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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 piles to 199·7 m2 per farm if only one pile was exposed or 399·5 m2 per farm if more than one pile was exposed. Exposed surface area on piles of silages at 20 dairies was quantified to determine impacts of these surface area restrictions. Herd size ranged from 490 to 7,200 milking cows, and the number of exposed piles ranged from one to four per farm as maize and/or wheat silage. Surface area of piles was quantified based on pile measurements and geometric shapes. The measured value was compared to the estimated value using the District 'online calculator'. The District calculator used inputs for base length and height with assumed constant relationships between base and top lengths. Five of 43 piles had >199·7 m2 of exposed surface area. Sixteen of 20 dairies with more than one exposed surface complied with the exposed surface area restriction. On average, the District calculator overestimated surface areas by 11·6% ± 14·8 (range −57·7 to 38·4%). Pile measurements and use of geometric shapes provide a more precise method to quantify exposed surface area. This will be of particular use for those operators who utilize the District calculator and find their exposed areas out of compliance. [ABSTRACT FROM AUTHOR]

The aim of the present study was to gather baseline information on corn silage-management practices to develop an outreach curriculum for dairy producers and growers. In spring 2013, dairy producers in the San Joaquin Valley (California) were surveyed on their silage-management practices. Response rate was 14.5% (n = 160) and herd size averaged 1,512 milking cows. Harvest date was set solely by the dairy producer (53.4%) or with the assistance of the crop manager, custom chopper, or nutritionist (23.3%). On some dairies (23.3%), the dairy producer delegated the harvest date decision. Most dairies (75.0%) estimated crop dry matter before harvest, and the preferred method was milk line evaluation. Dairy producers were mostly unfamiliar with harvest rate but the number [1 (35.9%), 2 (50.3%), or 3 to 5 (13.8%)] and size [6-row (17.7%), 8-row (67.3%), or 10-row (15.0%)] of choppers working simultaneously was reported. Most dairies used a single packing tractor (68.8%) and weighed every load of fresh chopped corn delivered to the silage pit (62%). During harvest, dry matter (66.9%), particle length (80.4%), and kernel processing (92.5%) were monitored. Most dairies completed filling their largest silage structure in less than 3 d (48.5%) or in 4 to 7 d (30.9%). Silage covering was completed no later than 72 h after structure completion in all dairies, and was often completed within 24 h (68.8%). Packed forage was covered as filled in 19.6% of dairies. Temporary covers were used on some dairies (51.0%), with filling durations of 1 to 60 d. When temporary covers were not used, structures were filled in no more than 15 d. After structure closure, silage feedout started in 1 to 3 wk (44.4%), 4 to 5 wk (31.4%), or 8 or more wk (24.2%). Future considerations included increasing the silage storage area (55.9%), increasing the number of packing tractors (37.0%), planting brown mid-rib varieties (34.4%), buying a defacer to remove silage (33.1%), and creating drive-over piles (32.6%). Survey results will serve to develop and disseminate targeted information on silage management practices at harvest, packing, covering, and feedout on California's San Joaquin Valley dairies. [ABSTRACT FROM AUTHOR]

Dairy products are an important source of nutrients in the Western diet. One criticism of milk fat relates to its low content of polyunsaturated fatty acids (PUFA) in particular the omega-3 fatty acids. Various methods to protect unsaturated fatty acids from rumen biohydrogenation have been developed. The most promising method employs formaldehyde, a carcinogen, and thus of limited use in the United States. A novel gel based on only whey protein, water, and oil (U.S. Patent Application 20040058003 A1 [Pending]; U.S. Patent Application 20050089550 A1 [Pending]) was developed at the University of California, Davis. The objective was to determine the efficacy a whey protein gel composite as a dietary method to increase the PUFA in milk lipids. Four primiparous Holstein cows were used in a 4x4 Latin square. The supplement lipid was a 1:1 (w:w) mixture of soybean:linseed oils (S/L) added to a total mixed ration. The S/L was fed in one of 4 chemical forms: (1) oil (O) where S/L was added directly to the diet unmodified, (2) calcium salts (CaS) of S/L, (3) whey protein concentrate (WPC) gel composite of S/L and (4) whey protein isolate (WPI) gel composite of S/L. Each diet provided a similar amount of total FA. Dietary treatment had no effect on dry matter intake, milk yield, and milk fat percentage. Milk triacylglycerol (TG) composition of linoleic acid averaged 2.77, 3.53, 3.59, and 6.35 g/100g fat and α-linolenic averaged 0.97, 1.33, 1.73, and 4.09 g/100g fat for O, CaS, WPC, and WPI. Total C18:1 trans FA decreased from 4.01 g/100g fat for O to 2.50 g/100 g fat for WPI. Similar changes in PUFA content of milk phospholipids were observed. The lower trans FA and higher PUFA in milk fat support a reduction in rumen biohydrogenation of PUFA. Feeding a whey protein gel composite successfully increased the PUFA of milk lipids. [ABSTRACT FROM AUTHOR]

Different methods exist to reduce rumen biohydrogenation of dietary polyunsaturated fatty acids (PUFA), but responses in flow of PUFA to the small intestine have been inconsistent. A novel gel composed by whey protein, water, and oil (U.S. Patent Application 20040058003 A1 [Pending]; U.S. Patent Application 20050089550 A1 [Pending]) was developed. The objective was to compare the efficacy of feeding PUFA in different chemical forms on rumen fermentation, nutrient digestibility in the rumen and postrumen, and flow of PUFA to the duodenum. The supplemental fatty acid (FA) source was a 1:1 (w:w) mixture of soybean:linseed oils (S/L) from which the three supplements were manufactured. Four primiparous Holstein cows were used in a 4x4 Latin square with 14 d periods. Cows were surgically fitted with cannulas in the rumen and duodenum. The S/L was included in the diet as (1) unmodified oil (O; 1.9%), (2) calcium salts (CaS; 2.2%), (3) whey protein concentrate (WPC; 2.6%) gel composite or (4) whey protein isolate (WPI; 2.8% of DM) gel composite. Gel composites were hand-mixed in the TMR twice daily, while O and CaS were part of the TMR. Diets were formulated to provide similar amounts of FA. Data were analyzed by the MIXED procedure of SAS and repeated measures were utilized for variables that contained a time component. Dry matter intake and production traits were not affected. Rumen pH (6.41, 6.51, 6.41 and 6.45) was unaffected by treatments. Molar concentrations of total VFA (117, 107, 113 and 113 mM/L) were similar across diets, for O, CaS, WPC and WPI, respectively, as well as acetate, propionate and butyrate concentrations. Changes in body weight (7.3, -0.12, 7.1 and -2.1 kg) and BCS were not affected. Feeding WPI increased the flow of C18:2 and C18:3 (g/d) to the duodenum compared to the other treatments. [ABSTRACT FROM AUTHOR]

Whole tomato seeds, a novel by-product feedstuff, were fed to lactating Holstein cows to determine the nutritive value of whole tomato seeds by replacing whole cottonseed in the total mixed ration. Four primiparous and 4 multiparous Holstein cows were used in a 4 x 4 Latin square design and fed 1 of 4 total mixed rations. Whole tomato seeds replaced whole cottonseed on a weight-to-weight basis for lipid. The proportion of whole tomato seeds to whole cottonseed in the diets were 100:0, 50:50, 25:75, and 0:100 on a lipid basis. Thus, tomato seeds were 4.0, 2.4, 1.1, and 0% of the ration dry matter, respectively. Milk yield and the concentrations and yields of protein, lactose, and solids-not-fat did not differ for the effect of diet. However, milk fat concentration decreased and milk fat yield tended to decrease as whole tomato seeds replaced whole cottonseed. Intakes of dry matter, lipid, and crude protein did not differ. Whole-tract apparent digestibility of dry matter and ash-free neutral detergent fiber did not differ, but digestibility of total fatty acids and crude protein decreased with increasing proportion of whole tomato seeds. Urea concentration in milk and plasma both decreased with increasing whole tomato seeds. Fecal concentration of linoleic and α-linolenic acids increased with increasing whole tomato seeds, suggesting that seeds were passing out of the digestive tract undigested. The concentrations of C18:2n-6 and C18:3n-3 in milk fat had small increases, but their yields were not different, suggesting that only a small amount of whole-tomato-seed lipid might have been digested postruminally. Amounts of trans C18:1 fatty acids in milk fat were higher with increasing whole cottonseed, which might suggest a shift in rumen biohydrogenation pathways. At the level of feeding used in the current study, whole tomato seeds replaced whole cottonseed in the diet of lactating dairy cows without a change in production. [ABSTRACT FROM AUTHOR]

California is the leading state for the production of almonds, with more than 400,000 bearing hectares of orchards that produced approximately 1 billion kilograms of shelled nuts in 2017. Almond hulls (AH) are a regional by-product feedstuff fed predominantly to dairy cattle in California. A 2012 study surveyed 40 dairy farms in California and found that 39 out of 104 total mixed rations contained AH, with a mean daily feeding rate of 1.45 kg/cow. In 2017, approximately 2 billion kilograms of AH was produced. At a feeding rate of 1.45 kg/cow daily, even if all 1.7 million lactating cows in California are consuming AH, there will be a surplus of AH on the market as the approximately 130,000 nonbearing hectares come into nut production. Therefore, the potential of feeding varying amounts of AH to lactating dairy cows was investigated using 12 Holstein cows with 4 primiparous and 8 multiparous cows. The dietary treatments were 4 total mixed rations containing 0, 7, 13, or 20% AH. The AH used contained 12.8% crude fiber (as-is basis), which was below the 15% legal limit set by state feed regulations. Diets were formulated so that as the inclusion rate of AH increased, the amount of steam-flaked corn and soyhull pellets decreased and soybean meal inclusion increased. Experimental design was a replicated 4 × 4 Latin square. Diet had a cubic effect on actual milk yield, energy-corrected milk yield, and dry matter intake, with the 7% AH diet having the highest values and the 13% AH diet having the lowest. The percent and yield of total solids and the yields of lactose and fat did not differ with diet, but percent and yield of protein declined linearly with increased AH inclusion, and fat percent increased linearly. Apparent total-tract digestibilities of dry matter and organic matter were higher with the inclusion of AH in the diet. Total percentage of the day spent ruminating increased linearly with higher amounts of AH. Overall, this work demonstrated that AH can be fed at varying amounts, up to 20% of the diet, to lactating dairy cows to support high levels of milk production and that increasing amounts of AH (up to 20%) in the diet could lead to improved digestibility and milk fat percentage but decreased milk protein production., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

The present study aimed to identify dairy producer needs and how best to direct and deliver cooperative extension (CE) programming. In March 2017, we mailed a needs assessment survey to grade A dairy producers in California (n = 1,080). The response rate was 15.4% (n = 166) and herd size averaged 1,405 milking cows (range 83-5,500). The geographic distribution of survey responses was representative of the distribution of dairies throughout the state. Producers were asked to indicate the level of concern for a predetermined list of 11 issues. Rank of concern had 3 numeric levels: (1) very concerned, (2) somewhat concerned, or (3) not concerned. Mean and percentage of responses in each rank for each issue topic were calculated. The top 5 concerns/obstacles indicated were (1) milk price, (2) labor availability/quality, (3) environmental issues/regulations, (4) labor costs, and (5) water quality/availability. Surveyed respondents were also asked to determine the level of priority of a predetermined list of 13 CE research and educational opportunities. Producers ranked topics as low, medium, or high priority. The 5 highest priority research topics were (1) herd health, (2) environmental issues, (3) reproduction, (4) milk quality, and (5) water quality. The 5 highest priority educational topics were (1) herd health, (2) milk quality, (3) reproduction, (4) environmental issues, and (5) calf and heifer management. Producers were then asked to identify the target audience for CE information delivery and preferred information delivery method. Most respondents indicated that the target audience should be dairy owners (93%) or managers (66%). Fewer producers indicated a target audience of dairy employees (27%) or allied industry (23%). Preferable information delivery methods were newsletter or magazine articles (81%), half-day/short meetings (47%), and on-farm training/meetings (39%). Webinars and 2- or 3-d destination meetings were the least preferable methods (27 and 9%, respectively). Survey results will serve to develop future dairy cooperative extension programs in California., (Copyright © 2019 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

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 shrink, mitigations often based on limited data of questionable relevance to large commercial silage piles where silage shrink may or may not be a problem of a magnitude equal to that assumed. Silage 'shrink' is generally ill defined, but can be expressed as losses of wet weight (WW), oven dry matter (oDM), and oDM corrected for volatiles lost during oven drying (vcoDM). As no research has documented shrink in large cereal silage piles, 6 piles ranging from 1456 to 6297tonnes (as built) were used. Three used cereal cut at an immature stage and three at a mature stage. Physiologically immature silages had generally higher (P<0.01) levels of total volatile fatty acids (especially acetic acid; P=0.01) and total alcohols (P<0.01) than did physiologically mature crops, suggesting higher carbon compound volatilization potential from immature silages. However expressed as WW, oDM and vcoDM, total shrink (as well as from where in the piles it occurred) was little impacted by crop maturity, and whole pile vcoDM shrink was only ~35g/kg. Overall, real shrink losses (vcoDM) of large well managed cereal silage piles were relatively low, and a lower potential contributor to aerosol emissions of volatile carbon compounds than has often been assumed. Losses from the silage mass and the exposed silage face were approximately equal contributors to vcoDM shrink. Mitigations to reduce these relatively low emission levels of volatile organic compounds from cereal silage piles should focus on the ensiled mass and the exposed silage face., (Copyright © 2016 Elsevier B.V. All rights reserved.)

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, but can be expressed as losses of wet weight (WW), oven dry matter (oDM), and oDM corrected for volatiles lost in the drying oven (vcoDM). Corn silage piles (4 wedge, 2 rollover/wedge, 1 bunker) from 950 to 12,204 tonnes as built, on concrete (4), soil (2) and a combination (1) in California's San Joaquin Valley, using a bacterial inoculant, covered within 24 h with an oxygen barrier inner film and black/white outer plastic, fed out using large front end loaders through an electronic feed tracking system, and from the 2013 crop year, were used. Shrink as WW, oDM and vcoDM were 90±17, 68±18 and 28±21 g/kg, suggesting that much WW shrink is water and much oDM shrink is volatiles lost during analytical oven drying. Most shrink occurred in the silage mass with losses from exposed silage faces, as well as between exposed face silage removal and the total mixed ration mixer, being low. Silage bulk density, exposed silage face management and face use rate did not have obvious impacts on any shrink measure, but age of the silage pile during silage feedout impacted shrink losses ('older' silage piles being higher), but most strongly for WW shrink. Real shrink losses (i.e., vcoDM) of large well managed corn silage piles are low, the exposed silage face is a small portion of losses, and many proposed shrink mitigations appeared ineffective, possibly because shrink was low overall and they are largely directed at the exposed silage face., (Copyright © 2015 Elsevier B.V. All rights reserved.)