A. S. Hodgson’s research while affiliated with Washington State University and other places

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Publications (8)


Nutrient Distribution and Retention during Winter Storage of Animal Wastes in Two-Stage Simulated Systems as Affected by Aeration and Buffering1
  • Article

November 1981

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3 Reads

Journal of Dairy Science

F. R. Murdock

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A. S. Hodgson

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M. H. Ehlers

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D. F. Bezdicek

Six two-stage animal waste storage simulators were designed, constructed, and used to measure the distribution and retention of nutrients during winter storage of liquid animal wastes from a dairy herd. Effects of surface aeration and pH buffering plus aeration on nutrient distribution and retention were deter- mined. Nutrients retained during simulated untreated (control) storage were total solids 99%, volatile solids 97%, total nitrogen 89%, and ash 100%. Aeration increased degradation of volatile solids but did not reduce total nitrogen retention appreciably in unbuffered systems. Aera- tion increased transfer of soluble nutrients to the low-solid stage. Buffering of waste at a pH from 6 to 7 with phosphoric acid effectively retained nitrogen in a system in which mild aeration was applied to the high-solid stage. From 30 to 42% of the total nitrogen was recovered in the second low-solid stages demonstrating the significance of the liquid phase as a valuable fertilizer resource for irrigation. Appreciable synthesis of protein by microflora apparently occurred through utilization of ammonia as a nitrogen source in the nonbuffered system. Odor intensity indexes of liquids in the surface layer were reduced by aeration of that layer. Oxidation-reduction poten- tials appear to be a reliable indication of degree of malodor production.


Nutritive Value of Wet Brewers Grains for Lactating Dairy Cows1

September 1981

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145 Reads

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55 Citations

Journal of Dairy Science

Forty Holstein cows of high potential for milk production were assigned pre- partum to five rations of varying protein percent and source. Protein was 85, 100, and 118% of the requirements recom- mended by the National Research Council. Within 100 and 118%, supplemental protein was either wet brewers grains or soybean meal. Wet brewers grains con- stituted 15 and 30% of ration dry matter or approximately 25 and 50% of total intake of concentrate dry matter for the 100 and 118% rations. The trial was the first 140 days of lactation. Production and composition of milk were not different between percents and sources of supplemental protein. However, production was reduced slightly by the unsupplemented ration containing 85% of recommendation. Rumen ammonia nitro- gen and urea nitrogen of blood plasma were correlated with intakes of ration protein and soluble nitrogen among all rations and within rations containing soybean meal but not within rations containing wet brewers grains. Calculated energy for wet brewers grains indicated total digestible nutrients of 78% and net energy for lactation of 1.76 Mcai/kg of dry matter. These are approximately 16% greater than those listed by National Research Council.


Response of High Producing Dairy Cows Fed Alfalfa Hay and Corn Silage to Supplemental Protein and Urea1

November 1979

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10 Reads

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21 Citations

Journal of Dairy Science

Thirty-two high producing Holstein cows were assigned randomly to three rations of varying percents and sources of protein: 1) 14.4% crude protein from natural sources, 2) 17.5% crude protein from natural sources, and 3) 17.7% crude protein from both natural and nonprotein nitrogen (urea) sources. Urea nitrogen constituted 11.1% of the total nitrogen in ration 3. Dietary treatments were examin- ed in two trials during the first 84 to 140 days of lactation. Mean daily intakes of dry matter and total digestible nutrients were higher for cows fed elevated protein: 20.1, 14.0; 21.7, 15.2; and 22.1, 15.2 kg for rations 1, 2, and 3. Means of 3.5% fat-corrected milk were 32.5, 34.8, and 34.3 kg/day. The principal effect of elevated protein was an increase in intakes of dry matter and energy which may have been con- tributory to the small increase in milk production. However, the trend for higher milk production was established during the first 28 days of lactation when energy intakes were equal. No adverse effects of urea supplementation on feed intake or milk production were apparent.


Effects of Roughage Type and Texture on Milk Fat Secretion and Body Weight Recovery by Lactating Dairy Cows1

March 1979

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18 Reads

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4 Citations

Journal of Dairy Science

Twenty-five lactating Holstein cows were fed five rations in which the rough- age portions (dry matter) consisted of either 1) baled hay; 2) cubed hay; 3) cubed hay, 90% and corn silage, 10%; 4) cubed hay, 80% and corn silage, 20%; or 5) cubed hay, 60% and corn silage, 40%. Hays were third-cutting alfalfa. Rations were fed in a continuous test during the first 168 days of lactation to determine effects of ration on feed intake, produc- tion and composition of milk, and change in body weight. Substituting corn silage for cubed hay depressed intake of roughage dry matter at 20 and 40% substitution and increased milk fat percent at 40%, but had no effect on solids-not-fat percent or produc- tion of fat-corrected milk. In early lactation mean milk fat percentages increased linearly as corn silage was substituted for cubed hay at 20 and 40%. Gross efficiencies of milk production of the 20 and 40% corn silage rations exceeded efficiencies of baled hay, cubed hay, or 10% corn silage rations. Rate of body weight recovery after parturition was slower for cows fed baled hay than for those fed cubed hay or mixed cubes and silage. The interrelationships of milk fat tests and rumen volatile fatty acids of cows fed coarse textured hay (baled), fine textured hay (cubed), and cubes supplemented with corn silage indicate milk fat percent-


Cubed Complete Rations for Lactating Dairy Cows

December 1977

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7 Reads

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10 Citations

Journal of Dairy Science

Production by cows fed cubed complete rations as compared to the same ration components fed separately as long hay and concentrate was determined in two experiments. The cubed rations reduced milk fat percentages in both experiments and total fat production in one experiment. Solids-not-fat was increased slightly by cubed rations. Lower efficiency of feed utilization for the production of 4% fat-corrected milk was evident for cows fed cubed rations. Losses of body weight following parturition were reduced, and subsequent weight recoveries were more rapid in cows fed cubed rations. Also, molar ratios of acetic/propionic acids in the rumen were reduced. Effects of rations on milk composition, changes in body weight, and ratios of volatile fatty acids appear to be related to differences in coarseness or texture of the roughage components of cubed and baled hay rations. The results of these feeding experiments indicate complete rations prepared by cubing chopped alfalfa hay and concentrates in conventional hay cubing equipment have limitations as the sole rations for high producing dairy cows.


Utilization of Nitrates by Dairy Cows

June 1972

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9 Reads

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5 Citations

Journal of Dairy Science

Oat hays of varying nitrate nitrogen content (.02 to .96%) were fed to lactating dairy cows and bred heifers under controlled conditions wherein intakes were ascertained. Some death losses, diagnosed as nitrate poisoning, had occurred previously in a beef herd on the farm where this hay was produced.No toxic symptoms were observed in either the heifers fed oat hay as the sole ration or the cows which received oat hay and supplemental concentrates according to production. High nitrate nitrogen intakes did not appreciably impair milk production.Blood methemoglobin was generally low. Elevated methemoglobin was not always coincident with high nitrate intake. Unknown physiological factors other than nitrate-nitrogen intake per se may contribute to high methemoglobin and development of toxic symptoms.


Input-Output Relationships of Roughage and Two Levels of During Complete Lactations Cows Fed Two Types of Concentrate

December 1969

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10 Reads

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11 Citations

Journal of Dairy Science

Total feed input, milk output, and body weight changes were determined on 24 cows fed: either alfalfa hay or high-moisture grass Silage plus hay in conjunction with concentrates at two levels during full lac- tation studies. Input-output data were summarized for a prepartum period, ten 28-day and one 25-day lactation periods, and a postpartum period. Although mean forage dry matter intake of hay-fed cows exceeded that of cows fed silage plus hay, cows fed the mixed forage maintained milk production equal to those fed hay and maintained slightly higher body weights (luring lactation. Although mean far-corrected milk pro- duction was slightly higher by cows fed concentrate at the challenge level than those fed at the ratio of one to four, differences in milk production for levels of concen- trate werenot significant (P: >0.10). Milk fat tests were significantly higher (P =


Milk Production Response of Dairy Cows Fed High-Moisture Grass Silage. I. Effect of Varying Levels of Hay and Concentrate1

January 1967

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8 Reads

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6 Citations

Journal of Dairy Science

Varying levels of bay and concentrate were fed in conjunction with high-moisture grass silage ad tibitum to 16 lactating cows, to determine the effects of these ration variables on milk production and composi- tion. Feeding the higher level of concen- trate (0.6 kg/kg 4% FCM over 8.16 kg) resulted in the production of more 4% FCM (P < 0.01), as well as higher percentages of milk protein (P < 0.01) and solids-not- fat (P < 0.01) than produced when the lower level of concentrate (0.3 kg/kg 4% FCM over 8.16 kg) was fed. Varying the level of hay fed between 0.5 and 1.0 kg/100 kg body weight had no significant effect on the amount of milk produced or its composition. Likewise, no significant effects on the per cent of milk fat were observed by varying levels of either hay or concentrate within the limits fed in this study. Increasing the level of concentrate fed was more effective than increasing the level of hay for maintaining high dry-matter intake and in meeting the estimated TDN requirements of the cows. The TDN sys- tem of feed evaluation provided a reliable estimate of the relative nutritive value of these rations. Grass silage is the principal winter forage fed dairy cattle on many farms. The bulk of the silage made on farms in the north Pacific coastal area is harvested by direct-cut methods, in spite of research evidence that partial wilting of immature, succulent forages before ensiling reduces dry-matter losses in storage (7, 13, 17) and increases silage dry matter intake when fed (10, 14, 16). Cool, damp weather prevailing during first-cutting harvest makes wilting a questionable practice on most farms in this area.

Citations (6)


... Wet brewers' grains have generally been included in up to 30% of the ration DM as a substitute, primarily for soybean meal (Murdock et al., 1981;Miyazawa et al., 2007;Imaizumi et al., 2015) or corn silage in ruminant diets (Firkins et al., 2002;Stefanello et al., 2019) without negatively affecting intake and digestibility. Owing to its high energy and protein content, WBG have the potential to replace soybean meal and corn silage; however, the effect concomitantly substituting corn silage and soybean meal with WBG on the intake and nutrient digestibility in ruminant diets is unknown. ...

Reference:

Mycotoxin concentration in salt-treated wet brewers’ grains and effects of their substitution for soybean meal and corn silage
Nutritive Value of Wet Brewers Grains for Lactating Dairy Cows1
  • Citing Article
  • September 1981

Journal of Dairy Science

... De otro lado, cuando se suplementan vacas en producción con 2,2% y 2,7% de urea en la ración diaria, se ha producido una merma importante en el consumo; no obstante, al suplementar urea a razón del 1% no se ha visto deprimido el consumo de alimento (Van Horn et al., 1967). Por su lado, Murdock y Hodgson (1979) suplementaron vacas en producción con urea a un nivel del 11,1% del total del nitrógeno de la ración (silo de maíz y heno de alfalfa) y no encontraron efectos adversos en el consumo ni en la producción de leche. ...

Response of High Producing Dairy Cows Fed Alfalfa Hay and Corn Silage to Supplemental Protein and Urea1
  • Citing Article
  • November 1979

Journal of Dairy Science

... Traditionellt sett används ensilage som grovfoder åt mjölkkor under stallperioden (Murdock & Hodgson, 1967;Keady et al., 2008). I Sverige odlas 85 % av åkerarealen för fodermedel till mjölkkorna framförallt vall-och foderspannmål (Emanuelson et al., 2006). ...

Milk Production Response of Dairy Cows Fed High-Moisture Grass Silage. I. Effect of Varying Levels of Hay and Concentrate1
  • Citing Article
  • January 1967

Journal of Dairy Science

... In the study of Gardner (1969), a high post-partum energy level increased production of milk, protein, and lactose without affecting percentages of milk components. In the experiment of Murdock and Hodgson (1969), mean FCM production was slightly higher in cows receiving concentrate in the diet than in cows fed only forage, differences in milk production for different levels of concentrates were not significant (p>0.10). Milk fat was significantly higher (p<0.05) for cows fed silage and hay than for those fed hay as the sole roughage. ...

Input-Output Relationships of Roughage and Two Levels of During Complete Lactations Cows Fed Two Types of Concentrate
  • Citing Article
  • December 1969

Journal of Dairy Science

... Lactating dairy cows increase their energy intake in response to the demands for milk synthesis (28,32,75), but this increase typically lags several weeks behind the increase in milk yield (52,79). There is usually a high correlation between milk production and nutrient intake (28,37,38), although the diet must have a minimal caloric concentration for a given rate of milk production as demonstrated by Bull et al. (30) (Figure 1) and Murdock and Hodgson (83). ...

Effects of Roughage Type and Texture on Milk Fat Secretion and Body Weight Recovery by Lactating Dairy Cows1
  • Citing Article
  • March 1979

Journal of Dairy Science

... Depending on the operating conditions of individual process steps in sugar production (temperature, pH value, dry substance content), thermophilic bacteria (denitrifying bacteria) show varying microbial activity and they are capable of reducing nitrate to nitrite, and thus of causing the nitrite content to rise (Mikoś et al., 2015;Van der Poel et al., 1998;Waterlander et al., 2011). Van Zijderveld et al. (2011) have observed the occurrence of methemoglobinemia in dairy cows when using feed containing nitrates at level 700 mg kg −1 of body weight whereas Murdock, Hudgson and Baker (1972) when using feed with lower nitrate content 20-460 mg kg −1 of body weight. In the case of beef Burrows et al. (1987) have reported the occurrence of methemoglobinemia after ingestion of feed containing nitrates at level 220-300 mg kg −1 of body weight whereas Lichtenwalner, Fontenot, and Tucker (1973) when using feed with much lower nitrate content 10-20 mg kg −1 of body weight. ...

Utilization of Nitrates by Dairy Cows
  • Citing Article
  • June 1972

Journal of Dairy Science