Comparing the yield and nutritional value of ensiled amaranth (Amaranthus hypochondriacus) cultivars with corn silage (Zea mays) in doublecropping condition.

Yield, chemical composition, and fermentation variables were compared for amaranth silages (AMS) from five cultivars (A5, A12, A14, A28, and Maria) and corn (Zea mays; CS). In vitro methane production, organic matter disappearance, microbial protein, ammonia-N concentration, volatile fatty acid levels, cellulolytic bacteria and protozoa populations, and in situ dry matter (DM) and crude protein (CP) degradability were evaluated. All crops were harvested when the plant was at the mid-milk line stage, then chopped, placed in sealed 5 L plastic bags and stored for 60 days. Data analysis was carried out using the PROC MIXED method of SAS with a randomized complete block design. The mean DM forage yield of CS was higher than the average DM yield of the amaranth cultivars (P < 0.001). In comparison with CS, the AMS had higher CP, lignin, ether extract, ash, calcium, phosphorus, magnesium, total phenolics and metabolizable protein (P < 0.001), but had lower DM, neutral detergent fiber, non-fiber carbohydrates, organic matter disappearance, lactic acid (P < 0.01) and in vitro methane production (P = 0.001). The AMS had higher (P < 0.01) pH, ammonia-N concentration, in vitro microbial protein, in situ digestible undegradable protein, and metabolizable protein compared to CS. Overall, in comparison to CS, the amaranths produced a silage of medium-quality.

Effects of yeast culture and oxalic acid supplementation on in vitro nutrient disappearance, rumen fermentation, and bacterial community composition.

Hemicellulose is an important polysaccharide in ruminant nutrition, but it has not been studied as thoroughly as cellulose. Further research is needed to explore supplements that can improve its digestibility and ruminal buffering effects. Our previous research demonstrated the efficacy of oxalic acid (OA) as an essential nutrient in yeast culture (YC) for improving rumen fermentation performance. Consequently, we conducted in vitro rumen digestion experiments to examine the effects of YC and OA on rumen fermentation and bacterial composition. Two diets containing different levels of hemicellulose were formulated: diet 1 with 10.3% and diet 2 with 17% hemicellulose. Three levels of YC (0.00, 0.625, and 1.25 g/kg) and three doses of OA (0.0, 0.4, and 0.8 g/kg, DM) were added into each diet with a 3 × 3 factorial design. A comprehensive assessment was conducted on a total of 18 experimental treatments at fermentation periods of 0, 6, 12, 24, and 48 h. In the first experiment (diet 1), the supplementation of YC, OA, and their interaction significantly increased in vitro DM disappearance (IVDMD) and NDF disappearance (IVNDFD; p < 0.001). In the second experiment (diet 2), the supplementation of OA and the interaction between YC and OA (p < 0.001) increased IVDMD and IVCPD, but had no significant effects on IVNDFD. The interactions of YC and OA significantly increased ammonia nitrogen (p < 0.001). The production of acetic acid, propionic acid, and total volatile fatty acids (TVFA), and pH levels were significantly higher in treatments supplemented with YC and OA (p < 0.001). YC and OA in both diets significantly altered the rumen bacterial community leading to increased Shannon and Simpson diversity indices (p < 0.001). In both diets, OA supplementation significantly increased the relative abundance of the phylum Bacteroidetes and Prevotella genus. The result also showed a positive correlation between the Prevotella and Selenomonas genera with IVDMD, IVNDFD, propionic acid, and TVFA production, suggesting that these dominant bacteria enhanced nutrient disappearance in the rumen. In conclusion, adding YC and OA resulted in modifications to the bacterial community's composition and diversity, and improved nutrient disappearance. These changes indicate improved rumen fermentation efficiency, which is promising for future in vivo studies.

Effects of harvest date and growth stage on triticale forages in the southwest USA: kinetics of in vitro disappearance of fiber and dry matter.

Recently, there has been interest in including triticale (X Triticosecale Wittmack) within forage programs in the southwest USA. Our objectives were to evaluate in vitro disappearance kinetics of neutral detergent fiber (NDF) and dry matter (DM) for cultivars identified during 2019 as positively or negatively deviant from typical cultivars, based specifically on regressions of 48-h in vitro disappearance of NDF on growth stage (GRST). All NDF analyses included the use of heat-stable α-amylase and sodium sulfite, as well as correction for residual ash (asNDFom). Seven triticale cultivars were established on December 18, 2019 at the University of Arizona Maricopa Agricultural Center, located near Maricopa, AZ. Forage plots were arranged in a randomized complete block design with three complete blocks (replications), and then harvested on seven dates the following late-winter and spring (February 26, March 17, April 1, April 14, April 28, May 12, and May 26). Based on a linear model, GRST was highly variable among cultivars on March 17 (44 ±â€…10.6), April 1 (57 ±â€…12.1), April 14 (67 ±â€…8.9), and April 28 (79 ±â€…7.2) compared with other harvest dates (SD ≤ 1.7). For concentrations of asNDFom, all cultivars exhibited linear (P ≤ 0.042) and quadratic (P < 0.001) polynomial contrasts in response to harvest date, and all cultivars except Merlin Max (P ≥ 0.063) exhibited at least one additional cubic or quartic effect (P ≤ 0.015). A contributing factor to the unique response by Merlin Max was the numerically greater maximum canopy height (145 ±â€…9.8 cm) compared with the mean of all cultivars (107 ±â€…17.7 cm), which also was associated with greater percentages of stem, as well as reduced percentages of DM partitioned within the grain head. Regressions of asNDFom disappearance after 30- or 48-h incubations on GRST indicated this was an effective independent variable (R2 ≥ 0.927), and responses were most often linear in nature. Generally, relationships for DM disappearance were quadratic, ostensibly due to the complicating effect of grain fill, but GRST was again an effective predictor variable with R2 statistics ≥ 0.852 for 12 of 14 combinations of cultivar and incubation time. Predicted percentages of digestible DM attributed to asNDFom disappearance were ≥50.3% through the fully flowered stage of growth, but digestible contributions from nonfiber components following the onset of grain fill profoundly affected overall DM digestibility among cultivars harvested at later GRST.

Recently, there has been increased interest in including triticale within forage programs throughout the southwest USA. Unless there is an urgency for removing the triticale crop, such as those created by a feed shortage or need to establish a secondary crop, harvest management decisions should be based on plant growth stage, and not calendar date. Assuming a common growth stage, this work suggests that most triticale cultivars will differ only modestly with respect to digestibility before the onset of grain fill. However, producers should be cautious of cultivars with unique or atypical phenotypic traits, such as exceptional canopy height, which may cause exceptions to the previous generalization. If yield is a critical management objective, harvest should most likely be delayed until after the onset of grain fill, but cultivar selection can become more complicated at that time because varying contributions from the filling grain head can radically affect overall digestibility of dry matter (DM). In this respect, producers should carefully evaluate their nutritional and production goals to assess whether their needs prioritize digestible fiber or overall DM digestibility, the latter of which can have limited contributions from digestible fiber.

Protein and energy concentrations of meat meal and meat and bone meal fed to pigs based on in vitro assays.

The objective of this study was to develop equations for estimating ileal digestible crude protein (CP) and metabolizable energy (ME) contents of meat meal (MM) and meat and bone meal (MBM) as feed ingredients for pigs based on in vitro assays. Test ingredients were 4 sources of MM and 3 sources of MBM. Ash and CP contents of the ingredients ranged from 3.8% to 33.1% and 46.8% to 82.9% (as-is basis), respectively. In vitro ileal disappearance (IVID) of CP was determined and ileal digestible CP content was calculated by multiplying CP content by IVID of CP. In vitro total tract disappearance (IVTTD) of dry matter (DM) was determined and ME was calculated using gross energy, CP contents, and IVTTD of DM. The IVID of CP and IVTTD of DM ranged from 77.2% to 88.7% and from 82.7% to 92.4%, respectively. Calculated ileal digestible CP and ME contents ranged from 37.8% to 73.5% DM and 2,405 to 3,905 kcal/kg DM, respectively. Ash contents were negatively correlated (P < 0.001) with CP (r = -0.99), in vitro ileal digestible CP (r = -0.97), gross energy (r = -1.00), in vitro digestible energy (r = -0.97), and adjusted ME (r = -0.97). The most fitting equations for ileal digestible CP and adjusted ME were: ileal digestible CP (% DM) = 11.91 - 0.90 × Ash (% DM) + 0.74 × IVID of CP (%) (R 2 = 0.99) and adjusted ME (kcal/kg DM) = 130.85 - 50.90 × ash (% DM) + 47.06 × IVTTD of DM (%) (R 2 = 0.99). To validate the accuracy of the prediction equations for ME, mean bias and linear bias were determined using a regression analysis. Calculated ME values of MM and MBM were in a good agreement with data obtained from animal experiments based on a statistically insignificant bias in the models. In conclusion, ME concentrations of MM and MBM as swine feed ingredients can be calculated using ash concentration and in vitro disappearance of dry matter.

Effects of supplemental xylanase on in vitro disappearance of dry matter in feed ingredients for swine / Efectos de la suplementación con xilanasa sobre la desaparición in vitro de materia seca en ingredientes de piensos para cerdos / Efeitos da xilanase suplementar no desaparecimento in vitro de matéria seca em ingredientes de rações para suínos

Abstract Background: Alternative feed ingredients are widely used in swine diets to lower feed costs, but these ingredients contain a large quantity of non-starch polysaccharides. Supplemental xylanase is known to break down non-starch polysaccharides. However, the effects of exogenous xylanase from Bacillus subtilis on various feed ingredients have rarely been compared. Objective: To evaluate the effects of supplemental xylanase on in vitro disappearance of dry matter (DM) in various feed ingredients for pigs. Methods: Nine feed ingredients were used to measure in vitro ileal disappearance and in vitro total tract disappearance of DM. Each ground ingredient was supplemented with either supplemental xylanase (9,000 U/g) or cornstarch at 1.0%. Results: Supplemental xylanase increased in vitro ileal disappearance of DM in wheat, barley, wheat flour, and wheat bran (p<0.05). The in vitro total tract disappearance of DM for barley and wheat bran increased with xylanase addition (p<0.05). Conclusion: Exogenous xylanase could increase in vitro ileal DM disappearance in barley, wheat, wheat flour, and wheat bran, but did not affect in vitro total tract DM disappearance in wheat and wheat flour.

Resumen Antecedentes: Los ingredientes alternativos se utilizan ampliamente en las dietas porcinas para reducir los costos del pienso, pero estos ingredientes contienen una gran cantidad de polisacáridos no-amiláceos. Se sabe que la xilanasa suplementaria descompone los polisacáridos diferentes al almidón. Sin embargo, rara vez se han comparado los efectos de la xilanasa exógena de Bacillus subtilis en algunos ingredientes del alimento. Objetivo: Evaluar los efectos de la xilanasa suplementaria sobre la desaparición in vitro de la materia seca (MS) en varios ingredientes alimentarios para cerdos. Métodos: Se utilizaron nueve ingredientes del alimento para medir la desaparición ileal in vitro y la desaparición del tracto total in vitro de MS. Cada ingrediente molido se complementó con xilanasa suplementaria (9,000 U/g) o almidón de maíz al 1,0%. Resultados: La xilanasa suplementaria aumentó la desaparición ileal in vitro de MS en trigo, cebada, harina de trigo y salvado de trigo (p<0,05). La desaparición de tracto total de MS in vitro para la cebada y el salvado de trigo aumentó con la adición de xilanasa (p<0,05). Conclusión: La xilanasa exógena podría aumentar la desaparición de la MS ileal in vitro en cebada, trigo, harina de trigo y salvado de trigo, pero no afecta la desaparición de la MS en tracto total in vitro del trigo y la harina de trigo.

Resumo Antecedentes: Ingredientes alternativos para rações são amplamente usados em dietas para suínos para reduzir os custos da alimentação, mas esses ingredientes contêm uma grande quantidade de polissacarídeos não amiláceos. A xilanase suplementar é conhecida por quebrar polissacarídeos não amiláceos. No entanto, os efeitos da xilanase exógena de Bacillus subtilis em vários ingredientes da ração raramente foram comparados. Objetivo: Avaliar os efeitos da xilanase suplementar no desaparecimento in vitro da matéria seca (MS) em vários ingredientesde rações para suínos. Métodos: Nove ingredientes da ração foram usados para medir o desaparecimento ileal in vitro e o desaparecimento de MS in vitro do trato total. Cada ingrediente moído foi suplementado com xilanase suplementar (9.000 U/g) ou amido de milhoa 1,0%. Resultados: A xilanase suplementar aumentou o desaparecimento ileal in vitro de MS em trigo, cevada, farinha de trigo e farelo de trigo (p<0,05). O desaparecimento in vitro de MS do trato total para cevada e farelo de trigo aumentou com a adição de xilanase (p<0,05). Conclusão: A xilanase exógena pode aumentar o desaparecimento in vitro da MS ileal em cevada, trigo, farinha de trigo e farelo de trigo, mas não afetou o desaparecimento in vitro do trato total da MS no trigo e na farinha de trigo.

In vitro disappearance characteristics of selected categories of commercially available dog treats.

Pet owners desire treats with adequate nutritional profiles, functional benefits, long-lasting properties and an interactive nature. Therefore, it is pivotal to understand the digestion characteristics of treats produced by different processing methods and having variable nutritional composition. The objective of the present study was to measure in vitro disappearance characteristics of selected categories of commercially available treats. In vitro procedures developed by Boisen and Eggum in 1991 were modified to handle larger sample sizes. Treat samples were evaluated in triplicate. Following incubation, in vitro DM disappearance (DMD) was calculated. In vitro DMD of selected treats varied widely. For the gastric phase, DMD ranged from 6·9 to 88·8 %, whereas intestinal phase digestion resulted in a DMD range of 10·7-100·0 % (P < 0·05). Because of differences in treat composition and size, they were divided into six categories: Biscuit, Bone, Chew, Dental, Meat Product and Rawhide. In general, Bone was the least digestible treat category in both gastric and intestinal phases. Meat Product and Rawhide treats had a DMD of 71·5-100 % after the intestinal phase, whereas Biscuit had values above 93 %. Chew and Dental treats had a wide DMD range (54·5-100 %). Understanding the DMD of commercially available treats is important to verify their safety for consumption and potential digestibility once ingested. These data indicate wide variation in DMD among and within different treat categories. This information will assist pet food sale associates, pet owners and veterinarians to make more educated decisions when it relates to selection and recommendations about commercially available treats. Future work is needed to expand the knowledge on in vitro DMD and safety of treats and to further investigate their impact on in vivo DM digestibility once fed to dogs.