Patrick J. Gunn

Effects of dried distillers grains with solubles and crude glycerin on performance, carcass characteristics, and metabolic parameters of early weaned beef calves12

ABSTRACT The effects of dried distillers grains with solubles (DDGS) and crude glycerin on performance, carcass, and metabolic parameters in early weaned (EW) beef calves were assessed. Fifty EW Anguscross calves (123 d of age; 170 kg of BW) were blocked by BW and randomly assigned to 1 of 5 dietary treatments: 1) haylage-based control (NEG), 2) corn-based control (POS), 3) 30% DDGS and corn (DDGS+C), 4) 30% DDGS with 15% glycerin replacing corn (15GLY), and 5) 30% DDGS with 30% glycerin replacing corn (30GLY). Diets were fed ad libitum for 160 d. Cattle were commingled on trial d 160 and fed a corn-based finishing diet until slaughter at a common 12th-rib fat depth of 1.0 cm. Final EW phase BW and ADG (P ≤ 0.04) were greater for DDGS+C and 15GLY when compared with 30GLY. Calves fed DDGS+C reached slaughter faster (P = 0.01) when compared with NEG, 15GLY, and 30GLY; however, DDGS+C and POS resulted in lighter slaughter BW and HCW (P ≤ 0.01). Calves fed 15GLY had a greater LM area (P = 0.04) than did POS and DDGS+C, and calves fed 15GLY obtained greater QG (P = 0.05) than did DDGS+C and 30GLY. Calves fed NEG had greater circulating blood glucose and BHBA concentrations (P

Co-ensiling of Wet Distiller’s Grains

Wet distiller’s grains with solubles (WDGS; nominally 50% moisture) was blended with corn silage, corn stalks, soyhulls, and wheat straw and stored as silage (approximately 65% moisture and in an anaerobic environment) in lab scale silos. The resulting feed resource was stable, having a final pH near or below 4.0 which significantly slows or inhibits yeast, mold, and fungal growth. Varying proportions of WDGS and feedstuffs can lead to different end product densities as well as nutrient composition. Aerobic stability, as measured by time to reach a 2oC temperature rise, was improved as the proportion of WDGS within the blend increased. A farm-scale study was also conducted using mixers to blend WDGS with either corn silage or haycrop silage which was placed into bag silos; these blends were successfully stored and used in subsequent nutrition studies.

Effects of dry or wet conditions during the pre-weaning phase on subsequent feedlot performance and carcass composition of beef cattle

Abstract Our objective was to determine the effects of dry and wet conditions during the preweaning on subsequent feedlot performance and carcass characteristics of beef cattle. Steers (n = 7,432) and heifers (n = 2,361) finished in 16 feedlots in southwestern Iowa through the Tri-County Steer Carcass Futurity Cooperative were used for a retrospective analysis. Cattle originated in the Midwest (Iowa, Missouri, Indiana, Illinois, and Minnesota) and were born in February, March, or April of 2002 through 2013. Feedlot performance and carcass composition data were obtained for each animal. Palmer Drought Severity Index (PDSI) values were obtained for each animal’s preweaning environment on a monthly basis. Mean PDSI values were used to classify conditions as dry (≤−2.0), normal (>−2.0 and <2.0), or wet (≥2.0) for the cool (April and May), warm (June through August), and combined (April through August) forage growing seasons preweaning. Mixed models were used to evaluate the effects of PDSI class on subsequent performance. Calf sex, date of birth (as day of year), year, and feedlot were also included as fixed effects. When considering PDSI class during the cool season, cattle from normal and wet classes had a greater feedlot delivery BW (P < 0.0001) than dry. Dry and normal classes had greater (P ≤ 0.02) delivery BW than wet during the warm and combined seasons, however. For the cool season, average daily gain was greater (P < 0.0001) for the dry class than normal and wet. Cattle from the normal class for the cool season had greater (P = 0.001) final BW than wet, but the wet class had the greatest (P < 0.04) and dry class had the lowest (P < 0.01) final BW during the warm season. During the cool season, HCW was greater (P < 0.007) for the normal than wet class, although HCW was greater (P ≤ 0.02) for wet compared with dry and normal during the warm season. Calculated yield grade was lower (P ≤ 0.006) for the normal class during the cool season compared with dry and wet. For both the warm and combined seasons, the dry class had lower (P ≤ 0.004) calculated yield grade compared with normal and wet. Carcasses from cattle that experienced normal or wet warm seasons had greater (P ≤ 0.0005) marbling scores than dry, and normal had greater (P = 0.0009) marbling score than dry for the combined seasons. In conclusion, these data indicate that both dry and wet conditions during the preweaning phase may impact ultimate feedlot performance and carcass composition.

Climatic factors affecting quantity and quality grade of in vivo derived embryos of cattle.

The present study investigated the effects of climatic variables on the quality grade and quantity of in vivo derived cattle embryos in the Midwestern United States. Climatic information included greatest and least daily temperature, average daily wind speed and average temperature-humidity index for each of the 765 records. The response variables included the number of ovarian structures, viable embryos, quality grade 1 embryos, quality grade 2 embryos, quality grade 3 embryos, freezable embryos (sum of quality grade 1 and quality grade 2 embryos), transferable embryos (sum of quality grade 1-3 embryos), degenerate embryos and unfertilized ova. Measures for variables among the breeds of donors and sires grouped by geographical origin were compared. A negative effect of greater temperatures during the early embryonic development stage tended (P < 0.10) to be associated with a decrease in the quality of embryos recovered. Interestingly, the greater the Temperature-Humidity Index (THI) during the early ovarian antral follicular development stage 40-45 days prior to ovulation was associated with a tendency for greater numbers of total number of freezable and transferable embryos recovered per uterine flushing (P < 0.10). Increased wind speed at the early antral follicular phase 40-45 days prior to ovulation was associated with an increase in the percentage of quality grade 1 embryos recovered (P < 0.05). Wind speed during the estrous synchronization period was also associated with a lesser number of embryos recovered (P < 0.05). This retrospective study confirms that climatic variables have significant effects on the in vivo production of cattle embryos and that wind speed should be considered in future analyses of factors affecting embryo quality.

Optimización de la Nutrición de Ganado de Carne de Concepción hasta Consumo

Feed cost and reproductive efficiency are the 1 and 2 largest factors, respectively, that dictate profitability of the cow-calf enterprise. It should not be forgotten that these two economic areas are not independent of one another, as nutritional management is the largest single factor that producers can control that influences the probability of pregnancy. Thus, without proper nutritional management, many reproductive processes are altered, and establishment and maintenance of pregnancy may be hindered or prevented entirely. Traditionally, the major concern related to the interface between nutrition and reproduction is the effect of under nutrition prior to breeding. However, recent research in the fields of fetal/developmental programming as well as post-breeding heifer management suggests nutrition can significantly impact not only reproductive capacity of the female, but long term growth and efficiency of her progeny. Therefore, developing appropriate nutritional programs for all phases of production is critical for the economic success and productivity of the beef operation for not only the current year, but for years to come.

Factors Affecting Timing and Intensity of Calving Season of Beef Cow-Calf Producers in the Midwest

Despite demonstrated market incentives to adopt controlled calving seasons, many producers still have herds that calve somewhat broadly throughout the year. Primarydata, collected through a coordinated survey effort withUSDA’s National Agricultural Statistics Service, were usedto quantify factors that affect producers’ decisions regardingtiming and intensity of calving season. Ninety-seven, 50, 33,and 26% of farms calve in the spring (Mar, Apr, May),summer (Jun, Jul, Aug), fall (Sep, Oct, Nov), and winter(Dec, Jan, Feb), respectively. Twenty-two percent observeda calving season exclusively in the spring. Sixty-six percentof respondents indicated calving season was dictated byweather, 34% because of labor availability, and 31%because of tradition. Least often reasons for calving seasonwere market timing (16%), feed availability (8%), and other(4%). Producer stated reasons for calving season explained62% of the variation in timing and intensity of calving on anoperation, whereas a model of producer demographic andoperation characteristics explained 83% of the variation.These results highlight the importance of evaluatingproducer and operation characteristics in addition toproducer input when making recommendations to enhanceproduction efficiency and profitability. Furthermore,understanding the factors which impact calving seasonprovides opportunities for improved extension and research programming.

Effects of Increasing Supplementation of Rumen Undegradable Protein on Plasma Essential Amino Acid Concentrations in Beef Cows Consuming Low Quality Forage

aud Implications The effects of pairing a low quality forage with increasing metabolizable protein (MP) supplementation from a moderately abundant rumen undegradable protein (RUP) source (corn gluten meal; 62% RUP) on essential plasma amino acid (AA) concentrations were evaluated in a 60-day trial. Non-pregnant, non-lactating cows (n=24) were offered ad libitum access to cornstalks and fed 1 of 3 isocaloric diets (0.48 NEm/lb) and supplemented primarily with corn gluten meal to provide 100% MP requirements (CON), 125% MP requirements (MP125), or 150% MP requirements (MP150). It was observed that increasing concentrations of MP in the diet from a moderately abundant RUP source increased the percent of essential AA, ketogenic AA, branched-chain AA and urea cycle AA in plasma. Also, as a percent of total AA, glycogenic AA were decreased with increased MP supplementation. Therefore, increasing supplementation of MP can the shift essential AA profiles of beef cows when fed with low quality forage.

Effect of estrus activity when evaluating feed efficiency in heifers

Introduction Feed efficiency measurements taken on individual heifers or bulls for the purpose of selection of replacement breeding stock tend to be taken when these animals are 200 to 400 days of age. During this time frame, many of these animals undergo puberty and the subsequent changes advancing sexual maturity initiates; however they do not all mature at the same rate. These changes tend to affect carcass characteristics due to the anabolic nature of the hormones associated with this stage of life, but also there are behavior changes that could have some effect on feed use. Estrus activity of heifers in the feedyard is discouraged and the use of additives such as melengestrol acetate (MGA) which suppresses estrus activity tends to improve feed conversion and weight gain in large pen studies. With this in mind along with the fact that puberty onset is variable within a weaning contemporary group, there was some concern that evaluation of feed efficiency may be confounded by the onset of puberty and estrus activity when evaluating heifers.