Bioactive metabolites of Asparagopsis stabilized in canola oil completely suppress methane emissions in beef cattle fed a feedlot diet.

Asparagopsis taxiformis (Asparagopsis) has been shown to be highly efficacious at inhibiting the production of methane (CH4) in ruminants. To date, Asparagopsis has been primarily produced as a dietary supplement by freeze-drying to retain the volatile bioactive compound bromoform (CHBr3) in the product. Steeping of Asparagopsis bioactive compounds into a vegetable oil carrier (Asp-Oil) is an alternative method of stabilizing Asparagopsis as a ruminant feed additive. A dose-response experimental design used 3 Asp-Oil-canola oil blends, low, medium, and high Asp-Oil which provided 17, 34, and 51 mg Asparagopsis derived CHBr3/kg dry matter intake (DMI), respectively (in addition to a zero CHBr3 canola oil control), in a tempered-barley based feedlot finisher diet, fed for 59 d to 20 Angus heifers (five replicates per treatment). On four occasions, live weight was measured and CH4 emissions were quantified in respiration chambers, and blood, rumen fluid, and fecal samples were collected. At the end of the experiment, all animals were slaughtered, with carcasses graded, and samples of meat and edible offal collected for testing of consumer sensory qualities and residues of CHBr3, bromide, and iodide. All Asp-Oil treatments reduced CH4 yield (g CH4/kg DMI, P = 0.008) from control levels, with the low, medium, and high Asp-Oil achieving 64%, 98%, and 99% reduction, respectively. Dissolved hydrogen increased linearly with increasing Asp-Oil inclusion, by more than 17-fold in the high Asp-Oil group (P = 0.017). There was no effect of Asp-Oil treatment on rumen temperature, pH, reduction potential, volatile fatty acid and ammonia production, rumen pathology, and histopathology (P > 0.10). There were no differences in animal production and carcass parameters (P > 0.10). There was no detectable CHBr3 in feces or any carcass samples (P > 0.10), and iodide and bromide residues in kidneys were at levels unlikely to lead to consumers exceeding recommended maximum intakes. Overall, Asp-Oil was found to be safe for animals and consumers of meat, and effective at reducing CH4 emissions and yield by up to 99% within the range of inclusion levels tested.

Red seaweed, Asparagopsis taxiformis (Asparagopsis), has been shown to be highly effective at inhibiting the production of methane (CH4) in ruminants. An alternative to feeding whole, freeze-dried Asparagopsis is steeping the biomass in vegetable oil to stabilize the bioactive compounds (Asp-Oil) and feeding Asp-Oil to ruminants as a component of their dietary intake. This experiment measured the CH4 reduction potential and safety of Asp-Oil in a trial with 20 Angus heifers, fed iso-fat feedlot diets containing one of the three levels of Asp-Oil, or a control oil. Compared to the control, bromoform inclusion levels of 17, 34, and 51 mg/kg of dry matter (DM; low, medium, high) reduced CH4 yield (g CH4/kg DM intake) by 64%, 98%, and 99%, respectively. There were no effects on animal production or carcass characteristics. There were no impacts on animal health, welfare, or rumen function. Carcasses were safe for human consumption, and there was no bromoform detected in any carcass samples. Overall, Asp-Oil was found to effectively reduce CH4 emissions and is safe for animals and consumers of meat and edible offal.

The phenotypic diversity in the production performance of Alabio ducks (Anas platyrhynchos Borneo) in South Kalimantan, Indonesia.

Objective: This study aimed to examine the diversity of phenotypic characteristics of female Alabio ducks (Anas platyrhynchos Borneo) and their eggs in South Kalimantan, Indonesia. Materials and Methods: A total of 200 18-month-old ducks and 300 eggs were selected using a survey method with multistage random sampling. These samples were obtained from two districts in the province of South Kalimantan [Banjar (BJ) districts and Tanah Laut (TL)]. The observed data were analyzed descriptively with variations using the independent t-test for each location. Principal component analysis (PCA) was deployed to assess the overall variance and define variables with greater discriminatory power between individuals. Results: The observations on the body's physical characteristics and the eggs of Alabio ducks showed significant differences between ducks from BJ and TL areas (p < 0.05) except for yolk diameter, albumen height, albumen index, and Haugh unit (HU) (p > 0.05). Most egg quality traits from BJ were greater than those from TL, which include egg weight, egg length, egg width, yolk weight, albumen weight, shell weight, shell thickness, and egg shape index. The PCA revealed medium-to-high communalities in the phenotypic body characteristics of Alabio ducks and their eggs. Conclusion: Significant physical characteristics and egg quality differences were found between the two locations, except for the albumen index and HU, with substantial variability within each trait. These traits could explain the total variation in the phenotypic characteristics of female Alabio ducks.

The effects of antibiotic-free supplementation on the ruminal pH variability and methane emissions of beef cattle under the challenge of subacute ruminal acidosis (SARA).

Subacute ruminal acidosis (SARA) in feedlot cattle during the feed transition to grain-based diets is a significant constraint to animal health and productivity. This experiment assessed an antibiotic-free supplement (ProTect®) effects on ruminal pH variability and methane (CH4) emissions of cattle during the challenge of SARA. Ten 18-month-old Angus steers (472 ± 4.8 kg) were randomly allocated into monensin (n = 5) and ProTect® groups (n = 5) and progressively introduced to grain diets incorporating monensin or ProTect® for 36 days of the experiment [starter (7 days; 45% grain), T1 (7 days; 56% grain), T2 (7 days; 67% grain), finisher (15 days; 78% grain)]. The pH variability on the finisher period was reduced by the ProTect® supplement (6.6% vs. 5.2%; P < 0.01), with CH4 emissions being significantly higher relative to the monensin group [88.2 g/day (9.3 g CH4/kg DMI) vs. 133.7 g/day (14.1 g CH4/kg DMI); P < 0.01]. There was no difference between treatments in the time spent on the ruminal pH < 5.6 or < 5.8 (P > 0.05). The model evaluation for the ruminal pH variation indicated that the mean absolute error (MAE) proportion for both groups was good within the same range [4.05% (monensin) vs. 4.25% (ProTect®)] with identical root mean square prediction error (RMSPE) (0.34). It is concluded that the ProTect® supplement is an effective alternative to monensin for preventing SARA in feedlot cattle by managing ruminal pH variation during the transition to high-grain diets. Both monensin and ProTect® supplemented cattle exhibited lower CH4 yield compared to cattle fed forages and low-concentrate diets.

Production performance of Alabio ducks (Anas platyrhynchos Borneo) under different levels of drinking water salinity.

Objective: To examine the effects of the salinity level of drinking water on the egg production and quality of Alabio ducks. Materials and Methods: A total of 60 female Alabio ducks, aged 6 months, were subjected to this study. All ducks were kept in stage-type cages (1 m length × 1 m width × 0.5 m height), where each cage was inhabited by 4 ducks for 56 days of experimentation. All ducks were offered a mixed ration ad libitum for laying ducks, according to the nutritional requirements for egg-type ducks. The treatment in this study was drinking water with five stratified salinity levels, namely P0 = freshwater (0% salinity); P1 = water with a salinity of 0.75 practical salinity unit (PSU) (equal to 0.75 g NaCl/l); P2 = water with a salinity of 1.5 PSU (1.5 gm/l); P3 = water with a salinity of 2.5 PSU (2.5 gm/l); and P4 = water with a salinity of 3 PSU (3.0 gm/l). Observations were made on water intake, feed intake, egg production, and egg quality (egg weight, egg shape index density, shell proportion, shell thickness, yolk index, albumen index, and Haugh unit). Results: The results showed that the difference in salinity levels in drinking water from 0.75 PSU to 3 PSU did not affect water intake, feed intake, egg production, or egg quality of Alabio ducks for the first 56 days of the laying period (p > 0.05). Conclusions: It was concluded that Alabio ducks have a good tolerance for drinking water salinity of up to 3 PSU, or equal to 3 gm/l NaCl.

A Pilot Study Using Accelerometers to Characterise the Licking Behaviour of Penned Cattle at a Mineral Block Supplement.

Identifying the licking behaviour in beef cattle may provide a means to measure time spent licking for estimating individual block supplement intake. This study aimed to determine the effectiveness of tri-axial accelerometers deployed in a neck-collar and an ear-tag, to characterise the licking behaviour of beef cattle in individual pens. Four, 2-year-old Angus steers weighing 368 ± 9.3 kg (mean ± SD) were used in a 14-day study. Four machine learning (ML) algorithms (decision trees [DT], random forest [RF], support vector machine [SVM] and k-nearest neighbour [kNN]) were employed to develop behaviour classification models using three different ethograms: (1) licking vs. eating vs. standing vs. lying; (2) licking vs. eating vs. inactive; and (3) licking vs. non-licking. Activities were video-recorded from 1000 to 1600 h daily when access to supplement was provided. The RF algorithm exhibited a superior performance in all ethograms across the two deployment modes with an overall accuracy ranging from 88% to 98%. The neck-collar accelerometers had a better performance than the ear-tag accelerometers across all ethograms with sensitivity and positive predictive value (PPV) ranging from 95% to 99% and 91% to 96%, respectively. Overall, the tri-axial accelerometer was capable of identifying licking behaviour of beef cattle in a controlled environment. Further research is required to test the model under actual grazing conditions.