Effect of Mineral Salt Blocks Containing Sodium Bicarbonate or Selenium on Ruminal pH, Rumen Fermentation and Milk Production and Composition in Crossbred Dairy Cows

Ruminal pH is an important physiological parameter that regulates microbe activity; optimizing ruminal pH may improve rumen fermentation and milk production. The purpose of this experiment was to determine the effect of sodium bicarbonate (NaHCO3) or selenium (Se) in mineral salt block (MSB) supplementation on ruminal pH, rumen fermentation, milk yield and composition in Holstein Friesian crossbred dairy cows. Four crossbred dairy cows with an initial weight of 456 ± 6 kg in mid-lactation were assigned at random using a 4 × 4 Latin square design. The experiments were divided into four periods, each lasting 21 days. Each cow was fed a basal diet supplemented with a different type of mineral salt block: a control with no MSB supplementation, and MSB groups with MSB containing NaHCO3 (MSB-Na), MSB containing Se (MSB-Se), and conventional commercial MSB (MSB-Com). MSB-Na contained NaHCO3 (500 g/kg) to prevent acidosis, MSB-Se contained organic Se (15 mg/kg) as an antioxidant, and MSB-Com was a positive control mineral salt block. The results show that there was no significant difference in feed intake between treatments, but there was a significant difference in mineral salt intake between treatments (p < 0.05). Supplementing mineral blocks had no effect on nutrient intake or apparent digestibility (p > 0.05). Ruminal pH was not different between treatments at 0 and 1 h post-feeding, but at 2 and 4 h post-feeding, ruminal pH in cows fed MSB-Na and MSB-Se was significantly higher (p < 0.05) than it was in cows fed MSB-Com and the control. Total volatile fatty acid (VFA), acetic, propionic, butyric, and ammonia nitrogen and blood urea nitrogen were not influenced by mineral blocks supplementation. Milk yield, milk composition and energy-corrected milk (ECM) were not affected by supplementing mineral blocks. However, compared with the control, the somatic cell count (SCC) in the milk was reduced (p < 0.05) by supplementation with the mineral salt block. Based on the results of the experiments, it was concluded that MSB-Na or MSB-Se supplementation improved ruminal pH while having no effect on feed intake, rumen fermentation, milk yield, or composition, though it did reduce SCC in milk. However, additional research should be conducted to investigate the effect of MSB on rumen ecology and milk production in dairy cows fed a high-concentrate diet.

Evaluation of gastrointestinal transit times and pH in healthy cats using a continuous pH monitoring system

Objectives The aim of this study was to characterize gastrointestinal (GI) transit times and pH in healthy cats. Methods GI transit times and pH were measured in six healthy, colony-housed, purpose-bred spayed female cats using a continuous, non-invasive pH monitoring system in a sequential order design. For the first period (‘pre-feeding’), food was withheld for 20 h, followed by oral administration of a pH capsule. Five hours post-capsule administration, cats were meal-fed by offering them their daily allowance of food for 1 h. For the second period (‘post-feeding’), food was withheld for 24 h and cats were fed for 1 h, after which a pH capsule was orally administered. Studies in both periods were repeated three times. GI transit times and pH were compared between the two periods. Results The median transit times for the pre- and post-feeding periods, respectively, were: gastric –94 mins (range 1–4101) and 1068 mins (range 484–5521); intestinal –1350 mins (range 929–2961) and 1534 mins (range 442–2538); and GI –1732 mins (range 1105–5451) and 2795 mins (range 926–6563). The median GI pH values for the first and second periods, respectively, were: esophageal –7.0 (range 3.5–7.8) and 4.5 (range 2.9–6.4); gastric –2.7 (range 1.7–6.2) and 2.0 (range 1.1–3.3); intestinal –8.2 (range 7.6–8.7) and 7.8 (range 6.7–8.5); first-hour small intestinal –8.2 (range 7.4–8.7) and 8.3 (range 7.9–8.6); and last-hour large intestinal –8.5 (range 7.0–8.9) and 7.8 (range 6.3–8.7). Gastric ( P <0.0020) and intestinal pH ( P <0.0059) were significantly increased in the pre-feeding period compared with the post-feeding period. Conclusions and relevance Gastric and intestinal pH differed significantly when the capsule was administered 5 h prior to feeding compared with 1 h after feeding. Transit times for both periods showed high degrees of intra- and inter-individual variability.

Feed intake, rumen metabolite and some blood parameters of yearling Bunaji bulls fed graded levels of palm kernel cake

The need to observe the changes taking place in the animal's body in response to external factors such as nutrition, housing system and microclimate as it affects intake, rumen metabolite, haematological and biochemical parameters cannot be over-emphasized. Against this background, a study was conducted to evaluate the effect of feeding diets containing graded levels of Palm Kernel Cake (PKC) on feed intake, rumen metabolites, haematological and biochemical characteristics of yearling Bunaji bulls. Twenty yearling Bunaji bulls with average weight of 130kg and aged 1-1.5 years were balanced for weight and allotted to five dietary treatments with four bulls per treatment in Completely Randomized Design. They were individually penned and fed diets containing graded levels of PKC at (0, 10, 20, 30 and 40%) and Digitaria smutsii (Wholly finger grass) hay at 4% body weight (2% concentrate and 2% hay). The feeding trial lasted for 90 days. Blood samples were collected at the beginning, middle and end of the feeding trial to determine some haematological and biochemical changes. Rumen fluid were collected at 0, 3, 6 and 9hrs intervals to determine the rumen pH, rumen ammonia nitrogen(RAN) and rumen total volatile fatty acids(TVFA) for the yearling bulls. The CP contents of the experimental diets varied between 14.19 and 17.75% while ME ranged from 11.79 to11.81MJ/kg DM. The crude fibre varied from 26.36-38.77%. Average feed intake ranged between 5.38-5.61Kg/day with animals on 10%, 20% and 40% PKC being statistically similar (P>0.05).Rumen parameters were significantly (P<0.05) affected by sampling time, such that at 0hrRumen pH was highest (7.08) and lowest at 3hrs post feeding(6.66),RAN value was similar at 0hr pre feeding (10.44 mg/100mL) and 3hr post feeding (9.93 mg/100mL) but differ at 6hr (8.25 mg/100ml) and 9hrs post feeding (8.34mg/100mL).There was significant difference (P< 0.05) among treatments for all the haematogical and biochemical parameters measured. Highest urea value was obtained at 0% PKC inclusion, animals on diets containing 20,30 and 40%PKC were statistically similar (P>0.05), Total protein ranged from 70.83 - 78.92 g/l and highest value was obtained at 30% PKC inclusion, animals on diets containing 10% and 20%PKC were statistically similar (P>0.05) but differ from 40%. The study concluded that up to 40% inclusion level of PKC could be added to the diets of yearling Bunaji bulls with no adverse effect on their feed intake, rumen metabolite and some of their blood parameters. La nécessité d'observer les changements qui se déroulent dans le corps de l'animal en réponse à des facteurs externes tels que la nutrition, le système de logement et le microclimat, car il affecte l'apport, le métabolite du rumen, les paramètres hématologiques et biochimiques ne peuvent pas être surestimés. Dans ce contexte, une étude a été menée pour évaluer l'effet de l'alimentation des régimes alimentaires contenant des niveaux classés de gâteau au noyau de palmier (GNP) sur l'apport alimentaire, les métabolites rumen, les caractéristiques hématologiques et biochimiques des taureaux de Bunaji d'Annulation. Vingt Bunaji Bunaji avec poids moyen de 130 kg et de 1 à 1,5 ans ont été équilibrés pour poids et alloué à cinq traitements diététiques avec quatre taureaux par traitement dans une conception complètement randomisée. Ils ont été individuellement engagés et nourris à des régimes alimentaires contenant des niveaux classés de GNP à (0, 10, 20, 30 et 40%) et digitariasmutsii (à 100% de l'herbe à doigts) à 4% de poids corporel (concentré de 2% et 2% de foin). L'essai d'alimentation a duré 90 jours. Les échantillons de sang ont été collectés au début, au milieu et à la fin de l'essai d'alimentation afin de déterminer des changements hématologiques et biochimiques. Les liquides de rumen ont été recueillis à des intervalles de 0, 3, 6 et 9hrs pour déterminer le pH de rumen, l'azote d'ammoniac rumen (AAR) et les acides gras volatils rumen (AGVV) pour les taureaux yearling. Le contenu du CP des régimes expérimentaux variait entre 14,19 et 17,75%, tandis que je suis allant de 11,79 à 11,81 MMJ / kg DM. La fibre brute variait de 26,36-38,77%. L'admission moyenne d'aliments allait entre 5,38 et 5,61 kg / jour avec des animaux sur 10%, 20% et 40% GNP étant statistiquement similaires (p> 0,05). Rumen Les paramètres étaient significativement (p <0,05) affectés par le temps d'échantillonnage, tel que à 0hr rumen Le pH était le plus élevé (7.08) et le plus bas à 3 heures d'alimentation post (6,66), la valeur de AAR était similaire à 0HR pré-alimentation (10,44 mg / 100 ml) et 3hrs post-alimentation (9,93 mg / 100 ml) mais diffèrent à 6h (8,25 mg / 100 mg). et 9 heures après l'alimentation (8h34 mg / 100 ml) était une différence significative (p <0,05) parmi les traitements pour tous les paramètres hématogiques et biochimiques mesurés. La valeur la plus élevée de l'urée a été obtenue à 0% d'inclusion de GNP, les animaux sur les régimes contenant 20,30 et 40% de GNP étaient statistiquement similaires (p> 0,05), une protéine totale allait de 70,83 - 78,92 g / l et une valeur la plus élevée a été obtenue à 30% de GNP. L'inclusion, les animaux sur les régimes contenant 10% et 20% de GNPétaient statistiquement similaires (p> 0,05) mais diffèrent de 40%. L'étude a conclu que jusqu'à 40% de niveau d'inclusion de GNP pouvait être ajouté au régime alimentaire des taureaux de la Bunaji qui n'y a pas d'effet défavorable sur leur consommation d'alimentation, le métabolite du rumen et certains de leurs paramètres de sang.

PSX-A-12 Late-Breaking: Effects of Renergy™ on ruminal fermentation in steers fed a high-grain diet

Renergy™ is a proprietary blend of organic acids with a proposed mode of action of increasing ruminal propionate production. Little is known about the efficacy of Renergy™ supplementation in modifying ruminal fermentation in beef cattle consuming high-grain diets. Therefore, eight Angus steers (BW 531.7 ± 20.4 kg) fitted with ruminal cannulae were used to determine the effects of Renergy™ on ruminal fermentation characteristics. Steers were fed a high concentrate diet (DM basis: 13.6% CP, 1.38 Mcal/kg NEg, and 2.02 Mcal/kg NEm) with no monensin sodium or tylosin phosphate added to the diet for 30 d prior to the initiation of the experiment. Treatments consisted of control (CON; no supplemental Renergy™) and Renergy (REN) fed at 27.6 g.animal-1.d-1 (n = 4 steers/treatment; experimental unit = animal). Following the 30 d diet adaptation period, dietary treatments were initiated for 28-d. On day 28, rumen fluid was collected at 3 h post feeding and analyzed for VFA, pH, and NH3. Ruminal pH (P = 0.62) and NH3 (P = 0.56) were unaffected by treatment. However, total VFA (P = 0.05) and propionate (P = 0.03) production were increased by Renergy, 13.3% and 25.7% respectively. There was a tendency (P = 0.14) for acetate production to be increased 10.9% in steers supplemented with Renergy™. Butyrate was unaffected (P = 0.51) by treatment. However, isobutyrate production was lower (P &lt; 0.01) in steers receiving Renergy™. Feeding Renergy™ also resulted in 25% less (P = 0.07) L-lactate production. Under conditions of this experiment, results indicate that supplementing Renergy™ for 28d to beef cattle consuming high concentrate diets impacts ruminal fermentation 3 h post feeding.

313 Effects of Bismuth Subsalicylate on Ruminal Fermentation of Cattle Consuming a Feedlot Diet

A replicated 3 × 3 Latin square was used to determine the effects of bismuth subsalicylate on ruminal fermentation parameters of beef cattle consuming a feedlot diet. Six ruminally-cannulated Angus-crossbred steers (n = 3; 573 ± 105 kg BW) and heifers (n = 3; 553 ± 77 kg BW) were assigned 1 of 3 treatments: 1) low sulfur (S = 0.27% diet DM; LSUL); 2) high sulfur (S = 0.38% diet DM; HSUL); and 3) HSUL + 0.33% bismuth subsalicylate in diet DM; (BSS). Cattle were adapted to treatments for 14 d followed by 7 d of collections. Ruminal gas cap samples were collected at 0, 4, 8, and 12 h post-feeding on d 14, and ruminal fluid samples were collected on d 15 every 3 h post-feeding for 24 h. Data were analyzed using the MIXED procedure of SAS. Treatment tended (P = 0.099) to affect H2S concentration where BSS and LSUL were 50 and 61% lesser when compared to HSUL, respectively. A tendency (P = 0.061) was also observed for concentration of NH3-N where HSUL and BSS were lesser than CTRL. There was also a tendency for a treatment effect (P = 0.082) where HSUL had a lower pH than LSUL with BSS being intermediate. Furthermore, treatment tended (P = 0.0712) to affect the concentration of acetate where HSUL was lesser than BSS. No effect of treatment (P ≥ 0.124) was observed on total VFA concentration nor concentrations of butyrate, propionate, or valerate (P ≥ 0.138). Treatment tended (P = 0.084) to affect branched chain VFA concentration where BSS decreased concentrations compared to LSUL. Molar proportions of the major VFA were not impacted by treatment (P ≥ 0.100). In conclusion, BSS appears to decrease H2S production in the rumen without having negative effects on the fermentation profile.

Developmental models of the carrion beetle Thanatophilus rugosus (Linnaeus, 1758) (Coleoptera: Silphidae)

Coleoptera are currently considered a fundamental tool to help solve criminal investigations, allowing forensic entomologists to estimate post-mortem intervals and obtain other ecology-related information. Thanatophilus rugosus (Linnaeus, 1758) is an important necrophagous beetle distributed through most of the Palaearctic region, where it is readily found on human bodies and animal carcasses. In this study, the new thermal summation models for all the developmental stages of Thanatophilus rugosus are provided. Beetles were reared at six different constant and ecologically relevant temperatures (12, 14, 16, 18, 20, and 22 °C), and their developmental times were measured. Thermal summation constants were calculated for each developmental stage (egg, three larval instars, post-feeding stage, and pupa).

Diurnal Ruminal pH and Temperature Patterns of Steers Fed Corn or Barley-Based Finishing Diets

This study evaluated the effects of corn or barley finishing diets on ruminal pH and temperature and their relationship to feed intake events using continuous reticulorumen monitoring of feedlot steers. Average daily ruminal pH and temperature were not impacted (p ≥ 0.17) by diet. However, diet did affect daily variation of ruminal pH and temperature (p < 0.01). Average hourly ruminal pH displayed a diet by hour post-feeding interaction (p < 0.01), where barley-fed steers had greater (p < 0.01) ruminal pH than corn-fed steers at 0, 1, 18, 19, 20, 21, 22 and 23 h post feeding, but had lower (p ≤ 0.05) ruminal pH than corn-fed steers at 6, 7, and 8 h post-feeding. Variation in ruminal pH hour post-feeding also displayed a diet by hour post-feeding interaction (p < 0.01), where barley-fed steers had greater (p ≤ 0.03) variation in ruminal pH at hours 1–17 post-feeding but did not differ (p ≥ 0.16) at 0, 18, 19, 20, 21, 22 and 23 h post-feeding. Additionally, average hourly ruminal temperature exhibited a diet by hour post-feeding interaction (p < 0.01). In summary, basal grain interacted with time post-feeding influencing ruminal pH and temperature in feedlot steers.

Life Cycle of Chrysomya rufifacies (Diptera: Calliphoridae) Under Semi-Controlled Laboratory Conditions

Adult Calliphoridae flies, as well as their immature stages collected from carcasses, have been used as evidence in forensic investigations to estimate the postmortem interval (PMI), particularly those of the genus Chrysomya as it is one of the first genera to colonize a corpse. Chrysomya rufifacies (Macquart 1842), due to its appearance in cadaveric remains, plays a fundamental role in the study of forensic entomology. For this reason, we determined the biological cycle of C. rufifacies under semicontrolled laboratory conditions: uncontrolled average fluctuating temperature of 29. 76 ± 3. 22°C, uncontrolled average fluctuating humidity of 48. 91 ± 11.13%, and a controlled photoperiod of 12/12 (L/O). We established that the total development time from oviposition to adult emergence of C. rufifacies was 6. 5 d. The eggs took 12 h to hatch after oviposition. The complete larval stage took 60 h (instar 1 = 12 h, instar 2 = 12 h, instar 3 = 24 h, instar 3 post-feeding = 12 h). The pupa had a duration of 84 h. The species needed a total of 4642.8(±4.59) accumulated degree-hours (ADH) to complete its biological cycle.

Disentangling the Complexity of the Rumen Microbial Diversity Through Fractionation Using a Sucrose Density Gradient

The ruminal microbial community is an important element in health, nutrition, livestock productivity, and climate impact. Despite the historic and current efforts to characterize this microbial diversity, many of its members remain unidentified, making it challenging to associate microbial groups with functions. Here we present a low-cost methodology for rumen sample treatment that separates the microbial community based on cell size, allowing for the identification of subtle compositional changes. In brief, the sample is centrifuged through a series of sucrose density gradients, and cells migrate to their corresponding density fraction. From each fraction, DNA is extracted and 16S rRNA gene amplicons are sequenced. We tested our methodology on four animals under two different conditions, fasting, and post-feeding. Each fraction was examined by confocal microscopy showing that the same sucrose fraction consistently separated similar cell-sized microorganisms independent of the animal or treatment. Microbial composition analysis using metabarcoding showed that our methodology detected low abundance bacterial families and population changes between fasting and post-feeding treatments that could not be observed by bulk DNA analysis. In conclusion, the sucrose-based method is a powerful low-cost approximation to untwine, enrich, and potentially isolate uncharacterized members of the ruminal microbiome.

Biological Parameters of Three Populations of Triatoma dimidiata s. s. (Hemiptera: Reduviidae) From Western Mexico

Chagas disease is a very important vector-borne disease in México, and Triatoma dimidiata sensu stricto (Latreille) is one of the most important vectors of Trypanosoma cruzi Chagas, mainly in southern and central states. In the Pacific Coast states with the highest prevalence of human T. cruzi infection, T. dimidiata s. s. is considered as a secondary vector. However, the vectorial capacity of those populations has not been studied. Therefore, the vector characteristics of three populations of T. dimidiata s. s. in western México were evaluated in this study. The populations were maintained in the laboratory at 27 ± 1°C and 75% ± 5% RH with a 12:12 h (light:dark) regime, fed on rabbits in a fortnight basis. The development times were short (172–238 d), and the number of bloodmeals to molt was low (11). Mortality was moderate (36–45%), the onset of feeding was relatively rapid (0.5–1.7 min), and feedings were extended (&gt;15 min). More than 40% of individuals in most instars defecated in one of three categories: &lt;1 min when feeding (5–37.9%), immediately after feeding (9–28.6%), or in &lt;1 min post feeding (7–25.8%). The median number of laid eggs was high (over 2.5) in the three populations, as were the egg eclosion rates (&gt;86%). Thus, the T. dimidiata s. s. in the three populations are potentially efficient vectors of T. cruzi and could contribute to the high prevalence of infection in human populations in western México.