower relative price of soybean meal (SBM) has created interest in how best to include it in diets containing CM and DDGS. Pens of ∼315 multipa...
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Research in the past 50 years has shown that the general health of dairy cows (i.e., immunity and uterine health) can be improved by higher post-ruminal delivery and absorption of poly unsaturated fatty acids (PUFA), especially omega-3 (n-3) PUFA. Since flaxseed contains high concentrations of n-3 PUFA, our objective was to evaluate effects of feed...
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The eight vitamins of the B vitamin (BV) complex (i.e., thiamine, riboflavin, niacin, pantothenic acid, vitamin B6, biotin, folate, cobalamine) are vital to numerous facets of mammalian metabolism. However a lack of organized requirements and duodenal delivery predictions limits their ability to be used in formulating rations for dairy cows. The ob...
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Optimal protein nutrition of dairy cattle is important to support efficient production of high producing lactating dairy cows. Canola meal (CM) and corn dried distillers’ grains with solubles (DDGS) have been primary protein meals on many dairy farms in the Western USA for over 10 years, but decreases in the relative price of soybean meal (SBM) has...
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Research conducted over the past 50 years has shown that the general health of dairy cows (i.e., immunity and uterine health) as well as pregnancy rates (i.e., fertilization and embryo development) can be improved through enhanced post-ruminal delivery, and absorption, of poly unsaturated fatty acids (PUFA), especially omega-3 (n-3) PUFA. Since fla...
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Thin plastic underlay films are commonly recommended to reduce spoilage and increase hygienic quality of commercial silages. However there has been a limited amount of research completed to ascertain the benefits of these underlay films, and even less to compare underlay films with differing oxygen permeability. This Short Communication comments on...
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Preserving silage in large piles is popular due to its flexibility and affordability that allows storage of large amounts of silage with low facility investment. Management of silage piles during feed-out impacts silage spoilage since, once the plastic covers are removed and silage near the exposed silage ‘face’ is exposed to air, undesirable micro...
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The goal of the article is to implement the CTR Dairy model using the Visual Basic for Application (VBA) language of Microsoft Excel. CTR Dairy is a dynamic simulation model for grazing lactating dairy cows that predicts milk production and profit over feeding based on ruminal digestion and absorption of nutrients under discontinuous feeding schedu...
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Phenylalanine (Phe) was first identified as a potentially limiting amino acid (AA) in lactating dairy cows in 1974. There is the possibility that conversion of Phe to tyrosine (Tyr) is not efficient enough to supply all Tyr requirements for milk production in high producing dairy cows, thereby suggesting that Tyr itself could become a functionally...
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If cows successfully transition the immediate post-partum (i.e., fresh) period, then it is likely they had a limited negative energy balance and avoided metabolic disease. Our objective was to determine if modulating fat metabolism during the fresh period, by feeding ruminally protected niacin (RPNi), had carry-over effects after cessation of its f...
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Ingredient substitution studies are common in the animal science literature. However such studies often confound changes of ingredient and nutrient levels, thereby begging the question as to whether responses measured among diets represent known differences among diets in measured nutrient levels, or to changes in unknown dietary factors/nutrients....
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This study aimed to contribute to understanding the interface between reproductive and nutritional energetic physiology in contemporary dairy cattle. Multiparous Holstein cows (n = 32) between 70 and 180 days in milk were used in a study starting 10 d prior to the artificial insemination (AI) date and were estrous synchronized using a hormonal regi...
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The objective of this study was to determine effects of inclusion of pomegranate pulp silage (PS) in lactating dairy cows’ rations, in replacement of mainly corn silage, on milk yield, chemical composition, somatic cells count, colony forming units, and fatty acid (FA) concentrations of milk, as well as on blood antioxidant status. Fifteen lactatin...
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Common contemporary diet formulation methods involve factorial or empirical models which simulate ruminal fermentation and post ruminal absorption to predict nutrient supply and needs. However, due to their inability to encompass all animal factors that affect digestion and absorption, metabolic models inadequately predict microbial protein (MCP) s...
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Silage 'shrink' (i.e., fresh chop crop lost between ensiling and feedout) represents losses of potential animal nutrients which degrade air quality as volatile carbon compounds. Regulatory efforts have, in some cases, resulted in semi-mandatory mitigations (i.e., dairy farmers select a minimum number of mitigations from a list) to reduce silage shr...
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Even though studies supplementing Phe to dairy cattle are rare, it has been identified as limiting in corn silage based rations, after Lys and Met, as well as being important to the mammary gland for overall milk production. Since canola meal (CM) is low in Phe, plasma Phe concentrations decrease as more CM is included in dairy rations. A previous...
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Our aim was to determine effects of two S. cerevisiae yeast based direct fed microbial (DFM) feed additives on the productive response of high producing early lactation dairy cows. The study consisted of three high producing Holstein cow pens (± 315 cows/pen) in a 3 × 3 Latin square design experiment with 3 periods of 28 d each. The 3 treatments we...
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Large silage piles, up to 15,000 tonnes, common in some dairy areas, present challenges since their large surface area creates an enhanced potential for oxygen to penetrate the mass. Use of thin inner (i.e. between the silage and main plastic cover) plastic films with enhanced oxygen barrier (EOB) properties are recognized by some governmental agen...
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Rectal temperature (RT) is the foremost physiological variable indicating if an animal is suffering hyperthermia. However, this variable is traditionally measured by invasive methods, which may compromise animal welfare. Models to predict RT have been developed for growing pigs and lactating dairy cows, but not for pregnant heat-stressed ewes. Our...
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Early lactation dairy cows are frequently in negative energy balance and susceptible to ketosis, fatty liver and metritis. Because of its anti-lipolytic properties, the B-vitamin niacin could reduce negative energy balance by reducing non-esterified fatty acids for ketogenesis, thereby reducing hyperketonemia. We determined effects of feeding rumin...
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Silage 'shrink' (i.e., loss of fresh chopped crop between ensiling and feedout) represents a nutrient loss which can degrade air quality as volatile carbon compounds, degrade surface waterways due to seepage, or degrade aquifers due to seepage. Virtually no research has documented shrink in large silage piles. The term 'shrink' is often ill defined...
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This study determined effects of feeding a citrus extract (CE) to high producing dairy cows during summer heat on measures of heat stress, as well as milk production and composition, in a replicated 2 × 2 Latin square experiment with two 28 d periods on a dairy farm near Hanford (CA, USA). Four ‘high group’ pens were used (i.e., cows which had clea...
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Canola meal is the second largest protein feed in the Northern latitudes and inclusion levels in dairy rations are expected to increase due to projected large increases in production of canola seed in Canada. However, a recent study (Swanepoel et al., 2014) showed that even though higher inclusions of canola meal (CM) had a positive effect on produ...
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Due to its potential toxicity to wildlife, selenium (Se) is a highly regulated trace element in the San Joaquin Valley (SJV) of California. Tall wheatgrass (TWG) is a Se-accumulating, salt tolerant forage suitable for cropping systems which re-use agricultural drainage waters. Utilization of TWG hay as an alternative Se supplement for dairy cattle...
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Analysis of exposed silage face surface area was conducted to better understand and provide feed management recommendations as well as evaluate potential compliance needs related to volatile organic compound emissions. Policy was developed by the San Joaquin Valley Air Pollution Control District (District) to restrict exposed surface area of silage...
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Use of canola meal (CM) and dried corn distillers grains with solubles (DDGS) as major supplemental protein sources are common practice in North American dairy rations and usage of both is projected to increase in the future. Since limited data is available on performance of cows fed diets with different ratios of CM and DDGS, our objective was to...
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Rice straw (RS) has generally not been considered as an ingredient in dairy heifer or cow rations in the developed world, at least partly due to its tough physical character. However, recent research aimed at developing harvesting methods that increase mixability and reduce animal-sorting problems has identified straw-preparation methods with subst...
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Current methods to determine rumen escape (as stability) of rumen protected nutrients (RPNU), such as ruminal in situ evaluation, only estimate the rate at which nutrients leave the in situ bag (rather than the rumen) and thus can provide only a rough estimate of actual rumen stability, which is also impacted by actual ruminal RPNU release rate, ra...
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Sodium bicarbonate (SB) is a common dairy feed supplement, although recent research on its rumen buffering efficacy in contemporary dairy diets with low starch levels is limited. In California, and other areas of the world, new environmental regulations aim to minimize the amount of fixed solids (FS), including Na, which are discharged from dairy f...
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This preface outlines the reasons for undertaking the special issue, comments on the review process and provides a brief summary of the papers included. It also discusses some of the currently used, and potential, plant based bioactive compounds in ruminant agriculture and their applications in promoting animal growth, mitigating enteric methane em...
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Heat stress resulting in animal production losses costs the dairy industry hundreds of millions of dollars annually, especially in tropical and semi-tropical areas. Niacin is a dietary supplement which typically induces flushing (i.e., increased blood flow to the skin), causing a decrease in core body temperature, which has been shown to reduce hea...
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Rice straw can be used as a forage for cattle, generally those whose intake potential exceeds their energy need, to provide economic savings in cattle production systems. This study evaluated how simulated field drying of rice straw, its silica level and location in the detergent fiber matrix, impacts in vitro gas production. We also determined how...
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Our previous research demonstrated that milk production of early lactation dairy cows benefits from postruminally delivered B vitamins in addition to those supplied in rumen microbes. In this study, our objective was to determine effects of supplementation of a complex of ruminally protected B vitamins (BV), using a fat based rumen protection techn...
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Two experiments were conducted to evaluate Se accumulation and health of non-pregnant, non-breeding beef cattle grazing on forages with a high Se content due to irrigation with saline drainage water. Heifers grazed experimental pastures of "Jose" tall wheatgrass (TWG; Thinopyrum ponticum var. "Jose") and creeping wildrye (CWR; Leymus triticoides va...
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The objective was to develop a linear programming model to formulate diets for dairy cattle when environmental policies are present and to examine effects of these policies on diet formulation and dairy cattle nitrogen and mineral excretions as well as methane emissions. The model was developed as a minimum cost diet model. Two types of environment...
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This editorial is an annex, essentially an amplification of earlier Animal Feed Science and Technology (AFST) editorials which focused on analytical and statistical issues of papers submitted for publication in AFST. This amplification is needed because, since publication of those editorials, there has been a sharp increase in papers submitted to A...
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Heat stress generates a significant economic impact for the dairy industry in arid and semi-arid regions of the world, so that heat abatement is an important issue for dairy producers. The objective of this study was to evaluate effects of two short-term cooling periods on physiological and productive status of lactating Holstein cows during hot am...
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In 2007, a descriptive survey was mailed to all dairies in Glenn (G) and Tulare (T) Counties to identify current and future opportunities of manure management practices on California dairies. The purpose was to provide baseline information for development of outreach curriculum and a decision support tool to quantify potential benefits of various N...
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Increased milk production requires high intakes of crude protein in the diet, and/or improved supply and profiles of amino acids (AA) delivered to the duodenum, in order to meet animal needs for milk and milk component synthesis. Our objective was to estimate the rumen escape of a ruminally protected lysine (RPL) product and determine effects of fe...
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This preface summarizes papers published in the special issue which were previously presented at the Greenhouse Gases (GHG) in Animal Agriculture Conference in Banff (Alberta, Canada) in October of 2010. The conference had over 400 delegates from 36 countries, an attendance which attests to the global research effort ongoing in this area. The meeti...
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The literature on post-ruminal lysine supplementation to diets of lactating dairy cows shows generally small negative responses to supplemental intestinally absorbable lysine, and our recent metabolic modeling of California dairy rations predicted other amino acid (AA) that could become co-limiting if supplies of intestinally absorbable lysine were...
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The objectives were to predict amino acid (AA) profiles of intestinally delivered protein in California high group (i.e., lactating but not yet confirmed to be in calf) dairy cattle fed contemporary rations using three metabolic models of dairy cows. This was done in order to predict limiting AA in dairy rations to determine if there was enough con...
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The sensitivity of the lactic acid bacteria (LAB) Lactobacillus plantarum and Enterococcus faecium), isolated from sheep faeces, to secondary compounds extracted from Acacia saligna leaves was investigated. Secondary compounds (SC) extracted from A. saligna foliage were: total phenolics (TP), saponins (SP), alkaloids (AK), a methanol extract (ME) a...
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Effects of varying the partitioning factor (PF, mg in vitro true digested organic matter: ml gas) and in vitro rate of gas production (k, h−1) of diets fed to crossbred dairy cows on intake, digestibility, an efficiency measurement of production of microbial N (MN) supplied to the duodenum, as well as milk production and composition, were determine...
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Experiments which used crossbred cows and heifers, from peer review publications originating from the Karnataka Veterinary, Animal and Fisheries Sciences University (Bidar) and Veterinary College (Bengaluru) in India were used to determine if ruminal microbial N (MN) supply could be predicted based upon the partitioning factor (PF, mg in vitro true...
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The aim of this study was to compare three cooling management systems to improve the physiological status and lactation performance of Holstein cows during summer heat. Multiparous Holstein cows, 32, were blocked according to milk yield divided into four treatments being: C) Control group, cows cooled before milking time (0500 and 1700h daily); AM)...
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Due to the recent expansion of the motor fuel ethanol industry, which is largely based upon traditional food and feed crops, supplies of ruminant feeds have become limited in many areas of the world thereby creating a need for alternatives. Rice straw, a substantial biomass source worldwide, could fill this role if its nutritional value was higher....
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Ruminants have the ability to utilize non-protein N compounds as N sources for rumen microbial protein synthesis. The objective of this experiment was to determine if use of a slowly rumen released urea could increase productive performance and/or decrease urinary N components of dairy cows when used as a replacement for urea in diets high in solub...
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Increased milk production requires high intakes of crude protein in the diet, and/or improved supply and ratios of amino acids (AAs) delivered to the duodenum in order to meet animal needs for milk and milk protein synthesis. The objective of this study was to estimate the rumen escape potential of a ruminally protected lysine product (RPL) and to...
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Essential oils (EO) have been shown to positively impact in vitro ruminal fermentation, but there are few in vivo studies that have examined animal responses. Our objective was to evaluate the efficacy of an EO complex (Agolin Ruminant from AGOLIN SA, Bière, Switzerland), which contained eugenol, geranyl acetate and coriander oil as major component...
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The dual purpose of this editorial is to outline effective ways to review manuscripts that have been submitted for consideration for publication in Animal Feed Science and Technology, as well as to discuss appropriate ways for authors to revise their manuscript after it has been returned with initial reviews and editor comments.
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A group of 22 treatments from 6 experiments in which lactating dairy cows were fed diets with different ingredient compositions, and in which the amino acid (AA) profile of their duodenal protein was measured with the same techniques and methodologies, were assembled. Correlative statistics were used to assess relationships between proportions of v...
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This experiment studied effects of a mixture of exogenous enzymes (ZADO®) from anaerobic bacteria on ruminal fermentation, feed intake, digestibility, as well as milk production and composition in cows fed total mixed rations (TMRs; 0.7 corn silage and 0.3 of a concentrate mixture). Twenty lactating multiparous Brown Swiss cows (500±12.4kg live wei...
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This study determined the chemical composition and metabolizable energy (ME) value for ruminants of seeds and pulps from grape pomaces (GP), which were produced from white and red Vitis vinifera cultivars in Italy and California (USA). Six Italian (i.e., three white and three red) and five California red cultivars were collected after the crush of...
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This study determined impacts of a commercial blend of microencapsulated essential oils (EO), fed at increasing dose levels to high yielding primiparous dairy cows, on milk yield and composition. Eight pregnant Holstein heifers, selected to have their parturition within a period of 30d, were kept in tie stalls equipped for individual feeding, and w...
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Multiparous Holstein cows (n=717) from two dairy farms were blocked at calving by parity and previous lactation milk yield and, within each block, randomly assigned to one of two treatments: a diet containing no yeast culture (Control; n=359) or 30 g/d of a culture of Saccharomyces cerevisiae (YC; n=358) from 20 to 140 d postpartum. Only cows calvi...
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Effects of diets (finger millet straw (FMS) and concentrate supplement (CS) differing in their in vitro determined rate of fermentation (k) on total DM intake, nutrient digestibility and nitrogen metabolism were studied in crossbred dairy cows. The two diets, viz high k (0.081/h) and low k (0.065/h), were formulated to be iso-energetic and iso-nitr...
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The brown midrib (BMR) gene has been reported to reduce the lignin concentration in plants, which contributed to increased fiber digestion in ruminants. Three studies were completed to compare the digestibility of a BMR mutant of sudangrass (sorghum bicolor subsp. Drummondii) versus a non-BMR (‘Piper’) variety when included in diets fed to sheep (S...
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Effects of feeding a culture of Saccharomyces cerevisiae to lactating cows on their lactational performance during heat stress were determined. Multiparous Holstein cows (n=723) calving during the summer months from two dairy farms were randomly assigned to a diet containing no yeast culture (control; n=361) or 30g/d of a S. cerevisiae yeast cultur...
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A ration formulated for ruminants is often a mixture of individual feeds, and its energetic value is generally calculated by summing the energy value of the individual feeds in it, on the assumption that the energy value of individual feeds will be the same when they are fed in combination with other feeds. In vitro gas production techniques were u...
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The objective was to measure effects of cooling technique (shade vs. water sprinklers) on performance, behavior, physiology, and the environmental effect of 40 Holstein heifers housed in drylot corrals during the hot summer months. The experiment was a replicated crossover design with four 21-d periods and 2 treatments: 1) shades installed in the f...
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The objective was to determine the nutrient profile, and variability, as well as estimate the net energy (NE) of four co-product feeds of the corn grain-based motor fuel ethanol distillation industry in the Midwestern USA. Ten samples each of conventional distillers dried grains with solubles (DDGS), raw-starch (i.e., uncooked) distillers dried gra...
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The objective was to determine effects of feeding increasing levels of a Yucca schidigera extract (YSE) to dairy cows on 24h in vitro gas production and 27h in vitro neutral detergent fibre (aNDFom) digestion of 11 common dairy feedstuffs, as well as in vivo rumen fermentation and performance of the cows to which the YSE was fed. The principle was...
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Effects of field scale maceration on voluntary intake of rice straw, diet digestibility of neutral detergent fiber (aNDF) and performance of growing cattle were evaluated through chemical, in vitro and animal feeding experiments over a 3-year period. Due to the sequential nature of the study (i.e., a discrete experiment was completed in each year),...
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Full-text available
Avendaño-Reyes, L., Alvarez-Valenzuela, F.D., Correa-Calderón, A., Fadel, J.G. and Robinson, P.H. 2008. Is soaking cows during dry period an effective management tool to reduce heat stress and improve pospartum productivity? J. Appl. Anim. Res., 34: 97–100.In order to determine the effect of a cooling system on prepartum physiological parameters an...
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This preface outlines the reasons for the special issue, comments on the review process and provides a brief summary of the papers. Research on feed additives of ‘natural’ or biological origin was provided an impetus due to the European ban on growth-promoting antimicrobial feed additives. However, the potential of feed additive enzymes, direct-fed...
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It is not clear if B vitamins supplied to the small intestine of dairy cows from dietary and rumen microbial sources are provided in sufficient quantity to maximize animal performance. Our objective was to determine effects of adding a ruminally protected B vitamin blend supplement, containing biotin, folic acid, pantothenic acid and pyridoxine, to...
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A simulation rumen model has been developed to function under non-steady state conditions in order to allow prediction of nutrient availability in dairy cows managed under discontinuous feeding systems. The model simulates availability of glycogenic, aminogenic and lipogenic nutrients to lactating dairy cows fed discontinuously. The model structure...
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In an experiment with 40 growing Florina (Pelagonia) lambs, effects of replacing barley grain, sugar beet pulp, and alfalfa meal with fermented olive wastes (FOW) and soybean meal on productivity and meat composition was determined. In the 45-day experiment, lambs were allocated to one of the four treatments of 10 lambs (5 male and 5 female) each....
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The objective was to determine performance and milk fatty acid changes of high producing dairy cows in early lactation, under summer heat, by adding a supplemental rumen inert fat in the form of a saturated free fatty acid (856g/kg C16:0/kg of total fatty acids) to the total mixed ration (TMR). Early lactation multiparous Holstein cows in two simil...