Derek Brake

Data on effects of hemp (Cannabis sativa L.) variety and botanical part on ruminal nutrient disappearance are currently limited. Plants were harvested from 2 fiber- (CFX-2 and CRS-1) and 2 flower-based (Grandi and Katani) hemp varieties. Plants were separated into stems, leaves and seeds by variety. In situ disappearance of dry matter (DM), organic matter (OM), detergent fiber and crude protein (CP) was obtained by incubating bags containing unique combinations of variety and botanical part in 2 ruminally cannulated heifers. Rates and amounts of ruminal nutrient disappearance were calculated using the NLIN procedures in SAS and data were analyzed using the GLIMMIX procedure with fixed effects of variety, botanical part and their interaction; animal was included as a random effect. Rates and amounts of DM, OM, detergent fiber and CP disappearance were influenced by the interaction of variety and botanical part, which seemed to be largely related to differences in nutrient disappearance from leaves and seeds between fiber- and flower-based varieties. CFX-2 had greater (P < 0.01) concentrations of soluble DM while Katani had the least, however, rates of DM disappearance were greater (P = 0.03) among Katani compared to CFX-2 and Grandi. Amounts of degradable DM and OM were greatest (P ≤ 0.03) in CFX-2. Among measures of fiber disappearance, CFX-2 had the least amount of soluble fiber (P < 0.01), and the greatest concentrations of slowly degradable fiber (P < 0.01). The nondegradable fraction was greatest (P = 0.03) in CRS-1 and least in Katani. Rates of disappearance (P = 0.02) were least for Katani. Amounts of soluble DM were greatest (P = 0.02) among leaves and the least in stems, but seeds were not different from either. Rates of DM disappearance were greatest (P < 0.01) among leaves, intermediate among seeds, and least in stems. Amounts of soluble OM and rates of OM disappearance were greater (P < 0.01) in leaves compared to stems and seeds; however, slowly degradable OM was greater (P < 0.01) in stems compared to leaves and seeds. Seeds had relatively small amounts of detergent fiber disappearance with less amounts (P < 0.01) of soluble material; however, they had greater amounts of CP degradation (P < 0.01). Effective degradability of CP was 25% less (P < 0.01) among Grandi compared to other varieties. These data clearly indicate that different varieties and botanical parts of industrial hemp impact measures of ruminal nutrient disappearance.

We introduce a high-throughput 3D scanning system designed to accurately measure cattle phenotypes. This scanner employs an array of depth sensors, i.e., time-of-flight (ToF) sensors, each controlled by dedicated embedded devices. The sensors generate high-fidelity 3D point clouds, which are automatically stitched using a point could segmentation approach through deep learning. The deep learner combines raw RGB and depth data to identify correspondences between the multiple 3D point clouds, thus creating a single and accurate mesh that reconstructs the cattle geometry on the fly. In order to evaluate the performance of our system, we implemented a two-fold validation process. Initially, we quantitatively tested the scanner for its ability to determine accurate volume and surface area measurements in a controlled environment featuring known objects. Next, we explored the impact and need for multi-device synchronization when scanning moving targets (cattle). Finally, we performed qualitative and quantitative measurements on cattle. The experimental results demonstrate that the proposed system is capable of producing high-quality meshes of untamed cattle with accurate volume and surface area measurements for livestock studies.

Soybeans can provide ruminally degradable protein, lipid and metabolizable amino acid (AA) to lactating dairy cows; however, soy-based trypsin inhibitors can limit protein digestion in nonruminants. Eight ruminally cannulated lactating Holstein cows were used to evaluate the impacts of soy-based trypsin inhibitors on nutrient disappearance, lactation, and plasma AA bioavailability. Treatments were abomasal infusion of 0 or 400 g/d casein or a crystalline AA analog of casein with unroasted or roasted soybeans fed at 10% dry matter. Data were analyzed using the MIXED procedure of SAS. Measures of digestion were determined from fecal output determined with acid detergent insoluble ash and urine output determined from measures of urine creatinine. Neither soybean processing (P ≥ 0.20) or source of abomasal infusion (P ≥ 0.60) impacted nutrient digestibility. Ruminal ammonia, isobutyrate, and isovalerate were increased (P ≤ 0.01) among cattle consuming unroasted soybeans. Source of infusion did not affect (P ≥ 0.38) ruminal volatile fatty acids or nitrogen metabolism. Ruminal N metabolism was largely unaffected by soybean processing although microbial N efficiency was greater (P < 0.01) among cows fed unroasted soybeans. Dry matter intake and energy-corrected milk were greater (P < 0.01) in cows fed roasted compared to unroasted soybeans. The proportion of fat, protein, lactose and solids not fat in milk did not differ between soybean processing or postruminal AA source, but fat, protein, lactose and solids not fat yield was greater (P ≤ 0.01) when cows were fed roasted soybeans because milk yields were greater when cows were fed roasted vs unroasted soybeans. As expected, infusion of casein or its crystalline AA analog increased plasma essential AA and milk urea nitrogen concentration. The rate of increase in essential AA concentration in plasma was 2.9-times greater for casein than for crystalline AA. These data seem to indicate that soy-based trypsin inhibitors have no impacts on postruminal AA bioavailability when fed to cows and that MP from casein is greater than from crystalline AA.

Probiotics are purported to improve gastrointestinal tract health across a variety of species. Thus, we evaluated the effects of supplementing a blend of Bacillus spp. on performance and immune function in immature beef cattle. Crossbred heifers (n = 192) were stratified by initial body weight (196 ± 15.4 kg) and randomly assigned to 1 of 24 pastures (1.8 ha each) of Kentucky 31 tall fescue. Heifers were offered 2.84 kg daily of a commodity feed blend and the supplement contained either no probiotic (CON) or of Bacillus spp. (BAC). Bacillus spp. was offered at 3 grams per head per day. Heifers were weighed on consecutive days on d 0 and 1, along with d 84 and 85 to establish initial and final body weight. Interim weights were taken every 28 d. A humoral response to chicken egg albumin (OVA) was established following a subcutaneous injection with OVA. To assess heifers’ immune responses, plasma was taken from two heifers per pasture on d 1, 15, 29, 43, and 57. Plasma samples were measured for the presence of anti-OVA IgG, proinflammatory cytokines, anti-inflammatory cytokines, and chemokines. There were no trt*day interactions (P ≥ 0.30) for plasma response variables. Concentrations of pro-inflammatory cytokines IL-1α and IFN-γ decreased (P ≤ 0.01) in heifers supplemented with BAC. The anti-inflammatory cytokine IL-1 F5 decreased (P = 0.02) with BAC supplementation. Chemokines MIG and MIP-1β also decreased (P ≤ 0.03) with BAC supplementation. Heifers fed BAC tended to display (P = 0.09) greater titers of anti-OVA IgG than the control. Body weight and average daily gain did not differ (P ≥ 0.53) throughout the experiment. Under the conditions of this experiment, heifers supplemented with Bacillus spp. demonstrated modulated immune responses.

The objective of this experiment was to evaluate effects of postruminal flows of casein or glutamic acid on small intestinal starch digestion and to quantify changes in energy and nutrient balance. Twenty-four steers (body weight = 179 ± 4 kg) were duodenally infused with raw cornstarch (1.46 ± 0.04 kg/d) and either 413 ± 7.0 g casein/d, 121 ± 3.6 g glutamic acid/d or water (control). Measures of small intestinal starch digestion and nutrient excretion were collected across 4 d after 42 d of infusion and measures of respiration via indirect calorimetry were collected across 2 d after 48 d of infusion. Ileal starch flow was least among calves provided casein, but ileal starch flow was not different between glutamic acid or control. Small intestinal starch digestion tended to be greatest among calves provided casein, least for glutamic acid and intermediate for control. Casein increased ileal flow of ethanol soluble oligosaccharides compared to glutamic acid and control. Large intestinal starch digestion was not different among treatments. By design, N intake was greatest among cattle provided casein, intermediate among calves provided glutamic acid and least for control. Nitrogen retention was greater in response to casein compared to control and glutamic acid. Intake of gross energy from feed was similar across treatments, and gross energy from infusate was greatest for casein, intermediate for glutamic acid and least for control. Variation in gross energy intake from feed resulted in no difference in overall gross energy intake across treatments. Similar to measures of small intestinal starch digestion and N retention, casein increased calories of digestible energy and metabolizable energy, compared to glutamic acid and control, which did not differ. Postruminal infusions did not influence methane production, but heat production was greatest in steers infused with casein, intermediate for steers provided glutamic acid, and least for control. Overall, amounts of energy retained by casein tended to be nearly 34% greater than control, but glutamic acid had no impact on energy balance. Improvement in small intestinal starch digestion in response to casein increased energy and N retained; however, glutamic acid did not influence small intestinal starch digestion and energy or N balance in cattle, which seems to suggest that responses in small intestinal starch digestion to greater postruminal flows of glutamic acid become refractory across greater durations of time.

This study used 18 calves (295 ± 29 kg) and 18 yearlings (521 ± 29 kg) fed whole, cracked or steam-flaked corn (SFC) to evaluate nutrient digestion and energy balance across different types of processed corn and sizes of cattle. Cattle were fed a diet comprised of 75% corn (DM-basis) from whole, cracked or SFC to 2.5-times maintenance energy requirements. Subsequently, cattle were placed in individual stanchions and urine and feces was collected together with measures of gas production via indirect calorimetry. Data were analyzed using the MIXED procedure of SAS. There was no interaction of corn processing and cattle size (P ≥ 0.40). Time spent ruminating (min/d) and rumination rate (min/kg DM intake; DMI) was not affected by corn processing or cattle size. Eating rate (min/kg DMI) was faster (P < 0.01) for yearlings compared to calves. Total tract starch digestion was greatest (P = 0.01) for cattle fed SFC (97.5%), intermediate in cattle fed cracked (92.4%) and least in cattle fed whole corn (89.5%). Dietary digestible energy and metabolizable energy (Mcal/kg DMI) were greater (P ≤ 0.05) for cattle fed SFC compared to cracked or whole. A greater proportion of digestible energy was lost to heat production (P = 0.01) in cattle fed whole corn compared to cracked and tended to be greater (P = 0.08) in cattle fed SFC than cracked. Conversion of digestible energy to metabolizable energy in this study was more closely related to a dynamic model used to estimate metabolizable energy of feeds to dairy cows than to a linear model used to predict metabolizable energy of feeds to beef cattle. If library estimates of net energy for maintenance are correct, then retained energy (Mcal/d) should have been similar between each type of processed corn; however, retained energy was greater (P < 0.01) for cattle fed cracked compared to whole corn and tended to be greater (P = 0.06) compared to SFC. Yet, observed amounts of net energy based on measures of retained energy were not different (P ≥ 0.60) between cracked and SFC. Nitrogen balance was not affected (P ≥ 0.30) by corn processing or cattle size, although cattle fed cracked had numerically greater (P ≤ 035) N retention. These data indicate that physical processing of corn provides greater net energy to cattle in comparison to whole corn.

Brassica cover crops are an option for producers to incorporate into their cropping system to improve soil health and also provide a feed resource for cattle. While brassica cover crops have been widely used for grazing cows, their use as a backgrounding feedstuff is relatively unknown. The objective of this study was to determine the impact of feeding a brassica cover crop mixture during backgrounding on live animal performance and carcass characteristics. A total of 30 Angus-based steers were assigned to one of two dietary treatments during backgrounding 1) ad libitum access to a diet containing freshly cut brassica cover crop forage (CC) containing radish, turnip, rapeseed, rye grass, and a liquid supplement or 2) common Midwestern dry lot growing diet containing silage, soybean meal, grass hay, and a liquid supplement (CON). Steers were assigned to electronic feed bunks (Insentec RIC, Hokofarm Group; Marknesse, the Netherlands) for collection of individual feed intake. Diets were formulated to be nutritionally similar on a dry matter basis. Steers were paired by weight across treatments and pair fed. Dry matter intake (DMI) was calculated daily for steers in the CC treatment and the following day, CON steers were allowed access to an equal amount of dry matter using the Insentec RIC system. Steers were weighed weekly and backgrounded for 44 days before transitioning to a common finishing diet and weighed every 28 days. Steers were harvested at an estimated average backfat thickness of 1 cm. Standard carcass data were measured and strip loins and shoulder clods were collected. Instrumental and subjective color were measured on ground beef for 8 days and instrumental color was measured on strip steaks for 11 days. Treatment did not influence carcass characteristics, average daily gain, and DMI (P > 0.17). However, CON steers exhibited increased gain to feed ratio (P = 0.02). Additionally, a treatment by day interaction was observed for ground beef discoloration as the CC treatment displayed increased discoloration on days 4, 6, and 7 of case life (P < 0.01). These data indicate that brassicas may be utilized in a backgrounding diet without negatively impacting carcass characteristics but may decrease case life of ground beef.

Two experiments were conducted to evaluate the bioavailability of AA between polymerized and less po-lymerized or unpolymerized sources of AA. In the first experiment, 6 bull calves (53.8 +/- 0.6 kg of body weight) were bottle-fed milk replacer that contained 0, 60, or 120 additional grams of AA from casein or acid hydro-lyzed casein every 12 h. Plasma essential AA increased linearly with increasing intake of casein from either source. Branched-chain amino acids accounted for 74% of increases in essential AA, regardless of source of AA. Concentrations of nonessential AA increased linearly with increased intake of AA from acid hydrolyzed ca -sein but only tended to increase in response to casein. Also, the rate of increase in total plasma AA concen-tration in response to acid hydrolyzed casein (4.3 mu M increase per g of supplemental AA) tended to be 145% greater than casein (3.0 mu M per g of supplemental AA). In a separate experiment, 6 additional bull calves (52.1 +/- 0.9 kg of body weight) were bottle-fed milk replacer that contained 0, 4.8, or 9.6 additional grams of Lys from epsilon-polylysine or Lys-HCl each 12 h to measure Lys bioavailability between a polymerized and unpolymer-ized source of Lys. Plasma Lys concentrations increased linearly in response to greater Lys intake from Lys-HCl (slope = 13.51 mu M/g Lys,), but plasma Lys concentra-tions did not change in response to increased intake of Lys from epsilon-polylysine. Plasma concentrations of Thr, Met, Glu, and Gln decreased linearly with increasing epsilon-polylysine intake, whereas concentrations of His, Val, Leu, and Ile increased linearly with increasing epsilon-polylysine intake. Data from these experiments sug-gest that the form of AA provided to calves should be considered when formulating diets to meet AA require-ments. tabolizable AA supply (Schwab et al., 1976; King et al., 1991; Abe et al., 1997). A myriad of dietary proteins has been evaluated as sources of metabolizable AA to mature cattle fed plant-based diets; however, measures of metabolizable AA supply from polymerized proteins to calves fed liquid-based diets are limited. Similar to mature cattle fed plant-based diets, most AA provided to calves fed liquid-based diets are derived from polymerized proteins, but bioavailability of protein sources between suckling calves and mature cattle may differ because of differences in digestive physiology between them. Furthermore, mature cattle have a functioning rumen that provides metabolizable AA from microbial proteins, which often have AA profiles well-suited for growth and production; however, preruminant calves

The objective of this study was to quantify the differences in the activity of jejunal maltase and isomaltase between 2 groups of steers with average dry matter intake (DMI) and differing average daily gain (ADG). Dry matter intake and ADG were measured in crossbred steers (n = 69; initial body weight = 456 ± 5.0 kg) consuming a finishing diet containing 67.8% dry-rolled corn, 20.0% wet distillers grains with solubles, 8.0% alfalfa hay, and 4.2% vitamin/mineral supplement on a dry matter basis for 84 days. Jejunal mucosal samples were collected from 8 steers with the greatest (high) or least (low) ADG and average DMI (± 0.55 standard deviation). Homogenates of jejunal mucosa were incubated with increasing amounts of maltose and isomaltose to determine the disaccharidase kinetics. Total mucosal protein concentration (mg protein/g tissue; P = 0.45) of the mucosa and small intestinal weights (P = 0.69) did not differ between the groups. Neither the K_m of isomaltase (P = 0.15) or maltase (P = 0.21) differed between groups. The isomaltase V_max expressed per gram of protein tended to differ (P = 0.10) between groups of steers but did not differ (P = 0.13) when expressed on a tissue basis. Similarly, neither the maltase V_max expressed per gram of protein (P = 0.31) or tissue (P = 0.32) differed between groups. While previous studies have indicated that disaccharidase expression is associated with differences in ADG, data presented here indicate that differences in enzyme activity at the end of the finishing period are minimal.

The ruminal microbiome remains an enigma, in part, because only 5% of ruminal bacteria have been isolated and cultured. Diet of the host can have large impacts on ruminal microbial composition. Indeed, considerable effort has been dedicated to the identification of fibrolytic bacteria, but understanding of ruminal lipid digestion remains limited. Therefore, we evaluated ruminal microbial composition among 5 ruminally cannulated steers fed a corn-based diet with inclusion of 0, 4 or 8% added saturated (tallow) or unsaturated (linseed oil) lipids. Steers were placed in a 5 x 5 Latin square and treatments were balanced for carry-over effects. Steers were allowed a 14-d adaptation to the diet prior to the collection of ruminal samples. Bacterial composition was determined by next generation sequencing of 16S rRNA amplicons targeting the V1-V3 region for 21 of the 25 possible samples. A total of 422,922 high quality reads were clustered into 37,788 Operational Taxonomic Units (OTUs). In 3 of the 5 steers, a single species-level OTU (OTU-DB-1) was found in much greater abundance when diets included saturated (41.5-44.6%) or unsaturated (32.3-56.3%) lipids. This OTU was, in contrast, found in much lower abundance in controls (Ruminococcaceaewhile database searches using BLAST revealed only one match (99%) to sequences of the NCBI “nt” database. To our knowledge, this is the first report of an OTU associated with greater lipid inclusion in diets to ruminants. Copyright © 2017. American Society of Animal Science .