Ruminal and morphometric parameters of the rumen and intestines of sheep fed with increasing levels of spineless cactus (Nopalea cochenillifera Salm-Dyck)

Red propolis extract as a natural ionophore for confined sheep: performance and morphological and histopathological changes

This study aimed to evaluate the effect of increasing levels of red propolis extract (RPE) in the diet of confined sheep on performance and histomorphometric parameters of rumen and intestine and histopathological parameters of liver and kidney. Thirty-five male sheep (17.08 ± 2.36 kg) were used, distributed in a completely randomized design, with five treatments (0, 7, 14, 21, and 28 mL day-1 RPE) and seven replications, submitted to 68 days of experiment. At the end of the experimental period, the animals were euthanized, and samples of rumen, intestine, liver, and kidney were collected to histomorphometry and histopathology analyzes. Higher RPE inclusions (21 and 28 mL day-1) maintained dry matter intake and increased total weight (5.78 x 6.14 and 6.95 kg, respectively) gain up to 20.24%. In the rumen, the inclusion of RPE led to an increase in the thickness of the epithelium and the highest level also increased the thickness of the keratinized portion of this epithelium (21.71 x 32.15 μm). The level of 21 mL day-1 provided larger ruminal papillae (1620.68 x 1641.70 μm) and greater ruminal absorption area (561791.43 x 698288.50 μm2). In intestine 21 and 28 mL-1 of RPE provided greater mucosal thickness (468.54 x 556.20 and 534.64 μm), higher goblet cell index (23.32 x 25.82 and 25.64) and higher hepatic glycogen index (1.47 x 1.64 and 1.62), supporting higher nutrients absortion and glicogenolise and intestinal health, corroborating the weight gain indices. The inclusion of RPE did not cause renal histopathological lesions. Therefore, levels of 21 and 28 mL day-1 of RPE can be used in sheep diets, promoting greater final weight gain, causing positive histomorphological changes in the rumen, intestine and liver, without causing kidney or liver damage.

Stall-Feeding of Sheep on Restricted Grazing: Effects on Performance and Serum Metabolites, Ruminal Fermentation, and Fecal Microbiota

This study investigated the effects of three feeding systems, indoor feeding (CONT), indoor feeding with time-restricted grazing artificial pasture (4 h/day, G4H), and indoor feeding with an eight-hour daily grazing artificial pasture (G8H), on the growth performance, serum metabolites, ruminal fermentation, and fecal microbiota composition of lambs. Average daily gain showed a tendency (p = 0.081) to be higher for the G4H group compared with the CONT group. Moreover, feeding systems did not have a significant effect on most of the serum biochemical indicators in lambs. Concentrations of serum glutathione peroxidase and immunoglobulins (IgA, gG, and IgM) were significantly lower (p < 0.01) in the CONT group. Additionally, a tendency towards higher levels of volatile fatty acids, acetate, and butyrate was found in animals of the G4H group compared to the CONT group. Furthermore, fecal microbiota composition was altered in G4H and G8H groups, resulting in the increased relative abundance of Firmicutes and Ruminococcaceae UCG-005, as well as the decreased relative abundance of Ruminobacter compared with the CONT group. Overall, these results suggest that indoor feeding with restricted grazing time does not significantly affect fattening performance or rumen fermentation but enhances antioxidation and immune function activity and also alters fecal microbiota composition.

Effect of spineless cactus [Nopalea cochenillifera (L.) Salm Dyck] on nutrient intake, ingestive behaviour, and performance of lambs

The objective of this study was to evaluate the effect of increasing levels of spineless cactus (SC) [Nopalea cochenillifera (L.) Salm Dyck] on nutrient intake, ingestive behaviour, and performance of lambs in a feedlot. Thirty-two male (non-castrated) Santa Inês lambs with a mean initial body weight (BW) of 20.4 ± 2.60 kg were distributed across four levels of spineless cactus: zero, 24, 52, and 75% of total diet dry matter (DM). Over 56 days, the animals had their intake and performance monitored. The inclusion of SC influenced (p<0.05) in a quadratic way the dry matter intake and total digestible nutrients, but linearly decreased (p<0.05) the neutral detergent fiber intake. Drinking water intake decreased linearly (p<0.05) with the inclusion of SC in the diet. The inclusion of SC influenced (p<0.05) in a quadratic way the digestibility of organic matter in the diet. The increase in the level of SC in the diet increased linearly (p<0.05) the feeding and rumination efficiencies of the lambs. The maximum daily gain of 0.237 kg/day was achieved with 44% SC in the diet. It is recommended to include up to 40% of spineless cactus in the diet of lambs.

Lambs fed diets containing by-product from coconut processing: histomorphometry characteristics in the digestive and renal systems

This study aimed to evaluate the histological characteristics in the digestive and renal systems of lambs fed diets containing coconut by-product (CB). A total of 35 male lambs with an initial weight of 16.9 ± 2.93 kg were distributed in a completely randomized design with five levels of CB in the diet (0; 4.8; 9.6; 14.4 and 19.2% in total dry matter). Samples of the liver, kidney, rumen, and intestine were histomorphometrically evaluated, and the data were submitted to regression analysis, at a 5% error probability. The inclusion of CB linearly decreased the dry matter intake and caused a quadratic effect for the height of ruminal papillae, absorption area, epithelium thickness, as well as for average daily gain. The inclusion of CB linearly increased the mucous layer and reduced the submucosal layer, as well as promoted a decrease in goblet cells in the small intestine. The inclusion of CB did not influence hepatic glycogen; additionally, the histopathological examination did not reveal liver damage or congestion, vacuolization, and necrosis of the renal tissue. Therefore, our results indicate that CB can be included in lambs diet up to the level of 7.2% without causing changes in the histomorphometry characteristics of the gastrointestinal tract and changes in liver and kidney tissue that compromise animal performance.

Effects of replacing ground corn with Nopalea cochenillifera meal on the intake, performance, and economic viability of grazing steers

The objective of this study was to evaluate the effects of replacing different levels of spineless-cactus meal instead of ground corn on supplements for crossbred steers grazing in Urochloa brizantha cv. Marandú pastures. Forty crossbred steers with an average body weight (BW) of 261 ± 7.46 kg were distributed in a completely randomized design. In supplements, the ground corn grain was substituted with 0%, 30%, 60%, and 90% spineless-cactus meal. The substitution of spineless-cactus meal instead ground corn promoted a linear decrease in the ether extract (EE; P = 0.03) and non-fibrous carbohydrates (NFC; P < 0.01) intakes. The apparent digestibility of EE was influenced (P < 0.05) showing a linear decrease. The apparent digestibility of NFC had a quadratic effect (P = 0.03). For the neutral detergent fiber corrected for ash and protein, the apparent digestibility increased linearly (P = 0.01). The average daily gain showed a quadratic effect (P < 0.01), with a maximum response estimated at 44.94% (1055.52 g/day) substitution with spineless-cactus meal for ground corn. The cost per animal per period and the cost per hectare decreased linearly (P < 0.01). The revenue, net revenue, exchange rate, and monthly revenue of the activity showed quadratic responses to the spineless-cactus meal supplements (P < 0.01), with maximum effects at 44.99%, 47.46%, 61.25%, and 57.35%, respectively. The substitution with up to 44.94% of spineless-cactus meal for ground corn provided daily gains, increased the feed conversion, and was favorable as a cost to the production system. Moreover, the profitability increased with maximum animal performance and improved use of fiber from pastures.

Rumen–reticulum organ mass and rumen mucosa surface area of white-tailed deer (Odocoileus virginianus) consuming two energy diets

Flexibility in gut morphology has fitness consequences in herbivores. To accommodate dietary variation in energy concentration, rumen–reticulum absorptive capacity and organ mass might also covary. We hypothesized that low energy diets result in greater food intake but lower volatile fatty acid concentrations. The consequence would be heavy rumen–reticulum organs and low absorptive capacity. We measured rumen–reticulum organ mass and absorptive capacity in captive white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) from central Texas, USA. Deer consumed a pelleted ration, ad libitum, of 1.77 kcal/g (low) or 2.67 kcal/g (standard) digestible energy from the time animals were weaned. In December, 4.5- and 5.5-year-old deer were euthanized, the rumen–reticulum was extracted, thoroughly rinsed, wrung out, and weighed. Four 1 cm × 3 cm samples were extracted from four regions of the rumen and mucosal surface area was measured. Our surrogate of food intake and mastication intensity was first molar height. Molar height was lower in animals consuming the low energy diet. Analyses indicated sex-specific responses. Males eating the low energy diet had heavier rumen–reticulum organs, but females did not. Females consuming the low energy diet had a lower surface enlargement factor, but males did not. The processes driving variation in rumen–reticulum morphology from dietary variation require further examination.

Morphometric and stereological methods for quantifying the coarse structural parameters of the ruminal tissues in sheep

In ruminants, the rumen is the largest and most significant fore-stomach. Stereological analysis of important structural parameters that may be used to assess the functional capacity of the rumen is lacking. In the current investigation, five rams were used to demonstrate the methods for quantifying salient structural parameters related to rumen function. The sheep were euthanized with 20% sodium pentobarbital intravenously, the rumen was dissected out and divided into the various sacs for gross examination, and fixation by total immersion in 10% formalin. Macroscopic ruminal surface area was estimated using the point-associated area method. Volumes of the ruminal tissues were estimated by the volume displacement method, while volume densities of the components of the ruminal wall were estimated by point counting methods. Tissue blocks for histology were obtained by systematic random sampling and processed to obtain vertical sections for surface area and volume estimations. Papillary densities and numbers were estimated from horizontal sections. The volume of ruminal tissue was 536.54 ± 80.52 cm³, the macroscopic surface area was 1091 ± 115.75 cm² with a papillary packing density of 84.64 ± 10.99 cm^-2. Average absolute surface area was 4726.74 ± 628.56 cm². The total number of ruminal papillae per rumen was 92,884.91 ± 6216.46. The methods documented here provide the possibility of doing a detailed stereological analysis of ruminal tissue in different experimental or even pathological conditions.

Evaluation of non-carcass components of goat grazing in Caatinga rangeland supplemented with spineless cactus and native plants

The objective of this study was to evaluate non-carcass components of goats submitted to grazing in the Caatinga rangeland and supplemented with spineless cactus (Nopalea cochelinifera Salm Dick), Jitirana hay (Merremia aegyptia L. Urban) and Mororó hay (Bauhinia cheilanta Bong Stend). Thirty male goats (castrated), with no defined breed, with an initial mean body weight of 19 ± 0.35 kg and approximately 90 days of age were used. The treatments consisted of grazing without supplementation (GWS), grazing + Jitirana hay (GJ); grazing + Jitirana hay + spineless cactus (GJSC); grazing + Mororó hay (GM); grazing + Mororó hay + spineless cactus (GMSC). The means of the variables were tested by Tukey's test at 5% probability. The goats fed GWS, GJSC, GM and GMSC presented higher weights and yields of the diaphragm, and the spleen weight (p < 0.05). The highest yield of omasum (p < 0.05) occurred with goats fed GJ treatment. There were treatments (p < 0.05) on omental fat weight and leg yield, with the highest values for goats, fed GWS, GJSC, GM, and GMSC. The "Buchada" EBW-1 yield was higher (p < 0.05) for animals fed GWS. Feeding supplementation of goats grazing in the Caatinga had few influences on weights and yields of non-carcass components.

Histomorphometric changes of the fore-stomach of lambs fed with diets containing spineless cactus genotypes resistant to Dactylopius sp

The histomorphometric parameters of the fore-stomach epithelium of lambs fed with spineless cactus genotypes resistant to Dactylopius sp. were evaluated. Thirty-two lambs (23.0 ± 2.06 kg body weight) were distributed in a completely randomized design with four treatments and eight replications. The treatments consisted of the base diet and diets in which part of the elephant grass hay and all ground corn was replaced by the Miúda, IPA-Sertânia, or Orelha de Elefante Mexicana (OEM) spineless cacti. The keratin layers of the ruminal epithelium of the animals consuming the spineless cacti Miúda and OEM presented greater thickening relative to the control diet: 47.31, 41.30, and 25.81 μm, respectively. The heights of the ruminal papillae were higher in the animals that were fed with the OEM spineless cactus. The Miúda spineless cactus caused an enlargement in the keratinized layer of the reticulum epithelium, as well as a decrease in the thickness of the non-keratinized layers. The diet containing OEM spineless cactus resulted in greater thickening of the keratin layer of the omasal epithelium and decreased thickness of the non-keratinized layers. The spineless cacti Miúda and OEM changed the morphology of the fore-stomach epithelium and increased the dry matter intake and weight gain of lambs.