bluuebunny/crossref_metadata_2025 huggingface dataset:
388 Effects of maternal nutrient restriction during late gestation on pre-pubertal beef calf testis size and histology
Authors: Redifer Colby A , Wichman Lindsey G , Meyer Allison M
Published: September 2024

Fall-calving Hereford-SimAngus heifers [single-sired; body weight (BW): 451 ± 28 (SD) kg; body condition score (BCS): 5.4 ± 0.7] bred to a single sire were individually-fed 100% (control; CON; n = 12) or 70% (nutrient restricted; NR; n = 13) of estimated metabolizable energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to calving. Post-calving, all females were fed to meet lactational nutrient requirements until weaning. From d 1 to 147 of lactation, dams were individually fed chopped tall fescue hay and supplemented in Calan gates to constrain diets of calves to milk only. After d 147, dams and calves were managed as a group in drylots, and calves could access the tall fescue hay offered to their dams. Bull calves (CON; n = 8; NR; n = 9) were castrated at 176 ± 3 (SD) d of age to represent a later pre-pubertal growth stage that is indicative of post-pubertal testis size. The epididymis and pampiniform plexus were removed, and calipers were used to determine the length and perpendicular widths of each testis. Testis weight was recorded, and testis volume was determined by water displacement in a graduated cylinder. Testis parenchyma was fixed in neutral buffered formalin for histological analyses. Seminiferous tubule diameter was measured on perpendicular diameters of 40 randomly chosen tubules with a visibly round cross-section. Data were analyzed with late gestational nutritional plane and calving date as fixed effects. Birth weight of bull calves was not affected (P > 0.99), but we previously reported that late gestational nutrient restriction decreased (P ≤ 0.04) milk production by 15% during the first 147 d of lactation. By d 63 of age, bull calves born to previously NR dams weighed less (P = 0.03) than bull calves born to CON dams. Body weight remained different (P ≤ 0.04) until castration, at which point bull calves born to previously NR dams weighed 14% less (P = 0.02) than bull calves born to CON dams. Average testis diameter was less (P = 0.03), and average testis length tended to be less (P = 0.07) for calves born to previously NR dams. Paired testes weight and volume were less (P ≤ 0.05) for calves born to previously NR dams, but testes weight relative to calf BW and average seminiferous tubule diameter were not affected (P ≥ 0.20) by late gestational nutritional plane. In the current study, pre-pubertal bull calves born to NR dams had decreased testis size, but it is difficult to delineate if this is a direct effect of gestational undernutrition on fetal development or its indirect effect on post-weaning development due to decreased milk production.
458 Advanced computing and information technology to address challenges in livestock production
Authors: Tulpan Dan
Published: September 2024

Advanced computing and information technology have a crucial role in addressing challenges in livestock production by offering innovative solutions to improve efficiency, productivity, and animal welfare. These technologies rely on intelligent combinations of data analytics, Machine and Deep Learning (ML, DL), Internet of Things (IoT), and robotics solutions. In livestock production, advanced computing facilitates the collection, management, and analysis of vast amounts of data generated from various sources such as sensors, wearable devices, and monitoring systems. This data can provide insights into animal behavior, health status, production, and environmental conditions, enabling farmers to make informed decisions in real-time. Machine learning algorithms can build data-driven models able to predict disease outbreaks, optimize feed formulations, and identify patterns for better breeding selection. IoT devices can monitor environmental parameters like temperature, humidity, and air quality, ensuring optimal conditions for animal comfort and health. Robotics technologies can automate tasks such as feeding, milking, and cleaning, reducing labor costs and improving efficiency. Additionally, advanced computing enables the development of virtual modelling and simulation tools to test different scenarios and optimize production processes without the need for extensive physical experimentation. This presentation will focus on various technical aspects and examples related to leveraging advanced computing and information technology such that livestock producers can enhance productivity, minimize resource wastage, and promote sustainable practices, ultimately leading to improved profitability and animal welfare in the industry.
60 Effects of a calcareous marine algae on dry matter intake, water intake, rumen temperature, rumen pH and average daily gain of grain-fed steers during a heat wave
Authors: Sammes Stephanie L , Gaughan John B , O’Connell Shane , Lees Angela
Published: September 2024

During summer, feedlot cattle are often subjected to multiple high heat load events which can cause heat stress and negatively impact on cattle performance and well-being. The objective of this study was to evaluate the effects of different dietary buffering feeding strategies, on dry matter intake (DMI), water intake (WI), rumen temperature (TRUM), rumen pH and average daily gain (ADG) of grain-fed beef steers exposed to a simulated heat wave event. Angus steers [n = 12; body weight (BW) = 582 ± 8.92 kg] were housed within climate control rooms for 21 d and randomly allocated into one of three dietary treatments (4 steers/treatment): 1) Treatment 1 (T1), finisher diet; 2) Treatment 2 (T2), transitioned from finisher to heat load diet (HLD) on d 4 and fed HLD until d 16; 3) Treatment 3 (T3), fed finisher and supplemented with a calcareous marine algae (CMA; Acid Buffer, Celtic Sea Minerals) on d 4 until d 16. On d 17, T2 and T3 transitioned back to the finisher. Days were split into three phases consisting of i) d 0 to 6 [PI, Temperature Humidity Index (THI), THI 65-78]; ii) d 7 to 11 (PII, THI 83-87); iii) d 12 to 20 (PIII, THI 65-78). Data were analyzed using a repeated measures model, with a first order auto-regressive error structure, including fixed effects for treatment, phase, day and hour, with animal ID as a random effect. Body weight declined (P < 0.005) during PII, with steers losing on average, 17.65 ± 3.06 kg BW/steer (T1), 12.30 ± 3.06 kg BW/steer (T2) and 16.20 ± 3.06 kg BW/steer (T3) at conclusion of PII, with muscle atrophy visually evident (Table 1). There were no effects (P ≥ 0.93) for treatment on ADG. During PII, DMI decreased (P < 0.005), with T2 and T3 having >2kg DMIּ steer-1ּ d-1 greater (P ≤ 0.006) DMI compared with T1. During PIII, T1 maintained decreased (P ≤ 0.001) DMI compared with T2 and T3. During PII, mean WI increased (P ≤ 0.05) for T1 and T3, although remained unchanged (P = 0.11) for T2, TRUM increased (P < 0.0001), whilst range in TRUM decreased (P ≤ 0.01) for all TRT and rumen pH for T2 and T3 decreased (P ≤ 0.0003), whilst T1 tended (P ≥ 0.05) to decrease. Rumen pH diurnal rhythms were disrupted during PII, range in rumen pH also reduced (P < 0.0001) for T1 and T3, remaining unchanged (P = 0.94) for T2. Mean rumen pH was lower (P ≤ 0.002) during PIII compared with PI for all treatments. Both T2 and T3 had a lower (P ≤ 0.05) range in rumen pH than T1 during PIII. Data from the current study suggest that feeding strategies to include CMA may aide in moderating DMI reductions observed during and post-heat stress periods, whilst also reducing the range in rumen pH during post-heat wave conditions when rumen dysfunction challenges may present.
64 Effects of alternative finishing methods on performance and carcass quality of beef feeder steers
Authors: Johnson Michelle , Gruber Cody , Shelton Cody , Jones Richard C , Gourley Grayson , Rivera Daniel , Vierck Kelly R , Rivera Daniel
Published: September 2024

There has been an interest in directly locally marketing finished beef end products in Arkansas; however, most beef operations do not have the infrastructure to finish cattle conventionally. The objective of this study was to evaluate two non-traditional finishing methods (pasture-based with supplement) compared with a conventional finishing method on live performance and carcass quality of feeder steers. Crossbred beef steers (n = 63; 363.9 ± 28.7 kg) were blocked by body weight (BW) and assigned to pens (n = 3 steers/pen) with 7 pens randomly allocated to each treatment: conventional feedlot finishing diet with roughage included in the ration (FDLT); high starch supplement fed at 2 to 2.25% of BW with ad libitum access to bermudagrass pasture (STCH); or high by-product supplement fed at 2-2.25% of BW with ad libitum access to bermudagrass pasture (BYPD). Steers were fed their respective diets once daily and weighed on d 0, 28, 56, 84, 112, 140, and 161. Once cattle reached their targeted endpoint, they were transported to and harvested at a commercial slaughter facility in Arkansas City, Kansas. Carcass data were collected including hot carcass weight (HCW), preliminary yield grade (PYG), yield grade (YG), quality grade (QG), dressing percentage (DP), and final carcass value. Data were analyzed using PROC GLIMMIX and MIXED (SAS 9.4); pen was the experimental unit, treatment was a fixed effect, and block was considered a random effect. Cattle fed FDLT and BYPD had a greater BW on d 84, 112, and 140 (P ≤ 0.02) and greater overall carcass-adjusted BW (P = 0.03) compared with STCH. Average daily gain (ADG) was greater on d 84 (P = 0.03) for FDLT compared with STCH and BYPD. Overall carcass-adjusted ADG tended (P = 0.09) to be greater for FDLT and BYPD compared with STCH. As expected, cattle fed FDLT had greater dry matter intake (DMI) compared with STCH and BYPD for the entire study (P ≤ 0.0005). Both STCH and BYPD had a more efficient feed-only feed conversion on d 28, 56, 112, 140, and 0-161 (P ≤ 0.05) and were more economical (P < 0.0001) than FDLT. In this study, cattle fed BYPD were more profitable (P ≤ 0.04) compared with STCH and FDLT. Hot carcass weight tended (P = 0.13) to be greater and final carcass value (P = 0.01) was greater for BYPD and FDLT compared with STCH. No differences (P ≤ 0.78) were noted for PYG, YG, QG, or DP. Data from this study suggests feeding supplemental diets to beef cattle grazing pasture could successfully be used as an alternative finishing method without affecting carcass quality.
183 Comparison of presynchronization and OvSynch protocols following fixed-time breeding in lactating dairy cattle
Authors: SHAHZAD Abid Hussain , Blouch Raafia Safdar , Abbas Shaista , Muhammad Sayyed Aun , Anwar Irem , Abbas Ali , Abbas Mazhar
Published: September 2024

Current study was carried out to compare two presynch-OvSynch protocols with standard OvSynch protocol in postpartum Holstein dairy cattle. Postpartum cows (n = 473) were randomly divided into one of the three protocols: I) G7G-OvSynch (n = 159), cows were subjected to PGF2α followed by GnRH 48 h later. After 7 d post-GnRH injection, standard OvSynch protocol was introduced, II) G7GM-OvSynch (n = 162), cows were subjected to the same protocol as in group I) except one extra PGF2α at 12 h interval in Ovsynch part, and III) standard OvSynch protocol (n = 152). The progesterone (P4) profile was subjected to d 30 and d 60 post FTAI. Ovarian status was monitored at the 1st GnRH, PG, and 2nd GnRH injection of the breeding part. Pregnancy/ AI was diagnosed on d 30,60, and 90 post-FTAI, and pregnancy loss was also on d 60 and 90 post-FTAI. Pregnancy data were analyzed using the Chi-square test and plasma P4 profile by ANOVA using SAS. Ovulatory follicle diameter (mean ± SD) was 15.44 ± 1.24 in G7G-Ovsynch, 15.21 ± 1.36 in G7GM-OvSynch, and 14.90 ± 1.02 in OvSynch, respectively (P > 0.05). Plasma P4 profile (ng/mL; Mean ± SD) on d 30 post TAI was 6.50 ± 1.39,7.01 ± 1.13 and in 6.49 ± 1.32 G7G-OvSynch, G7GM-Ovsynch and OvSynch groups, respectively (P = 0.09). On d 60 post TAI, P4 profile was recorded to be 7.75 ± 1.20, 7.58 ± 1.36 and 6.80 ± 0.96 in G7G-OvSynch, G7GM-OvSynch and OvSynch, respectively (P < 0.05). P/AI on d 30 was 51.57% (83/159), 57.41% (93/162) and 42.76% (65/152) G7G-Ovsynch, G7GM-OvSynch, and OvSynch, respectively (P = 0.033). Similarly, AI on d 60 and d 90 post FTAI was 44.65% (1/159):51.85% (84/162), 38.16% (58/152): 43.40% (69/159) and 51.23% (83/162):36.18% (55/152) in G7G-Ovsynch, G7GM-OvSynch, and OvSynch protocols (P = 0.051: 0.027), respectively. Pregnancy loss on d 60 and d 90 post FTAI was 13.41%: 2.90%, 9.68%: 1.20% and 10.77%: 5.20% in G7G-Ovsynch, G7GM-OvSynch, and OvSynch, respectively (P = 0.73: 0.35). Although statistically non-significant (P = 0.56), overall pregnancy loss on d 90 post-FTAI was also numerically greater in the G7G-OvSynch (15.85%) protocol as compared with G7GM-OvSynch (10.75%) and OvSynch (15.38%). We concluded that the G7GM-OvSynch protocol has resulted in an increased P/AI, P4 profile in comparison with G7G-OvSynch and OvSynch. Similarly, pregnancy loss was also less in the G7GM-Ovsynch protocol, which makes it a protocol of choice for postpartum dairy cows.
184 Effects of cattle hide color and changing environmental conditions at northern latitudes on feeder cattle performance and behavior
Authors: Schlagel Katrina J , DelCurto-Wyffels Hannah , DelCurto Timothy , Van Emon Megan L , Boss Darrin L , Wyffels Sam
Published: September 2024

While suitable research has been done on the influence of climatic conditions on feeder cattle welfare, we have seen limited work done that assesses the relationship of hide color and cattle thermoregulation in response to extreme environmental changes, particularly of those seen at northern latitudes. Specifically, there is limited research on the effects of environmental stressors and cattle hide color on performance and intake. Therefore, the objective of this study is to evaluate feeder cattle performance in response to environmental conditions and hide color. Angus-based yearling steers [n = 40; average body weight (BW) = 409.28 kg were stratified by BW and hide color (red, white, and black) and were randomized into 10 pens at the Northern Agricultural Research Center in Havre, MT. Steers were on trial from 20 February 2023 to 11 July 2023 (141 d) and fitted with an electronic ear tag and adapted to the Vytelle system (Vytelle, Lenexa, KS) for 14 d prior to the start of the study. All 10 pens consisted of two electronic feed bunks equipped with an antenna to detect animal presence, load cells to measure feed disappearance and wireless transfer to a data-acquisition computer. Finishing diet (8.6% CP, 75% TDN) consisted of 69% corn, 21% corn silage, 10% wheat straw, and 0.45 kgּ animal-1ּ d-1 of beef grower pellet with a fortified mineral and vitamin package. Initial and final unshrunk BW were obtained on two consecutive days and averaged. Every 28 d during the experiment, steers were weighed prior to feeding and a measurement of coat depth was taken. Animal surface temperature was recorded via a FLIR E5xt thermal imaging camera on the same day of every week at 0730 h (prior to feeding) and 1330 h (6 h post feeding), for 20 wk. There was no difference in hair depth between the white hided steers and other treatments (P ≥ 0.26). However, there was a treatment effect (P = 0.01) of hide color on cattle surface temperature, with black and red hided steers averaging 2.85°C greater than white hided steers. There was no effect of treatment on average daily gain (P = 0.55) averaging 1.34 kg/d. Additionally, there was no treatment effect on average daily intake (P = 0.36), averaging 10.76 kg per day. There was a treatment effect on gain to feed efficiency (P = 0.05); however, post hoc means separation analysis showed no difference between treatments. In summary, although there were treatment effects on animal surface temperature, they were not reflected in animal performance.
91 Awardee Talk: Using respiration calorimetry to estimate energy balance to estimate energy balance and methane emissions
Authors: Hales Kristin E
Published: September 2024

Understanding relationships between chemical components of the diet and methane production will allow nutritionists to develop formulation strategies to decrease methane emissions. Diets that produce acetate liberate hydrogen that can be used by methanogenic archaea to produce methane. Propionate is a hydrogen sink and diets that lead to increased propionate production decrease acetate and methane production. The objective was to evaluate relationships between methane emissions and dietary chemical components and feed intake using published databases and make diet formulation recommendations that could be used to decrease methane production in finishing beef cattle. A total of 263 treatment mean observations from respiration calorimetry studies with beef cattle and dairy steers and heifers were used to evaluate relationships between methane emissions, dietary chemical components, and feed intake. Among the chemical components evaluated, dietary neutral detergent fiber and starch were strongly related to methane yield. The relationship between dietary ether extract and methane yield was variable and there was no relationship between dietary crude protein concentration and methane yield. Additionally, the ratio of metabolizable energy relative to gross energy intake had a strong relationship to methane yield. Formulation strategies to increase dietary starch and decrease dietary neutral detergent fiber should allow the feedlot industry to decrease enteric methane production.
124 Effects of Saccharomyces cerevisiae and dietary type offered to beef cattle on intake, feeding behavior, nutrient digestibility, and ruminal fermentation
Authors: Dos Reis Beatriz Q Queiroz , Sarturi Jhones O , Silva Kaliu , Karges Kip , Johnson Bradley J , Rodrigues Barbara , Goulais Marie
Published: September 2024

The effects of live yeast and diet type offered to beef steers on intake, feeding behavior, nutrient digestibility, and ruminal fermentation profile were evaluated. Ruminally cannulated beef steers [n = 8; body weight (BW) = 550 ± 20 kg] were used in a duplicated 4 × 4 Latin square design following a 2 × 2 factorial arrangement of treatments: A) presence of live-yeast [Saccharomyces cerevisiae (CNCM I-1077), at 1 × 1010 CFUּ animal-1ּ d-1]; and B) diet type [steam-flaked corn-based grower or finisher diets (ad libitum intake)]. Live yeast was delivered with gel-capsules (0.25 g, as is) twice daily via ruminal-cannula. Four, 35 d periods were used. Feed refusal was subtracted from offered (dry matter basis) to calculate feed intake (DMI). The 24 h feeding behavior assessment was conducted on d 31 by trained personnel (time spent eating, ruminating, chewing, drinking, resting, and meal size/number). A 5-d fecal collection (twice daily) was used for the digestibility assessment. Ruminal pH was continuously measured (7 d, intra-ruminal Dascor wireless data loggers). Ruminal ammonia-N and volatile fatty acids (VFA) were analyzed at 0, 2, 4, 8, 16, and 23 h on d 35. The GLIMMIX procedure of SAS was used with animals as the experimental unit. No live yeast × diet interactions (P ≥ 0.17) were observed. Intake was not affected (P = 0.83) by live yeast, while steers offered the grower diet consumed more (P ≤ 0.01) NDF, ADF, and hemicellulose compared with the finisher diet. Live yeast increased (P ≤ 0.02) the dietary NDF, ADF, and hemicellulose digestibility of the grower diet by 13.7, 12.8, and 14.6%, and on the finisher diet by 6.7, 9, and 6.4%, respectively. Live yeast did not affect (P ≥ 0.23) major feeding behavior activities measured. Steers offered grower diet spent more time (P ≤ 0.01) on each meal, ruminating, eating, and chewing and less time (P < 0.01) resting. Live yeast did not affect (P ≥ 0.81) ruminal pH variables measured. Steers offered the grower diet had a greater (P < 0.01) ruminal pH pattern compared with the finisher diet. The ruminal ammonia-N and volatile fatty acids were not affected (P ≥ 0.16) by live yeast, while steers offered the finisher diet had a greater (P ≤ 0.01) total VFA and propionate molar proportion, while a lower (P ≤ 0.01) ammonia-N and acetate molar proportion compared with the grower diet. Regardless of the diet type, live yeast improved digestibility of fiber fractions, while dry matter intake was unaffected. Grower diets were more prone to stimulate feeding behavior activities than finisher, while live yeast seemed to not affect such variables. Expected effects of diet type on ruminal fermentation were ratified, while live yeast inclusion did not affect the ruminal fermentation variables evaluated.
134 Effects of different feed additives to beef cattle in a commercial feedyard: Productive performance
Authors: Rabelo Lucas S , Pellizzer Sergio E M , Perdigão Alexandre , Carvalho Victor , Acedo Tiago S S , Machado Fernando F , Oliveira Alexandre B , Matos Isabelle E
Published: September 2024

Nellore bulls [n = 22,500; Initial body weight (BW) = 400.39 ± 24.39 kg] were used to evaluate the effects of feeding different additives on growth performance and carcass production by feedlot beef cattle in a commercial feedyard (Fazenda Conforto, Nova Crixás – Goiás, Brazil). Animals were ranked by arrival date, ascending order of BW, number of animals in the pen, and assigned to 5 blocks based on initial BW. The animals within the block were randomly assigned to 102 pens, and pens were assigned randomly to 1 of 2 dietary treatments within block; thus, treatments were replicated in 51 pens. Treatments were arranged in a randomized complete block design, as following 1) MON+VM - Sodium Monensin (MON, 27 mg/kg DM, Elanco Animal Health, Indianapolis, IN), + Virginiamycin (VM, 25 mg/kg DM, Phibro Animal Health Corporation, Guarulhos, São Paulo), and 2) Crina+Hy-D (Crina Ruminants; a blend of essential oils, 90 mg/kg DM + Hy-D;25-hydroxy-vitamin-D3 at 1 mgּ animal-1ּ d-1 (DSM Nutritional Products, Basel, Switzerland). Cattle were fed a high-concentrate diet (R:C; 15:85) for 118 d on average. Data were analyzed using PROC MIXED of SAS and means were separated using the PDIFF statement, adopting P < 0.05. Pen was the experimental unit, treatment was a fixed effect, and block was a random effect, with the Kenward-Roger adjustment included for degrees of freedom. Feeding Crina+HyD increased dry matter (DM) intake by 0.47 kg (10.23 kg vs. 9.76 kg; P = 0.0004), improved average daily gain (ADG) by 0.09 kg (1.58 vs. 1.49 kg/d; P < 0.0001) and final BW weight by 10 kg (586 vs. 576 kg; P = 0.01; Table 1) compared with animals fed MON+VM. In addition, animals fed Crina+Hy-D had heavier hot carcass weight by 8 kg (336 vs. 328 kg; P = 0.002), greater dressing percentage by 0.4 percent points (57.4 vs. 57.0%; P = 0.02), and greater average daily carcass gain by 0.07 kg (1.16 vs. 1.09 kg; P < 0.0001) compared with animals fed MON+VM. Feed efficiency (G:F; ~0.155; P = 0.54) and carcass conversion, calculated as kg of DM per each 15 kg of carcass produced (~133.73 kg; P = 0.63) were similar between the treatments. In conclusion, feeding Crina+Hy-D can be used as a strategy to increase carcass production by feedlot cattle, and to dismiss use of antibiotic and growth promotant usage in diets.
193 Evaluation of in-dwelling pH monitoring technologies
Authors: Weir Colton , Duncan Zach M , Spore Tyler , Corrigan Mark , Titgemeyer Evan C , Ellis William , Hollenbeck William R , Blasi Dale A
Published: September 2024

We compared ruminal pH measurements determined using smaXtec bolus (SMAX; smaXtec Inc., Graf, Austria), Moonsyst bolus (MOON; Moonsyst International, Kinsale, Republic of Ireland), and handheld pH meter (METER; PH8500 pH/mV Meter, Apera, Columbus, OH) over time and during an ex vivo acidosis challenge. Ruminally cannulated heifers (n = 8) were used for 6 consecutive 21-d periods. On d 0, SMAX and MOON were placed in the reticulum of each heifer and continuously measured ruminal pH. On d 20 of each period, ruminal digesta samples were collected prior to feeding and again 2, 4, 6, 8, 12, 18, and 24 h post-feeding pH was measured with METER. MOON yielder lower (P < 0.01) pH measurements compared with SMAX and METER at all time points. From h 0 to 2 post-feeding measurements from SMAX were similar compared with METER (P = 0.54); however, measurements from SMAX tended to be greater 4 h post-feeding (P < 0.07) and differed at all subsequent timepoints (P < 0.05) compared with METER. On d 21 of each period, boli were removed and placed in a pH 4 and pH 7 solution, each for 3 h. In pH 4 solution, MOON pH measurements did not differ (P > 0.39) from 4 from periods 1 to 5; however, pH measured by MOON in period 6 was less (P < 0.01) than 4. Smaxtec pH measurements did not differ (P ≥ 0.39) from 4 during periods 2 to 5 but was greater (P < 0.01) than 4 in period 6. In pH 7 solution, pH measures with MOON did not differ (P > 0.26) from 7 for period 1 and 2 but declined in period 3 and were less than 7 from periods 4 to 6 (P < 0.05). In pH 7 solution, SMAX measurements varied over time and yielded greater (P < 0.05) than 7 for periods 2, 3, and 6. Subsequently, boli were placed in a container of strained ruminal fluid (6.5 L), and pH was measured for 1 h using SMAX, MOON, and METER. Following, 500 mL of vinegar was added to the ruminal fluid to simulate an acidosis challenge, pH was measured and change in pH detected by SMAX and MOON, relative to METER was determined. With change in pH detect by METER considered the true response, MOON provided a better measurement of the pH decrease than did SMAX, particularly during periods 1 to 3 (P < 0.01). Overall, pH measurements differed between SMAX, MOON, and METER. MOON and SMAX pH measurements began to drift after approximately 100 d. MOON was more accurate than SMAX in detecting a change in ruminal pH, whereas pH measurements over time were more precise for SMAX than for MOON.
194 Evaluation of a method to optimize diets of individual dairy cows to maximize income over feed cost
Authors: Innes David , Fieguth Braeden , Kedzierski Patty , Cant John
Published: September 2024

Recent optimization methods have demonstrated the potential to maximize marginal profits in beef (Marques et al., 2020) and dairy (Campos et al., 2023) by optimizing diet formulation. These methods present an opportunity to explore how diets could be optimized for individual dairy cows, such as in a closed-loop precision feeding system. Therefore, our objectives were to 1) compare individual income over feed costs (IOFC), calculated with observed dry matter intake (DMI), milk yield (MY), milk protein and milk fat, with a predicted IOFC for the same diet and cows using the NASEM (2021) model, and 2) optimize the inclusion rate of ingredients in the diet to maximize predicted IOFC. Previously, 20 multiparous (lactation 2 through 4) and 9 primiparous cows, ranging from 22 to 472 d in milk (DIM), were housed in a free-stall pen at the Ontario Dairy Research Centre (Canada) equipped with sensors to record DMI, body weight (BW; walk-over-weight) and body condition score (BCS; DeLavel 3D camera), in addition to daily MY, weekly milk component tests, and 4 X/d respiratory gas exchange measurements (GreenFeed, C-Lock Inc, USA) for estimation of daily energy flows (Kedzierski, 2020). Weekly means for each cow were used to evaluate IOFC in this study (n = 116). Each IOFC was calculated as milk revenue minus total feed cost. Milk revenue was calculated from milk fat, protein and other solids, consistent with pricing on Canadian dairy farms. The observed IOFC was calculated using the observed MY, milk components and DMI, and the same diet formulation and costs for all cows, whereas the predicted IOFC estimated these values using the NASEM (2021) model with all available observed animal inputs (e.g., BW, BCS, DIM). However, the observed DMI and MY had to be provided initially for the model, as the DMI prediction equation requires a target MY, but the prediction of MY requires DMI. Final predicted DMI and MY values were used in the calculation of predicted IOFC. The differential evolution algorithm from the ‘SciPy’ package (v 1.11.4) in python (v 3.12.0) was used to maximize IOFC by adjusting the inclusion of wheat straw, alfalfa silage, corn silage and high moisture corn grain, while fixing minerals to their original proportions. Overall, the concordance correlation coefficient (CCC) indicated moderate agreement (0.62) between the predicted IOFC and observed IOFC and good agreement (0.99) between the predicted IOFC and the optimized IOFC, suggesting the optimization method was able to select diets to meet a similar objective. Results indicate that a strategy is needed to minimize the residual error between predicted and observed values for individual cows, such as algebraic reparameterization of the NASEM model, before using an optimization method to automatically formulate diets.
253 Effect of dietary straw withdrawal in high-concentrate diets on efficiency, carcass performance, rumen characteristics and seized livers in dairy beef crossbred bulls housed with straw bedding
Authors: Llonch Lourdes , Marti Sonia , Verdú Marçal , Riera Joan , Medinya Carles , Cucurull Jordi , Devant Maria
Published: September 2024

The aim of this study was to evaluate the effect of dietary straw withdrawal in high-concentrate diets on efficiency, carcass performance, rumen characteristics and seized livers in dairy beef crossbred bulls housed with straw bedding. Bulls [n = 93; 335 ± 9.0 kg body weight (BW); 218 ± 4.0 d age] were group-housed in 6 straw-bedded pens according to 3 different feeding programs (2 pens/treatment): 1) CTR (n = 32), concentrate (13.1% CP, 5.9% fat content, 16.1% NDF, 40.8% starch content) and straw ad libitum fed in two separate feeders; 2) TSW (n = 32), like CTR, however, dietary straw withdrawal took place the first 84 study days; and 3) NSS (n = 29), concentrate with a reduced starch content (12.2% CP, 4.6% fat content, 22.0% NDF, 39.6% starch content) without dietary straw for the whole study. The study lasted 155 d divided into eleven 14-d periods. Individual concentrate intake was recorded daily, and dietary straw consumption was recorded per pen biweekly, as was individual BW. Carcass performance, rumen characteristics and seized organs were recorded at the slaughterhouse. Data were analyzed with a mixed-effects model. The first period was an adaptation where a dietary straw bale per pen was offered in all treatments; thereafter, only in CTR, and in TSW, after period 6. Treatment by period interactions (P < 0.01) in efficiency parameters were observed. Specifically, BW was greater in CTR than in TSW and NSS bulls while straw withdrawal periods; however, TSW bulls increased BW compared with NSS bulls when dietary straw was reintroduced, with final BW greater in CTR and TSW than in NSS bulls (569, 557 and 536 ± 8.0 kg, respectively). Regarding feed consumption, while dietary straw withdrawal for the first 6 periods, concentrate and straw intake were less in TSW and NSS than in CTR bulls, regardless the type of concentrate; after period 7, concentrate intake did not differ among treatments, and straw intake was greater in CTR and TSW than in NSS bulls, except in period 7, just after dietary straw reintroduction, that was greater in TSW than in CTR bulls. Hot carcass weight was greater (P < 0.01) in CTR than in TSW and NSS bulls (314, 296 and 299 ± 6.0 kg, respectively); dressing percentage was greater (P < 0.01) in CTR and NSS than in TSW bulls (55.1, 55.9 and 53.2 ± 0.65%, respectively); and carcass conformation tended (P = 0.06) to have greater classification in CTR bulls, and reduced classification in TSW bulls. Number of sized livers tended (P = 0.07) to be greater in NSS than in CTR and TSW bulls (22, 3 and 9%, respectively). In conclusion, short and long-term dietary straw withdrawal decreased animal and carcass performance regardless concentrate’s starch content in dairy beef crossbred bulls fed high-concentrate diets housed with straw bedding.
254 Nutrient intake, rumen fermentation and growth performance of Hu sheep fed extruded rapeseed straw as a replacement for peanut vine
Authors: Ma Junnan , Ma Tao , Tu Yan
Published: September 2024

The objective of this study was to investigate the effects of extruded rapeseed straw (ERS) as a replacement for peanut vine (PV) on nutrient intake, rumen fermentation, and growth performance of Hu sheep of China. Male Hu sheep [n = 36; body weight (BW) = 19.5 ± 1.0 kg] were randomly assigned to one of three experimental diets: 1) 0% ERS (Control): 100% PV, no ERS; 2) 50% ERS: 50% ERS+50% PV; or 3) 100% ERS: 100% ERS, no PV. The preliminary trial period was 10 d, and the formal trial period was 90 d. Feed intake was recorded once daily, and weighing was conducted every 30 d. Over all periods, substituting of PV with ERS had no effect on intake of starter feed, metabolizable energy (ME), digestible energy (DE), but had greater total intake energy (GE; P < 0.05). Also, 50% ERS had greater fecal energy but decreased urinary energy compared with control group. Compared with the control, 100% ERS resulted heavier BW and average BW gain per day (ADG) during d 61 to 90 of the experiment (P < 0.05), together with greater feed efficiency (P < 0.05). Compared with control, the rumen concentration of NH3-N increased for 50% ERS and the rumen pH was higher (P < 0.05). When compared with PV, total volatile fatty acids concentrations, propionate and valerate concentrations, and the molar proportions of ruminal acetate were less in ERS groups (P < 0.05), while the concentrations of acetate, isobutyric, isovaleric acid and acetate propionate were greater when substituting of PV with ERS in 50% and 100% (P < 0.05). Concentration of butyrate was not different among treatments. Body measurements were not affected by the treatments. In conclusion, substitution of PV with ERS may improve nitrogen utilization efficiency and rumen fermentation in Hu sheep, also slightly improve growth performance during later fattening period without negative affect on energy intake.
477 Effect of induced hindgut acidosis on gastrointestinal tract microbiome
Authors: Linder Haley F , Loman Brett R , Gutierrez-Nibeyro Santiago D , Garrett Edgar F , McCann Joshua C
Published: September 2024

The objective was to determine the effects of induced hindgut acidosis in sheep on rumen, cecal, and fecal microbiome. Ruminally and cecally cannulated ewes [n = 11; body weight (BW) = 49 ± 4 kg] were assigned to one of two treatments: control (CON; n = 5) or induced hindgut acidosis (HGA; n = 6). To induce hindgut acidosis, 3 g wheat starch/kg BW per 24 h was continuously infused via the cecal cannula for 4 d. Control ewes received a constant infusion of deionized water. The diet contained 40% grass hay pellets, 35% whole shelled corn, 15% dried distillers grains, and 10% alfalfa cubes. On d 0, 2, and 4, immediately before feeding, and 12 h after feeding, rumen fluid, cecal fluid, and fecal samples were frozen in liquid nitrogen and stored at -80°C. Microbial DNA from samples were extracted using the QIAamp PowerFecal Pro DNA Kit. Full length 16S rRNA amplicon libraries were prepared using Kinnex kits and then sequenced on the PacBio Revio platform. Reads were analyzed using DADA2 and QIIME2. Statistical analysis was performed with the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC) with the fixed effect of treatment, time, and their interaction. Data from d 0 was utilized as a covariate. There was a treatment effect (P < 0.01) for relative abundance of Christensenellaceae R7 group, Bacteroides, Akkermansia, Ruminococcus, and Treponema in cecal contents, with CON ewes having greater relative abundance than HGA ewes. Conversely, HGA had greater (P < 0.01) relative abundance of Bifidobacterium, Streptococcus, and Limosilactobacillus in cecal contents than CON ewes. Fusobacterium necrophorum was detected in all cecal samples after h 0 averaging 4.3% of reads, but was not affected by treatment, time, or their interaction. Trueperella pyogenes was detected in more than 80% of cecal samples after h 0 and averaged 0.25% of detected reads. In feces, there was a treatment effect (P < 0.01) for relative abundance of Bacteroides, Akkermansia, and Treponema, with CON ewes having greater relative abundance than HGA ewes. Relative abundance of Bifidobacterium and Streptococcus were greater (P < 0.01) in HGA feces than CON. A treatment by time interaction (P = 0.02) was observed for both fecal Ruminococcus and Christensenellaceae R7 group relative abundance, as relative abundance did not change in CON ewes but decreased in HGA after h 24. There were no effects of treatment, time, or their interaction (P ≥ 0.15) for relative abundance of Prevotella, Ruminococcus, Christensenellaceae R7 group, Selenomonas, or Rikenellaceae RC9 gut group in rumen fluid. Prevotellaceae UCG-001 relative abundance was affected (P = 0.04) by treatment with CON ewes having greater relative abundance than HGA ewes. Induced hindgut acidosis drastically altered the microbiome composition of cecal contents and feces.
288 Maternal fatty acid supplementation and its impact on dam and offspring performance
Authors: Marques Rodrigo , Ogg Makayla A , Cruz Vinicius Alves , Cidrini Iorrano A , Nascimento Keuven , Limede Arnaldo C Cintra , de de Queiroz Amanda Caroliny Marques de Caroliny Marques de , McCoski Sarah , Posbergh Christian , Mercadante Vitor R G , Harvey Kelsey M , Cordero Juan , Geary Tom W
Published: September 2024

Fatty acid supplementation has multiple benefits to the offspring when supplemented to the dam during pregnancy; limited to no benefits to the dam have been documented. We hypothesized that maternal fatty acid supplementation during pregnancy would result in improved body weight (BW) and body condition score (BCS) in the ewes and improve lamb growth until weaning and male offspring growth following weaning when ewes were supplemented fatty acids. On d -8 of the study (35 d of gestation), all ewes were weighed, BCS was collected, and pregnancy status determined. Pregnant Targhee ewes (n = 83) were assigned to a treatment group based on age, BW, and BCS, to one of four treatment gr: 1) 22 g/ewe daily of Ca salts of saturated and monosaturated fatty acids based on palmitic and oleic acids (CON; EnerGII, Virtus Nutrition, LLC, Corcoran, CA); 2) 22 g/ewe daily of Ca salts of PUFA based on eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids (ɷ-3, Strata; Virtus Nutrition LLC); 3) 22 g/ewe daily of Ca salts of PUFA based on linoleic acids (ɷ-6, Prequel; Virtus Nutrition LLC); or 4) 11 g/ewe of Ca-salts enriched with EPA+DHA (Strata) and 11 g/ewe of Ca-salts enriched with linoleic acid (Strata) daily (ɷ-3 + 6; Virtus Nutrition LLC). Fatty acid supplementation occurred from d 0 until d 88 of the study, and all ewes were fed grass hay. Ewe BW and BCS were recorded at d -8, 51, 93, and 240 of the study. Twenty-four hours after birth, lamb sex was identified and weighed (n = 136 lamb; CON = 33; ɷ-3 = 32; ɷ-6 = 36; ɷ-3 + 6 = 35). Lambs were weighed at d 175 and 240 (weaning) of the study (n = 86; CON = 22; ɷ-3 = 22; ɷ-6 = 21; ɷ-3 + 6 = 21). Body weight, BCS, and scrotal circumference (SC) were collected on all ram lambs at d 352, 380, and 408. No differences were observed in ewe BW or BCS at d -8, 51, or 93 of the study (P ≥ 0.26) between the treatment groups (Table 1). A treatment × day interaction was observed at d 240 of the study when ɷ-6 ewes had a greater (P = 0.03) BCS compared with group cohorts. No differences in lamb birth weight, lamb weight or average daily gain at d 175 or 240 of the study between treatment groups (P ≥ 0.25; Table 2). No differences were reported in ram lamb BW, BCS, or SC at d 352, 380, and 408 (P ≥ 0.31; Table 3). These results indicate that maternal fatty acid supplementation alters ewe BCS at the time of weaning; however, supplementation does not impact lamb growth from birth until weaning or ram lamb growth and scrotal circumference.
287 Effects of crude glycerin supplementation of beef cattle grazing wheat pasture on forage intake and characteristics of rumen fermentation
Authors: Lucero Naomi , Soto-Navarro Sergio A , Campa-Madrid Sara E , Carrera Vinicio , Ropp Kate E
Published: September 2024

Crude glycerin (CG), mainly composed of glycerin, is a by-product of biodiesel production. Glycerin can be utilized as a substrate of gluconeogenesis by either rapid fermentation to propionate in the rumen or can be directly absorbed through the rumen epithelial wall, resulting in the conversion to glucose in the liver. Therefore, CG supplementation may increase the energy intake of cattle grazing wheat pasture. Ruminally cannulated Angus-crossbred cows [n = 9; 564.4 ±101.6 kg initial body weight (BW)] grazing wheat pasture were utilized in a split-plot design with the objective of evaluating the effects of CG supplementation and forage maturity on forage intake and rumen fermentation characteristics. Treatment was the main plot, and stage of forage maturity was the subplot. Treatments were unsupplemented control (CON) and crude glycerin supplementation (SUP; 37.2% glycerin, DM basis) dosed at 0.11% BW (DM basis). Supplementation levels correspond to 5% of the diet, assuming forage intake of 2.2% of BW on a DM basis. The stages of wheat maturity pasture were March (MAR; vegetative stage) and April (APR; early reproductive stage). Cows grazed a single wheat pasture and were supplemented directly through the rumen cannula twice daily at 0700 and 1900 h. Forage intake in kg/d and as % of BW was greater (P = 0.04) for SUP than CON. Ruminal pH, ammonia, and VFA concentrations, as well as proportions of VFAs, were not affected by CG supplementation (P ≥ 0.34; Table 1). However, ruminal pH (5.77 and 5.99 ± 0.049) and ammonia concentration (0.67 and 3.37 ± 0.307 mM) were greater, while total VFA concentration (136.3 and 110.8 ± 5.23 mM) was less (P = 0.01) for APR compared with MAR. Acetate, propionate, and butyrate molar proportions, as well as acetate: propionate ratio, were not affected (P ≥ 0.27) by the stage of wheat pasture maturity. Results indicate that crude glycerin used as an ingredient in supplementation strategies for cattle grazing wheat pasture may increase cattle energy intake without negatively affecting forage intake and ruminal fermentation.
PSII-6 Tick infestation and its implications on health and welfare of cattle under pastoral system in Nigeria
Authors: Alabi Olufemi Mobolaji , Alabi Oyekemi S , Adeyanju Taiwo , Ajayi Mary-Ann
Published: September 2024

The pastoral system is a predominant form of cattle production in Nigeria, characterized by extensive grazing on communal lands. However, this system is challenged by various factors, including tick infestation, which significantly affects cattle health and welfare hence this investigation which aims to provide an in-depth understanding of tick infestation in the context of Nigerian pastoral systems, emphasizing its impact on cattle health and welfare. The country harbors a diverse array of tick species that affect cattle. These ticks belong to different genera, including Rhipicephalus, Amblyomma, and Hyalomma, among others. Each species has unique characteristics, life cycles, and host preferences, contributing to the complexity of tick infestation dynamics in pastoral settings. Tick infestation has numerous detrimental effects on cattle health. The direct effects include blood loss, anemia, skin damage due to feeding, and the transmission of pathogens that cause diseases such as anaplasmosis, babesiosis, and theileriosis. Indirectly, tick infestation can lead to reduced productivity, weight loss, and increased susceptibility to other diseases. The welfare of cattle in Nigerian pastoral systems is significantly impacted by tick infestation. Infested cattle often exhibit signs of distress, including restlessness, reduced grazing activity, and altered behavior. Furthermore, the discomfort caused by tick bites can lead to chronic stress, compromising the overall welfare of the animals. Effective tick control is crucial for mitigating the impact of infestation on cattle health and welfare. Strategies such as acaricide application, pasture management, genetic selection for tick resistance cattle, and vaccination against tick-borne diseases are commonly used. Tick infestation presents a significant challenge to cattle production under the pastoral system in Nigeria. It not only impacts cattle health but also compromises their welfare. Addressing the issue of tick infestation requires a multifaceted approach that integrates effective control strategies with sustainable management practices. Further research is needed to develop tailored interventions that account for the unique characteristics of Nigerian pastoral systems, ultimately ensuring the well-being and productivity of cattle in these settings.
PSIII-29 Evaluating the efficacy of bioelectrical impedance analysis using machine learning models for the classification of parasitized goats
Authors: Terrill Thomas H , Siddique Aftab , Erukulla Tharun Tej , Batchu Phaneendra , Chelkapally Sai , Brown davia , Stegall Kensley , Kannan Govind , Mahapatra Ajit , Panda Sudhanshu , Morgan Eric , van Wyk Jan
Published: September 2024

Rapid identification and evaluation of animal health condition is one of the most important concerns when it comes to livestock productivity, particularly for small ruminants susceptible to infection from blood-feeding gastrointestinal nematodes, like Haemonchus contortus. The present study was designed to optimize the process of differentiating parasite infected goats from healthy goats. This study used male intact Spanish goats (n = 65), aiming to establish a proof of concept for the efficacy of bioelectrical impedance, specifically through the metrics of Resistance, and Reactance, in identifying the health status of goats. The research involved the development and comparative analysis of seven machine learning (ML) models, divided into four classification-based models and three regression models, to assess their capabilities in accurately classifying goats based on bioelectrical properties. The data for this study were gathered from live animals using CQR 3.0 (Sea food analytics), with measurements taken from both ear and tail ends to ensure comprehensive and reliable bioelectrical readings. Among the classification models evaluated, the Random Forest Classification model emerged as the most effective, demonstrating a validation accuracy of 71.8% and a testing accuracy of 77.1%. This was closely followed by the K-NN Classification model, which showed a promising testing accuracy of 86.7%. Conversely, the Support Vector Machines and Boosting Classification models displayed decreased accuracies, indicating variability in the performance of classification models in this context. The regression models, evaluated through metrics such as Mean Squared Error (MSE) and R-square, revealed the K-NN Regression model as the most proficient, with the least Test MSE of 0.13 and an R-square of 0.482. This suggests a moderate correlation and predictive capability in determining the health status of goats based on bioelectrical impedance measurements. The Decision Tree Regression and Support Vector Regressor models showed varying degrees of effectiveness, with the latter indicating a minimal R-square value, highlighting the challenges in applying regression models to this domain. The conducted proof of concept research not only underscores the potential of bioelectrical impedance analysis in veterinary diagnostics, but also opens avenues for further refinement of ML algorithms in classifying and predicting the health status of farm animals. The outcomes of this study could significantly influence management strategies for small ruminants, offering a non-invasive, rapid, and potentially cost-effective tool for early detection of parasitism, thereby enhancing animal welfare and productivity in the agricultural sector.