Supplementation with live Saccharomyces cerevisiae boulardii during the initial 42 days of the feedlot phase in Nellore beef cattle.

This study aimed to assess the effect of Saccharomyces cerevisiae boulardii CNCM I-1079 supplementation during the initial feeding period on the performance of Nellore bulls in a feedlot system. One hundred ninety-eight Nellore bulls were used in a completely randomized block design, with blocking based on weight within each treatment group: light (331.4 kg; 4 pens), medium (349.7 kg; 4 pens), and heavy (362.5 kg; 3 pens). The treatments included CON-a basal diet, and SCB-basal diet plus a probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079; 1.0 × 1010 CFU/head/d). Experimental diets were administered for the first 42 d (21 d in the step-up phase and 21 d in the finishing diet -870 g concentrate/kg dry matter [DM]). Subsequently, both treatment groups were transitioned to the same basal diet for an additional 76 d, completing 118 d on feed. Linear regression analysis was conducted for dry matter intake (DMI) data. During the initial 42 d, DMI tended to be higher for SCB (P = 0.09); also bulls fed SCB reached the plateau of the curve at 9.17 kg DMI/d earlier (39 d, R2 = 0.97) than those fed CON (43 d; R2 = 0.96) diets. For the first 42 d, the SCB treatment exhibited higher final weight (393.0 vs. 401.4 kg, P = 0.02), total gain (49.3 vs. 53.5 kg, P = 0.02), daily weight gain (1.124 vs. 1.274 kg, P = 0.02), and G:F (0.174 vs. 0.188, P = 0.04). Over the entire 118-d period, SCB-fed bulls had greater final body weight (509.5 vs. 518.0 kg, P = 0.02), total body weight gain (163.7 vs. 170.3 kg, P = 0.01), and average daily gain (1.366 vs. 1.420 kg, P = 0.01). The feed efficiency of SCB-supplemented bulls was 8.05% higher than CON (P = 0.04), and the final carcass weight was 1.69% greater for animals fed SCB (283.8 vs. 288.6 kg, P = 0.04). Total carcass weight gain (110.9 vs. 114.7 kg) and daily carcass weight gain (0.924 vs. 0.956 kg) tended (P = 0.06) to increase by 3.46% in SCB-fed animals compared with those fed CON. Gain yield, carcass conversion, and carcass yield did not differ between treatments. There were no significant differences in the apparent digestibility of DM, crude protein, neutral detergent fiber, and ether extract between treatments. However, starch digestibility (92.7% vs. 88%) was greater for the control treatment (P < 0.001). Including live Saccharomyces cerevisiae boulardii yeast as a probiotic supplement during the initial 42 d in the feedlot enhanced early-stage growth performance in Nellore bulls. Notably, this supplementation carried over carcass gain over the entire feedlot period.

Performance, nutrient utilization and meat quality traits in Bos indicus cattle: a meta-analysis examining the effect of residual feed intake.

This meta-analysis aims to investigate the effects of residual feed intake (RFI) phenotype on performance, nutrient utilization and meat quality traits in Zebu (Bos indicus) cattle. Twenty-three peer-reviewed publications with 37 treatment means were included in the dataset. Weighted mean difference analysis compared animals categorized into low RFI (more efficient) versus medium or high RFI (less efficient) groups. Data heterogeneity via meta-regression and subgroup analysis, considering variables such as animal age, sex class, experimental duration, RFI group, dietary concentrate, and estimated metabolizable energy intake were also explored. The predominant genetic group of cattle in the dataset was Nellore (89.18%), followed by Brahman (10.81%). More efficient animals (low RFI phenotype) exhibited less dry matter intake (DMI; P < 0.010) than medium or high RFI animals (-0.95 kg vs. -0.42 kg/d). Cattle dietary crude protein and fiber digestibility were consistent across RFI groups (P > 0.05), while dietary ether extract digestibility tended to decrease (P = 0.050) in low RFI animals (-13.20 g/kg DM). Low RFI animals tended to increased (P = 0.065) ribeye area (REA) compared to the high/medium RFI groups, while carcass backfat thickness (BFT) decreased (P = 0.042) compared to high/medium RFI groups. Moreover, there was an increase (P < 0.001) of 0.22 kg in Warner-Bratzler shear force (WBSF) and a reduction (P < 0.001) in the myofibrillar fragmentation index (MFI) in low RFI animals. Meat color parameters (lightness [L*] and yellowness [b*]) and visual marbling scores were consistent (P > 0.05) across RFI groups. In conclusion, Zebu cattle classified as efficient (low RFI) exhibited reduced DMI, which improves their feed efficiency. However, BFT and meat quality parameters such as tenderness (WBSF and MFI) and redness [a*] were compromised by low RFI phenotype, highlighting the challenge of enhancing feed efficiency and meat quality traits in Zebu cattle.

Interaction between residual feed intake and thermal environment on performance, nitrogen balance, ingestive behavior and carcass yield of dorper lambs.

Residual feed intake (RFI) is a nutritional variable used in genetic improvement programs, the relationship between the environment and the availability of energy and protein in the diet has not yet been explored. Thus, the aim was to evaluate interactions between RFI and thermal environment on performance, nitrogen balance, ingestive behavior and carcass yield of Dorper lambs receiving diets containing different concentrate levels. Dorper lambs (male, n = 64, 17.83 ± 2.43 kg and 110 ± 10 days of age) were confined individually for 40 days for RFI classification. Lambs were separated into positive RFI (n = 30) and negative RFI (n = 30) and remained confined for another 60 days. The animals were distributed in a randomized block design, with a 2 × 2 × 3 factorial scheme, with 2 confinement environments (full sun or shade), 2 groups of feed efficiency (RFI positive or RFI negative) and three diets containing different concentrate levels (30, 45 and 60%), with 5 replications in each treatment. Isolated effects of concentrate level were observed for dry matter intake and digestibility, feeding, rumination, idle and chewing times, feeding efficiency, ingested, excreted and absorbed nitrogen, and on cooling losses, hot and cold carcass yield (P < 0.05). There was an effect of environment × concentrate interaction on performance, retained nitrogen and nitrogen balance (P < 0.05). There was an effect of RFI × environment interaction on the dry matter rumination efficiency, hot and cold carcass weight (P < 0.05). Under experimental conditions, RFI did not influence the productive performance of Dorper lambs. Interactions between environment and diet indicate better performance for Dorper lamb confined in the shade and receiving a higher proportion of concentrate. Animals with negative RFI show better performance and carcass weight when confined in shade, while animals with positive RFI showed better responses to these variables when confined in full sun.

Chromium in the Diet of Dairy Calves: Benefits for Growth Performance, Feed Efficiency, Digestibility, and Health.

Chromium (Cr) is a mineral that helps animals subjected to stressful conditions. The suckling period is characterized by several stressful episodes, particularly during the first hours after birth and at weaning. There is little consumption of concentrate by calves in the first weeks of life; consequently, consuming any supplement added to feed would be negligible. Thus, the hypothesis was that the calves would take it in earlier if Cr were consumed in a milk replacer instead. Therefore, our study aimed to determine whether including organic Cr in calf feed (via milk replacer or concentrate) during the suckling phase would improve calf health and growth performance. Twenty-four male Holstein calves with an average age of 8 ± 4 days and 39.8 ± 6.9 kg average body weight were used. Calves were randomly divided into three groups: (a) Chromium-Milk (CR-M), receiving 4 mg Cr/animal/day via milk replacer during the 60 experimental days of suckling (n = 8); (b) Chromium-Concentrate (CR-C), receiving 4 mg Cr/animal/day via concentrate (n = 8); (c) Control (C), animals that did not receive Chromium (n = 8). The experiment lasted 75 days, divided into two well-defined stages: suckling (1-60 days) and weaning (61-75 days). Body weight weekly, daily feed intake, and blood samples taken every two weeks during the experiment were evaluated. At the end of the experiment, the apparent digestibility evaluation was carried out, with the results of weight and consumption carried out, and a feed efficiency analysis was carried out. It was observed that the inclusion of organic Cr (regardless of whether it was milk or concentrate) increased body weight gain (kg) for the CR-C group: 41.8 kg, CR-M: 40.4 kg compared to the C: 34.2 kg (p = 0.01). The protein digestibility was higher in the CR-M group (52%, p = 0.05). Cr consumption increased Cr concentrations in the serum of the calves and was higher in the first week in the animals in the CR-M group. This did not happen for the C group; however, with higher concentrate consumption, Cr concentrations increased and remained high until the end of the experiment. Glucose concentrations were higher in the groups that consumed Cr. Total protein concentrations were higher in the CR-M and CR-C groups than in group C. Immunoglobulin A concentrations were higher in groups CR-C and CR-M than in group C (days 40 and 60). In conclusion, the adding Cr to calf feed improves their health, indirectly favors growth performance, and increases protein digestibility.

Effects of replacement of dietary fish oil with plant oil on growth performance and fatty acid composition of spinefoot rabbitfish, Siganus rivulatus

A 95-day feeding study was carried out to evaluate the impact of complete replacement of fish oil by plant oils in the growth performance, feed consumption fatty acid and body composition of juvenile rabbitfish, Siganus rivulatus. There were four treatments i.e., A (fish oil diet), (linseed oil diet), C (soybean meal oil diet) and D (sunflower oil diet). The experimental trial was conducted in twelve 1.5-m3 fiber glass tanks (n=3). Spinefoot rabbitfish juveniles had an average initial weight of 0.948 g ± 0.124 g and they were stocked at 50 fish per tank. Fish fed diet A showed significantly better growth rate, final body weight, and total body weight than fish fed on the other diets. Moreover, the best FCR was observed for diet A followed by diet C and diets B and D had the worst FCR. Fish body composition for crude protein, dry matter, ashes and gross energy at the end of the trial had not differed between the treatments. The highest polyunsaturated fatty acids (PUFA) was found in fish fed diet A followed in decreasing order by diets D, B, and C. Fish oil is a better dietary lipid source for Spinefoot rabbitfish juveniles, Siganus rivulatus, than plant oils. Among plant oils, soybean oil was better than linseed oil and sunflower oil as the main dietary fat source.

Um estudo de alimentação de 95 dias foi realizado para avaliar o impacto da substituição completa de óleo de peixe por óleos vegetais no desempenho de crescimento, composição corporal e consumo de ração de juvenis de coelho, Siganus rivulatus. Houve quatro tratamentos, ou seja, A (dieta de óleo de peixe), (dieta de óleo de linhaça), C (dieta de óleo de farelo de soja) e D (dieta de óleo de girassol). O ensaio experimental foi conduzido em doze tanques de fibra de vidro de 1,5 m3 (n=3). Os juvenis de peixe-coelho-de-espinho apresentaram peso inicial médio de 0,948 g ± 0,124 g e foram estocados com 50 peixes por tanque. Os peixes alimentados com a dieta A apresentaram taxa de crescimento, peso corporal final e peso corporal total significativamente melhores do que os peixes alimentados com as outras dietas. Além disso, a melhor CAA foi observada para a dieta A seguida da dieta C e as dietas B e D tiveram a pior CA. A composição corporal dos peixes para proteína bruta, matéria seca, cinzas e energia bruta ao final do experimento não diferiu entre os tratamentos. O maior teor de ácidos graxos poliinsaturados (PUFA) foi encontrado nos peixes alimentados com a dieta A seguido em ordem decrescente pelas dietas D, B e C. O óleo de peixe é uma melhor fonte de lipídios dietéticos para juvenis de peixe-coelho, Siganus rivulatus, do que os óleos vegetais. Entre os óleos vegetais, o óleo de soja foi melhor que o óleo de linhaça e o óleo de girassol como principal fonte de gordura da dieta.

Effects of particle size of corn and stocking densities on the performance, carcass traits and gastrointestinal tract development of Muscovy ducks in housing.

The current investigation was conducted to investigate the effects of different particle sizes of corn and stocking densities on performance, carcass traits and gastrointestinal tract (GIT) development of Muscovy ducks in housing. 200 Muscovy ducks were distributed in a factorial scheme (2 × 2) where the treatments were constituted by two stocking densities (2 or 3 birds/m2) and two particle sizes of corn (6 or 8 mm), with five replicates of 10 birds each. At 1, 35, 70, and 90 days old, Muscovy ducks were slaughtered to evaluate the development of heart and GIT. Muscovy ducks managed in the density of 3 birds/m2 presented higher (P < 0.05) GIT development, performance and carcass traits regardless of age evaluated. In the same way, Muscovy ducks fed diets using a particle size of corn of 6 mm (Mean Geometric Diameter (MGD) = 781 µm) presented higher (P < 0.05) GIT development, performance and carcass traits regardless of age evaluated. Conclusively, the stocking density of 3 birds/m2 and the particle size of corn of 6 mm (MGD = 781 µm) were considered ideal recommendations for Muscovy ducks, providing higher GIT development, which resulted in better performance and carcass traits.

Strategies of virginiamycin supplementation in the postweaning phase on growth performance and carcass quality of beef cattle.

The present study evaluated the effects of supplementing VM in grazing cattle during the rearing phase on performance and carcass quality of beef cattle in the finishing phase. Two experiments with a randomized block design were conducted in consecutive years to contrast two post-weaning supplementation strategies using VM at 45 mg/100 kg body weight (BW). In the first year, treatments were protein supplement in the dry season and mineral supplement in the rainy season versus the addition of VM both in the protein and mineral supplements. In the second year, was contrasted with protein supplement in the dry season and protein-energy supplement in the rainy season. Performance, carcass traits, and carcass quality were evaluated at the end of both phases. In Year 1, adding VM in mineral supplement increased final backfat thickness (P=0.05), backfat gain (P=0.06), final rump fat thickness (P=0.02), and rump fat gain (P=0.01). In the finishing phase, VM-treated cattle had a greater dry matter intake (P=0.03) and tended to show a greater backfat thickness than non-treated cattle (P=0.07). In Year 2, no VM effects were observed on post-weaning phase performance and carcass traits. However, cattle-fed VM during the post-weaning phase tended to show a lower feed conversion ratio (P=0.09) and had a significantly higher gross feed efficiency (P=0.03) than non-treated cattle at slaughter. Virginiamycin supplementation during rearing on pasture improves performance and carcass fattening in the growth phase and has a residual effect in the finishing phase that may reflect greater backfat thickness and gross feed efficiency.

Short communication: Impact of corn grain particle size on production performance of lactating dairy cows.

Corn grain particle size has the potential to influence the performance of lactating dairy cows and the overall profitability of a dairy farm. The objective of this study was to evaluate the productive performance of lactating cows fed diets containing finely or coarsely ground corn grain. Fifty lactating Holstein cows (n = 50; 10 primiparous and 40 multiparous), averaging (mean ± standard deviation, SD) 658 ± 64 kg of BW, 38.8 ± 7.3 kg of milk/d, and 155 ± 80 DIM, were fed diets with finely ground corn grain (FGC) or coarsely ground corn grain (CGC) in a randomized block design with a 28-d treatment period. Finely and coarsely ground corn grain had an average particle size of 660 and 915 µm, respectively. Dry matter intake (DMI) was reduced (p < 0.01) for cows fed FGC (22.1 vs. 21.2 kg d-1). Milk yield and efficiency were not affected by treatments (37.9 vs. 36.8 kg d-1; p = 0.12 and 1.78 vs. 1.79; p = 0.15). Concentrations of milk protein and fat, as well as other milk solids, were unaffected (p > 0.05) by treatments. Fecal starch (FS) concentrations were greater (p < 0.01) for cows fed CGC (7.0 vs. 4.9%), whereas plasma concentrations of D-lactate were greater (p < 0.05) for cows fed FGC (98.5 vs. 79.7 µM). Overall, feeding finely ground corn grain increased total-tract starch digestibility and reduced DMI while maintaining milk yield.

Factors Affecting Enteric Emission Methane and Predictive Models for Dairy Cows.

Enteric methane emission is the main source of greenhouse gas contribution from dairy cattle. Therefore, it is essential to evaluate drivers and develop more accurate predictive models for such emissions. In this study, we built a large and intercontinental experimental dataset to: (1) explain the effect of enteric methane emission yield (g methane/kg diet intake) and feed conversion (kg diet intake/kg milk yield) on enteric methane emission intensity (g methane/kg milk yield); (2) develop six models for predicting enteric methane emissions (g/cow/day) using animal, diet, and dry matter intake as inputs; and to (3) compare these 6 models with 43 models from the literature. Feed conversion contributed more to enteric methane emission (EME) intensity than EME yield. Increasing the milk yield reduced EME intensity, due more to feed conversion enhancement rather than EME yield. Our models predicted methane emissions better than most external models, with the exception of only two other models which had similar adequacy. Improved productivity of dairy cows reduces emission intensity by enhancing feed conversion. Improvement in feed conversion should be prioritized for reducing methane emissions in dairy cattle systems.

Aerobic physical exercise modifies the prostate tumoral environment.

Exercise is recognized for its potential role in reducing the risk of certain cancers. However, the molecular mechanisms behind this risk reduction are not fully understood. Here, we hypothesized that aerobic physical exercise induces cancer attenuating effects through the modulation of oxidative stress and inflammation. To test this hypothesis, twenty male Sprague Dawley rats with chemically induced prostate tumors were divided into two groups: Prostate cancer (PC) in the absence and presence of exercise (PC + Ex). Rats in the PC + Ex group performed exercises on a treadmill for 8 weeks, 5 sessions per week, at an intensity of 60 % of maximum capacity. Weight and feed efficiency, Ki-67, apoptosis, prostatic inflammation, and markers of oxidative stress were analyzed. We found that aerobic physical exercise significantly decreased prostate cell proliferation (p < 0.05) across modulation, tumor size, and prostate weight. The PC + Ex group also significantly reduced anti-apoptosis protein expression (p < 0.05) and increased pro-apoptotic protein expression. Furthermore, physical exercise increased enzymatic antioxidant defenses in the prostate, plasma, and whole blood. Moreover, PC + Ex reduced lipid peroxidation and protein carbonyl levels (p < 0.05). In the prostate, there was an increase in anti-inflammatory cytokines (IL-10), and a reduction in pro-inflammatory cytokines (IL-6, TNF-α, and NF-κB) after 8 weeks of physical exercise. In conclusion, we found that aerobic physical exercise is a functional, beneficial, and applicable approach to control PC progression, because it modifies the systemic environment, including the regulation of glucose and circulating lipids. This modification of the cancer cells environment has anti-inflammatory and antioxidant effects that attenuate tumor growth.

Non-invasive methods to quantify the carcass parameters of sheep: Interaction between thermal environment and residual feed intake.

The thermal environment is important in unit production because the perception of thermal stress can reduce fertility, and productive performance, therefore its management is necessary. The use of non-invasive methods, such as infrared thermography and real-time ultrasonography, are widely used to evaluate indicators in animal production, without the need to slaughter the animals. Thus, we aimed to assess the effect of the thermal environment on the physiological parameters and carcass characteristics of Dorper sheep with positive and negative residual feed intake (RFI) using infrared thermography and real-time ultrasonography techniques. Twenty uncastrated male Dorper sheep (17.8 ± 2.4 kg) were confined for 40 days for RFI classification. Sheep were separated into positive RFI (n = 10) and negative RFI (n = 10). The experimental design was in randomized blocks, in a 2 × 2 factorial arrangement, with 2 thermal environments (full sun or shade) and two feed efficiency groups (positive RFI or negative RFI), with 5 replications. The sheep remained in confinement for 60 days. The animals were slaughtered at the end of the experiment and the carcasses dissected for tissue separation. Rectal temperature (RT) and respiratory rate (RR) were measured at two times (14:00 h and 18:00 h) for periods of 5 days. The RR was determined by indirect auscultation of heart sounds at the level of the laryngotracheal region. The RT was measured introduced a digital clinical thermometer into the animal's rectum. Surface temperature (ST) was obtained using a thermographic infrared camera, collecting the temperatures of the eyeball and skin surface in the regions of the head, ribs, rump, flank and shin. Sheep confined in full sun showed higher RR (P = 0.0001), ST ribs (P = 0.0020), ST rumb (P = 0.0055), ST flank (P = 0.0001) and heat tolerance coefficient (HTC) (P = 0.0010). For sheep confined in full sun, a strong correlation was observed between the RR and the mean ST (MST; r = 0.6826; P = 0.0236) and between the final loin eye area (LEAf) with the real LEA (LEAr) (r = 0.9263; P = 0.0001) and slaughter body weight (SBW) (r = 0.7532; P = 0.0325). For negative RFI sheep, a positive correlation was observed between the RR and the ST rump (r = 0.7343; P = 0.0025) and ST ribs (r = 0.6560; P = 0.0178) and the MST (r = 0.7435; P = 0.0001), between the MST and the LEAr (r = 0.6837; P = 0.0025) and the final LEA (r = 0.6771; P = 0.0144), and between the final LEA and LEAr (r = 0.9942; P = 0.0001), BW (r = 0.8415; P = 0.0277) and MST (r = 0.6771; P = 0.0045). Positive RFI sheep confined to shade showed a high correlation between final LEA and LEAr (r = 0.9372; P = 0.0001). The use of shading in confined Dorper sheep, regardless of the RFI classification, reduces the effects of heat stress on physiological parameters.

Performance, Intake, Feed Efficiency, and Carcass Characteristics of Young Nellore Heifers under Different Days on Feed in the Feedlot.

Two studies evaluated the productive characteristics of young Nellore heifers receiving different days on feed (DOF) to determine the biological slaughter endpoint. In Experiment 1 (Exp. 1), fifty-one Nellore heifers [324 ± 19.3 kg of body weight (BW); 16 ± 1 months] were split into three DOF lengths (45, 75, or 105 days), while in Experiment 2 (Exp. 2), thirty-six Nellore heifers (362 ± 25.5 kg of BW; 18 ± 1 months of age) were split into three DOF lengths (45, 90, or 135 days). In both studies, all animals were distributed in complete randomized blocks according to initial BW and stratified via carcass ultrasound. The diet was supplied ad libitum, allowing 3% of refusals. The point at which the animals achieved 25% of ether extract of shrunk body weight (EESBW) was defined as the biological endpoint. Thus, relationships were made between some characteristics obtained in both studies. Positive linear relationships were found between backfat thickness (BFT) vs. EESBW (p < 0.001, r = 0.84) and BFT vs. body weight (p < 0.001, r = 0.77). Our results suggest that the biological slaughter endpoint for young Nellore heifers is 6.97 mm of backfat thickness or 402 kg shrunk body weight, corresponding to around 75 DOF.

Orange molasses as a new energy ingredient for feedlot lambs in Brazil.

The objectives of this experiment were to evaluate the effects of increasing levels of orange molasses in replacement of flint corn grain in high-concentrate diets on dry matter intake (DMI), average daily gain (ADG), and feed efficiency (FE) of feedlot lambs. Thirty male lambs without defined racial pattern (30.3 ± 5.3 kg of initial BW; mean ± SD) were used in a randomized complete block design with 10 blocks and 3 treatments. The treatments were defined by partial replacement of flint corn by orange molasses in the diet with 90% of concentrate and 10% of Cynodon spp. hay, as follows: 0OM-control diet without orange molasses; 20OM-20% of orange molasses replacing flint corn; and 40OM-40% of orange molasses replacing flint corn (DM basis). The experiment lasted 72 days divided into 3 subperiods, with 1 subperiod of 16 days and 2 subperiods of 28 days. Animals were weighed after a 16-h fast on days 1, 16, 44, and 72 of the experimental periods to determine the ADG and FE. The DMI, ADG, and FE showed an interaction between treatments and experimental periods. The DMI in the first period decreased linearly (P < 0.01); in the third period, there was no effect of treatments (P > 0.05) on DMI. The ADG decreased linearly (P < 0.01) in the first period as the orange molasses increased. Otherwise, in the third period, ADG increased linearly (P = 0.05) as flint corn was replacement by orange molasses. The FE showed an interaction between treatment and period (P = 0.09). The first period had a decreased linear effect; in the third period, there was a trend (P = 0.07) of increased linear effect. There was no difference between the diets regarding the final BW of the lambs. In conclusion, the orange molasses can replace up to 40% of flint corn in diets for feedlot lambs without affecting final BW. However, it is important to consider the adaptation time proved to be very important for better use of orange molasses as a source of energy in diets for lambs.

Metagenomic approach to infer rumen microbiome derived traits of cattle.

Ruminants enable the conversion of indigestible plant material into animal consumables, including dairy products, meat, and valuable fibers. Microbiome research is gaining popularity in livestock species because it aids in the knowledge of illnesses and efficiency processes in animals. In this study, we use WGS metagenomic data to thoroughly characterize the ruminal ecosystem of cows to infer positive and negative livestock traits determined by the microbiome. The rumen of cows from Argentina were described by combining different gene biomarkers, pathways composition and taxonomic information. Taxonomic characterization indicated that the two major phyla were Bacteroidetes and Firmicutes; in third place, Proteobacteria was highly represented followed by Actinobacteria; Prevotella, and Bacteroides were the most abundant genera. Functional profiling of carbohydrate-active enzymes indicated that members of the Glycoside Hydrolase (GH) class accounted for 52.2 to 55.6% of the total CAZymes detected, among them the most abundant were the oligosaccharide degrading enzymes. The diversity of GH families found suggested efficient hydrolysis of complex biomass. Genes of multidrug, macrolides, polymyxins, beta-lactams, rifamycins, tetracyclines, and bacitracin resistance were found below 0.12% of relative abundance. Furthermore, the clustering analysis of genera and genes that correlated to methane emissions or feed efficiency, suggested that the cows analysed could be regarded as low methane emitters and clustered with high feed efficiency reference animals. Finally, the combination of bioinformatic analyses used in this study can be applied to assess cattle traits difficult to measure and guide enhanced nutrition and breeding methods.

Effect of Particle Size of Silage of Flint Corn Grain on Dairy Cows Fed Tropical Pasture: Performance, Intake, Ruminal Fermentation, and Digestibility.

The particle size (PS) of reconstituted corn (REC) can affect the grinding rate and starch digestibility in dairy cows. We evaluated the effect of the PS of REC ensiled for 40 days on the pasture dry matter intake (DMI), lactation performance, total tract digestibility, and ruminal fermentation of grazing dairy cows. The treatments were coarse REC (CO, 1694 µm), fine REC (FI, 1364 µm), or finely ground (GC, 366 µm) flint corn (68% vitreousness) at 29.6 ± 1.4% of diet DM (mean ± SD). Eighteen dairy cows (mean milk yield 21.3 kg/d) were split into three groups by production level and were assigned within each group to a sequence of treatments in 3 × 3 Latin squares of 21-day periods. Cows were individually fed a constant amount of whole-plant corn silage 3 ×/d (2.7 kg DM/d) and corn treatments and soybean meal according to their group. There was no significant interaction between treatment and the production level. Cows fed FI had a lower DMI (16.7 vs. 18.1 kg/d) than those fed GC, and both did not differ from CO (17.7 kg/d). There was no treatment effect on milk yield (mean: 19.2 kg/d). Cows fed CO had the lowest total tract digestibility of starch (86.3 vs. 92.3% of intake) and the highest fecal starch concentration (7.0 vs. 4.0% of DM). The NDF digestibility was lower for GC-fed cows than CO- and FI-fed cows. Plasma glucose was higher in cows fed FI and CO (75.0 mg/dL) than those fed GC (70.8 mg/dL). Ruminal volatile fatty acids and the pH did not differ. Fine grinding of REC increased the feed efficiency relative to CO and GC. Coarse grinding of REC ensiled for 40 days reduced the total tract starch digestibility relative to FI and GC.

Methane emission, intake, digestibility, performance and blood metabolites in sheep supplemented with cupuassu and tucuma cake in the eastern Amazon.

The use of co-products as a feed supplement for ruminants makes livestock sustainable and optimizes the use of available areas and animal performance. Furthermore, when cakes are used, the residual fat composition can influence ruminal metabolism and methane (CH4) production. This study aimed to assess the effects of a diet containing cupuassu (CUP; Theobroma grandiflorum) and tucuma (TUC; Astrocaryum vulgare Mart.) cakes on intake, digestibility, serum metabolites, performance, and CH4 emissions in confined sheep in the Amazon. Approximately 28 animals, Dorper-Santa Inês, castrated, with an average initial live weight (ILW) of 35 ± 2.3 kg, were distributed in metabolic cages, in a completely randomized design, with four treatments and seven replications: (1) Control (C40), without the addition of Amazonian cake and with 40 g of ether extract (EE)/kg of dietary dry matter (DM); (2) CUP, the inclusion of the CUP cake and 70 g of EE/kg; (3) TUC, the inclusion of the TUC cake and 70 g of EE/kg; and (4) Control (C80), without the addition of Amazonian cake and with 80 g of EE/kg of dietary DM, with roughage to concentrate ratio of 40:60. The use of the TUC cake as a feed supplement reduced the intake of DM, crude protein (CP), and EE compared to the inclusion of the CUP cake (p < 0.05); however, it increased the intake of neutral detergent fiber (NDF) by 32% (p < 0.01). The highest averages of DM (732 g/kg) and CP (743 g/kg) digestibility were presented in C40, while the highest digestibility of NDF was presented in TUC (590 g/kg). Albumin levels stayed above and protein levels were below the reference values, and the C40 diet also obtained below results for cholesterol, triglycerides and High Density Lipoprotein (HDL) (P < 0.05). Sheep fed CUP (91 g) and TUC (45 g) had lower daily weight gains (DWGs) than those fed with diets without the inclusion of cakes (C40 = 119 g; C80 = 148 g), and feed efficiency (FE) was also lower in CUP (84) and TUC (60) diets than in C40 (119) and C80 (137) diets. CH4 emissions were lower in animals fed TUC (26 L/day) and higher in C40 (35 L/day); however, TUC resulted in higher CH4 emissions in grams/body live weight (BW) gain/day (353 g/BW/day) vs. 183 g/BW/day (C40), 157 g/BW/day (C80), and 221 g/BW/day (CUP). The supplementation with cakes did not improve intake, digestibility and performance, did not compromise blood metabolites and did not reduce the enteric CH4 emission in confined sheep in the Amazon; however, the use of CUP cake showed similar results to the control treatments and did not increase CH4 emissions, as occurred with the inclusion of TUC cake.

Supplement feed efficiency of growing beef cattle grazing native Campos grasslands during winter: a collated analysis.

Supplementing growing cattle grazing native subtropical Campos grasslands during winter improves the low, even negative, average daily weight gain (ADG) typical of extensive animal production systems in Uruguay. Nonetheless, to render the practice profitable, it is crucial to control supplement feed efficiency (SFE), that is, the difference in ADG between supplemented and control animals (ADGchng) per unit of supplement dry matter (DM) intake. Little has been studied specifically on how SFE varies in these systems. The objective of this study was to quantify the magnitude and variation in SFE of growing beef cattle grazing stockpiled native Campos grasslands during winter and assess putative associations with herbage, animals, supplements, and climatic variables. We compiled data from supplementation trials carried out in Uruguay between 1993 and 2018, each evaluating between one and six supplementation treatments. The average ADG of unsupplemented and supplemented animals were 0.13 ±â€…0.174 and 0.49 ±â€…0.220 kg/animal/day, respectively. In both cases, ADG decreased linearly as the proportion of green herbage in the grazed grassland was lower, but the ADG of unsupplemented animals was further reduced when winter frosts were numerous. Estimated SFE were moderately high, with an average of 0.21 ±â€…0.076 ADGchng/kg DM, resulting from average ADGchng of 0.38 ±â€…0.180 kg/animal/day in response to an average supplementation rate of 1.84 ±â€…0.68 kg supplement DM intake/animal/day (0.86%  ±â€…0.27% body weight). No association was found between SFE and supplementation rate or type (protein vs. energy-based; P > 0.05), but forage allowance negatively affected it, and herbage mass positively affected it, yet in a smaller magnitude, suggesting that a balance is needed between the two to maximize SFE. Weather conditions during trials affected SFE (P < 0.05), with greater SFE in winters with lower temperatures and more frosts. Daytime grazing time was consistently lower in supplemented animals compared to their unsupplemented counterparts, whereas ruminating time during the day was similar, increasing as the proportion of green herbage decreased. Herbage intake estimated from energy balance suggested the existence of some substitution effect. This agrees with the moderately high SFE and with the total digestible nutrients-to-protein ratio of these subtropical humid grasslands being higher than in semi-arid rangelands and dry-season tropical pastures but lower than in sown pastures.

Effect of increasing levels of fat-soluble and water-soluble vitamins on improving performance and plasma vitamin concentration in modern hybrids pig's growth and finishing phase / Efeito do aumento dos níveis de vitaminas lipossolúveis e hidrossolúveis na melhoria do desempenho e na concentração plasmática de vitaminas em suínos híbridos modernos nas fases de crescimento e terminação

The objective was to evaluate the supplementation of fat-soluble and water-soluble vitamins on the performance and plasma concentrations of vitamins in modern hybrids pigs. A total of 144 commercial hybrid castrated male, 43.531 ± 1.099kg, were used in a randomized block design with six treatments, eight replicates and three animals per pen. The experimental treatments were different vitamin supplementation levels - 0, 25, 50, 75, 100, and 125% of the recommended by Rostagno et al. (2011) for male pigs in growth I (40 to 50kg), growth II (50 to 70kg), and finishing I (70 to 90kg) phases. For growth phases I and II, a linear effect (P<0.05) due to increase in vitamin supplementation was observed on performance. For finishing phase I and total phase, a linear effect (P<0.05) was observed with increased final average weight (FAW) and improved feed conversion ratio (FCR). For average daily weight gain (ADWG) and average daily feed intake (ADFI) a quadratic effect was observed (P<0.05). A linear (P<0.05) increase in plasmatic α-tocopherol and B12 was observed with the 125%. Thus, it is concluded that the 125% vitamin supplementation improved performance of modern hybrids pigs (40 to 90kg).

Objetivou-se avaliar a suplementação de vitaminas lipossolúveis e hidrossolúveis sobre o desempenho e as concentrações plasmáticas de vitaminas em suínos híbridos modernos. Um total de 144 híbridos machos castrados, 43,531 ± 1,099kg, foram distribuídos em delineamento de blocos ao acaso, com seis tratamentos, oito repetições e três animais por baia. Os tratamentos foram diferentes níveis de vitaminas - 0, 25, 50, 75, 100 e 125% do recomendado por Rostagno et al. (2011) para suínos machos nas fases de crescimento I (40 a 50kg), crescimento II (50 a 70kg) e terminação I (70 a 90kg). Para as fases de crescimento I e II, observou-se efeito linear (P<0,05) devido ao aumento na suplementação vitamínica sobre o desempenho. Para a fase de terminação I e a fase total, observou-se efeito linear (P<0,05) com o aumento do peso médio final (PMF) e melhoria da conversão alimentar (CA). Já para as variáveis de ganho de peso médio diário (GPMD) e consumo de ração médio diário (CRMD,) observou-se efeito quadrático (P<0,05). Houve aumento linear (P<0,05) em α-tocoferol e cobalamina plasmáticos devido à suplementação de 125%. Assim, conclui-se que a suplementação com 125% de vitaminas melhorou o desempenho de suínos híbridos modernos (40 a 90kg).

Processing methods of flint corn and protein supplement in forage-free diets for feedlot lambs.

Diets without forage increase the productivity in less time and favor greater practicality and better quality carcass. The corn grain is mostly used associated with pellets but processing these ingredients can bring benefits. The present study evaluated the effect of diets without forage based on whole or coarse ground corn associated with pelleted or ground protein supplement on performance, eating behavior, carcass characteristics, and ruminal morphology of feedlot lambs. Thirty-five Dorper × Santa Inês lambs were used, with 23.85 ± 3.88 kg of initial body weight and 88 ± 9 days old. The experimental design was in a randomized complete block, defined by body weight and age. The experimental diets were control (CONT), containing 90% of concentrate and 10% of forage (coastcross hay), and 4 diets without forage: WC+P, 70% whole flint corn and 30% pelleted protein supplement; WC+G, 70% whole flint corn and 30% ground protein supplement; GC+P, 70% ground flint corn and 30% pelleted protein supplement; and GC+G, 70% ground flint corn and 30% ground protein supplement. There was an interaction between treatments and experimental periods for DMI in kg/day (P = 0.01) and g/kg of BW0.75 (P < 0.01; Table 3). For the DMI in kg/day, no significant differences were observed between the treatments in any of the experimental periods. However, for DMI expressed in g/kg of BW0.75, the animals fed WC+P had lower DMI than the animals on the CONT (P < 0.01) only in the first period. The ADG, FBW, and FE were not affected by the treatments. Compared to CONT, forage-free diets decreased ingestion time (min/day) and rumination and chewing (min/day and min/g of dry matter). There was no effect of treatments for any of the carcass traits evaluated. The diets did not cause lesions suggestive of ruminitis. Forage-free diets containing whole or ground corn associated with pelleted or ground protein supplement can be used successfully for feedlot lambs; they provide proper performance and carcass characteristics, without harming the animal's health.

Microbial Populations in Ruminal Liquid Samples from Young Beefmaster Bulls at Both Extremes of RFI Values.

The gut microbiota is involved in the productivity of beef cattle, but the impact of different analysis strategies on microbial composition is unclear. Ruminal samples were obtained from Beefmaster calves (n = 10) at both extremes of residual feed intake (RFI) values (5 with the lowest and 5 with the highest RFI) from two consecutive days. Samples were processed using two different DNA extraction methods. The V3 and V4 regions of the 16S rRNA gene were amplified using PCR and sequenced with a MiSeq instrument (Illumina). We analyzed 1.6 million 16S sequences from all 40 samples (10 calves, 2 time points, and 2 extraction methods). The abundance of most microbes was significantly different between DNA extraction methods but not between high-efficiency (LRFI) and low-efficiency (HRFI) animals. Exceptions include the genus Succiniclasticum (lower in LRFI, p = 0.0011), and others. Diversity measures and functional predictions were also mostly affected by DNA extraction methods, but some pathways showed significant differences between RFI levels (e.g., methylglyoxal degradation, higher in LRFI, p = 0.006). The results suggest that the abundance of some ruminal microbes is associated with feed efficiency and serves as a cautionary tale for the interpretation of results obtained with a single DNA extraction method.