Browsing by Author "DelCurto, Timothy"

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Effects of pelleted versus loose salt-limited protein supplement on supplement intake behavior of yearling heifers grazing dryland pastures
(Oxford University Press, 2022-08) White, Hayley C; Van Emon, Megan L; DelCurto-Wyffels, Hannah M; Wyffels, Samuel A; DelCurto, Timothy
The objectives of this study were to evaluate the impacts of supplement form on supplement intake behavior, body weight (BW), and body condition score (BCS) change of yearling heifers grazing dryland pastures during the summer. In each of the two years, Angus crossbred heifers (14 mo of age; year 1, N = 57, BW = 449 ± 3.60 kg; year 2, N = 58, BW = 328 ± 3.57 kg) were used in a 84-d completely randomized design evaluating the following treatments: 1) control, no supplement; 2) salt-limited supplement in pelleted form; and 3) a salt-limited supplement in loose form. Individual supplement intake, and time spent at the feeder were measured throughout the course of the study using a SmartFeed Pro self-feeder system (C-Lock Inc., Rapid City, SD, USA). On days 0, 42, and 84, the heifers were weighed, and body condition scored following a 16-h shrink. Supplementation and form of supplement did not influence (P ≥ 0.62) BW change for yearling heifers within or across study grazing periods. Body condition score was not influenced (P ≥ 0.26) by supplementation and form within the 0 to 42 (period 1) or 42 to 84 (period 2)-d periods but displayed a treatment by year interaction (P < 0.01) for the 84-d summer grazing period. Supplement intake (kg/d and g/kg BW) displayed a treatment × period interaction (P < 0.01). Supplement intake (kg/d) of heifers consuming pelleted supplement was 28% and 31% greater (P ≤ 0.02) than heifers consuming loose supplement in periods 1 and 2, respectively. Supplement intake (g/kg BW) of heifers consuming pelleted supplement was 24% and 32% greater (P ≤ 0.05) than heifers consuming loose supplement in periods 1 and 2, respectively. Overall, across both years, supplement intake in period 1 was less than half (P < 0.01) that of period 2, averaging 0.50 and 1.14 kg/day, respectively. Variation in supplement intake (% CV) was greater (P = 0.03) in period 1 compared to period 2, averaging 119% and 91%, respectively. In addition, variation in supplement intake was greater (P = 0.03) in year 2 than year 1, averaging 122% and 88%. Our results suggest that salt-limited supplements have a high degree of intake variation and pelleting could have a masking effect as indicated by the greater intake and intake rate of supplement with heifers consuming the pelleted supplement.
Evaluation of sustained release mineral boluses as a long-term nutrient delivery method for beef cattle
(2021-09) Carlisle, Tanner J.; Wyffels, Samuel A.; Stafford, Steve D.; Taylor, Anna R.; Van Emon, Megan L.; DelCurto, Timothy
Two studies were conducted to evaluate the efficacy of sustained release mineral boluses as an alternative nutrient delivery method for beef cattle. For both studies 16 ruminally-cannulated cows were used in a completely randomized design. In study 1, we evaluated degradation rates of two bolus prototypes and cow age (2-yr-old versus 3-yr-old cows) over an 87-d study period. In study 2, we evaluated two bolus types (90-d degradation target versus 180-d degradation target), as well as two diet qualities contrasting a low-quality high-fiber forage (> 600 g/kg neutral detergent fiber and < 80 g/kg crude protein, dry matter basis) and high-quality low-fiber forage (< 500 g/kg neutral detergent fiber and> 150 g/kg crude protein, dry matter basis). For both Study 1 & 2, intake and digestion periods were conducted to evaluate cow age (study 1) or diet quality (study 2) effects on intake and rumen/reticulum function. In study 1, models containing an asymptotic effect of day and an interaction between day and bolus type were the best supported of the candidate models for bolus degradation rate. Cow age did not affect (P= 0.48) bolus degradation rates ( = -0.81 ± 1.13) and degradation rates were greater (P < 0.01) for bolus prototype B compared to bolus A ( prototype B = -20.39 ± 1.13; prototype A = -9.64 ± 0.81). Bolus degradation rate displayed an asymptotic relationship (P < 0.01) to bolus surface area for prototype A ( = 5.83 ± 0.57) and a linear relationship (P < 0.01) for prototype B ( = 0.001 ± 0.0001). In study 2, models containing a linear effect of day and an interaction between day and diet were the best supported of the candidate models for the degradation rate of the 90-d and 180-d prototype. In addition, both bolus protoypes displayed a diet quality × time interaction (P < 0.01) for bolus degradation rate. Cattle treated with the 90-d bolus and fed a high-quality diet had a greater (P < 0.01) degradation rate ( High-quality = -2.64 ± 0.08; Low-quality = -1.97 ± 0.10) than the cows that were fed a low-quality diet. In contrast, cattle treated with the 180-d bolus had an inverse effect (P < 0.01), with bolus degradation rates greater ( Low-quality = -0.09 ± 0.007; High-quality = -0.04 ± 0.005) with cows on the low-quality diet versus the high-quality diet. Across both studies, two of four bolus prototypes met target release rates at 90 days. However, bolus prototype degradation characteristics varied and were influenced by diet quality.
Influence of residual feed intake and cow age on dry matter intake postweaning and peak lactation
(Oxford University Press, 2021-11) Parsons, Cory T; Dafoe, Julia M; Wyffels, Samuel A; DelCurto, Timothy; Boss, Darrin L
Supplemental nutrition for cattle is the greatest operating cost for cow-calf producers, accounting for 65% of the annual expenses (Meyer et al., 2008). Therefore, selection pressure for efficient animals that have lower feed intake but maintain production, or average intake with higher production, could have positive impacts on cow–calf profitability (Meyer et al., 2008). Thus, improving feed efficiency through genetic selection holds significant opportunity for the beef industry. Residual feed intake (RFI) is currently being used as a selection tool for purchasing and retaining heifers and for selecting bulls and semen. Most studies have used steers and terminal heifers when evaluating RFI impact on various aspects of beef cattle production (Kelly et al., 2010). Additionally, the majority of RFI studies have included energy-dense diets and rations focusing on feedlot performance (Lawrence et al., 2011). However, the use and relevance of RFI as a selection tool for the commercial cow–calf industry needs further research (Manafiazar et al., 2015). Research pertaining to RFI of cattle offered forage-based diets is limited (Arthur et al., 2005), with even fewer data available related to beef cattle forage-based production systems (Meyer et al., 2008). As a result, more research is needed to evaluate the utility of RFI estimates on the beef production in extensive forage base systems (Kenny et al., 2018). Therefore, the objectives of this study were to evaluate the influence of heifer postweaning RFI and cow age on dry matter intake (DMI), intake behavior, as well as milk production of dry-lotted black Angus beef cows. We hypothesized that heifers identified as low RFI eat less and the influence of RFI may interact with cow age.
Influences of increasing levels of sulfate in drinking water on the intake and use of low-quality forages by beef cattle
(American Registry of Professional Animal Scientists, 2023-02) Wyffels, Samuel A.; Van Emon, Megan L.; Nack, Makae F.; Manoukian, Marley K.; Carlisle, Tanner J.; Davis, Noah G.; Kluth, Janessa A.; DelCurto-Wyffels, Hannah M.; DelCurto, Timothy
Objective. This study evaluated the effects of varying sulfate concentrations of water on forage and water intake, digestibility, digestive kinetics, and rumen fermentation characteristics of cattle consuming low-quality forages provided a protein supplement, with and without salt. Materials and Methods. Eight ruminally cannulated cows (2 yr of age) were used in 2 concurrent 4 × 4 Latin squares (4 cows per square) to test the effects of increasing water sulfate concentrations on forage and water intake, digestibility, digestive kinetics, and rumen fermentation characteristics of cattle consuming low-quality forages provided protein supplement with and without salt. Within each square, cows were randomly assigned to the following treatments: (1) control (<10 mg/L sulfate); (2) 473 mg/L; (3) 946 mg/L; and (4) 1,420 mg/L. All cattle were provided a crude protein supplement at 0.18% of BW daily (0800 h daily); however, protein supplement NaCl composition differed by square (no NaCl vs. addition of 25% NaCl). Each period consisted of a 14-d adaptation period, followed by a 7-d intake and digestion period with ruminal profiles conducted on d 22 and complete ruminal evacuations on d 23, 5 h after feeding. Results and Discussion. There were no observed effects of sulfate (SO4) levels on forage intake, water intake, ruminal DM and liquid fill, ruminal DM and NDF digestibility, ruminal liquid passage rate, ruminal liquid turnover, ruminal liquid flow rate, ruminal pH, ruminal ammonia, ruminal total VFA concentrations, ruminal individual VFA concentrations, or the ruminal acetate-to-propionate ratio (P ≥ 0.16). Furthermore, the addition of 25% salt to supplement had no effect on forage intake, ruminal DM and liquid fill, DM and NDF digestibility, liquid passage rate, liquid turnover, liquid flow rate, ruminal pH, or the acetate-to-propionate ratio (P ≥ 0.24). Conversely, water intake was greater for animals provided 25% salt in supplement compared with animals not provided salt (P = 0.05). Implications and Applications. Sulfate water concentrations as high as 1,420 mg/L had minimal effects on intake, digestibility, and rumen fermentation characteristics of cattle consuming low-quality forage-based diets when provided a protein supplement containing up to 25% salt.
Rumen microbiome response to sustained release mineral bolus supplement with low- and high-quality forages
(Frontiers Media SA, 2023-06) Eberly, Jed O.; Wyffels, Samuel A.; Carlisle, Tanner J.; DelCurto, Timothy
Introduction: Limited forage quantity and quality are challenges faced in livestock production systems in semi-arid rangelands of the western United States, particularly when livestock face stressors such as cold weather or have increased nutritional requirements such as during pregnancy and lactation. To meet livestock nutrient requirements, producers frequently provide supplemental nutrition, however there is limited knowledge regarding the effects of these practices on the rumen microbiome in these environments. Methods: A study was conducted to evaluate changes in the rumen microbiome in response to high- and low- quality forage with sustained release mineral boluses. The study consisted of 16 ruminally-cannulated 2–3-year-old black angus cows fed high quality grass alfalfa hay or low-quality grass hay with a 90 or 180 day sustained release mineral bolus. Rumen samples were collected pre-feeding and 8 hours post feeding and bacterial 16S rRNA gene amplicons were sequenced from the rumen fluid. Results: Alpha diversity as measured by Shannon’s diversity index decreased significantly over time (p<0.01) and averaged 5.6 pre-feeding and 5.4 post- feeding and was not significantly different between high- and low-quality forages or between mineral bolus types (p>0.05). Principal coordinates analysis (PCoA) of the Bray-Curtis dissimilarity matrix showed distinct grouping by feed quality and time but not by mineral bolus type. Bacteroidetes and Firmicutes were the dominant phyla in all treatments and significant increases (p<0.05) in the relative abundance of the family Lachnospiraceae and the genus Prevotella were observed in high quality forage diets. Rumen VFA and NH3-N concentrations were also strongly associated with the high-quality forage diet. Predictive functional profiling indicated that functions associated with methanogenesis were negatively correlated with feed quality. Discussion: The results of this study suggest that mineral bolus type is unlikely to affect rumen bacterial community structure or function while forage quality can significantly alter community structure and predicted functions associated with methanogenesis and VFA production.
Rumen microbiome response to sustained release mineral bolus supplement with low- and high-quality forages
(Frontiers Media SA, 2023-06) Eberly, Jed O.; Wyffels, Samuel A.; Carlisle, Tanner J.; DelCurto, Timothy
Introduction: Limited forage quantity and quality are challenges faced in livestock production systems in semi-arid rangelands of the western United States, particularly when livestock face stressors such as cold weather or have increased nutritional requirements such as during pregnancy and lactation. To meet livestock nutrient requirements, producers frequently provide supplemental nutrition, however there is limited knowledge regarding the effects of these practices on the rumen microbiome in these environments. Methods: A study was conducted to evaluate changes in the rumen microbiome in response to high- and low- quality forage with sustained release mineral boluses. The study consisted of 16 ruminally-cannulated 2–3-year-old black angus cows fed high quality grass alfalfa hay or low-quality grass hay with a 90 or 180 day sustained release mineral bolus. Rumen samples were collected pre-feeding and 8 hours post feeding and bacterial 16S rRNA gene amplicons were sequenced from the rumen fluid. Results: Alpha diversity as measured by Shannon’s diversity index decreased significantly over time (p<0.01) and averaged 5.6 pre-feeding and 5.4 post- feeding and was not significantly different between high- and low-quality forages or between mineral bolus types (p>0.05). Principal coordinates analysis (PCoA) of the Bray-Curtis dissimilarity matrix showed distinct grouping by feed quality and time but not by mineral bolus type. Bacteroidetes and Firmicutes were the dominant phyla in all treatments and significant increases (p<0.05) in the relative abundance of the family Lachnospiraceae and the genus Prevotella were observed in high quality forage diets. Rumen VFA and NH3-N concentrations were also strongly associated with the high-quality forage diet. Predictive functional profiling indicated that functions associated with methanogenesis were negatively correlated with feed quality. Discussion: The results of this study suggest that mineral bolus type is unlikely to affect rumen bacterial community structure or function while forage quality can significantly alter community structure and predicted functions associated with methanogenesis and VFA production.