bluuebunny/crossref_metadata_2025 huggingface dataset:
97 Effects of alkalization treatment on chemical composition and in vitro ruminal fermentation of anaerobically stored rice stover
Authors: Ma Yulin , Chen Xu , Xiao Jianxin , Liu Shuai , Wang Jingjun , Cao Zhijun
Published: November 2020

The objective of this trial was to evaluate the effects of urea and calcium hydroxide on the chemical composition and in vitro ruminal fermentation of rice stover. Rice stover was stored in polyethylene bags (35 × 25 cm, 350g per bag) with: (i) no additive (CON); (ii) 4% calcium hydroxide (CA, dry matter (DM) basis); (iii) 2.5% urea and 4% calcium hydroxide (UCA, DM basis); and (iv) 9% corn steep liquor and 2.5% urea and 4% calcium hydroxide (CUCA, DM basis). Dry matter were kept at the same level at 55% for all treatments. Totally, 36 bags (4 treatments × 3 store periods × 3 repeats) were prepared and stored at ambient temperature (25 ± 3 °C). The chemical composition was measured at day 7, 10 and 15 after storage. And the in vitro ruminal fermentation was tested in vitro at d 15. Date was subjected to two-way analysis of variance (ANOVA) with the fixed effects of treatments, times and treatments × times by using SPSS 24.0. All alkali treatments reduced neutral detergent fiber (NDF) and acid detergent fiber (ADF) content (P < 0.05), and increased the in vitro DM digestibility (IVDMD) of the rice stover compared with the CON. The in vitro NDF degradability (IVNDFD) and ADF degradability (IVADFD) were increased in UCA and CUCA rice stover (P < 0.05) compared to others. The highest acetic acid (AA), propionic acid (PA), butyric acid (BA), total volatile acids (TVFA) concentrations and 48-h cumulative gas production were observed in CUCA rice stover (P < 0.05). With the delay of storage time, dry matter (DM) and crude protein (CP) were decreased in CA and CUCA groups (P < 0.05). Results in this study suggested that 9% corn steep liquor and 2.5% urea and 4% calcium hydroxide might be an effective treatment combination.
345 Digital Technologies Ease the Burden of Pasture Intake Measurements: A New Hope
Authors: Kallenbach Robert , Hamilton Stacey , Lock Thomas Ryan
Published: November 2020

A short while ago, in fields not so far away, graziers guessed forage mass and intake of grazing livestock in pastures. Then a period ensued where only laborious, expensive methods existed to measure the same. Faced with such a galactic dilemma, researchers made one of two practical choices: 1) collect minimal amounts of pasture growth information and give up precision, or 2) ignore pasture growth and forage measures altogether. Neither approach provides the data needed to describe forage intake of grazing animals. Smart devices — now carrying 120 million times more computing power than navigation systems onboard Apollo 11 — bring a new hope to pasture researchers, managers and farmers. This paper evaluates technological advances that enable the next generation of pasture measurements (including animal intake) using sensors. The list of sensors-based tools includes platemeters, digital rules, sonic waves, stereo photography, dual-tuned ultrasound, surround sound, lasers, light bars, and satellite images. These tools — coupled with artificial intelligence systems — give creative thinkers new ways to measure, monitor and manage forage intake in pastures. It’s the future.
101 Evaluation of Growth Curve Functions for predicted weight in small holder crossbred dairy cattle in Tanzania
Authors: Ekine Chinyere , Mrode Raphael , Oyieng Edwin , Komwihangilo Daniel , Msuta Gilbert , Eliamoni Lyatuu , Ojango Julie , Mwai Okeyo
Published: November 2020

Modelling the growth curve of animals provides information on growth characteristics and is important for optimizing management in different livestock systems. This study evaluated the growth curves of crossbred calves from birth to 30 months of age in small holder dairy farms in Tanzania using a two parameter (exponential), four different three parameters (Logistic, von Bertalanffy, Brody, Gompertz), and three polynomial functions. Predicted weights based on heart girth measurements of 623 male and 846 female calves born between 2016 and 2019 used in this study were from the African Dairy Genetic Gains (ADGG) project in selected milk sheds in Tanzania, namely Tanga, Kilimanjaro, Arusha, Iringa, Njomba and Mbeya. Each function was fitted separately to weight measurement of males and females adjusted for the effect of ward and season of birth using the nonlinear least squares (nls) functions in R statistical software. The Akaike’s information criterion (AIC) and Bayesian information criterion (BIC) were used for model comparison. Based on these criteria, all three polynomial and four parameter functions performed better and did not differ enough from each other in both males and females compared to the two-parameter exponential model. Predicted weight varied among the models and differed between males and females. The highest estimated weight was observed in the Brody model for both males (278.09 kg) and females (264.10 kg). Lowest estimated weight was observed in the exponential model. Estimated growth rate varied among models. For males, it ranged from 0.04 kg-0.08 kg and for females, from 0.05 kg-0.09 kg in the Brody model and logistic model respectively. Predictive ability across all fitted curves was low, ranging from 25% to approximately 29%. This could be due to the huge range of breed compositions in the evaluated crossbred calves which characterizes small holder dairy farms in this system and different levels of farm management.
107 Skeletal muscle mitochondrial parameters correlate with sales price in weanling racing-bred Thoroughbred horses
Authors: Guy Chloey P , Latham Christine M , Owen Randi N , Fowler Ashley L , White-Springer Sarah H
Published: November 2020

Thoroughbred horse sales prices rely heavily on animal conformation and ancestral race performance, as well as the current economic landscape. However, little information exists on the relationship between physiological parameters and sales price. We aimed to test the hypothesis that weanling sales price would positively correlate with skeletal muscle mitochondrial parameters in racing-bred Thoroughbreds. Gluteus medius muscle samples were collected from racing-bred Thoroughbred weanlings (n = 19; mean ± SD; 5.7 ± 0.3 mo) and evaluated for mitochondrial volume density (citrate synthase activity; CS) and function (cytochrome c oxidase activity; COX) by colorimetry, and oxidative and electron transport system capacities by high resolution respirometry. Horses were sold at the 2018 and 2019 Keeneland November Breeding Stock Sales at 8.5 ± 0.7 mo of age. Data were analyzed using Pearson Correlation Statistics in SAS (v9.4). Weanling sales price was positively correlated with intrinsic mitochondrial function (COX activity per unit CS; r = 0.6269, P = 0.004) and coupling efficiency with substrates for complex I+II (r = 0.4424, P = 0.05). A trend for a negative correlation was observed between weanling sales price and CS activity (r = -0.4179, P = 0.07), while a trend for a positive correlation between sales price and intrinsic oxidative phosphorylation capacity with complex I substrates (r = 0.3974, P = 0.09) was observed. In this cohort of weanling Thoroughbreds, mitochondrial parameters measured at 6 mo of age correlated with sales price at 8 mo of age. Implications of these relationships as they relate to race performance should be further investigated.
106 The effects of Total Equine™ grain with Ascophyllum nodosum seaweed extract and chelated minerals on forage intake and cecal digestibility in mature Quarter horse mares under performance conditions
Authors: Boyd Jamie A , Smith Kaylee A
Published: November 2020

A study was conducted in fall 2019 at Sul Ross State University to evaluate the effects of Total Equine™ containing Ascophyllum nodosum seaweed and chelated minerals on intake and cecal digestibility in comparison to a product without Ascophyllum nodosum seaweed or chelated minerals. Six quarter horse mares (avg 9 yrs) were used in a complete randomized block study. Horses were offered an ad libitum Bermuda hay for a 2wk standardization period and then blocked into pairs based on weight, age, and fitness level. Horses were assigned randomly within block to the Ctrl or Trt diets for an 8wk study with ad libitum access to water. Hay was offered 2xd in port-a-grazer tubs to control for waste. Grain was offered at a rate of 0.5% BW (manufacturer suggestions) and divided into 2 equal feedings. Horses were weighed weekly and grain amounts were adjusted weekly. Hay orts were collected 2x daily and hay offered was adjusted daily for a 3% refusal rate. Horses were exercised 6 d/wk on a hot-walker for 2 hrs. Horses were conditioned prior to the study and speed and duration were increased throughout the study. Horses worked 30 min at a walk and 1.5 hrs at a trot broken into periods. Feed samples were collected 2xwk and dried for DM and ground for analysis for NDF, ADF, CP, EE, and Ash. Blood samples were collected for 3x (1 wk, 4 wk, 8 wk) pre/post exercise to be tested for cortisol levels. A significant difference in total DMI was observed at 13.1 ± 0.14 kg Ctrl versus 12.02 ± 0.11 kg Trt (P = 0.0001). When looking at forage intake only 10.07 ± 0.13 kg Ctrl versus 9.04 ± 0.11 kg Trt (P = 0.0001). Overall, it appears that the inclusion of the grain product with Ascophyllum nodosum and chelated minerals reduced forage intake and overall DMI without affecting weight or animal performance.
358 Understanding the role of the fecal bacterial microbiota in equine colic
Authors: Pitta Dipti , Indugu Nagaraju , Hennessy Meagan , Vecchiarelli Bonnie , Stewart Holly , Willette Jackie , Dobbie Tamara , Engiles Julie , Southwood Louise
Published: November 2020

The horse is uniquely adapted for hindgut fermentation, and the microbiota within the hindgut contribute to immune system stimulation, protection against harmful pathogens and toxins, and regulation of gene expression within the host. Many factors, such as dietary changes, antimicrobials, pathogens, and changes in management, can perturb the microbial communities leading to gastrointestinal complications such as colitis and colic in horses. With advances in genomic tools to characterize microbiota, efforts to expand the body of knowledge on the community structure and function of equine gut microbiota in health and disease are increasing within the equine research community. Colic is an important equine disease. While epidemiological studies have identified risk factors for colic, and intestinal inflammation may play a role in some horses with recurrent colic, there are very few studies investigating the role of the intestinal microbiota in colic. We compared the microbial communities of horses admitted to the hospital for colic to those of horses admitted for an elective procedure. We found a significant difference at the community level (alpha and beta diversity) and also between individual bacterial populations. Furthermore, we also found that location of lesions in the GI tract, duration of colic (acute vs. chronic), and other factors altered the microbial ecology of the equine gut microbiota. Notably, we also investigated whether the changes in microbiota induced by colic were confounded by withholding feed. We found that withholding feed from horses for 24 h induced a significant shift in the microbiota, which reverted to normal within 12 h after the horses gained access to feed. From our experiments, it is becoming increasingly clear that colic in horses induces changes in specific bacterial populations along with generalized changes that are confounded with many other factors. Further research is needed particularly in horses with recurrent colic to determine the association between the intestinal microbiota, diet and management factors, and inflammation.
359 Awardee Talk: Equine Science: A community that grew
Authors: Coleman Robert J
Published: November 2020

Research, teaching, and extension related to horse production and management was once a part of land grant universities. Extension publications from the 1900s noted equine research and how to use that research in the feeding and management of horses used primarily for agricultural purposes. As the use of the horse in agriculture declined, so did the activities related to horses at those institutions. Times changed, and as horses regained in popularity for sport and recreation, so did the need for research, teaching, and extension. In the late 1960s, a group of researchers who were doing nutrition research on horses gathered to discuss the possibility of providing a forum for promoting equine research, facilitating effective communications between those who could use the information and develop a symposium. From this conversation came the Equine Nutrition and Physiology Society. The first meeting was held in 1968 in Lexington, Kentucky; with over 20 participants, the society started to meet its goals. The original materials presented were related to nutrition and digestive physiology, but the focus has expanded to include reproductive physiology, exercise physiology, genetics, biosciences and production and management. In addition to the research topics, there are also sections for those involved with Extension and Teaching to discuss how to use the new information. The support of graduate students has grown since they were first invited in 1977 to current participation across the spectrum of research topics and the addition of a strong undergraduate research section as well. The society started with 20 plus in attendance and grew to a membership of over 300 from around the world who come together every two years to discuss topics related to the horse.
362 Utilizing Chicken Breast with Wooden Breast and White Striping in Processed Meat Products
Authors: Stelzleni Alexander M
Published: November 2020

Wooden breast (WB) and white striping (WS) are two myopathies impacting the broiler market. Wooden breast and WS may occur individually or in concert with each other. Wooden breast is characterized by increased rigidity and firmness in the pectoralis major and has been associated with breast meat from larger, faster growing broilers. It begins in the ventral-cranial region and increases in severity, moving toward the deeper and more caudal portions of the muscle. Although the etiology is not fully understood, compositional characteristics of WB include increased collagen and lipid deposition and decreased water holding capacity. Breast fillets exhibiting WS are characterized by the size and amount of striping that occurs on the surface of the pectoralis major. These breasts express similar compositional characteristics to those with WB. Both WB and WS have been associated with decreased organoleptic and rheological properties, causing industry losses estimated in excess of $200 million annually through value downgrades, trim loss, and diversion to rendering. Although WB and WS meat have decreased rheological properties, some lost value may be recaptured through further processing. Recent studies have shown that both blade tenderization and marination improved the textural properties of afflicted breast meat, but neither were able to overcome the differences between afflicted and normal breast meat. Research investigating comminuted and emulsified products containing WB or WS meat have shown similar results due to the lower extraction of salt-soluble proteins and subsequent low bind and gelation properties. When WB/WS meat was included as a portion of the meat block with normal breast meat, textural and rheological differences were ameliorated. Using WB or WS meat in further processed products may give processors an alternative use for afflicted breast meat. Additional research should continue to explore how WB and WS meat can be incorporated into further processed and value-added products.
131 The effect of increasing phytase dose to 1000 FTU/kg on phosphorous and calcium digestibility in pigs fed diets without inorganic P
Authors: Rundle Carly M , Hillen Barthold , Dersjant-Li Yueming , Debicki-Garnier Anne-Marie , Stein Hans H
Published: November 2020

An experiment was conducted to compare two sources of phytase, Buttiauxella phytase expressed in T. reesei (Phytase B) and a hybrid phytase expressed in A. niger (Phytase H), on the apparent total tract digestibility (ATTD) of phosphorous (P) and calcium (Ca) in pigs fed diets without inorganic P. Eighty barrows (12.8 ± 1.04 kg) were placed in metabolism crates and fed 8 diets (10 pigs/diet). A positive control diet (PC) based on corn, wheat, canola meal, and soybean meal was formulated to contain 0.29% standardized total tract digestible (STTD) P and 0.60% Ca. A negative control (NC) was formulated without inorganic P, and this diet contained 0.48% Ca and 0.19% STTD P. Six additional diets were formulated by adding 250, 500, or 1000 units of each phytase (FTU)/kg to NC. After 5 d of adaptation, feces were collected from the feed fed during the following 4 days. Data were analyzed using contrast statements to compare source of phytase and determine the linear and quadratic effects within each source of phytase. With increasing dosage, fecal excretion of P decreased with phytase B (quadratic, P < 0.05) and tended to decrease with phytase H (P < 0.10), but fecal P was greater (P < 0.05) for phytase H than phytase B. The ATTD of P increased quadratically with increasing dose of either phytase B or phytase H (P < 0.05). Across dose levels, phytase B had greater (P < 0.05) ATTD of P and Ca (77.3 and 83.5%) than phytase H (71.0 and 79.3), indicating that phytase B increases the ATTD of P and Ca to a greater extent than phytase H. In conclusion, both phytase B and phytase H, to a different extent, reduced fecal P excretion and increased ATTD of Ca and P in a dose dependent manner.
116 Meta-analysis of 3 trials: the effect a novel consensus bacterial 6-phytase variant on phosphorus digestibility and retention in piglets fed inorganic phosphate free diets
Authors: Velayudhan Deepak , Hardy Rachael , Marchal Leon , Dersjant-Li Yueming
Published: November 2020

A meta-analysis was conducted to investigate the effect of a novel consensus bacterial 6-phytase variant on apparent total tract digestibility (ATTD) of phosphorus (P) and P retention in piglets (initial body weight of 9.6 ± 1.8 kg). Database was constructed using 3 studies (unpublished), contributing 189 data points. All studies had a positive control (PC) diet with adequate levels of calcium (Ca; 0.57–0.85%) and digestible P (0.25–0.29%), a negative control (NC) diet with low Ca and digestible P levels (total removal of inorganic P). Piglets were fed a corn or wheat soybean meal-based diet with rice bran or sunflower meal for 7–10 d, followed by 4 d fecal and urine collection. Total analyzed Ca, total P, calculated digestible P and phytate P levels in NC varied from 0.48 to 0.79%, 0.37 to 0.40%, 0.16 to 0.18%, and 0.24 to 0.28%, respectively, among studies. The NC diet was supplemented with a novel consensus bacterial 6-phytase variant (PhyG) or a commercial Buttiauxella sp. phytase (PhyB), at 500 and 1,000 FTU/kg. Data were analyzed using Mixed Model by JMP 14.0. Addition of both phytases improved (P < 0.05) ATTD P compared to NC diets. The NC reduced digestible P (g/kg) vs PC, both phytases showed greater (P < 0.05) digestible P (g/kg) when compared to NC and recovered to the level of PC. Digestible P improvement (g/kg) over NC showed a significant phytase effect, where PhyG supplementation had 17% greater (P < 0.05) digestible P improvement when compared to PhyB. Phosphorus retention improved (P < 0.05) with phytase supplementation, with 1,000 FTU/kg showing greater (P < 0.05) P retention when compared to 500 FTU/kg. It was concluded that both PhyG and PhyB are efficient in improving ATTD P and P retention, PhyG showed greater digestible P improvement when compared to PhyB, and 1,000 FTU/kg showed greater effect than 500 FTU/kg.
130 Effects of a multi-strain Bacillus subtilis-based direct-fed microbial on immunity markers, intestinal morphology, and microbial communities in diets fed to weanling pigs
Authors: Lewton Jaron R , Woodward Adrienne , Moser Ronny , Thelen Kyan M , Moeser Adam J , Trottier Nathalie , Tempelman Robert , Rozeboom Dale W
Published: November 2020

The objective of this experiment was to evaluate the effects of a multi-strain Bacillus subtilis-based direct-fed microbial (DFM) on intestinal mucosal and blood plasma immunological markers, intestinal morphology, and microbiota of nursery pigs as indicators of health status. Eighty pigs, of equal number of barrows and gilts (initial BW: 6.99 ± 1.67 kg), weaned at 21 ± 1 days of age were randomly allotted to sixteen pens, with five pigs per pen. Two dietary treatments were implemented, a basal control (CON) and a control plus DFM (DFM). Both diets were corn, soybean meal, and distillers dried grains based, formulated to meet all or exceed all nutritional requirements, and manufactured on site. Diets were fed for 42 days. On d 21 and 42 of the experiment, one pig per pen was randomly selected and euthanized, with equal number of males and females represented. Blood samples were collected prior to euthanasia for assessment of plasma levels of immunoglobin A (IgA) and intestinal fatty acid binding protein. Segments of the gastrointestinal tract including duodenum, jejunum, ileum, ascending and distal colon were removed for analysis of intestinal morphology, microbial communities, and levels of interleukin 6, interleukin 10 (IL-10), and tumor necrosis factor alpha. Jejunal villus height was greater (P = 0.02) in DFM compared with CON (422 vs. 385 ± 10 µm, respectively) and ascending colon crypt depth tended to be greater (P = 0.10) on d 21 (373 vs. 337 ± 14 µm, respectively). Compared to CON, DFM tended to increase IgA (P = 0.06) on d 21 (0.34 vs. 0.54 ± 0.07 mg/mL, respectively) and tended to increase IL-10 (P = 0.12) on d 42 (133 vs. 237 ± 49 pg/mL, respectively). Addition of a multi-strain Bacillus subtilis-based DFM may have a potential early benefit to nursery pig health status.
133 Effects of methionine source and zinc level on growth performance of nursery pigs
Authors: Cemin Henrique S , Swalla Luke A , Hansen Sharlie A , Pietig Jamie L , Galloway Stewart T , Hansen Ernie L
Published: November 2020

A 44-d experiment was conducted to evaluate the effects of Met source and Zn level on growth performance of nursery pigs. Treatments were arranged in a 2 × 2 factorial treatment structure with main effects of Met source (DL-Met or MHA-Ca) and added Zn level (100 or 3,000 mg/kg). A total of 1,008 pigs (PIC 337 × Camborough), initially 5.6 kg, were used, with 9 replicates per treatment. The basal Zn level of 100 mg/kg was from organic source, while the added level of 2,900 mg/kg was from Zn oxide. The different added Zn levels were fed from d 0 to 20, whereas the different Met sources were fed throughout the experimental period (d 0 to 44). Pigs were weighed and feed disappearance measured to calculate ADG, ADFI, and G:F. Data were analyzed with SAS MIXED procedure. There was no evidence (P > 0.10) for Met × Zn interactive effects. From d 0 to 20, pigs fed DL-Met had a tendency (P < 0.10) for higher ADG and BW. Pigs fed 3,000 mg/kg added Zn had higher (P < 0.05) ADFI, ADG, and BW. From d 20 to 44, there was no evidence for differences (P > 0.10) between Met source. Pigs previously fed 100 mg/kg added Zn had improved (P < 0.05) ADFI and ADG. Overall (d 0 to 44), pigs fed DL-Met had a tendency (P < 0.10) for higher ADG and final BW. No evidence for differences (P > 0.10) was observed between pigs fed 100 or 3,000 mg/kg added Zn. In conclusion, pigs fed DL-Met tended to have improved performance. Feeding 3,000 mg/kg added Zn improved performance until d 20, but no differences were observed in the overall nursery period.
122 Nutrient digestibility of heat pretreated or multienzyme treated corn whole stillage for pigs
Authors: Jerez-Bogota Kevin , Woyengo Tofuko A
Published: November 2020

A study was conducted to determine standardized ileal digestibility (SID) of amino acids (AA) and net energy value (NE) for pigs of heat-pretreated or enzyme-predigested corn whole stillage (WS; slurry material that is dried into DDGS). Ten ileal-cannulated barrows (initial BW = 65.6 ± 3.5 kg) were fed 5 diets in a replicated 5 × 5 Latin square design. The diets were cornstarch-based, containing corn DDGS, untreated WS (C-WS), heat-pretreated WS (Heat-WS) or enzyme-predigested WS (Predigested-WS), and N-free diet. Digestibility of AA in feedstuffs was determined by the direct method. Energy digestibility in feedstuffs was determined by difference from the N-free diet. The WS was heat pretreated at 140 °C and 70 psi for 15 min. Predigestion of the WS was achieved by incubating with multienzyme that supplied xylanase, celullase, α-galactosidase at 2.4, 2.0 and 2.3 mg per gram of WS, respectively, for 12 h at 55 °C. On DM basis, DDGS, C-WS, Heat-WS, Predigested-WS contained 32.8, 30.8, 28.18, and 39.7% CP, 39.8, 51.0, 52.2 and 53.8% NDF, and 4.5, 4.6, 5.7 and 4.5% EE, respectively. The SID of Lys for C-WS (75.5%) was greater (P < 0.05) than that for C-DDGS (67.4%) and Heat-WS (53.9%), but lower (P < 0.05) than for Predigested-WS (84.1%). The NE value for C-WS (2,793 kcal/kg) did not differ from that of C-DDGS (2,668 kcal/kg DM). The NE value for C-WS was greater (P < 0.05) than that for Heat-WS (1,834 kcal/kg DM) and lower than that for Predigested-WS (2,814 kcal/kg DM). In conclusion, enzymatic predigestion of WS increased its SID of Lys and NE value, and hence it can be an attractive technology to increase the nutritive value of corn DDGS for pigs. Heat pretreatment reduced SID of AA and NE values of the WS.
117 Functionality of a novel consensus bacterial 6-phytase variant in enhancing phosphorus digestibility in gestating and lactating sows
Authors: Velayudhan Deepak , de Grave Xandra Benthem , Waller Katie , Marchal Leon , Dersjant-Li Yueming
Published: November 2020

Two experiments were conducted to determine the efficacy of phytase on apparent total tract digestibility (ATTD) of phosphorus (P) in gestating and lactating sows. In Exp. 1, a total of 40 sows (parity 2–6) at d 78 of gestation were randomly assigned, based on parity, over 4 experimental diets. In Exp. 2, 40 sows (parity 2.0–6.0) at d 4 of lactation were randomly assigned based on parity, over 4 experimental diets. Both studies had a positive control (PC) diet with adequate levels of calcium (Ca) and digestible P (6.5 and 2.5 g/kg and 7.0 and 3.2 g/kg for gestation and lactation diets, respectively), a negative control (NC) diet with low Ca and digestible P levels (5.0 and 1.0 g/kg and 5.0 and 1.5 g/kg for gestation and lactation diets, respectively), and NC supplemented with a novel consensus bacterial 6-phytase variant (PhyG) or a commercial Buttiauxella sp. phytase (PhyB), both at 500 FTU/kg. Diets were corn, soybean meal and sunflower meal based (phytate P of 3.0 g/kg) with restricted feeding during gestation and ad libitum during lactation. In both studies, fecal samples were collected after an adaptation of 14 d on 4 successive days to determine ATTD of P. Data were analyzed using ANOVA, treatment mean comparison using Tukey test using JMP 14. In addition, data from the Exp. 1 and 2 were pooled to further investigate their combined effect, using trial as random effect. In both studies, supplementation of both phytases improved (P < 0.05) ATTD of P vs NC. With data combined from two trials, sows fed PhyG showed greater (P < 0.05) ATTD of P when compared those fed PhyB. In conclusion, PhyG at 500 FTU/kg showed a greater ATTD of P in sows when compared to the PhyB at 500 FTU/kg, when data combined from two trials.
134 Effects of Aspergillus oryzae prebiotic on in vitro digestibility and fermentability of fibrous ingredients and diets
Authors: Zhu Jinlong , Jang Jae-Cheol , Shurson Gerald C , Whitacre Lynsey , Ipharraguerre Ignacio R , Urriola Pedro E
Published: November 2020

It has been an increasing interest to develop strategies to improve utilization of fibrous ingredients in swine. The objective of this study was to determine the effects of an Aspergillus oryzae prebiotic (AOP, Amaferm®) on in vitro digestibility and fermentability of energy and dry matter using a 3-step in vitro enzymatic digestion and fermentation. Three diets were formulated based on corn-DDGS (DDGS), rice bran (RB), and wheat middlings (WM). During in vitro hydrolysis and fermentation, 0.05% AOP was added to the diets (DDGS+AOP, RB+AOP, and WM+AOP) and sole ingredients. Each 2-g sample was hydrolyzed for 2 h with pepsin and for a subsequent 4 h with pancreatin. Hydrolyzed residues were filtered, washed, dried, weighed, pooled within the same sample, and used for subsequent fermentation using swine fecal inoculum. Volume of gas produced was recorded at 11 time points during 72 h of incubation. Parameters of gas production kinetics were calculated using a nonlinear monophasic model, and differences among treatment groups were compared using a mixed model. Supplementation of AOP increased (P < 0.05) in vitro digestibility of gross energy (IVDGE) and dry matter (IVDDM) in the diets and AOP tended to increase (P = 0.06) dry matter fermentability of the diets. Supplementation of AOP during fermentation did not (P > 0.1) affect maximum gas production in ingredients or diets. AOP decreased the half-time to asymptote (T/2) in the ingredient of DDGS+AOP compared with that of DDGS and increased the fraction rate of degradation at T/2 in the diet of RB+AOP compared with that of RB. In conclusion, supplementation of AOP increased energy and dry matter digestibility of the diets during in vitro hydrolysis and modified gas production kinetics during in vitro fermentation and the effects were dietary- and ingredient-type dependent.
140 Effect of hCG on the last day of the 5-d CIDR-Synch and/or on day 5 of the estrous cycle on luteal dynamics in recipient Holstein heifers
Authors: El Azzi Marcelo Siqueira , Galvan Everardo Anta , Arciniega Teresita Valdes , Leão Iago , Sala Rodrigo , Fosada Meliton , de Souza José , Martins Joao Paulo N
Published: November 2020

The objective was to determine the effect of hCG (3,300 IU) administered on days 0 and/or 5 of the estrous cycle on total luteal area (TLA) and circulating concentrations of progesterone (P4) in recipient heifers. All heifers (n = 232; BCS = 3.3 ± 0.2) were synchronized with a 5d CIDR-Synch protocol (d-8: used CIDR inserted; d-3: CIDR removed and PGF2α treatment; d0: 100µg GnRH or hCG). Heifers were randomly assigned to four treatments: control, hCGd0, hCGd5, and hCGd0&5. Controls were treated with GnRH on d0, while hCGd0 received hCG on d0. hCGd5 heifers were treated with GnRH on d0 and hCG on d5, while hCGd0&5 received hCG on d0 and 5. Ovaries were scanned by ultrasound on d0, 5, and 12. Blood was collected on d0, 5, 7, and 12. Synchronization rate (94%) did not differ (P = 0.94) by treatment. Treatment differences were only tested in synchronized heifers (n = 218). Proportion of heifers with 1 or 2+ CL on d5 did not differ (P = 0.10) for hCG d0 treatments (hCGd0 + hCGd0&5) vs. GnRH d0 treatments (controls + hCGd5). However, heifers treated with hCG on d0 had greater (P < 0.01) TLA and P4 on d5 vs. treatments with GnRH on d0 (311 ± 13 vs. 257 ± 9 mm2; and 2.39 ± 0.15 vs. 1.90 ± 0.09 ng/mL). Ovulation rate for d5 hCG did not differ (P = 0.63) for hCGd5 vs. hCGd0&5 (93 vs. 84%). Controls had the lowest serum P4 on d7 and 12. In contrast, hCGd0&5 had the highest serum P4 on d7 (Table 1). Serum P4 on d7 did not differ for hCGd0 vs. hCGd5. On d12, serum P4 and TLA were not different for hCGd5 vs. hCGd0&5. These data indicate that hCG can be used on d0 to induce an increase in serum P4 on d5 compared to GnRH. However, only heifers treated with hCG on d5 achieved mean serum P4 > 8ng/mL.
375 Economic Consequences of Pregnancy Loss in Beef Cattle
Authors: Mercadante Vitor R G , Dias Nicholas W , Timlin Claire L , Pancini Stefania
Published: November 2020

Over the last four decades, several advances in reproductive biotechnologies have helped beef producers improve genetic traits of their cattle, tighten the breeding season and shorten the calving season, leading to an increase in overall profitability of cow-calf production systems. However, even with these advancements, reproductive failure and embryo mortality are still a major cause for economic loss in beef production. Recently, we projected a loss of $6.25 per exposed cow for every 1% decrease in pregnancy rate, with an estimated gross loss of $2.8 billion annually in the United States due to pregnancy failure in beef females. It is estimated that 75 to 80% of embryonic loss occurs by d 20 of gestation; a large portion of these losses occur during the first week of gestation and likely are caused by issues relating to fertilization failure, incompetence of embryos originated from poor quality oocytes and suboptimal uterine conditions. Furthermore, within the first month of gestation, nearly half of all cows submitted to breeding will not be pregnant 30 d later, and another 5% will lose their pregnancy by d 100 of gestation. In addition, breeding related costs, including bull purchase, breeding soundness exam, estrous synchronization, semen purchase, labor associated with artificial insemination and pregnancy diagnosis, are estimate at $65 per cow exposed. Assuming a 90% pregnancy rate at the end of the breeding season, and a scenario where all 30 million beef females in the U.S. are exposed to fixed-time artificial insemination and undergo one pregnancy diagnosis, the added lost revenue of not producing a live calf to sell at weaning and the cost of breeding, would represent a loss of over $21 billion annually in the United States. Strategies that reduce pregnancy loss in beef cattle are essential to improve productivity and profitability of cow-calf production systems.
169 Investigating relationships between weather variables and dry matter intake of beef cattle in feedlot
Authors: Fernandes Arthur Francisco Araujo , Dorea Joao R , Amaral Thais B , Rosa Guilherme J M
Published: November 2020

Currently, the amount of feed delivered daily in feedlots is based on the previous day’s consumption and the estimated animal growth. Nevertheless, factors such as weather variables may influence feed consumption. The objective of this study was to evaluate the effect of weather on dry matter intake (DMI) in beef cattle finished in a commercial feedlot facility in South America. A total of 8.388 animals (Nellore and crossbreed Nellore x Angus) divided across 55 pens were evaluated from July 2018 to April 2019. The animals entered the feedlots with average body weight (BW) of 337 ± 28 kg and had a harvest BW of 517 ± 33 kg, with an average of 125 ± 25 days in feedlot. Daily feed consumption in each pen was estimated by subtracting any morning leftover feed from the total feed amount delivered on the previous day. Data on 16 weather variables for the farm location (latitude and longitude) was acquired using the Dark Sky API and processed in R. The weather variables were clustered via hierarchical cluster into groups given by: G1) humidity, cloud cover, and precipitation; G2) dew point, temperature (max, min, apparent max and apparent min), and day length; G3) atmospheric ozone and pressure; G4) UV index and visibility; G5) wind speed and gust; and G6) moon phase. Variables in G3 were positively correlated with DMI, while G2 and G4 presented negative correlations. The most important correlations were for day length (r = -0.74, P < 0.01), apparent max temperature (r = -0.65, P < 0.05), dew point (r = -0.65, P < 0.05), ozone (r = 0.62,P < 0.05), and pressure (r = 0.61, P < 0.05). In conclusion, several weather variables presented potential as candidate for the development of predictive models of DMI of beef cattle in feedlots.
170 Effects of Dietary Phytogenic Supplementation to a Finishing Diet on Intake, Digestibility, Nitrogen Balance and Carcass Measures
Authors: Althaber Colton A , Coffey Ken , Caldwell James D , Pruden Michael C
Published: November 2020

Dietary manipulations to include tannins can change the proportion and amount of nitrogen (N) excreted in the urine and feces as well as improve N-use efficiency in ruminants. Our objective was to determine the effects of different levels of phytogenic supplementation (Actifor®) on intake, digestibility, carcass measures, and N balance of lambs offered a corn-based finishing diet. Twenty-six lambs (31.5 ± 5.39 kg BW) were allocated randomly to 1 of 3 corn-based finishing diets (85% concentrate) that were offered for ad libitum consumption. Lambs were housed individually in 1 × 1.5-m pens with plastic-coated grate flooring (n = 18; 6/trt) or 1.5 × 4.3-m pens with rubber mat flooring (n = 8; 2 or 3/trt). Diets were not supplemented or supplemented with 4 or 8 g/d of Actifor® (n = 8, 9, and 9 lambs/trt, respectively). A 7-d total fecal and urine collection period (n = 6 lambs/trt) began on d 43. On d 50, rumen samples were taken at 0800, 1100, and 1400 h for measurement of pH and VFA concentrations. Data were analyzed using the MIXED procedure of SAS, and orthogonal linear and quadratic contrasts were used to assess phytogenic supplementation level effects. Intake and digestibility of DM and OM were not different across treatments (P ≥ 0.32). Average fecal N and lamb shrink before slaughter increased linearly (P ≤ 0.05) with increasing levels of phytogenic supplementation. Propionate and acetate:propionate decreased (P ≤ 0.05) and acetate, valerate, and pH tended to increase quadratically (P ≤ 0.08) with increasing phytogenic inclusion. Back-fat and yield grade tended (P = 0.06) to decrease linearly and dressing percentage tended (P = 0.06) to decrease quadratically with increasing phytogenic inclusion. Phytogenic supplementation increased average fecal N and improved some carcass measures, but did not affect diet digestibility.
159 Effect of ionophore, implant, and beta-adrenergic agonists on key indicators of sustainable beef production
Authors: Baber Jessica , Sawyer Jason T , Holland Ben , Karr Kendall , Word Alyssa , Wickersham Tryon
Published: November 2020

Net protein contribution (NPC) of the beef value chain has been evaluated and it has been demonstrated that the beef value chain positively contributes to NPC; however, the specific role of growth-enhancing technologies has not be evaluated. To compare effects of technology on NPC baseline, performance data from 8 commercial feedlots located in the Texas panhandle (n = 6) and Kansas (n = 2) were used to create 8 scenarios: 1) no technology (NT), 2) ionophore (ION), 3) implant (IMP), 4) beta-agonist (B), 5) ionophore and implant (ION+IMP), 6) ionophore and beta-agonist (ION+B), 7) implant and beta-agonist (IMP+B), and 8) ionophore, implant and beta-agonist (I+I+B). An IMP×B interaction was observed for human-edible protein conversion efficiency (HePCE) and NPC (P ≤ 0.03). Implants and beta-agonists increased HePCE and NPC compared to NT (P < 0.01), and IMP+B was greater than combined effects of IMP and B. Ionophore scenarios had greater HePCE and NPC compared to NT (P < 0.01). Interactions for ION×IMP and IMP×B were observed for NPC of beef value chain (P < 0.03), but an ION×B interaction was not observed (P = 0.07). All technology scenarios were lower than NT for NPC (3.21 vs 3.74, respectively; P < 0.01) because HePCE for the beef value chain was reduced when cattle were fed longer in the technology scenarios. Interactions for ION×IMP, IMP×B, and ION×B were observed for enteric CH4 production feedlot cattle (P ≤ 0.03), and a three-way interaction was observed for enteric CH4 production of the beef value chain (P < 0.01). All technologies reduced enteric CH4 produced per kg of HePg compared to NT (P < 0.01). Net protein contribution should be balanced with other indicators of sustainability for a representative understanding of technology impacts on sustainable beef production.
181 Evaluation of mixer performance in cattle finishing diets with 15 or 30 percent dry matter basis inclusion of corn silage
Authors: Buckhaus Elizabeth M , Smith Zachary K
Published: November 2020

Batch fraction (BF), corn silage inclusion level (DIET), and mixing duration (DUR) were evaluated in an experiment using finishing diets based on corn silage and a blend of dry-rolled (DRC) and high-moisture corn (HMC). A 2.35 m3 horizontal mixer was used to manufacture all diets. The experiment was designed as a 5 x 2 x 2 factorial arrangement with nine replications per simple treatment mean. Factors included: 1) BF (n = 5), 2) DIET (n = 2) containing (DM basis) 15% corn silage or 30% corn silage replacing the corn blend, and 3) DUR (n = 2) of 20 or 25 mixer revolutions. Diets contained corn silage, a 1:1 ratio of DRC:HMC, a liquid supplement (5% DM inclusion), and a meal supplement (7% DM inclusion). Data were analyzed as a completely randomized design using the GLIMMIX procedure of SAS 9.4 (SAS Inst., Inc., Cary, NC) using a multinomial approach. The Penn State Particle Separator was used to separate fractions of the total mixed ration (TMR) with special interest on the portion of the TMR retained on the 19 mm sieve. No interactions between BF, DIET, and REV were detected (P ≥ 0.44). There was a 53.5% increase (P = 0.01) in retention on the 19 mm sieve from the first BF (first 20% of the TMR unloaded from the mixer) compared to the last BF (last 20% of the TMR unloaded from the mixer). The LOW diet had 71.3% decrease (P = 0.01) in retention on the 19 mm sieve (2.13 vs. 7.43 ± 0.220%) compared to the HIGH diet. Increasing DUR from 20 to 25 revolutions had no appreciable influence (P = 0.23) on particles greater than 19 mm. These data indicate that BF fed could alter dry matter intake, dietary net energy content, and influence daily gain.

Wednesday, July 22, 2020
177 Development of Feasible Pre-Conditioning Programs for Limited Resource Cow-Calf Producers in North Florida
Authors: Elder Kasey A , Gay Colby , Hernandez Raymond , Coble Derrick J , Odhiambo John F
Published: November 2020

Cost-effective calf pre-conditioning programs utilizing high-quality pastures and minimal grain supplements can improve net returns of limited-resource cow-calf operations. The objective of the study was to evaluate the feasibility of utilizing two different supplements in a forage-based 45-day pre-conditioning program. Twenty-one Angus-cross calves averaging 6 months of age were assigned randomly at weaning to two groups based on sex and initial body weights: commercially available complete feed, 16% crude protein (Group 1), and corn-mineral mix, 10% crude protein (Group 2, Control). Calves were backgrounded on natural pastures that were predominantly Bahia grass and acclimated to the feeds for 2 weeks prior to the start of the actual trial. Supplementation rates for both groups were maintained at 1.0 lb./150 lb. calf BW equivalent to 2.0 lbs./calf/day. Groups were rotated among pasture plots weekly depending on forage availability. Calves were weighed at 2-week intervals during the study. Data were analyzed by analysis of covariance using GLM methods of SAS. No differences were observed among groups in calf BW gain (P < 0.74) and net returns (P < 0.92). Initial calf BW were 357.2 ± 15.2 vs. 370.9 ± 16.6 lbs., whereas final BW were 398.2 ± 17.2 vs. 408.6 ± 20.1 lbs., for groups 1 and 2, respectively. Thus, average weight gains were 41.0 vs 37.7 lbs., for groups 1 and 2, respectively (Table 1). Feed costs were $17.97 vs. $16.97 for groups 1 and 2, respectively culminating in a $0.44 vs. $0.45 cost per lb. of gain, respectively. The current market price of a 400 lb. calf at the North Florida Livestock market averages $1.39/lb. Therefore, pre-conditioning calves using complete feed provides a $0.95/lb. return, whereas using corn-mineral mix returns a profit of $0.93/lb. Therefore, the corn-based supplement compared favorably to the commercially available complete feed in this system.
182 The effect of previous lactation milk production on twinning prevalence in US dairy cows
Authors: Schambow Rachel , Bennett Thomas B , Dopfer Dorte , Martins Joao Paulo N
Published: November 2020

The present study aimed to identify associations with previous lactation production on twinning prevalence in US dairy farms using data comprising over 7.9 million dairy calving and production records from 827 herds between 2001 and 2020. Inclusion criteria were breed (Holstein, Jersey, dairy and mixed cross), herd size (> 50 calvings/year), and 305-d milk production > 3,182 kg (7,000 lbs). Cows without previous production information or calving date were removed from the final data set, including all first lactation cows. Parity was grouped into 2 and 3+. Final data included n = 2,894,163 records from 2009 to 2020 from 577 herds in 24 states with average herd size from 50 to 14,948 calvings/year. Data were analyzed by logistical regression using the GLIMMIX procedure of SAS with herd within state as random effects. Absolute 305-d milk production from each cow’s previous lactation, parity, breed, calving month, year, calving interval (CI), and interaction terms of production by parity, production by breed, CI by parity, and CI by breed were used as predictors for next lactation twinning prevalence. All fixed effects were significantly associated with the outcome (P < 0.001). Twinning prevalence was increased for higher levels of milk production within parity 2 and 3+ (OR: 1.067, 1.064; CL: 1.057–1.078, 1.054–1.075), and within Holstein, Jersey, mixed crossbreed, and dairy crossbreed (OR: 1.042, 1.068, 1.085, 1.07; CL: 1.038–1.046, 1.053–1.082, 1.056–1.114, 1.051–1.09). Parity 3+ had increased twinning compared to parity 2 (OR: 1.497; CL: 1.478–1.517). Holsteins had increased twinning compared to Jerseys (OR: 1.466, CL: 1.394–1.542). Year showed no clear trend. Twinning was increased for calving in spring/summer (April-September) with peak in June and July (OR: 1.377, 1.374; CL: 1.346–1.409, 1.344–1.405), correlating to conception months of September and October. These data can be instrumental to guide research focus and producer decisions to reduce twin births in lactating dairy cows.
163 Investigating relationships between life history events, carcass quality and price of cull dairy cows sold through auction markets
Authors: Moreira Ligia da Cunha , Passafaro Tiago Luciano , Rosa Guilherme J M
Published: November 2020

Cull dairy cows comprise almost 10% of the national beef production in the United States and contribute with an important additional income source for farmers. However, cull dairy cows present high variation due to many reasons, which affect live animal characteristics, carcass traits, and market price. The objectives of this study were 1) to assess relationships between price and carcass quality of cull dairy cows sold through auction market, and 2) to investigate the effect of animal life history events on price, as an indicator of carcass quality. Data from four dairy operations in Wisconsin included 3,375 cull dairy cow records during the period of 2015 to 2019. Life history events data were collected from Dairy Comp software; live weight and price were obtained periodically from an auction barn, and the carcass data were provided by a local packing plant. Price ($/cwt) and adjusted price (price divided by the national average price) were the two outcome variables. Canonical correlation analysis (CCA) and multiple linear regression were used to investigate the relationship between variables. On average (standard deviations within parenthesis), live weight was 701.54kg (123.15kg), carcass weight of 324.97kg (68.92), dressing of 46.26% (4.92%), and price of $56.98/cwt (5.57$/cwt). CCA between adjusted price and carcass quality traits was 0.76, indicating that price is a good indicator of carcass quality. Lactation number, culling reason, month, and year of sale drastically affect price (R2 0.7532) and adjusted price (R2 0.4706). Higher live weight and days open led to higher adjusted price, and longer days dry and high milk production decreased price ($/cwt). A large variation between farms was noted. In conclusion, culling and marketing decisions should consider these factors, as an attempt to increase the price received for cull cows, and ultimately improve carcass quality.