bluuebunny/crossref_metadata_2025 huggingface dataset:
171 The Northeast Georgia Beef Cattle Short Course: An Eight-year Review
Authors: Blackwell Marrissa J , Lamm Alexa , Stewart R Lawton
Published: October 2021

A study was conducted to assess the economic impact and knowledge retention of participants that attended the Northeast Georgia Beef Cattle Short course over an eight-year period. The course is an educational program hosted by the University of Georgia Extension Service that brings evidence-based science, technology, and economic and management strategies to Georgia beef cattle producers. The short course is taught annually, lasts a full day, and offers guest speakers and demonstrations from University of Georgia faculty and staff along with industry professionals. Non-formal feedback received from participants showcases its value and supports its continuation, but little is known about how the program impacts beef production in Georgia. The goal of the study was to quantify the long-term impact of the short course while developing an assessment tool that can be used to analyze and improve the course moving forward. Qualtrics was used to distribute a survey to 308 attendees of the short course to gather information on respondents’ role in the cattle industry, knowledge of the concepts taught, comfort level utilizing what was learned, and self-reported economic impact. The response rate was 22% for this study. 41% of respondents are retired individuals, 18% were involved in agricultural production and the remainder of participants represented outside professions. 14% of respondents reported that they believed the knowledge they gained during the short course allowed them to save or gain more than $20 per head. An additional 84% reported an economic impact up to $20/head. The most frequently reported source of cattle information was extension programs, at 17%. Based on these data, Extension has a significant impact on the Georgia cattle industry. In order to further develop the program, the recommendation is made that future courses can be developed to further build relationships with cattle producers and larger operations across the state.
178 Grazing Toxic Endophyte-infected Tall Fescue Alters Monocyte Abundance and White Blood Cell Expression of Prolactin and NF-kB Pathway Genes in Beef Steers
Authors: Winfrey Cecilia , Lindemann Merlin D , Matthews James
Published: October 2021

The hypotheses tested were that (a) summer-long (84 d) grazing of endophyte-infected tall fescue (TE) would alter the count of circulating leukocytes (WBC) and WBC expression of key prolactin and NF-kB pathway genes and (b) that ad libitum intake of an 1:1 blend (MIX) sodium selenite (ISe) and SELPLEX vs ISe in a vitamin-mineral mix (V-M, 27 ppm Se) would ameliorate negative TE effects. Sixteen TE-naïve beef steers depleted of Se were randomly assigned to ad libitum consumption of ISe vs MIX for 35 d. Within Se-form treatments, 2 steers (ISe = 316±37 kg, MIX = 314±39 kg) were randomly assigned to graze each of 4, 2-acre TE paddocks for 84 d and had ad libitum access to their respective V-M. Paddock was the experimental unit (n = 4). The MIXED procedure of SAS was used to assess effect of grazing TE (d 0 vs 84), Se-form (ISe vs MIX), and their interaction on clinical parameters WBC, and relative mRNA content (RT-PCR) in blood. Whole blood Se was 24% greater (P < 0.01) for MIX steers and decreased (P < 0.01) 34% by d 84. Serum prolactin decreased 88% by d 84 and was 98% greater (P < 0.01) for MIX steers on d 84. Monocytes decreased (P < 0.01) 47% with TE and were 67% lower (P = 0.04) in MIX steers. Grazing of TE altered mRNA content of CISH, STA5B, PPIB, AGAP2, and SPRLR; and IL-8, RELA, NFKBIA, TLR, IKBKG, ZAP70, and LCK; of the prolactin (P ≤ 0.05) and NF-kB (P ≤ 0.04) pathways, respectively. In contrast, Se form had no effect (P ≥ 0.07) on mRNA content. Summer-long consumption of TE by steers altered monocyte numbers and expression of prolactin and NF-kB genes, but ad libitum intake of MIX Se forms did not ameliorate these effects.
208 MicroRNA Expression in Longissimus Muscle Biopsies During Feedlot Finishing of Angus Steers
Authors: Thomas Alexandra R , Justice S Maggie M , Duckett Susan K
Published: October 2021

Intramuscular fat or marbling (IMF) is highly desired in beef products due to its ability to improve carcass value. Studies indicate that finishing cattle on high concentrate diets increase marbling deposition over time-on-feed (TOF). Angus-cross steers (n = 7; 433 + 17 kg) were individually fed a high concentrate diet for a period of 124 d. Steers were weighed and ultrasounded every 30 d on feed. Longissimus muscle biopsies were taken between the 11th and 13th rib on alternating sides at d 0, 90, and 124. RNA was extracted from the biopsy samples and subjected to microRNA (miRNA) sequencing and qPCR for mRNA expression of key lipogenic genes. Data were analyzed with time-on-feed in the model. ADG was increased between d30 and d90 (P < 0.05). The feed conversion ratio was lowest during d0 to d60 and increased from d90 to d124 (P < 0.05). Fat thickness increased (P < 0.05) between 90 to 124 d. Ultrasound intramuscular fat percentage increased (P < 0.05) between 60 and 90 d. miRNA sequencing results showed that mir-122 was differentially expressed from d0 to d90 (6.72 log fold change; P = 0.0048) and from d0 to 124 (3.83 log fold change; P = 0.026). Several miRNA were down regulated (> 2 log fold change; P < 0.05) during TOF, which included miR-2411, -449a, -1197, -323, and -485. Relative expression of key lipogenic genes, stearoyl Co-A desaturase (SCD-1) and fatty acid synthase, were up-regulated (P < 0.05) between d90 and 124 d. These results show that miR-122 appears to be a novel miRNA associated with marbling deposition and lipid metabolism.
207 Satellite Cells Participate in the wnt/ca2+ Pathway Controlled Porcine Myofiber Determination
Authors: Ye Mao , Song Zhiwen , Jin Chenglong , Gao Chunqi , Yan Huichao , Wang Xiu-qi
Published: October 2021

The type of myofiber is important for porcine meat quality. Meanwhile, the nt/Ca2+ pathway has been showed multiple roles in skeletal muscle formation; however, the distinct mechanism is still unclear. In this study, the weaned piglets and satellite cells were designed into the control group, lysine deficiency group and lysine rescue group to investigate the function of Wnt/Ca2+ pathway in governing skeletal muscle typing. After we confirm the growth of weaned piglets was controlled by lysine, the isobaric tag for relative and absolute quantification (iTRAQ) analysis of skeletal muscle detected that Wnt/Ca2+ pathway was involved in the transition of fast and slow fiber. Then, we found the ratio of type I myofiber in Semimembranous (fast muscle) was significantly increased after lysine deficiency (P < 0.05), and decreased by lysine rescue (P < 0.05). In contrast, the ratio of type I myofiber in Semitendinous muscle (slow muscle) was significantly decreased in the lysine deficiency group, and increased in the lysine rescue group (P < 0.05). Furthermore, the Wnt/Ca2+ pathway was significantly increased in Semimembranous muscle, while decreased in Semitendinous muscle with lysine deficiency, and this phenomenon was inversed after lysine rescue (P < 0.05). Meanwhile, the Wnt/Ca2+ pathway was stronger in satellite cells isolated from Semitendinous muscle (StSCs) than that of Semimembranous satellite cell (SmSCs) (P < 0.05). And we also found the StSCs enter in differentiation is more easily than SmSCs (P < 0.05). Besides, the ratio of type I myofiber originated from StSCs showed greater than StSCs (P < 0.05). In summary, we conclude that satellite cells participate in the Wnt/Ca2+ pathway controlled porcine myofiber determination.
212 Fatty Acid Analysis and Composition in Meat by Mass Spectrometry
Authors: Dinh Thu
Published: October 2021

Fatty acids determine the physical and chemical properties of fats. Animal fats, regardless of species, have more saturated and monounsaturated than polyunsaturated fatty acids. The major fatty acids in meat are palmitic (16:0), stearic (18:0), palmitoleic (16:1), oleic (18:1), linoleic (18:2), and linolenic (18:3) acids, among which oleic acid is the most predominant. Arachidonic acid (20:4 cis 5,8,11,14) is an essential fatty acid only found in animal fats and can be used as a quality control indicator in the fatty acid analysis. Fatty acid analysis has been traditionally performed by gas chromatography (GC) of volatile fatty acid derivatives, prominently the methyl esters, and flame ionization detection (FID), in which the carbon chain of fatty acids is degraded to the formylium ion CHO+. The FID is very sensitive and is the most widely used detection method for GC, providing a linear response, i.e., peak area, over a wide range of concentrations. Researchers have been used the FID peak area to calculate the percentages of fatty acids. However, the FID is a “carbon counter” and relies on the “equal per carbon” rule; therefore, at the same molar concentration, fatty acids with a different number of carbons produce different peak areas. The recent development of mass spectrometry technology has improved the specificity of fatty acid detection. Specific target and qualifier ions provide better identification and more accurate quantification of fatty acid concentrations. Although fatty acids can be identified through comparing ion fragmentation with various databases, authentic standards are needed for quantification purposes. Using mass spectrometry, more than 50 fatty acids have been identified in meat samples. Some branched-chain fatty acids may have flavor, safety, and shelf life implications in meat products.
218 Replacement of Soybean Meal with Corn DDGS and Crystalline Amino Acids Impacts Performance and Carcass Characteristics of Finishing Pigs
Authors: Anderson Brooke E , Holt Jonathan P , Boyd R D , van Heugten Eric
Published: October 2021

This study evaluated the effects of replacing soybean meal (SBM) with DDGS and crystalline amino acids on growth, carcass lean, and carcass yield of finishing pigs. Pigs (n = 480; 83.1±0.35 kg) were blocked by BW and sex and assigned to 80 pens (3 gilts and 3 barrows/pen). Treatments were arranged as a 2×4 factorial with DDGS included at 0 or 20% and L-lysine·HCl (LYS) added at 0.0, 0.2, 0.4, or 0.6%. Diets were balanced for ideal protein and NE and contained 0.75% and 0.67% SID lysine for Phase 1 (21 days) and Phase 2 (to market, 13 or 20 days), respectively. Only 0.49% LYS was necessary to meet the SID lysine requirement for the highest LYS (0.6%) diet for Phase 2. As LYS increased, dietary SBM inclusion decreased from 21.75% to 2.85% (Phase 1) and 18.75% to 3.35% (Phase 2) for control diets. It decreased from 18.40% to 0% (Phase 1) and 15.40 to 0% (Phase 2) for DDGS diets. During Phase 1, DDGS decreased ADG (992 vs. 1039 g/d; P = 0.031) and ADFI (3424 vs. 3503 g/d; P = 0.061). Increasing LYS linearly decreased ADG (1031, 1037, 1035, 959 g/d; P=0.026) and G:F (299, 295, 298, 281 g/kg; P = 0.026). Treatments did not impact Phase 2 performance. Overall, DDGS reduced ADG (1098 vs. 1131 g/d; P = 0.048) and ADFI (3638 vs 3712 g/d; P = 0.070). Supplemental LYS linearly decreased ADG (1133, 1141, 1120, and 1064 g/d; P = 0.005) and G:F (310, 305, 304, and 295 g/kg; P = 0.006). ADFI increased quadratically (P = 0.002) with LYS within SBM control, but not DDGS (interaction; P = 0.009). Ultrasound loin-eye-area corrected for BW tended to decrease quadratically (48.3, 48.8, 49.1, 47.4 cm2; P = 0.060) with increasing LYS. DDGS reduced carcass yield (72.62 vs. 73.04%; P = 0.034). Replacement of SBM with DDGS and high amino acid inclusion negatively impacted growth performance and carcass yield of finisher pigs.
216 Effect of Dietary L-valine Supplementation on Growth Performance, Immune Response, and Microbial Metabolites in Weaned Pigs Raised in Varying Sanitary Conditions
Authors: Koo Bonjin , Nyachoti Martin
Published: October 2021

This study investigated the effects of dietary L-valine supplementation and sanitary conditions on growth performance, immune response, and microbial metabolites in weaned pigs. Thirty-two weaned pigs (6.98 ± 0.47 kg) were randomly assigned to treatments in a 2 × 2 factorial arrangement based on dietary Val level and sanitary condition (clean or unclean). The pigs were fed either a basal diet containing the standard levels of Val suggested by NRC (2012) or the basal diet with an additional 0.1% of L-Val. A room designated as the clean room was washed weekly, whereas the designated unclean room was not washed throughout the experiment and 5 kg of manure from the nursery pig barn was spread on the pen floors on day 1. All data were analyzed using a mixed procedure of SAS, with the individual pen as the experimental unit. The pigs raised in unsanitary conditions exhibited a lower average daily gain and average daily feed intake and a higher incidence of diarrhea than those raised in sanitary conditions during the 14-day experimental period (P < 0.05). The pigs in the unclean group also had a lower concentration of butyrate in the jejunum and a higher concentration of ammonia-N in the colon than those in the clean group (P < 0.05). Dietary valine supplementation reduced plasma interleukin (IL)-1α and IL-1 receptor antagonist concentrations as well as isovalerate and ammonia-N concentrations in the colon (P < 0.05). Interactions between dietary Val supplementation and sanitary conditions were observed in the abundance of mRNA-encoding β-defensins 113, 125, and 129 (P < 0.05). In conclusion, dietary Val supplementation beneficially modulates inflammatory response and microbial metabolites regardless of sanitary condition, while transcriptional levels of β-defensins are regulated by dietary Val supplementation in a manner dependent on housing hygiene conditions.
231 Applications of Insect-derived Ingredients in Animal Diets
Authors: Koutsos Liz
Published: October 2021

Insects have applications in many animal feeding programs for several reasons. First, increased emphasis on sustainable ingredients supports the use of insect-derived ingredients since insects have the capacity to sustainably re-purpose waste streams from food and feed production into nutrient dense ingredients. Second, many animals would naturally consume insects, thus incorporation into feeding programs may enhance animal welfare. Third, nutrient composition and availability is generally very high for insect-derived ingredients relative to requirements and formulae needs, although this varies with insect species, stage of development, feedstock on which they are raised and processing method. In addition to the essential nutrients that can be provided by feeding insect-derived ingredients, components including chitin and proteins and fatty acids with anti-microbial activity provide additional application in animal feeding programs. These concepts will be discussed relative to current knowledge about the primary insect species being reared at commercial scale: house crickets (Acheta domesticus), yellow mealworms (Tenebrio molitor), and black soldier fly larvae (Hermetia illucens).
229 Yeast Proteins Extracted from Saccharomyces Cerevisiae as Alternative Sources of Protein in Swine Nutrition
Authors: Kiros Tadele G , Nadege Richard , Marden Jean Philippe , Kuhn Geraldine , Catunda Fabio
Published: October 2021

Proteins obtained from microbial biomass like bacteria, yeast, and algae, coined as single cell proteins (SCP), are considered as new and unconventional sources of protein supply both for animal and human use. These microbes convert low value by-products and wastes into protein rich biomass through the process of fermentation. In this regard, yeast was the first microorganism used as source of protein in animal feed. Different industrial methods including plasmolysis, autolysis or enzyme digestions are used to extract the protein rich inner content of a yeast cell known as yeast extract (YE). The protein content of YE may vary depending on the method of extraction, but generally ranges between 50–60% and contains free amino acids and functional peptides. In swine the weaning transition is a critical period where piglets are exposed to different kinds of stresses including the abrupt change from milk to solid feed. To match the highly digestible and protein rich diet in milk, pig producers are using a highly complex diet containing animal products including spray-dried porcine plasma (SDPP) in the pre-starter diet. However, the use of animal products is under scrutiny for biosecurity reasons and SCP from yeast are emerging as good alternatives to replace animal products in piglet diets. Reports from various studies have shown proteins from YE can provide highly digestible proteins with good profile amino acids. Furthermore, it has been shown that yeast proteins improve health and performance of pigs by enhancing immunity and strengthening gut integrity of weaning piglets. Moreover, comparative animal studies in weaned piglets confirmed no significant difference between SDPP and YE proteins in energy content, AA composition, as well as apparent and standardized ileal digestibility of AA suggesting that SCP from yeast could be a good alternative to replace SDPP in weanling piglet diets.
245 Prenatal Transportation Stress Does Not Impact Ovarian Follicle Count in Brahman Offspring
Authors: Quail Lacey , Randel Ron D , Welsh Thomas H , Branco Rui d’Orey , Neuendorff Don A , Cushman Robert A , Yake Hannah , Perry George A
Published: October 2021

Calves from transported dams had greater concentrations of plasma cortisol when restrained and cleared plasma cortisol at a slower rate than calves from non-transported dams. Considering this hypothalamic-pituitary-adrenal axis effect, investigation of other parameters influencing reproduction is warranted in offspring exposed to prenatal transportation stress. The purpose was to determine impact of prenatal transportation stress on offspring ovarian follicle count. Brahman cows were transported for 2 h on d 60, 80, 120, and 140 (± 5 d) of gestation. Offspring from transported (Stressed, n = 19) or non-transported (Control, n = 15) dams were slaughtered at 5 yr (Replication 1, n = 14) or ovariectomized at 8 yr (Replication 2, n = 20). A cross-section of ovary was collected, serially sectioned, and stained. Numbers of total, primordial, primary, secondary, and antral follicles were determined per section. Total ovarian follicle count for each stage was calculated using ovary dimensions. The MIXED procedure of SAS was used to analyze ovarian follicle count with treatment, replicate, and the interaction as fixed effects. Total ovarian follicle count decreased with age (P < 0.01; R1 = 383,663, R2 = 154,560); however, there was no difference in total ovarian follicle count between offspring due to treatment (P = 0.17; S = 221,813, C = 316,409). Similarly, there was no difference in primordial (P = 0.22; S = 127,300, C = 188,304), primary (P = 0.28; S = 58,610, C = 77,237), or antral (P = 0.48; S = 23,202, C = 28,695) follicle count between offspring due to treatment. Fewer secondary follicles were observed in Stressed offspring compared to Control offspring (P = 0.03). These results suggest that the ovarian follicular reserve, AFC, and potential fertility of cows may not be impacted by exposure to prenatal transportation stress. USDA is an equal opportunity provider and employer.
247 Metabolic Adaptation to Short-term of Dietary Nutrient Imbalances in Mid Lactation Dairy Cows
Authors: Gross Josef J , Stürmlin Remo , Bruckmaier Rupert M
Published: October 2021

This study investigated the short-term metabolic and endocrine responses to different levels of concentrate formulated to particularly provide one major macronutrient source. Based on parity number, lactational stage, milk yield and BW, 9 mid lactating cows (211 ± 19 d in milk) were grouped into 3 blocks of 3 animals each. Concentrate supplements (aminogenic: rich in crude protein and nitrogen sources; glucogenic: high content of carbohydrates and glucogenic precursors; lipogenic: high lipid content) were fed in a factorial arrangement at 3 increasing levels for 3 d each. Milk yield, BW and feed intake were recorded daily. Blood and milk were sampled every 3 d at the end of each concentrate level. Statistical analysis was carried out using a mixed model with concentrate supplement and level as fixed, and block and animal as random factors. Milk fat, protein, lactose and urea contents were determined. In blood, concentrations of various metabolites, endocrine factors and enzyme activities (e.g. glucose, non-esterified fatty acids (NEFA), β-hydroxybutyrate, urea, cholesterol, triglycerides, insulin, glucagon, ASAT, GGT, GLDH) were measured. Milk yield, milk composition and BW were not affected by diets and concentrate levels. Feed intake increased in cows receiving the aminogenic and lipogenic diet. Milk und plasma urea concentrations were clearly elevated in the aminogenic and to a lesser extent in the lipogenic treatment compared to the glycogenic diet (P < 0.05). Glucose concentrations in plasma were not affected by treatments, whereas insulin and glucagon increased only in the aminogenic treatment with concomitantly reduced NEFA concentrations (P < 0.05). Activities of ASAT, GGT and GLDH as well as the total antioxidant capacity were not affected by diets (P >0.05). To conclude, immediate metabolic and endocrine responses occurred due to the short-term dietary changes. Particularly a surplus of nitrogen supply affected metabolic responses and stimulated insulin and glucagon secretion.
254 Effects of Nutrition on Bull Fertility
Authors: Geary Tom W , Dahlen Carl R , Zezeski Abigail L
Published: October 2021

The greatest effects of nutrition on bull fertility occur by providing a relatively high plane of nutrition during calfhood when the seminiferous epithelium of the testes is developing. A high plane of nutrition from 5 to 25 weeks of age results in greater circulating gonadotropin concentrations, greater testicular volume, and greater sperm production at maturity. At this age, diet can be manipulated by creep feeding bull calves with both protein and energy supplements which could accelerate puberty and increase sperm production. Increased rate of gain in bull calves post-weaning can accelerate puberty a few weeks, but excess post-weaning gain and fat buildup in the neck of the scrotum can have detrimental effects on fertility. Considerable emphasis has been placed on specific micronutrient (especially minerals) effects on peripubertal bull fertility. Trace mineral supplementation is believed to be critical for optimal fertility and both copper (Cu) and zinc (Zn) supplementation have influenced male fertility in other species. However, there are no guidelines for recommended levels of these minerals to ensure fertility. Providing organic or complexed compared to inorganic mineral to peripubertal bulls have increased liver concentrations of mineral and in some cases, have accelerated puberty, but enhanced fertility-associated measures have not been realized. Because both Cu and Zn are present in the ejaculate, mineral needs during the breeding season may differ from the off-season. During the breeding season, bulls can lose 10 to 20% of their weight and need to re-gain this weight before the next breeding season. Divergent planes of nutrition provided to mature bulls during the off-season revealed enhanced sperm energy and stress-fighting potential with decreasing plane of nutrition. Specific mineral supplementation during the off-season in mature bulls provides no beneficial effect on fertility-associated measures. In summary, significant effects of nutrition post-weaning on bull fertility-associated measures have not been realized.
253 Physiological Responses to Heat Stress of Holstein Heifers Carrying the SLICK1 Allele of the Prolactin Receptor (PRLR) Gene
Authors: Denicol Anna C , Carmickle Allie T , Pereira Jessica , Ferreira Fernanda C , Larson Colleen C , Sosa Froylan , Jansen Laura , Haimon McKenzie L , Hansen Peter J
Published: October 2021

The objectives of this study were to evaluate physiological responses to heat stress of Holstein heifers carrying the SLICK1 allele of the PRLR, i.e., the slick mutation. Slick and non-slick females were produced in central CA (n = 3 farms) and south FL (n = 3 farms) by inseminating cows with semen from two heterozygous slick Holstein sires. In July 2020, a subgroup of heifers of both genotypes (slick=93; non-slick=110) and two age groups (Group 1: 6–8 months old; n = 131; Group 2: 9–51 days old; n = 72) in both states were evaluated for rectal temperature (RT), surface temperature (ST) and sweating rate (SR). Dry bulb temperature, relative humidity and dew point were recorded every 15 min during testing for temperature humidity index (THI) calculation. Statistical models included the effects of genotype, state, farm within state, group, sire, THI, and interactions. Significant effects were considered as those with P < 0.05. Although the THI in CA was lower than FL (80 ± 0.1 vs 84 ± 0.2; P < 0.01), both were above 77 (estimated heat stress threshold for young animals). Slick heifers raised in FL had lower RT compared to non-slick siblings (39.6 ± 0.1 vs 40.1 ±0.1; genotype P < 0.01); this difference was not observed in CA (39.1 ± 0.04 vs 39.1 ± 0.05; genotype P = 0.5; state x genotype P < 0.01). In both states, slick heifers tended to have lower ST (34.7 ± 0.2 vs 35.1 ± 0.2; P = 0.07); CA heifers had lower RT and ST and higher SR (P < 0.01) regardless of genotype. Current results show that presence of the SLICK1 allele can improve the ability of Holstein heifers to regulate body temperature, particularly in high humidity conditions. Next steps will include analysis of performance as study animals enter the reproductive phase. Funding sources: Holstein Association USA and L.E. “Red” Larson Endowment.
283 Precision versus Group Supplementation at Two Levels on Growth and Development of Replacement Heifers
Authors: Duckett Susan K , Cathcart Jacob , Cathcart Austin , Dantzler Zach , Dove Hunter , Andrae John G , Hersom Matt
Published: October 2021

Two experiments were conducted to evaluate use of the Super SmartFeeder (SSF; C-Lock, Inc.) for individual versus group supplementation of heifers grazing stockpiled, novel tall fescue. In experiment 1, Angus heifers (n = 64; 267 + 31.7 kg) had access to the SSF and were allowed 3.6 kg/d of grower supplement. Individual intake was recorded daily and analyzed to determine adoption. Twenty-four percent of the heifers did not adopt to individual SSF supplementation (P < 0.05). In experiment 2, heifers (n = 64; BW= 275 + 31.3 kg) were allotted, based on adoption to SSF, to supplementation system of group feeding (n = 2 reps/level; GRP) or SSF precision feeding (n =16/level; PRE) at two levels (0.5% or 1% of BW) for 127-d in a 2 x 2 factorial. Data were analyzed using Mixed procedure. The interaction between supplementation level and feeding system tended to be significant (P = 0.10) for overall ADG. Average daily gain was greater for 1% BW than 0.5% BW (0.81 vs. 0.47 kg/d) for PRE but did not differ for GRP (0.69 kg/d). Daily supplement dry matter intake differed (P < 0.05) by supplementation level and total BW gain was greater (P < 0.05) by 24.3 kg for 1% versus 0.5% supplementation level. Ultrasound ribeye area and fat thickness measures were greater (P < 0.05) for 1% BW supplement compared to 0.5% BW at the end of the 127d study. When PRE was analyzed independently, heifer BW differed (P < 0.05) on d 91, 117 and 127 between supplement levels. The correlation between individual heifer daily supplement intake and overall ADG for PRE was 0.68 (P < 0.0001). The use of technology to precisely control intake in a grazing system created greater divergence in growth by supplementation level compared to group feeding systems.
294 Effect of Supplementing Rumen-protected Methionine on Production, Apparent Digestibility and Economic Effectiveness in Lactating Holstein Dairy Cows
Authors: Wei Jialin , Cao Zhijun , Li Yuanxiao
Published: October 2021

The aim of the present study was to evaluate the effects of reducing dietary crude protein (CP) levels and supplementing rumen-protected methionine (RPM) on production, apparent digestibility of nutrients and economic effectiveness of lactating Holstein cows. A total of 96 (60 ± 7 d in milk; 34.39 ± 5.74 kg/d of milk production; mean ± SD) lactating Holstein dairy cows were randomly assigned to 1 of 2 treatments: diet containing 17.3% CP without RPM (control group; CON); diet containing 16.4% CP with supplementing 15.0 g/d of RPM (treatment group; RPM). All the data were analyzed using one-way analysis of variance (ANOVA) of SAS (SAS version 9.2, SAS Institute Inc., Cary, NC.). No effects were observed of reducing dietary CP on somatic cell counts, milk yield and milk composition including fat, protein, lactose, total solid, solids-not-fat and milk urea nitrogen. The total apparent digestibility of nutrients was similar between treatments, while RPM group had higher calcium digestion (44.24% vs. 42.75% ± 10.13%) and phosphorus digestion (48.50% vs. 45.96% ± 12.90%) numerically. In addition, supplying the diet of 16.4% CP with RPM supplementation to cows could reduce feeding cost by 0.5 $/d per cow and boost net profits. In conclusion, lower dietary CP with RPM supplementation did not limit milk yield, milk composition and apparent digestibility of nutrients, and also could improve the economic benefits of the dairy farms.
292 Reducing the Fermentability of Wheat with a Starch Binding Agent Has the Potential to Ameliorate Heat Stress in Sheep
Authors: Prathap Pragna , Chauhan Surinder S , Leury Brian J , Cottrell Jeremy J , Joy Aleena , Tunkala Bereket Z , DiGiacomo Kristy , Zhang Minghao , Jefferis Peter , Sawyer Ian , Dunshea Frank R
Published: October 2021

Two experiments were conducted to determine whether a starch binding agent could (1) reduce the rate of fermentation of wheat grain and (2) improve heat tolerance in sheep. Firstly, fermentation kinetics and buffered rumen fluid pH variation were measured during in vitro incubation of wheat with 0, 1, 2, and 4% Bioprotect® (Feedworks Pty Ltd, Australia). Bioprotect® reduced gas production at 12 h in a dose-dependent manner (-6.4, -11 and -20% respectively; P < 0.001) and increased pH (P < 0.001), indicating slower ruminal fermentation. In a randomized control experiment, Merino lambs (n = 24) were fed either 50% wheat (WD, fast fermenting), corn (CD, slow fermenting), or wheat treated with 2% Bioprotect® (BD), with the balance of the diets being forage. Lambs were housed in climate-controlled rooms and exposed to 3 experimental periods: period 1 (P1: 7 days of thermoneutral conditions [18–21°C and 40–50% relative humidity (RH)] and fed 1.7×maintenance); period 2 [P2: 7 days of HS (28–40°C and 30–50% RH) and fed 1.7×maintenance]; and period 3 (P3: 7 days of HS as in P2, and 2×maintenance) with ad libitum water. Increases in respiration rate (RR), heart rate (HR), rectal temperature (RT) and left and right flank skin temperature (P < 0.001) occurred during HS, particularly during P3 (P < 0.001). Lambs fed CD and BD had lower RR (150, 137 and 140 breaths/min for WD, CD and BD, P < 0.001), HR (91.3, 85.3 and 85.9 beats/min, P < 0.001 and RT (39.7, 39.7 and 39.7°C P < 0.05). While there was no effect of diet, lambs reduced feed intake (-4%, P < 0.05) during P2 but consumed more (+16%) during P3. These data confirm that feeding corn or Bioprotect® treated wheat can be used as an ameliorative strategy to reduce the thermal load in lambs during summer.
304 Effects of Supplementing Phix-up® on Productive, Physiological, and Rumen Responses of Feedlot Cattle Consuming a Corn-based Finishing Diet
Authors: Colombo Eduardo , Cooke Reinaldo F , Harvey Kelsey , Wiegand Jacob , Araujo Ana Clara , Ferreira Vitor , Duclos Julie , Brandão Alice
Published: October 2021

This experiment (d -14 to 118) compared rumen pH, productive, and physiological responses in finishing cattle supplemented or not with a rumen-buffering agent (pHix-up®; Timab, Dinard, France). Angus-influenced yearling cattle (58 heifers and 62 steers) were ranked by sex and body weight (BW) and allocated to 4 groups of 30 animals each (d -14). Groups were housed in 1 of 4 drylot pens equipped with GrowSafe automated feeding systems, and assigned to receive a corn-based diet containing monensin, and with the inclusion of pHix-up® at 0.00% (control) 0.25%, 0.50%, or 0.75% (d 0 to 118). Cattle BW was recorded twice monthly (d -14 to 118), and blood samples were collected on d 0, 28, 56, 84 and 112. Hair samples from the tail-switch were collected on d 0, 56 and 112. Cattle were slaughtered on d 119. Eight rumen-cannulated steers were also assigned to this experiment (d 42 to 98), with 2 steers housed with each group in a replicated 4 × 4 Latin Square design (4 periods of 14 d). Rumen pH was measured on d 7 and 14 of each period at 0800h, 1200h, 1600h and 2000h. No treatment effects were noted (P ≥ 0.13) for cattle BW gain, feed intake, and feed efficiency. Inclusion of pHix-up® linearly increased (P < 0.01) plasma Mg concentrations and tended to linearly decrease (P = 0.09) plasma haptoglobin concentrations. Cattle receiving pHix-up® had greater (P < 0.01) mean plasma cortisol concentrations compared with non-supplemented cattle. Hair cortisol concentration linearly decreased (P < 0.01) as pHix-up® inclusion increased on d 112 (treatment × day interaction; P = 0.02). In rumen-cannulated steers, pHix-up® inclusion linearly increased (P = 0.03) mean rumen pH. Collectively, pHix-up® supplementation improved rumen pH and modulated stress-related physiological responses in finishing cattle, but without improving their productive responses.
298 The Effects of Chromium Propionate Supplementation to Calf-fed Steers in a Commercial Feedyard on Growth Performance, Carcass Characteristics and Health
Authors: Trojan Sara J , Hergenreder Jerilyn , Canterbury Landon , Leonhard Tyler , Long John M
Published: October 2021

Crossbred steers [British x Continental x Bos Indicus; n = 1844; initial body weight (BW) = 248 ± 28 kg] were used to evaluate the effects of chromium propionate supplementation to calf-fed steers in a commercial feedyard on growth performance, carcass characteristics and health. Steers were blocked by initial BW; pens were assigned randomly to one of two dietary treatments within block. Treatments, replicated in 15 pens/treatment with 57 to 62 head per pen, included: 1) control, 0 mg supplemental Cr/kg dietary dry matter (DM) (CTL); 2) 0.50 mg supplemental Cr/kg dietary DM (chromium propionate; KemTRACE® Chromium 0.04%, Kemin Industries, Des Moines, IA) (CR). Due to inadvertent oversight, during the final 30 days on feed, CR cattle did not receive trace minerals, vitamins, an ionophore, antibiotic, or ractopamine-hydrochloride. Final BW, average daily gain (ADG) and DM intake did not differ among treatments (P ≥ 0.25). Gain efficiency was greater (P = 0.03) for CTL than CR (0.16 vs. 0.15). Hot carcass weight and dressing percentage were similar among treatments (P ≥ 0.19). Yield grade was higher for CR than CTL (2.44 vs. 2.27; P < 0.01); 12th-ribfat tended to be greater for CR than CTL (P = 0.09), and longissimus area was greater for CTL vs. CR (P < 0.01). Marbling score tended (P = 0.10) to be greater for CR than CTL. Steers fed CR tended (P = 0.07) to have a greater distribution of prime carcasses than CTL (1.9% vs. 0.07%), and percentage choice carcasses was higher for CR than CTL (67.34% vs. 61. 71%, P = 0.01). Respiratory morbidity (12.20%), and retreatment rate did not differ among treatments (P ≥ 0.20). In the absence of a beta-agonist, CR steers had higher quality carcasses, and similar ADG and HCW to CTL.
312 Effects of Bismuth Subsalicylate and Different Sulfate Concentrations on in vitro Ruminal Fermentation Using a Warm-season Perennial Hay Substrate
Authors: Madrid Kenneth S , Osorio Andrea M , Ciriaco Francine M , Coello Kymberly D , Raudales Angel A , Onorino Sarturi Jhones O , Penner Gregory B , Henry Darren D
Published: October 2021

A randomized complete block design was used to evaluate the effects of bismuth subsalicylate (BSS) on in vitro ruminal fermentation with differing concentrations of sulfate. In vitro fermentation consisted of 50 mL of a 4:1 buffer:ruminal fluid inoculum and 0.7 g (pre-dehydrated) of substrate [WW-B Dahl bluestem hay (Bothriochloa bladhii)] incubated for 48 h (39oC). Treatments were arranged as a 3 × 4 factorial with concentration of sulfate (0.2, 2.9, or 5.6 g sulfate/L buffer) and BSS (0.0, 0.165, 0.330, or 0.495% substrate DM) as the main factors. In vitro organic matter digestibility (IVOMD), and CH4, H2S, and total gas production (TGP) were measured. Data were analyzed using the MIXED procedure of SAS with the fixed effects of BSS, sulfate, and their interaction. Incubation day (block) was considered a random effect. The average of 2 bottles within day was considered experimental unit. A BSS × sulfate interaction was observed for TGP (P = 0.040) and H2S production (P < 0.001), where BSS had a larger negative impact on TGP and production of H2S with greater concentrations of sulfate. A linear effect (P < 0.001) of sulfate was observed for CH4 production per gram of incubated OM, where CH4 was decreased as sulfate concentration increased. A quadratic effect of sulfate was observed for IVOMD (P = 0.010) and pH (P = 0.009). Production of H2S linearly decreased (P = 0.001) as BSS concentration increased. The addition of BSS to in vitro incubations did not affect (P > 0.10) any other variables measured. Bismuth subsalicylate does not appear to have negative effects on in vitro fermentation parameters while decreasing H2S production; however, elevated concentrations of sulfate in the buffer appears to have negative impacts on fermentation. Further in vivo research is warranted to support BSS supplementation to cattle with high dietary sulfate.
307 Effect of Feeding Distilllers Grain from Wheat on Growth Performance of Growing and Finishing Beef Cattle
Authors: Yang Wenzhu
Published: October 2021

The uniqueness of wheat-based distiller grain (wDG) with high protein and digestible fibre gives great feeding opportunities for cattle as energy, protein or fiber source. This abstract summarizes recent research findings on the use of wDG in beef cattle diets. For growing beef cattle, steers fed diets (forage:concentrate, 55:45) with increasing replacement of barley grain with wDG from 0, 8, 16, 24 to 32% (DM basis) linearly (P < 0.01) increased average daily gain (ADG) from 1.09 to 1.28 kg/d and DM intake (DMI) from 7.26 to 7.94 kg/d without affecting gain:feed (0.158). By comparing protein source of canola meal and corn DG in diets containing 60% of silage and 40% of barley grain, steers fed wDG diet had similar ADG (1.46 kg/d) with corn DG (1.51 kg/d), and had no differences in gain:feed (0.178) with canola meal (0.183). For finishing beef cattle, with increasing wDG from 10, 20 to 40% in the place of barley grain of finishing diets, the DMI linearly (P < 0.01) increased from 10.2 to 10.9 kg/d, whereas, the gain:feed linearly (P < 0.01) decreased from 0.172 to 0.159 without altering the ADG (1.74 kg/d). The wDG was also suggested to be fed as fiber source to replace roughage in finishing diet. Entirely substitution of wDG for roughage of finishing diet decreased (P < 0.01) ruminal pH from 5.95 to 5.75 of beef heifers; however, the ADG and gain:feed of steers were not affected. The results suggested that although substitution of wDG for roughage in finishing diets may increase the incidence of ruminal acidosis, this outcome does not appear to adversely impact the performance of the cattle. The wDG can be successfully incorporated to substitute a portion of grain or roughage within growing and finishing diets with minimal or no adverse impact on cattle growth performance.
317 Effect of the Whole Cottonseed with Pre-treatment on the Digestibility, Productivity, and Milk Fat Profile of Dairy Cattle
Authors: Sun Xiaoge , Su Yitong , Hao YangYi , Liu Gaokun , Gong Yue , Wang Yajing , Cao Zhijun , Wang Wei , Li Shengli
Published: October 2021

To improve the efficiency of whole cottonseed (WCS) on dairy cattle, crush and alkali treatment were combined (Table 1) in this study. The gastrointestinal tract digestibility of WCS were measured by in situ ruminal incubation and in vitro fermentation, respectively. Finally, animal feeding experiment was conducted to evaluate the effect of processed WCS on dairy cattle. A total of 30 Holstein dairy cows with similar physiological status were allocated to three groups (CON, Group I, and Group II). Ration for the CON group was a basic ration with no WCS, ration with about 8% non-processed WCS was for Group I (DM basis), while the Group II was provided by the ration added with 8% Crush-Alkali (4% mixed alkali solids with NaOH/CaO ratio at 1:1) treated WCS. Results of the in situ and in vitro experiments showed that, compared with non-treated WCS, Crushing-Alkali treatment groups significantly improved WCS ruminal effective degradation rate of dry matter (DM), crude protein (CP), ether extract (EE), and neutral detergent fiber (NDF) (P < 0.05). Furthermore, Crush-Alkali (4% mixed alkali solids with NaOH/CaO ratio at 1:1) was the most beneficial to improve WCS gastrointestinal degradation of DM, CP and NDF, as well as enhance WCS rumen-bypass of EE. With the lowest free gossypol content (P< 0.05). Results of animal feeding experiment showed that DMI, 4% fat corrected milk production (4% FCM), milk protein, milk fat, and content of short-chain saturated fatty acids in milk in Group II significantly increased (P < 0.05) compared with CON group. DMI, ω-6 polyunsaturated fatty acids (PUFA) in milk, and the ratio of ω-6 to ω-3 PUFA were significantly higher in Group II than that in Group I (P < 0.05). Additionally, free gossypol concentration in serum and milk, as well as parameters reflecting liver function were not notably different among the three groups (P > 0.05).
325 The Diagnosis of Sub-acute Ruminal Acidosis (SARA) in Dairy Cows on Commercial Farms Using the Milk Fatty Acid Profile
Authors: Plaizier Jan C , Mowete Sharon Y , Santchi Debora , Kwiatkowski Ken , De Neve Nympha , Fievez Veerle
Published: October 2021

The accuracy of the milk fatty acid profile as a diagnostic tool for the diagnosis of sub-acute ruminal acidosis (SARA) has been determined when SARA was experimentally induced. This had not yet been done not on commercial dairy farms, where SARA can occur naturally. The objective of this study was to determine this accuracy in individual cows on commercial dairy farms. A total of 336 cows from 24 commercial dairy farms in Quebec were included. Farms were blocked based on geographical location and management, with each block having one high risk SARA farm and one low risk SARA farm. Farm Risk of SARA was determined based on the milk fat content and the proportions of de novo fatty acids and long chain unsaturated fatty acids in the bulk tank. On each farm, 7 early/mid-lactation (< 150 days in milk DIM) and 7 mid/late lactation (< 150 DIM) cows were randomly selected. The fatty acid profile of pooled milk samples from these cows were determined by gas chromatography. Farm risk of SARA did not affect the milk fat proportion of fatty acids, with the exception of trans 10 cis 12 C18:2, which was higher in At Risk Farms. Later lactation cows had a higher milk fat content and higher milk fat proportions of de novo, C16 fatty, and odd and branch chain fatty acids. The prevalence of SARA was likely higher in earlier lactation cows than in later lactation cows, but non-SARA related animal and dietary factors also affect the milk fatty acid profile. Hence, the milk fatty acid profile alone may not be accurate enough to diagnose SARA on farm. This profile can, however, contribute to this diagnosis, the identification of causes of milk fat depression, and the development of strategies to optimize the milk fatty acid profile.
321 Extrusion of Grass Silage Increase Intake and Milk Yield in Dairy Cows
Authors: Rustas Bengt Ove , Managos Markos , Eriksson Torsten
Published: October 2021

This research evaluated effects of grass silage extrusion on dairy cow performance. A grass dominated (70% timothy, 26% meadow fescue, 3% red clover and 1% undefined) first cut ley was harvested on June 13, 2019, and 10 days later near Uppsala, Sweden (58°83′ N, 17°82′ E). Crops were wilted (45% DM for early cut, 50% DM for late cut), round baled and wrapped into plastic film for ensiling. At feeding out, bales were chopped in a TMR feeder, and a portion was processed in an extruder, where screws shear the material under pressure, for further particle size reduction and cell wall break up. Eight Swedish Red cows in two blocks (4 ruminally fistulated, 143 ± 38 DIM and 4 intact, 68 ± 10 DIM) were used in a Latin square design experiment with 4 periods of three weeks each and 4 treatments. The 2x2 factorial arrangement of treatments included silage from early or late harvest that was chopped or extruded. Silage was fed separately ad libitum and supplemented (daily amounts on an as fed basis) with 2 kg of soybean meal, a compound feed (6 kg for fistulated and 8 kg for intact cows), and 120 g of a mineral mix. Extrusion increased silage DMI (1.8 kg/d, P < 0.001) with greater effect at late harvest (P = 0.021 for interaction between processing and harvest) and milk yield (1.8 kg ECM/d, P = 0.004) with a tendency to greater effect at late harvest (P = 0.055). Extrusion depressed total tract OM digestibility (2.3 percentage points, P < 0.001), eating time (0.5 h/d, P = 0.014), rumination time (2.0 h/d, P < 0.001) and rumen pH (0.1 units, P = 0.008). Extrusion improves intake and milk production in dairy cows, despite depressed digestibility.
332 Effect of Chemical and Biological Preservatives on in vitro Fermentation and Methane Production of Ensiled and Aerobically Exposed Wet Brewer’s Grains
Authors: Killerby Marjorie A , Zamudio Diego , Ames Kaycee , Henry Darren D , Schwartz Thomas , Robinson Anna , Oppong Godloves M , Romero Juan Jose J
Published: October 2021

This study evaluated the effects of preservatives on the in vitro fermentation measures of wet brewer’s grain (WBG) silage at different stages of storage. Treatments (TRT) were sodium lignosulfonate at 1% (NaL1) and 2% (NaL2; w/w of fresh WBG), propionic acid (PRP; 0.5% w/w of fresh WBG), a combination inoculant (INO; Lactococcus lactis and Lactobacillus buchneri each at 4.9 log cfu/fresh WBG g), and untreated WBG (CON). WBG (Fresh) were packed into 8.8 L mini-silos and stored for 60 d at 21°C (Ensiled), then they were opened and aerobically exposed for 10d (AES). Samples from each stage of storage (STG; Fresh, Ensiled and AES) were analyzed for in vitro ruminal digestibility (24 h).Gas kinetics were recorded using the Ankom RF Gas Production System. Data were analyzed as a randomized complete block design (5 blocks) with a 5 (TRT) × 3 (STG) factorial arrangement. Apparent in vitro DM digestibility (DMD) decreased across STG, (51.5, 47.2 and 40.9 for Fresh, Ensiled and AES, respectively) and increased for NaL1, NaL2 and PRP (~47.8) vs. CON (43.0 ± 2.12%). PRP increased apparent in vitro OM digestibility (OMD) when Ensiled (54.5) and NaL2 increased it for AES (47.1) vs CON (46.3 and 39.9 ± 1.73%, respectively). The asymptotic maximal (M) and rate (k) of gas production decreased across STG (214.6, 181.5, 155.1 and 14.6, 12.6, and 9.8, for Fresh, Ensiled and AES, respectively). PRP increased (200.0) and NaL1 decreased (169.3) M vs. CON (183.9± 7.81ml/incubated DM g), while NaL1 and NaL2 (~11.4) decreased k vs. CON (13.4 ± 0.85%/h). Methane concentration and yield were higher in Fresh vs. other STG (0.94 vs. ~0.84 ± 0.07mM and 0.27 vs. ~0.23 ± 0.03mmol/g fermented OM). Spoilage of WBG decreases fermentability and methane production while PRP and NaL improve digestibility with the former also increasing M and k.