Survey of California dairy nutritionists on extent of byproduct usage
Byproduct feedstuffs play a crucial role in California dairy rations and contribute to the sustainability of the industry, but the extent of their usage in the state has not been widely investigated. In March 2022, we sent a byproduct feeding and management survey via email to 61 dairy cattle nutritionists in California. Twenty-six completed surveys were included in the final data analysis (response rate = 46%; n = 26/61). Nutritionists reported servicing 498 dairy farms that represented approximately 936,700 milking cows. Respondents serviced mostly cows housed in San Joaquin Valley herds (87.6%), with some cows housed in Northern California (5.5%) and Southern California (6.9%) regions. Survey respondents also reported 58 byproducts that were fed on California dairies; almond hulls and whole cottonseed were the most frequently utilized byproducts. The average lactating ration byproduct inclusion rate was estimated at 40.9% on a dry matter (DM) basis. Looking ahead to the next five years, 20 nutritionists (80%) thought byproduct usage would increase in California dairy rations, with fewer anticipating decreased (n = 3; 12%) or unchanged (n = 2; 8%) usage.
- Research Article
35
- 10.1371/journal.pntd.0004291
- Jan 21, 2016
- PLOS Neglected Tropical Diseases
BackgroundTrypanosoma cruzi, causative agent of Chagas disease in humans and dogs, is a vector-borne zoonotic protozoan parasite that can cause fatal cardiac disease. While recognized as the most economically important parasitic infection in Latin America, the incidence of Chagas disease in the United States of America (US) may be underreported and even increasing. The extensive genetic diversity of T. cruzi in Latin America is well-documented and likely influences disease progression, severity and treatment efficacy; however, little is known regarding T. cruzi strains endemic to the US. It is therefore important to expand our knowledge on US T. cruzi strains, to improve upon the recognition of and response to locally acquired infections.Methodology/Principle FindingsWe conducted a study of T. cruzi molecular diversity in California, augmenting sparse genetic data from southern California and for the first time investigating genetic sequences from northern California. The vector Triatoma protracta was collected from southern (Escondido and Los Angeles) and northern (Vallecito) California regions. Samples were initially screened via sensitive nuclear repetitive DNA and kinetoplast minicircle DNA PCR assays, yielding an overall prevalence of approximately 28% and 55% for southern and northern California regions, respectively. Positive samples were further processed to identify discrete typing units (DTUs), revealing both TcI and TcIV lineages in southern California, but only TcI in northern California. Phylogenetic analyses (targeting COII-ND1, TR and RB19 genes) were performed on a subset of positive samples to compare Californian T. cruzi samples to strains from other US regions and Latin America. Results indicated that within the TcI DTU, California sequences were similar to those from the southeastern US, as well as to several isolates from Latin America responsible for causing Chagas disease in humans.Conclusions/SignificanceTriatoma protracta populations in California are frequently infected with T. cruzi. Our data extend the northern limits of the range of TcI and identify a novel genetic exchange event between TcI and TcIV. High similarity between sequences from California and specific Latin American strains indicates US strains may be equally capable of causing human disease. Additional genetic characterization of Californian and other US T. cruzi strains is recommended.
- Abstract
- 10.1182/blood-2021-146677
- Nov 5, 2021
- Blood
Community Experience with Pediatric Inspired Treatment of Acute Lymphoblastic Leukemia in the Adolescent and Young Adult Population in Kaiser Permanente Northern and Southern California Regions
- Research Article
6
- 10.7717/peerj.11515
- Jul 13, 2021
- PeerJ
BackgroundA survey of California (CA) dairies was performed in spring 2018 to characterize antimicrobial stewardship practices, antimicrobial drug (AMD) use, and health management of adult cows on CA dairies since the implementation of the Veterinary Feed Directive (VFD) and the CA Senate Bill 27 (SB 27). Effective January 1, 2017, the U.S. Food and Drug Administration (FDA) implemented regulatory changes requiring veterinary oversight for therapeutic uses of medically-important antimicrobial drugs (MIADs) administered in feed (VFD) and water (veterinary prescription). Similarly, effective January 1, 2018, the CA legislature enacted California Food and Agricultural Code (FAC) 14400–14408, formerly known as Senate Bill 27 (SB 27) requiring veterinary prescriptions for all other dosage forms of MIADs.MethodsThe questionnaire consisted of 43 questions partitioned into three sections to assess herd information, management practices, and AMD use and perspectives. The questionnaire was mailed to 1,282 grade A licensed dairies in CA and 149 responses (11.6%) were collected from 19 counties across the three defined regions of CA: Northern CA (NCA), Northern San Joaquin Valley (NSJV), and Greater Southern CA (GSCA).ResultsMost dairies reported treating all dry cows with intramammary AMD and/or teat sealant at the end of a lactation (87.2%). In 92.3% of dairies, producers relied on the veterinarian for information about AMD used to treat cows. Treatment duration for cows treated with AMD was based on the drug manufacturer’s label and veterinarian’s instructions in most dairies (98.6%). Most respondents to the survey confirmed having a valid veterinarian-client-patient-relationship (VCPR) for their dairies (91.7%), participated in animal welfare audit programs (81.8%) and dairy quality assurance programs (52.9%). Approximately 98.6% respondents were aware that all uses of MIADs in livestock required a veterinary feed directive (VFD) or prescription and are no longer sold over-the-counter (OTC) in CA since January 1, 2018. Multiple factor analysis (MFA) was performed and identified seven components composed of 21 variables (questions) that explained 99.7% of the total variance in the data. Hierarchical cluster analysis on the principal coordinates of the MFA based on conventional dairy survey responses identified two clusters characterized as large conventional dairies (median herd size: 1,265 cows) and mid-sized conventional dairies (median herd size: 715 cows) mostly in GSCA and NSJV. The organic dairies grouped into a single cluster of median herd size of 325 cows mostly in NCA.ConclusionsThe survey results contribute to the knowledge of AMD use and antimicrobial stewardship practices on CA dairies since the implementation of the SB 27 and VFD laws and provide useful information for future evaluation of resistance-related risk in adult cows.
- Research Article
2
- 10.1093/tas/txae025
- Jan 1, 2024
- Translational Animal Science
Almond hulls and shells are a by-product of almond production that can be incorporated as a feed ingredient in beef cattle diets. Three experiments were conducted to determine the effects of hammermill screen size on almond hull and shell bulk density and inclusion of ground or non-ground almond hulls and shells in limit-fed growing diets on growth performance, diet digestibility, and ruminal fermentation characteristics of beef cattle. In experiment 1, almond hulls and shells were ground with a laboratory-scale hammermill using no screen, a 11.1-mm screen, a 19.1-mm screen, or a 25.4-mm screen. Each screen-size treatment was ground at three separate time points (n= 3 replications/treatment). Grinding almond hulls and shells with no screen increased bulk density by 111% and minimized proportions of fine particles; therefore, almond hulls and shells ground using no screen were included as a treatment in the following experiments. In experiment 2, 364 steers (initial body weight [BW]: 257± 20.7kg) were blocked by truckload (n = 4), stratified by BW, and assigned to pen within block. Pens were randomly assigned to 1 of 4 experimental diets (n= 10 pens/treatment). The control diet (CON) contained (DM basis) 39.5% dry-rolled corn, 7.5% supplement, 40% wet-corn gluten feed, and 13% prairie hay. Non-ground (13AH) or ground (13GAH) almond hulls and shells replaced prairie hay and were fed at 13% of diet DM or non-ground almond hulls and shells were fed at 26% of diet DM and replaced 13% prairie hay and 13% dry-rolled corn (26AH). Diets were limit-fed at 2.2% of BW daily (DM basis) for 56 d. Overall average daily gains (ADG) were greater (P ≤ 0.05) for CON, 13AH, and 13GAH compared with 26AH. In addition, ADG from days 14 to 56 were greater (P= 0.03) for 13GAH and tended to be greater (P = 0.09) for 13AH compared with CON. Experiment 3 was a 4 × 4 replicated Latin square in which 8 ruminally cannulated heifers (initial BW = 378 ± 44.0kg) were fed diets from experiment 2. Apparent dry matter digestibility did not differ (P = 0.21) among treatments. Total ruminal volatile fatty acid concentrations were greater (P ≤ 0.03) for 13GAH and 13AH compared with 26AH and tended (P = 0.06) to be greater for 13GAH compared with CON. Overall, almond hulls and shells can be utilized as an alternative to prairie hay in limit-fed growing diets without negatively influencing rates of gain or diet digestibility.
- Research Article
9
- 10.9734/arrb/2014/6413
- Jan 10, 2014
- Annual Research & Review in Biology
Aims: To determine the chemical composition and estimation of nutritive value of different by-product feedstuffs (BPF) using in vitro gas production technique. Place and Duration of Study: Department of Animal Science, between February 2013 and June 2013. Methodology: In an anaerobic batch culture system, 50 ml of buffered rumen fluid was dispensed into a 125-ml serum bottle containing 0.2 g dry matter (DM) of the experimental treatments. Experimental treatments included five by-products (pomegranate peel and seed, apple pomace, walnut hull, almond hull). All bottles were purged with anaerobic CO2, sealed and placed in a shaking water bath for 96 h at 38.6oC. Gas production of each bottle was recorded at 3, 6, 9, 12, 24, 36, 48, 72 and 96h of the incubation and then gas released. The batch cultures were repeated in three incubation runs. The biomass residues were centrifuged and the pellet was dried at 65oC for the determination of the residual DM and in vitro DM disappearance (IVDMD). Results: The total tannins and phenol content were higher (P<0.01) in almond hull and pomegranate peel than in the other BPF. The total tannins content ranged from 0.34% in apple pomace to 9.78% in almond hull. The total phenol of pomegranate peel, pomegranate seed, apple pomace, walnut hull and almond hull were 10.9, 1.20, 0.76, 3.80, Original Research Article Annual Research &Review in Biology, 4(7): 1121-1128, 2014 1122 and 10.6%, respectively. The rate (c) and cumulative gas volume (b) was significantly higher (P<0.01) for apple pomace than the other feedstuffs. There were significant differences (P<0.01) among feedstuffs about lag time. Apple pomace showed higher (P<0.01) organic matter digestibility (OMD), in vitro dry matter digestibility (IVDMD), metabolizable energy (ME), short chain fatty acid (SCFA) and lower (P<0.01) pH than the other feedstuffs. Conclusion: The higher values obtained for the potential gas production in apple pomace will indicate a better nutrient availability for rumen microorganisms (P<0.01).
- Research Article
23
- 10.1016/j.seares.2008.10.009
- Oct 25, 2008
- Journal of Sea Research
Spatial patterns in recruitment and growth of the mussel Mytilus californianus (Conrad) in southern and northern California, USA, two regions with differing oceanographic conditions
- Research Article
36
- 10.3168/jds.2015-9394
- Dec 17, 2015
- Journal of Dairy Science
Survey of management practices related to bovine respiratory disease in preweaned calves on California dairies
- Research Article
4
- 10.1017/s0021859621000794
- Sep 1, 2021
- The Journal of Agricultural Science
The aim of this study was to determine the in vitro digestibility and in sacco disappearance of dry matter (DM) and neutral detergent fibre (NDF) in total almond hulls (TAH), pure almond hulls (PAH) or Debris. The TAH were used because there are no data on the effect of debris (non-hull material) on the nutritional value of almond hulls. Twelve samples of commercial almond hulls were used, with one subsample representing the TAH and the other subsample hand sorted to separate the hulls (PAH) from Debris. Gas production and Ankom Daisy method were used to determine in vitro digestibility, while two rumen-fistulated cows were used to measure in sacco disappearance of PAH and TAH. For in vitro digestibility, both PAH and TAH were more digestible and had greater gas production than Debris. The PAH had greater in vitro true digestibility on a DM basis and NDF digestibility at 48 and 72 h compared with TAH. Nonpareil hulls provided greater metabolizable energy (ME) concentration when compared with other almond varieties, with PAH supplying numerically more ME than TAH for both varieties. For in sacco disappearance, PAH had greater DM and NDF disappearance along with a greater rate of disappearance for NDF compared with TAH. This research demonstrated that Debris is highly indigestible; therefore, hulling, agronomic and harvesting practices should be focused on reducing Debris in commercial almond hulls to improve their nutritive value as a feedstuff for livestock.
- Research Article
25
- 10.3168/jds.2020-19109
- May 10, 2021
- Journal of Dairy Science
Feeding high amounts of almond hulls to lactating cows
- Research Article
- 10.3168/jds.2025-27115
- Nov 1, 2025
- Journal of dairy science
Effect of feeding almond hulls on energy partitioning, nutrient balance, milk yield, and methane emissions in lactating dairy goats.
- Research Article
29
- 10.3354/dao02663
- Nov 25, 2013
- Diseases of Aquatic Organisms
Pathogen introduction by invasive species has been speculated to be a cause of declining western pond turtle Emys marmorata populations in California, USA. This study determined the prevalence of Ranavirus spp., Herpesvirus spp., Mycoplasma spp. (via polymerase chain reaction of blood and nasal flush contents), and Salmonella spp. infection (via fecal culture) in native E. marmorata and invasive red-eared sliders Trachemys scripta elegans and compared infection prevalence in E. marmorata populations sympatric with T. scripta elegans to E. marmorata populations that were not sympatric by sampling 145 E. marmorata and 33 T. scripta elegans at 10 study sites throughout California. Mycoplasma spp. were detected in both species: prevalence in E. marmorata was 7.8% in the northern, 9.8% in the central, and 23.3% in the southern California regions. In T. scripta elegans, Mycoplasma spp. were not detected in the northern California region but were detected at 4.5 and 14.3% in the central and southern regions, respectively. All turtles tested negative for Herpesvirus spp. and Ranavirus spp. Enteric bacteria but not Salmonella spp. were isolated from feces. E. marmorata populations that were sympatric with T. scripta elegans did not have increased risk of Mycoplasma spp. infection. For E. marmorata, there was a significant association between Mycoplasma spp. infection and lower body weight and being located in the southern California region. This study is the first of its kind to document pathogen prevalence in native E. marmorata habitats and those sympatric with T. scripta elegans in California.
- Research Article
47
- 10.3168/jds.s0022-0302(84)81271-0
- Jan 1, 1984
- Journal of Dairy Science
Nutritional Value of Almond Hulls for Dairy Cows
- Research Article
9
- 10.3168/jds.2015-10620
- May 4, 2016
- Journal of Dairy Science
Deviation from the formulated target weight of ingredients loaded into high milk yield cow recipes on California dairies
- Research Article
60
- 10.1007/s00382-012-1322-3
- Mar 3, 2012
- Climate Dynamics
Effects of atmospheric river (AR) landfalls in the California coast on the cold-season precipitation in California are examined for the cold seasons of 10 water years (WYs) 2001–2010 using observed data and regional modeling in conjunction with AR-landfall inventory based on visual inspections of precipitable water vapor (PWV) from remote sensing and reanalysis. The PWV in the SSM/I and SSMIS retrievals and the ERA-Interim reanalysis shows 95 AR-landfall days in the California coast that are almost evenly split between the northern and southern coasts across 37.5N. The CPC/NCEP gridded daily precipitation analysis shows that 10–30% of the cold-season precipitation totals in California have occurred during these AR landfalls. The analysis also reveals that the percentage of precipitation and the precipitation intensity during AR landfalls in California are characterized by strong north-to-south gradient. This north–south contrast in the AR precipitation is reversed for the non-AR precipitation in the coastal range. The frequency of AR landfalls and the cold-season precipitation totals in the Sierra Nevada region are only marginally correlated. Instead, AR landfalls are closely related with the occurrence of heavy precipitation events. The freezing-level altitudes are systematically higher for AR wet days than non-AR wet days indicating warmer low-troposphere during AR storms. Cold season simulations for the 10 WYs 2001–2010 show that the Weather Research and Forecast (WRF) model can reasonably simulate important features in both the seasonal and AR precipitation totals. The daily pattern correlation coefficients between the simulated and ERA-Interim upper-air fields exceed 0.9 for most of the period. This suggests that the simulated temporal variations in the atmospheric circulation agree reasonably with the reanalysis over seasonal time scales, characteristics critical for reliable simulations of regional scale hydrologic cycle. The simulated seasonal and AR precipitation totals also agree reasonably with the CPC/NCEP precipitation analysis. The most notable model errors include the overestimation (underestimation) of the season-total and AR precipitation in the northern (southern) California region. The differences in the freezing-level altitudes during the AR- and non-AR wet days in the simulation agree with those from the ERA-Interim reanalysis. The freezing level altitudes are systematically overestimated in the simulations, suggesting warm biases in the low troposphere. Overall, WRF appears to perform reasonably in simulating the key features in the cold season precipitation related with AR landfalls, an important capability for assessing the impact of global climate variations and change on future hydrology in California.
- Research Article
- 10.1016/j.prevetmed.2025.106658
- Dec 1, 2025
- Preventive veterinary medicine
Effects of short-term climatic conditions on the risk of bovine respiratory disease in preweaned calves on California dairies.
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