Reduction In Dry Matter Intake Research Articles

163 Impact of feeding wet or dry traditional or fractionated (Solbran) distiller’s grains on feedlot cattle performance and carcass characteristics

Abstract Solbran (ICM, Colwich, KS) is new corn byproduct of ethanol production composed of fiber plus condensed distiller’s solubles and can be fed dry (Dry Solbran; NDF = 41.1%; CP = 21.84%; Ether extract = 8.4%), or wet (Wet Solbran; NDF = 49.7%; CP = 22.67%; Ether extract = 8.5%). The objective of this study was to evaluate the energy value of dry and wet Solbran compared with traditional dry- (DDGS) and wet- distiller’s grains plus solubles (WGGS) in beef cattle finishing diets. The treatments included a control (CON) with no distiller’s grains compared with the inclusion of DDGS, WDGS, Dry Solbran and Wet Solbran at two levels (20% and 40%) resulting in a 2 × 2 × 2 + 1 factorial. Orthogonal contrasts defined linear and quadratic effects of byproduct inclusion through the common intercept of CON. Additionally, interactions among inclusion (20% or 40%), moisture (dry and wet) and processing method (Solbran or traditional) were evaluated as a 2 × 2 × 2 factorial without CON. There was a linear increase in dry matter intake (DMI) by adding DDGS, Dry Solbran, and Wet Solbran (P < 0.01) and a tendency for a linear increase in dry matter intake (DMI) with WDGS (P = 0.07). There was a linear increase in ADG by adding DDGS or Wet Solbran (P < 0.05) and a tendency for a linear increase in average daily gain (ADG) with the addition of Dry Solbran or WDGS (P < 0.10). These changes in DMI and ADG resulted in a linear decrease in gain to feed ratio (G:F) when Dry Solbran was added (P < 0.01), and a tendency towards a linear decrease in G:F when DDGS was added (P < 0.10). The inclusion of Wet Solbran or WDGS did not influence G:F (P = 0.45). For the 2 × 2 × 2 factorial, there was a 2-way interaction for moisture by inclusion of byproduct for G:F where wet byproduct fed at 40% of the diet resulted in the greatest G:F and 40% dry byproduct resulted in the least G:F (P = 0.04). This interaction was driven by an increase in DMI for 40% byproduct when fed dry, and a reduction in DMI for both 20 and 40% byproduct fed wet. There was no difference in ADG between the treatments (P = 0.75). For the main effect byproduct type, steers fed Solbran had greater DMI (P < 0.01) with no difference in ADG (P = 0.79), resulting in a 3% reduction in G:F (P = 0.03) for steers fed Solbran but greater marbling (P < 0.01). Impact of feeding distillers grains byproducts on DMI, ADG, and G:F are impacted by the processes used in the ethanol plant, whether wet or dry, and dietary inclusion.

The Impact of Liver Abscesses on Performance and Carcass Traits in Beef Cattle: A Meta-Analysis Study

The use of high-grain diets in feedlots is associated with the development of acidosis and ruminitis, which can lead to the occurrence of liver abscesses (LAs). However, the effect of LA on carcass traits is not well known. This study assessed the effects of LA on the performance and carcass traits of beef cattle. Nine peer-reviewed publications with forty-seven treatment means were included in the data set. The effects of the LA were evaluated by examining the weighted mean difference (WMD) between LA (animal with LA) and control treatment (animal without LA). Heterogeneity was explored by meta-regression, followed by a subgroup analysis of the scores and percentages of liver abscess and concentrate level in the feedlot diet. Animals affected by LA showed a reduction in dry matter intake (−1.03%) and feed efficiency (−1.82%). Animals with an LA score of “A” (one or two small abscesses) exhibited a decrease in carcass weight (WMD = 3.41 kg; p = 0.034) and ribeye area (WMD = −1.37 cm2; p = 0.019). When assessing the impact of LA on carcass traits, the most reliable finding indicates a 1.21% reduction in the ribeye area, with no adverse effects observed on subcutaneous fat thickness or the marbling score in the carcass.

Effects of heat stress on feed intake, milk yield, milk composition, and feed efficiency in dairy cows: A meta-analysis

Heat stress compromises dairy production by decreasing feed intake and milk yield, and it may also alter milk composition and feed efficiency. However, little information is available for evaluating such effects across different levels of heat stress and cows enrolled in heat stress studies. The objectives of this study were to evaluate the effects of heat stress on dry matter intake (DMI), energy-corrected milk (ECM), milk composition, and feed efficiency (kg ECM/kg DMI) and to investigate the relationship between such effects and heat stress intervention and animal characteristics by using meta-analytical approaches. Data from 31 studies (34 trials) fulfilled the inclusion criteria and were used for analysis. Results showed that heat stress decreased DMI, ECM, and milk protein concentration, but did not alter milk fat concentration or feed efficiency. Meta-regression confirmed that such reductions in DMI and ECM were significantly associated with increasing temperature-humidity index (THI). Over the period of heat stress, for each unit increase in THI, DMI and ECM decreased by 4.13% and 3.25%, respectively, in mid-lactation cows. Regression models further revealed the existence of a strong interaction between THI and lactation stage, which partially explained the large heterogeneity in effect sizes of DMI and ECM. The results indicated a need for more research on the relationship between the effect of heat stress and animal characteristics. This study calls for the implementation of mitigation strategies in heat-stressed herds due to the substantial decrease in productivity.

Gas exchange, rumen hydrogen sinks, and nutrient digestibility and metabolism in lactating dairy cows fed 3-nitrooxypropanol and cracked rapeseed

Fat in the form of cracked rapeseed and 3-nitrooxypropanol (3-NOP, market as Bovaer) were fed alone or in combination to 4 Danish Holstein multicannulated dairy cows, with the objective to investigate effects on gas exchange, dry matter intake (DMI), nutrient digestion, and nutrient metabolism. The study design was a 4 × 4 Latin square with a 2 × 2 factorial treatment arrangement with 2 levels of fat supplementation; 33 g of crude fat per kg of dry matter (DM) or 64 g of crude fat per kg of DM for low and high fat diets, respectively, and 2 levels of 3-NOP; 0 mg/kg DM or 80 mg/kg DM. In total, 4 diets were formulated: low fat (LF), high fat (HF), 3-NOP and low fat (3LF), and 3-NOP and high fat (3HF). Cows were fed ad libitum and milked twice daily. The adaptation period lasted 11 d, followed by 5 d with 12 diurnal sampling times of digesta and ruminal fluid. Thereafter, gas exchange was measured for 5 d in respiration chambers. Chromic oxide and titanium dioxide were used as external flow markers to determine intestinal nutrient flow. No interactions between fat supplementation and 3-NOP were observed for methane yield (g/kg DM), total-tract digestibility of nutrients or total volatile fatty acid (VFA) concentration in the rumen. Methane yield (g/kg DMI) was decreased by 24% when cows were fed 3-NOP. In addition, 3-NOP increased carbon dioxide and hydrogen yield (g/kg DM) by 6% and 3,500%, respectively. However, carbon dioxide production was decreased when expressed on a daily basis. Fat supplementation did not affect methane yield but tended to reduce methane in percent of gross energy intake. A decrease (11%) in DMI was observed, when cows were fed 3-NOP. Likely, the lower DMI mediated a lower passage rate causing the tendency to higher rumen and total-tract neutral detergent fiber digestibility, when the cows were fed 3-NOP. Total VFA concentrations in the rumen were negatively affected both by 3-NOP and fat supplementation. Furthermore, 3-NOP caused a shift in the VFA fermentation profile, with decreased acetate proportion and increased butyrate proportion, whereas propionate proportion was unaffected. Increased concentrations of the alcohols methanol, ethanol, propanol, butanol, and 2-butanol were observed in the ruminal fluid when cows were fed 3-NOP. These changes in rumen metabolites indicate partial re-direction of hydrogen into other hydrogen sinks, when methanogenesis is inhibited by 3-NOP. In conclusion, fat supplementation did not reduce methane yield, whereas 3-NOP reduced methane yield, irrespective of fat level. However, the concentration of 3-NOP and diet composition and resulting desired mitigation effect must be considered before implementation. The observed reduction in DMI with 80 mg 3-NOP/kg DM was intriguing and may indicate that a lower dose should be applied in a Northern European context; however, the mechanism behind needs further investigation.

Modeling the relationship between heat stress, feed intake, and day relative to calving in nonlactating dairy cows

Heat stress (HS) during the dry period can affect animal welfare, health, dry matter intake (DMI), and milk production in the subsequent lactation, which will negatively affect the profitability of dairy farms. In this study, the objective was to model the changes in DMI in pregnant nonlactating heat-stressed dairy cows with or without access to evaporative cooling systems. A database composed of individual DMI records from 244 pregnant nonlactating heat-stressed dairy cows from 7 experiments averaging from -35 (-42 to -21 d) to -1 d relative to calving (DRC) and housed in environmental conditions in which temperature-humidity index (THI) ranged from 58.4 to 83.3, with or without access to evaporative cooling systems was built. Generalized additive mixed-effects models were used to describe the relationships of DMI with HS and DRC. Changes in DMI with the increase in THI and the progression of pregnancy in cows with or without evaporative cooling systems were estimated using differential equations. On average, cows housed in barns without evaporative cooling systems had a reduction in DMI of 1.30 kg/d and increased rectal temperature in 0.22°C in relation to those housed in barns with evaporative cooling systems. Dry matter intake decreased as THI increased, but the reduction was greater for non-cooled cows as THI values increased. In addition, regardless of the THI, DMI started to decrease at DRC = -14 for cooled cows, while for non-cooled cows it already started at DRC = -30 relative to the previous days evaluated. The intensity of the reduction was lesser for cows that had access to evaporative cooling systems and/or were in the dry period in May-June as compared with those that were in the dry period in July-August or September-October. The models generated in this study, which include environmental variables, should lead to more accurate predictions of DMI during heat stress that can be used to formulate diets to meet the needs of the late pregnant cow because it is possible to predict changes in DMI as the heat load and DRC change. Such models are also expected to help dairy nutritionists to decide when and how to apply the dietary strategies available to attenuate the reductions in DMI with the intensity of heat stress and progression of pregnancy.

Effect of IGF-1 C472T, GH C2141G, and GHR T914A polymorphisms on growth performance and feed efficiency in young Kazakh white-headed cattle.

Improving the feed efficiency of beef cattle is necessary to increase the profitability of meat production. Implementing marker-assisted selection breeding systems can improve the genetic potential of beef cattle for increased productivity. This research aimed to study the effects of insulin-like growth factor (IGF)-1 C472T, growth hormone (GH) C2141G, and GH receptor (GHR) T914A polymorphisms on growth performance and feed efficiency in young Kazakh white-headed cattle. Young Kazakh white-headed cattle (n = 50) were grouped after weaning according to sex (28 bulls and 22 heifers) and they were genotyped according to the IGF-1 C472T, GH C2141G, and GHR T914A polymorphisms. The test period was conducted from 8 to 15 months of age. The experimental animals were evaluated for live weight (LW) at the beginning and end of the test period. They were also assessed for average daily gain, hip height, metabolic mid-weight (MMWT), actual dry matter intake (DMI), and residual feed intake (RFI). Significant differences in MMWT were found between the bulls with the IGF-1TT and IGF-1CT genotypes, which was a 2.2 kg increase in heterozygous cattle (p < 0.05). Heterozygous IGF-1CT bulls differed with a higher DMI of 0.087 kg/day (p < 0.05) compared to IGF-1TT homozygotes. Carriers of the IGF-1TT genotype had the greatest feed efficiency at 0.068 kg/day (p < 0.05). Heifers with the GHCC genotype differed in their maximum DMI with an increase of 1.17%-1.57% (p < 0.05) relative to the other genotypes. The G allele in the GH C2141G polymorphism was associated with better (p < 0.05) feed efficiency in the Kazakh white-headed breed. The minimum DMI and RFI in GHR T914A heterozygous heifers were significantly inferior (p < 0.05) to the other genotypes. Association studies of the IGF-1 C472T, GH C2141G, and GHR T914A polymorphisms indicate a relationship between growth, development, and feed efficiency with the genetic characteristics of young Kazakh white-headed cattle. A significant (p < 0.05) dominant effect was found in the IGF-1 gene in bulls and in the GHR gene in heifers, which should be considered when breeding with heterogeneous parental pairs. The negative effect of the allele substitution in the IGF-1 C472T polymorphism was observed in the LW of heifers (-3.25 kg) at the age of 8 months and bulls (-6.05 kg) at 15 months. The substitution in the GH C2141G polymorphism was associated with a significant reduction in DMI by 0.036 kg (p < 0.05) and an increase in feed efficiency by 0.023 kg (p < 0.05) during the rearing of heifers. These results can improve the production efficiency of mature herds of Kazakh white-headed cattle.

Effect of nitrate supplementation, dietary protein supply, and genetic yield index on performance, methane emission, and nitrogen efficiency in dairy cows

The objective was to investigate the effect of nonprotein nitrogen source, dietary protein supply, and genetic yield index on methane emission, N metabolism, and ruminal fermentation in dairy cows. Forty-eight Danish Holstein dairy cows (24 primiparous cows and 24 multiparous cows) were used in a 6 × 4 incomplete Latin square design with 4 periods of 21-d duration. Cows were fed ad libitum with the following 6 experimental diets: diets with low, medium, or high rumen degradable protein (RDP):rumen undegradable protein (RUP) ratio (manipulated by changing the proportion of corn meal, corn gluten meal, and corn gluten feed) combined with either urea or nitrate (10 g NO3-/kg of dry matter) as nonprotein nitrogen source. Samples of ruminal fluid and feces were collected from multiparous cows, and total-tract nutrient digestibility was estimated using TiO2 as flow marker. Milk samples were collected from all 48 cows. Gas emission (CH4, CO2, and H2) was measured by 4 GreenFeed units. We observed no significant interaction between dietary RDP:RUP ratio and nitrate supplementation, and between nitrate supplementation and genetic yield index on CH4 emission (production, yield, intensity). As dietary RDP:RUP ratio increased, intake of crude protein, RDP, and neutral detergent fiber and total-tract digestibility of crude protein linearly increased, and RUP intake linearly decreased. Yield of milk, energy-corrected milk, and milk protein and lactose linearly decreased, whereas milk fat and milk urea nitrogen concentrations linearly increased as dietary RDP:RUP ratio increased. The increase in dietary RDP:RUP ratio resulted in a linear increase in the excretion of total purine derivatives and N in urine, but a linear decrease in N efficiency (milk N in % of N intake). Nitrate supplementation reduced dry matter intake (DMI) and increased total-tract organic matter digestibility compared with urea supplementation. Nitrate supplementation resulted in a greater reduction in DMI and daily CH4 production and a greater increase in daily H2 production in multiparous cows compared with primiparous cows. Nitrate supplementation also showed a greater reduction in milk protein and lactose yield in multiparous cows than in primiparous cows. Milk protein and lactose concentrations were lower for cows receiving nitrate diets compared with cows receiving urea diets. Nitrate supplementation reduced urinary purine derivatives excretion from the rumen, whereas N efficiency tended to increase. Nitrate supplementation reduced proportion of acetate and propionate in ruminal volatile fatty acids. In conclusion, no interaction was observed between dietary RDP:RUP ratio and nitrate supplementation, and no interaction between nitrate supplementation and genetic yield index on CH4 emission (production, yield, intensity) was noted. Nitrate supplementation resulted in a greater reduction in DMI and CH4 production, and a greater increase in H2 production in multiparous cows than in primiparous cows. As the dietary RDP:RUP ratio increased, CH4 emission was unaffected and RDP intake increased, but RUP intake and milk yield decreased. Genetic yield index did not affect CH4 production, yield, or intensity.

Enteric Methane Emissions from Dairy-Beef Steers Supplemented with the Essential Oil Blend Agolin Ruminant.

Agriculture is the largest source of methane globally, and enteric methane accounts for 32% of methane emissions globally. Dairy-beef is an increasingly important contributor to the beef industry. The objective of this study was to investigate if supplementation with a blend of essential oils (Agolin Ruminant) reduced enteric methane emissions from dairy-bred steers. Methane was measured from thirty-six Holstein Friesian steers (18 control and 18 treatment) in open-circuit respiration chambers, at three time-points relative to the introduction of Agolin Ruminant: (i) -3 (pre-additive introduction co-variate), (ii) 46 days after introduction, and (iii) 116 days after introduction. A significantly lower methane yield was observed in treated animals compared to control animals at both 46 days (p < 0.05) and 116 days (p < 0.01) after the introduction of Agolin Ruminant, although there was no difference in methane production (g/day). Control animals appeared to be more affected by isolation in respiration chambers than animals receiving Agolin Ruminant, as indicated by a significant reduction in dry matter intake by control animals in respiration chambers.

Modeling the effects of heat stress in animal performance and enteric methane emissions in lactating dairy cows

Heat stress (HS) negatively affects dry matter intake (DMI), milk yield (MY), feed efficiency (FE), and free water intake (FWI) in dairy cows, with detrimental consequences to animal welfare, health, and profitability of dairy farms. Absolute enteric methane (CH4) emission, yield (CH4/DMI), and intensity (CH4/MY) may also be affected. Therefore, the goal of this study was to model the changes in dairy cow productivity, water intake, and absolute CH4 emissions, yield, and intensity with the progression (days of exposure) of a cyclical HS period in lactating dairy cows. Heat stress was induced by increasing the average temperature by 15°C (from 19°C in the thermoneutral period to 34°C) while keeping relative humidity constant at 20% (temperature-humidity index peaks of approximately 83) in climate-controlled chambers for up to 20 d. A database composed of individual records (n = 1,675) of DMI and MY from 82 heat-stressed lactating dairy cows housed in environmental chambers from 6 studies was used. Free water intake was also estimated based on DMI, dry matter, crude protein, sodium, and potassium content of the diets, and ambient temperature. Absolute CH4 emissions was estimated based on DMI, fatty acids, and dietary digestible neutral detergent fiber content of the diets. Generalized additive mixed-effects models were used to describe the relationships of DMI, MY, FE, and absolute CH4 emissions, yield, and intensity with HS. Dry matter intake and absolute CH4 emissions and yield reduced with the progression of HS up to 9 d, when it started to increase again up to 20 d. Milk yield and FE reduced with the progression of HS up to 20 d. Free water intake (kg/d) decreased during the exposure to HS mainly because of a reduction in DMI; however, when expressed in kg/kg of DMI it increased modestly. Methane intensity also reduced initially up to d 5 during HS exposure but then started to increase again following the DMI and MY pattern up to d 20. However, the reductions in CH4 emissions (absolute, yield, and intensity) occurred at the expense of decreases in DMI, MY, and FE, which are not desirable. This study provides quantitative predictions of the changes in animal performance (DMI, MY, FE, FWI) and CH4 emissions (absolute, yield, and intensity) with the progression of HS in lactating dairy cows. The models developed in this study could be used as a tool to help dairy nutritionists to decide when and how to adopt strategies to mitigate the negative effects of HS on animal health and performance and related environmental costs. Thus, more precise and accurate on-farm management decisions could be taken with the use of these models. However, application of the developed models outside of the ranges of temperature-humidity index and period of HS exposure included in this study is not recommended. Also, validation of predictive capacity of the models to predict CH4 emissions and FWI using data from in vivo studies where these variables are measured in heat-stressed lactating dairy cows is required before these models can be used.

Effect of short-term nutritional supplementation of green microalgae on some reproductive indicators of Anglo-Nubian crossbred goats

Background and Aim: Despite the wide spectrum of uses, one of the chief drawbacks to expanding microalgae as a food supplement in livestock is the lack of a regimen protocol with established dosage and time length of supplementation. Therefore, this study aimed to investigate the effect of short-term supplementation with increasing doses of microalgae on ovarian response in goats reared in northeast Brazil. Materials and Methods: Twenty-eight goats had their follicular waves synchronized using three injections of a prostaglandin analog at 7-day intervals. Goats were allocated to groups that received daily oral Chlorella supplementation for 7 days, respectively: 5 g, GMA5 group (n = 7), 10 g (GMA10; n = 7), and 20 g (GMA20; n = 7). The control group (GMA 0; n = 7) received a drench of water. Results: The groups showed a quadratic increase (p = 0.0156) in kidney fat thickness but there was a significant reduction in dry matter intake in the GMA20 group. The GMA20 group showed higher glucose levels and glutathione peroxidase (p &lt; 0.05). There was a decrease in plasma cholesterol (p &lt; 0.05) in the 10 and 20 g treatments. The number of total follicles increased quadratically. Follicles &lt;3 mm increased linearly (p = 0.0113) for microalgal supply. The GMA10 and GMA20 groups had the highest values (p &lt; 0.05) among the treatments. After inducing ovulation, there was a significant increase in follicles &gt;3 mm in the GMA10 group, which also showed a greater (p &lt; 0.05) area of intraovarian blood perfusion and pulsatility index of the ovarian artery. Conclusion: We conclude that for 7 days of supplementation, the administration of 10 g of microalgae appears to be the most efficient dosage for stimulating the ovarian response in tropical goats. Keywords: Doppler, follicles, goat, microalga, ovarian blood flow, ovarian response.

Effect of short-term nutritional supplementation of green microalgae on some reproductive indicators of Anglo-Nubian crossbred goats.

Despite the wide spectrum of uses, one of the chief drawbacks to expanding microalgae as a food supplement in livestock is the lack of a regimen protocol with established dosage and time length of supplementation. Therefore, this study aimed to investigate the effect of short-term supplementation with increasing doses of microalgae on ovarian response in goats reared in northeast Brazil. Twenty-eight goats had their follicular waves synchronized using three injections of a prostaglandin analog at 7-day intervals. Goats were allocated to groups that received daily oral Chlorella supplementation for 7 days, respectively: 5 g, GMA5 group (n = 7), 10 g (GMA10; n = 7), and 20 g (GMA20; n = 7). The control group (GMA 0; n = 7) received a drench of water. The groups showed a quadratic increase (p = 0.0156) in kidney fat thickness but there was a significant reduction in dry matter intake in the GMA20 group. The GMA20 group showed higher glucose levels and glutathione peroxidase (p < 0.05). There was a decrease in plasma cholesterol (p < 0.05) in the 10 and 20 g treatments. The number of total follicles increased quadratically. Follicles <3 mm increased linearly (p = 0.0113) for microalgal supply. The GMA10 and GMA20 groups had the highest values (p < 0.05) among the treatments. After inducing ovulation, there was a significant increase in follicles >3 mm in the GMA10 group, which also showed a greater (p < 0.05) area of intraovarian blood perfusion and pulsatility index of the ovarian artery. We conclude that for 7 days of supplementation, the administration of 10 g of microalgae appears to be the most efficient dosage for stimulating the ovarian response in tropical goats.

Effects of dietary organic acid and pure botanical supplementation on growth performance and circulating measures of metabolic health in Holstein calves challenged by heat stress

To evaluate the effects of heat stress environmental conditioning and dietary supplementation with organic acid and pure botanicals (OA/PB) on growth in dairy calves, we enrolled 62 bull (noncastrated) and heifer calves in a study with a completely randomized design. Calves were assigned to 1 of 5 groups (n = 11 to 14/group): (1) thermoneutral conditions (TN-Con), (2) HS conditions (HS-Con), (3) thermoneutral conditions and pair-fed to match nutrient intake with HS-Con (TN-PF), (4) HS with low-dose OA/PB [75 mg/kg of body weight (BW); 25% citric acid, 16.7% sorbic acid, 1.7% thymol, 1.0% vanillin, and 55.6% triglyceride; HS-Low], or (5) HS with high-dose OA/PB (150 mg/kg of BW; HS-High). Supplements were delivered as a twice-daily bolus via the esophagus from wk 1 through 13 of life; all calves, including those on the control treatments, received an equivalent amount of triglyceride used for microencapsulation. Calves were raised in TN conditions from birth until weaning. After weaning, calves (62 ± 2 d; 91 ± 10.9 kg of BW) were transported to a new facility and remained in TN conditions [temperature-humidity index (THI): 60 to 69] for a 7-d covariate period. Thereafter, calves remained in TN or were moved to HS conditions (THI: diurnal change 75 to 83 during night and day, respectively) for 19 d. Clinical assessments were performed thrice daily, BW was recorded weekly, and blood was sampled on d 1, 2, 3, 8, 15, and 19. Upon experiment completion, calves from HS-Con and TN-Con were euthanized, and hot carcass and visceral organ weights were recorded. The mixed model included calf as a random effect; treatment, day, hour (when appropriate) as fixed effects, and the interactions of treatment × day and treatment × hour (when appropriate). Rectal and skin temperatures and respiration rates were greater in HS-Con than in TN-Con. During heat stress exposure, dry matter intake (DMI), average daily gain (ADG), and gain to feed (G:F) were lower in HS-Con relative to TN-Con. Comparing HS-Con and TN-PF, ADG and G:F were similar. Plasma fatty acid concentrations were elevated in TN-PF compared with HS-Con and TN-Con. Despite tendencies for increased aspartate aminotransferase, HS conditions did not overtly influence liver and inflammation markers. Liver weights were lower in HS-Con relative to TN-Con. During the first week of heat exposure, DMI was greater for HS-Low relative to HS-Con. Supplementation of OA/PB at low and high levels had a similar G:F to HS-Con. We conclude that reductions in DMI accounted for production losses during HS conditioning and that dietary OA/PB supplementation was not able to improve growth performance in heat-stressed calves.

Yerba mate (Ilex paraguariensis) as a source of antioxidants with soybean grain in supplementation of lactating ewes reared in tropical pastures.

The hypothesis tested is that the association of soybean grain and yerba mate as an antioxidant source can increase the concentration of polyunsaturated fatty acids (PUFA) with lower oxidation of milk from lactating ewes reared in tropical pastures. Sixteen ewes were randomly distributed in a 2x2 factorial scheme (with or without yerba mate at 110 g / kg of dry matter (DM); with or without soybean grain at 210 g/kg of DM). Yerba mate intake reduced DM intake, and concentrations of ether extract (EE), protein, lactose, defatted dry extract, density, omega-3 concentrations, and the ratio between saturated/monounsaturated fatty acids (FA), but increased the concentration of monounsaturated FA and the sequestering power of free radicals by DPPH without altering the concentrations of conjugated dienes and the concentrations of substances reactive to thiobarbituric acid in milk. Supplementation with soybean grain decreased the birth weight of the lambs and increased the concentrations of conjugated linoleic acid (CLA), PUFA, omega - 6, omega ratio - 6/omega - 3, and total blood cholesterol. The addition of yerba mate did not influence the oxidative profile of milk. Supplementation with soybean grain improved the FA profile of milk, increasing the concentrations of CLA and PUFA. The results suggest that the association of yerba mate and soybean grain helps to improve the fat quality of milk from ewes raised in tropical pastures, as shown by the enhanced antioxidant activity, although it does not help prevent oxidation of milk rich in PUFA.

Impact of Probiotic Geotrichum candidum QAUGC01 on Health, Productivity, and Gut Microbial Diversity of Dairy Cattle.

Gut microbial diversity is a determinant of animal productivity and health. Probiotic supplementation in feed has been known to modulate the gut microbial diversity resulting in better feed utilization and resistance against diseases. The current study was designed to determine the probiotic potential of Geotrichum candidum QAUGC01 (VHDP00000000) in Sahiwal-Friesian crossbred dairy cows and its impact on gut microbial diversity, health, and productivity. To evaluate health and productivity, growth performance, determination of blood parameters, serum biochemistry, feed efficiency, milk yield & composition, and nutrients digestibility was determined and compared between control and experimental groups. Moreover, at the end of the experiment, the gut microbial diversity was evaluated through MiSeq (Illumina) sequencing of bacterial and fungal/yeast DNA in dung samples of both control and experimental cows. Inspite ofa significant reduction in dry matter intake the increase in feed efficiency and milk yield was observed in experimental cows with normal hematological and serum biochemical profile. The increase in anaerobic bacterialcount and decrease in the shredding of pathogenic flora was observed in experimental cows. Metagenomic analysis revealed Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes to be the four dominating phyla among bacteria and, Ascomycota followed by Basidiomycota and Neocallimastigomycota among the fungal population in both groups. The diversity of the core microbiome revealed high bacterial and Fungal Alpha diversity in the experimental group than in control via the Shannon index. This study provided insights into the safe use of G. candidum as a probiotic, to improve growth performance, health, productivity and gut microbial diversity of dairy cattle.

PSVI-18 Effect of Processing Method and Severity for Hybrid Fall rye on dry Matter Intake, Ruminal Fermentation, and Apparent Total Tract Nutrient Digestibility in Ruminally Cannulated Beef Heifers

Abstract This study evaluated the effect of processing method and severity of hybrid fall rye on dry matter intake (DMI), ruminal fermentation, and apparent total tract nutrient digestibility for beef cattle. Ruminally cannulated Simmental heifers (n = 8; 327±33 kg) were used in a replicated 4×4 Latin square (21-d periods) balanced for carry-over effects with a 2×2 factorial treatment. Tempered rye [water added to achieve 80% dry matter (DM)] was compared with dry-rolled rye. Roller gap width of 1.23-mm and 0.8-mm were used for coarse and finely processed rye, respectively. This resulted in processing index values of: 80.9% for dry-rolled and coarse; 72.7% for dry-rolled and fine; 92.9% for tempered and coarse; and 88.2% for tempered and fine processed rye. Diets (DM basis) included hybrid rye grain (86%), barley silage (15%), mineral (6%), and dry distillers’ grain plus solubles (3%). Feeding tempered rye increased (P&amp;lt; 0.01) DMI by 0.87 kg compared with dry-rolled rye, and feeding coarse rye increased (P=0.04) DMI by 0.33 kg compared with fine rye. Cattle fed dry-rolled and finely processed rye had greater (P&amp;lt; 0.04) area that pH was &amp;lt; 5.5 compared with tempered and coarse rye, respectively. Ruminal short-chain fatty acid concentrations and ammonia were not affected (P≥0.12). Feeding dry-rolled rye increased DM digestibility by 2.4% (P=0.02), and crude protein digestibility in 3.0% (P=0.01) compared with tempered rye. Starch digestibility was not affected by processing severity of dry-rolled rye, but increased from 92.8 to 95.9% for tempered rye with increasing severity (interaction, P=0.03). Rolling tempered rye at the same roller gap as dry-rolled rye decreases processing severity but may allow for a greater severity of processing without marked reductions in DMI and ruminal pH, while achieving similar total tract starch digestibility. When increasing processing severity (81 vs. 73%), dry-rolling hybrid rye may reduce DMI and ruminal pH.

Haemonchus contortus Parasitism in Intensively Managed Cross-Limousin Beef Calves: Effects on Feed Conversion and Carcass Characteristics and Potential Associations with Climatic Conditions.

The objectives of the study were: (a) to study the effect of Haemonchus spp. on the growth performance characteristics of fattening calves, (b) to assess any potential effects on carcass characteristics and (c) to investigate the potential role of climatic conditions in the process of the infection. The study was conducted for 201 days in an intensively managed cross-Limousin herd. The animals were divided into two equal groups: those receiving anthelmintic treatment (AT) and the untreated (C) controls. The same nutritional regime was applied to both groups and the feed consumption was calculated daily. Standard parasitological examinations were performed at weekly intervals. At slaughter, carcasses were weighed and assessed for conformation and fat cover classes. Climatic variables were obtained for the location of the farm and a temperature-humidity index was calculated. Before anthelmintic treatment with ivermectin, there was no difference in parasitic burdens between the two groups: 544 (AT) vs. 554 (C) epg, whilst after it, counts were 0 and 450–700 epg, respectively, with over 96% of larvae identified as Haemonchus spp. and, later, confirmed as Haemonchus contortus. It was concluded that treated animals had a higher average total bodyweight gain, higher feed conversion ratio and carcass yield of superior quality than controls. There was a difference between the two groups in the pattern of reduction of dry matter intake as the temperature-humidity index increased.

The feeding behavior of dairy cattle under tropical heat stress conditions at smallholder urban farming

Abstract. Despal, Faresty C, Zahera R, Toharmat R. 2022. Title The feeding behavior of dairy cattle under tropical heat stress conditions at smallholder urban farming. Biodiversitas 23: 3771-3777. Dairy cattle (Bos taurus) feeding behavior influences feed intake and affect animal welfare and disease management. This study observed dairy cattle feeding behaviors under tropical smallholder urban farming environments. Thirty-six cattle at the Kebon Pedes area of Bogor City were observed during 12 h feeding (6 am-6 pm). These traits included eating, ruminating, resting duration, and frequencies, measured using a continuous method. Temperature, humidity, temperature-humidity index (THI), feed and nutrient intake, milk production, and components were measured. The results showed that the cattle were in mild to severe heat stress. The average cow daily eating, ruminating, and resting frequencies were 6.61, 7.61, and 22.33 times, while the average eating, ruminating, and resting durations per cow per 12 h were 129.64, 105.67, and 484.69 minutes, respectively. The dry matter intake was 11.17 kg with a roughage to concentrate ratio of 0.73:1. The protein, ash, ether extract, and crude fiber intake were 10.25, 6.62, 3.67, and 22.08% DM, respectively. The average milk productions and fat contents were 11.01 L/head/d and 5.44%. The results showed that eating and ruminating levels correlated positively with feed, and CF intakes while resting correlated negatively. It was concluded that the cattle were in heat-stressed (THI of &gt;78) condition, reduced DM intake, and deficient in energy and CP, which led to lower milk production but higher milk components, specifically milk fat. It is recommended to improve forage quality that promotes eating and ruminating and reduces resting durations, improving milk production.

Effect of processing method and severity for hybrid fall rye on dry matter intake, ruminal fermentation, and apparent total tract nutrient digestibility in ruminally cannulated beef heifers

This study compared dry-rolled and tempered hybrid rye when processed to a coarse or fine severity on dry matter intake (DMI), ruminal fermentation, and apparent total tract nutrient digestibility for beef cattle. Eight ruminally cannulated Simmental heifers (327 ± 33.1 kg, mean ± SD) were used in a replicated 4 × 4 Latin square (21-day periods with 16 days for adaptation and 5 d collection) balanced for carry-over effects with a 2 × 2 factorial arrangement of treatments. Feeding tempered rye increased ( P = 0.01) DMI when compared to dry-rolled rye, but there was no effect of processing severity. Cattle fed dry-rolled rye had a greater ( P = 0.04) area that pH was &lt;5.5 when compared to those fed tempered rye. Feeding dry-rolled rye increased dry matter digestibility ( P = 0.02) and crude protein digestibility ( P = 0.01) when compared to tempered rye, and there was a greater effect to increase total tract starch digestibility with increasing severity of processing for tempering than for dry rolling (interaction, P = 0.03). In conclusion, tempered hybrid rye processed to a fine severity may result in similar total tract starch digestibility to dry-rolled hybrid rye without the marked reductions in DMI and ruminal pH.

Performance, Digestibility, Nitrogen Balance and Ingestive Behavior of Young Feedlot Bulls Supplemented with Palm Kernel Oil.

Simple SummaryVegetable oil can be used to increase energy density in diets; manipulate ruminal fermentation; alter nutrient degradation, digestion and absorption; and improve carcass characteristics and quality. Palm kernel oil (PKO) is extracted from the fruit of the oil palm (Elaeis guineenses), a plant of African origin adapted to tropical regions. The aim of this study was to evaluate PKO as a supplementary fat source in ruminant diets. Thus, two studies were developed to understand the effects of PKO inclusion on performance, ingestive behavior, nutrient digestibility, fermentation parameters and carcass characteristics. The results showed a reduction in dry matter intake with consequent negative effects on digestibility, performance and carcass characteristics due to the dietary inclusion of PKO. However, the addition of the lipid source reduced protozoa counts and the acetate/propionate ratio, important characteristics for reducing ruminal methanogenesis, in further studies.Vegetable oils can be used to increase energy density in diets; manipulate rumen fermentation; and alter the capacity for degradation, digestion and absorption of nutrients. Two experiments were conducted to evaluate palm kernel oil (PKO) in the diet of confined bulls with the inclusion of 0.0, 11.5, 23.0 and 34.6 g PKO/kg dry matter (DM). The first experiment evaluated nutrient intake, performance, ingestive behavior and carcass characteristics. In the second experiment, steers crossbred with a ruminal cannula were used to evaluate digestibility, nitrogen balance, microbial protein synthesis, short-chain fatty acid levels and protozoal counts. The results showed that the inclusion of PKO linearly reduced intake in kg/day (DM, crude protein—CP, neutral detergent fiber—NDFap, nonfibrous carbohydrates—NFC and total digestible nutrient—TDN) and digestibility (DM, NDFap and TDN). Ether extract intake increased quadratically with the predicted maximum intake of 15.4 g/kg DM. Regarding ingestive behavior, there was a quadratic increase in rumination time and a quadratic reduction in idle time. Nitrogen balance, nitrogen intake, nitrogen retention, microbial protein production, acetate, butyrate, acetate/propionate ratio and protozoa count showed linear decreases due to dietary PKO inclusion. Regarding the carcass characteristics, linear decreases were observed for the final weight, average daily gain, hot carcass weight, cold carcass weight, hot carcass yield, cold carcass yield, loin eye area and subcutaneous fat thickness. The inclusion of PKO at up to 34.6 g/kg DM in diets for confined bulls reduces intake, negatively affecting digestibility, performance and carcass characteristics.

Effects of calcium ammonium nitrate fed to dairy cows on nutrient intake and digestibility, milk quality, microbial protein synthesis, and ruminal fermentation parameters

We evaluated the effects of supplemental calcium ammonium nitrate (CAN) fed to dairy cows on dry matter (DM) intake, nutrient digestibility, milk quality, microbial protein synthesis, and ruminal fermentation. Six multiparous Holstein cows at 106 ± 14.8 d in milk, with 551 ± 21.8 kg of body weight were used in a replicated 3 × 3 Latin square design. Experimental period lasted 21 d, with 14 d for an adaptation phase and 7 d for sampling and data collection. Cows were randomly assigned to receive the following treatments: URE, 12 g of urea/kg of DM as a control group; CAN15, 15 g of CAN/kg of DM; and CAN30, 30 g of CAN/kg of DM. Supplemental CAN reduced DM intake (URE 19.0 vs. CAN15 18.9 vs. CAN30 16.5 kg/d). No treatment effects were observed for apparent digestibility of DM, organic matter, crude protein, ether extract, and neutral detergent fiber; however, CAN supplementation linearly increased nonfiber carbohydrate digestibility. Milk yield was not affected by treatments (average = 23.1 kg/d), whereas energy-corrected milk (ECM) and 3.5% fat-corrected milk (FCM) decreased as the levels of CAN increased. Nitrate residue in milk increased linearly (URE 0.30 vs. CAN15 0.33 vs. CAN30 0.38 mg/L); however, treatments did not affect nitrite concentration (average: 0.042 mg/L). Milk fat concentration was decreased (URE 3.39 vs. CAN15 3.35 vs. CAN30 2.94%), and the proportion of saturated fatty acids was suppressed by CAN supplementation. No treatment effects were observed on the reducing power and thiobarbituric acid reactive substances of milk, whereas conjugated dienes increased linearly (URE 47.6 vs. CAN15 52.7 vs. CAN30 63.4 mmol/g of fat) with CAN supplementation. Treatments had no effect on microbial protein synthesis; however, molar proportion of ruminal acetate and acetate-to-propionate ratio increased with CAN supplementation. Based on the results observed, supplementing CAN at 30 g/kg of DM should not be recommended as an optimal dose because it lowered DM intake along with ECM and 3.5% FCM, although no major changes were observed on milk quality and ruminal fermentation.