The objective of this study was to quantify the impact of Zn and Cu supplementation and nutritional factors on the digestible content of these minerals using a meta-analysis approach. A database derived from 24 publications and describing 142 experimental treatments was compiled. A model showed that positive effects of chelated, (linear and quadratic, P < 0.01) and inorganic Zn supplementation (P < 0.05) (linear and quadratic, P < 0.01), Zn from ingredients (linear, P < 0.01) and a negative linear effect of dietary Cu concentration (P = 0.067; R²= 94%) on digestible Zn content. In other model, addition of phytase showed linear improvement of digestible Zn (P < 0.01; R²= 96%). For digestible Cu, a model showed that chelated and inorganic Cu supplementation (P < 0.01) linearly increased digestible Cu while dietary Zn level decreased it (P < 0.01; R² = 93%). Dietary phytase did not impact digestible content of Cu. The digestibility of Zn and Cu depends on dietary supplementation of these minerals in diets but also on the interaction between these minerals. Finally, phytase supplementation improves digestible Zn content but not Cu.

This study evaluated the effects of (i) increasing the concentration of sulfate in drinking water on dry matter intake (DMI), water intake, ruminal fermentation, and apparent total-tract digestibility, and (ii) water sulfate concentration and bismuth subsalicylate (BSS) dose on in vitro ruminal fermentation. Eight ruminally cannulated beef heifers (382 ± 45 kg) were used in a replicated incomplete 3 × 3 Latin square design. Water treatments contained low (342 ± 29 mg/L; LS), medium (2785 ± 72 mg/L; MS), or high (4948 ± 163 mg/L; HS) sulfate. Ruminal digesta was collected to evaluate water sulfate and BSS dose (0.0%, 0.2%, 0.4%, and 0.6% dry matter) on ruminal H₂S production in vitro. Water intake increased linearly as water sulfate concentration increased (p = 0.002), but DMI was not affected. Heifers drinking MS and HS had greater ruminal H₂S at 10.5 h after water provision than LS (sulfate × time, p < 0.001). In vitro H₂S production (µg and µg/mL of rumen inoculum) increased and plateaued with increasing sulfate (p < 0.001) and was linearly reduced (p < 0.001) by increasing BSS dose. Increasing water sulfate concentrations did not negatively affect water or feed intake but increased ruminal H₂S concentrations. Bismuth subsalicylate may reduce H₂S production.

In Canada, new forage varieties need not undergo grazing trials before registration and sale. To evaluate the effect of grazing, six cool-season species including meadow bromegrass (Bromus riparius Rehmann), orchardgrass (Dactylis glomerata L.), sainfoin (Onobrychis viciifoila Scop.), and three alfalfa varieties (Medicago sativa L.) were established in monocultures and grass–legume binary mixtures in Saskatchewan, Canada. Forage treatments were randomly established within each of three 3.5 ha paddock replicates. In Year 1, 69 Bos taurus crossbred steers, and in Year 2, 149 steers were homogenously allocated to the three paddocks for the grazing trials. Alfalfa monocultures had the greatest (p < 0.05) pre-graze forage yields and crude protein content. Leaf area index was greater in alfalfa monocultures than in all other treatments (p < 0.01). Etiolated growth differed (p < 0.05) among binary mixtures but not monocultures. Alfalfa monoculture stands were preferred over grass monocultures and most grass–legume mixtures, and sainfoin was avoided relative to alfalfa. Killarney orchardgrass was the least productive and least preferred among forages evaluated. In summary, alfalfa monocultures had greater (p < 0.05) forage yields and quality than sainfoin monocultures, grass–legume binary mixtures, or grass monocultures.

This study evaluated performance and ruminal fermentation for cows fed short-season high-moisture shelled corn stover with corn dried distillers’ grains with solubles (COR) or barley greenfeed (BAR) that was either swathed (S-COR; S-BAR; Experiment 1) or baled (B-COR; B-BAR; Experiment 2) as winter-feeding systems. In Experiment 1, cows were randomly assigned to S-COR or S-BAR and fed for 52 days in the fields where crops were grown. Body weight (BW), subcutaneous rib and rump fat, and body condition score (BCS) were measured, with no differences detected between treatments (P > 0.05). However, S-COR had a lower estimated dry matter intake (DMI) than S-BAR (P ≤ 0.03). In Experiment 2, cows were assigned to B-COR or B-BAR for 42 days and fed in field paddocks. Cows fed B-COR had less (P ≤ 0.01) DMI, final BW, rib fat, rump fat, and BCS than B-BAR, with no differences (P > 0.05) for ruminal pH. Total SCFA concentration was greater (P ≤ 0.05) on day 21 for B-BAR than B-COR, but not on day 42. Under western Canadian conditions, COR may reduce DMI and the performance of pregnant cows, suggesting that additional preservation and supplementation strategies should be investigated.

The objectives were to develop equations for predicting ileal digestible phosphorus (P) based on nonphytate P, phytate P, calcium to nonphytate P ratio, and exogenous phytase concentrations in broiler diets and to evaluate the accuracy of the models. The modified Michaelis–Menten model was used to predict apparent ileal digestible (AID) or standardized ileal digestible P in broiler diets. Two different methods were used to analyze 25 published ileal digestible P data to evaluate the accuracy of the equation for predicting AID P. The first method assessed mean and linear biases. While the mean bias was significant (P < 0.05), the linear bias was not significant. The second method involved regressing the 25 AID P data against those predicted by the current model. The results showed that the intercept and slope of the regression were not statistically different from 0 and 1, respectively. This suggests that the current equation accurately represents the test data. In conclusion, the accuracy of the model depends on validation processes. Considering that the current model was developed using various phytase products, it would be preferable to use an equation that is based on a single phytase product if requisite quantity of data is available.

This study aimed to evaluate the effect of dietary zinc (Zn) and copper (Cu) levels on their apparent ileal digestibility (AID) and total tract digestibility (ATTD) and that of calcium (Ca), manganese (Mn), iron (Fe), phosphorus (P), and fiber in pigs. The experiment was carried out with six individuals fitted with a T-cannula. Pigs received one of four diets with two levels of Zn (100 [low] and 500 [high] mg/kg) and Cu (40 [low] and 80 [high] mg/kg). High Zn increased AID of Zn and Mn, but decreased that of Ca (p < 0.05). High Cu tended to improve AID of Cu, but only when high Zn was used (Interaction Zn × Cu, p = 0.051). ATTD of Zn, Cu, Mn, and P was greater in high Zn (p < 0.05). High Cu also increased ATTD of Cu, but reduced that of Ca (p < 0.05) as it likely did for ATTD of P in low Zn (Interaction Zn × Cu, p = 0.065). There was an improving trend for ATTD of NDF (Interaction Zn × Cu, p = 0.069), and ATTD of ADF was increased with a combination of high Zn and high Cu (Interaction Zn × Cu, p < 0.05). This research showed that the levels of Cu and Zn modified the digestibility of minerals but also the degradability of fiber.

This study investigated the effects of the multi-probiotics consisting of Bacillus subtilis and Clostridium butyricum with varying doses (0%, 0.05%, 0.1%, and 0.2%) on the growth performance, nutrient digestibility, meat quality, and cecal microbes of male broiler chickens. Seven hundred and twenty Ross 308, 1-day-old male broiler chicks were distributed into four dietary groups. Over 35 days of feeding, the average daily gain (ADG) was linearly elevated (P < 0.05) during days 1–21 and 1–35 as probiotic doses increased. The average daily feed intake (ADFI) tended to be linearly (P = 0.059) increased from day 22 to 35, and was improved from day 1 to 35 (P = 0.031). Ascending doses of multi-probiotics tended to (P = 0.060) reduce Clostridium perfringens counts on day 35 and prompted (P = 0.001) the proliferation of Lactobacillus. Moreover, broilers fed a 0.1% dose of multi-probiotics had a higher pH and water-holding capacity (P < 0.05) in the breast meat. In conclusion, the 0.2% multi-probiotics could boost ADG by improving ADFI and modulating the cecal microbe. The dietary 0.1% multi-probiotics contributed to better meat quality.

The calpastatin gene has been extensively studied as a candidate gene because of its regulatory function within muscle development of animals. However, little is known about the association between variation of the calpastatin gene and growth traits in Tibetan sheep. Using DNA sequencing, four single-nucleotide polymorphisms g.3844A>G, g.88874T>C, g.89126C>T, and g.89157A>C were identified in this study. An association analysis indicates that the g.3844A>G and g.89126C>T polymorphisms affected body weight (P < 0.05). The g.89157A>C polymorphism was significantly correlated with body weight and chest circumference (P < 0.05). The quantitative real-time polymerase chain reaction analysis revealed that the expression of calpastatin gene presented an increasing trend with an increase in age. Remarkably lower mRNA expression was detected at the fetal stage compared with adult ewes (P < 0.05). These findings indicated that the calpastatin gene polymorphisms were involved in growth-related traits in Tibetan sheep, which can be considered as genetic markers for improving the growth traits of Chinese Tibetan sheep.

In a 42-day study, 195 growing pigs (Landrace × Yorkshire × Duroc) weighing 23.83 ± 1.95 kg were randomly divided into three treatments, each with 13 replicates and 5 pigs (3 barrows and 2 gilts) per pen. The treatments were control (CON)—basal diet, and basal diet with 3% and 6% almond hull as treatment (TRT) 1 and 2, respectively. The results show a significant increase (p < 0.05) in average daily gain (ADG) and average daily feed intake (ADFI) for both treatment 1 and treatment 2 by week 6 when compared to the control group. This improvement in ADG and ADFI exhibits a consistent trend (p < 0.10) throughout the overall trial period in comparison to the control group. Additionally, there is a tendency for enhanced gain-to-feed ratio (G:F) at the end of week 6 (p < 0.10) in comparison to the control group and remained constant (p > 0.05). No significant impact (p > 0.05) on nutrient digestibility and fecal microbiota was observed. However, NH₃ gas showed a tendency to decrease (p < 0.10). Results suggested that almond hulls could improve growth and reduce ammonia gas without adverse effects on digestion, microbiota, and fecal score.

This study assessed the environmental impacts of beef cattle production and their effects on the overall sustainability of Canadian beef production. Cradle to farm gate, cradle to processor’s gate, and cradle to consumer plate life cycle assessments were carried out to quantify greenhouse gases (GHG), resource use (i.e., water, land, and fuel), and potential water and air pollution (i.e., freshwater eutrophication, terrestrial acidification, and photochemical oxidants formation). Across the production chain, feed production had the greatest impact on most environmental indicators. The GHG intensity without dairy meat was estimated as 10.4 kg CO₂-eq per kg of live weight (LW), corresponding to 32.8 kg CO₂-eq per kg of consumed boneless beef. Including dairy meat reduced GHG intensity by 5.8% (0.6 kg CO₂-eq kg LW^–1) compared to when it was excluded. Other environmental metrics per kg of LW were 657 L, 38.7 m² annual crop-eq, 0.4 kg oil-eq, 2.6 kg P-eq, 115.9 kg SO₂-eq, and 8.7 kg NO_x-eq for water use, land use, fossil fuel use, freshwater eutrophication, terrestrial acidification, and photochemical oxidants, respectively. Data provide benchmarks for use in future regional and national assessments that are designed to encourage the adoption of sustainable management practices that can lower the environmental footprint of Canadian beef production.

Inclusion of a source of non-protein nitrogen (NPN) may improve essential amino acid (EAA) and nitrogen (N) utilization in N-limiting diets. Growing barrows (20.4 ± 0.5 kg) were randomly assigned to 1 of 10 dietary treatments (n = 9 pigs/treatment) in nine blocks. Diets contained no ammonium phosphate (NAP) or 1.7% ammonium phosphate (AP) to have an EAA-N:total N ratio of 0.36 and 0.33, respectively, with graded levels of dietary lysine (Lys; 0.8%, 0.9%, 1.0%, 1.1%, and 1.2% standardized ileal digestible (SID)). Following a 7-day dietary adaptation, a 4-day N-balance collection period was conducted. Blood samples were obtained on day 2 of the collection period. Nitrogen retention (NR) increased and urinary N output decreased with inclusion of NPN and increasing Lys (P < 0.01). Plasma urea N decreased with increasing Lys (P < 0.05). Total plasma EAA content was reduced with NPN supplementation (P < 0.05), while content of Arg, Asp, Gln, and Glu was increased (P < 0.01). The linear breakpoint model indicated that NR was maximized at 1.00% SID Lys in NAP-fed pigs and at 1.09% SID Lys in AP-fed pigs. These results indicate that diets deficient in dietary N reduce NR and Lys requirement, which were in turn increased with NPN supplementation.

Stress in farrowing sows is associated with the number of piglets crushed or attacked. Sow’s behaviour is variable and heritable, therefore genetic selection can be a viable approach for improving pig’s welfare. In this report, we used first parity litter records of Yorkshire sows to test a genetic evaluation model for piglet crushing. The data were split into training and validation to check the prediction accuracy of piglet crushing estimated breeding values (EBVs) for young sows. We found that the estimated heritability of piglet crushing was 0.07 ± 0.03. The difference in the EBVs in the validation set was equivalent to 0.15 more piglets crushed in the top 10% group than in the bottom group of sows. These results indicate that the genetic selection may be used to reduce piglet crushing which will improve the welfare of pigs as well as production efficiency. The average reliability of the estimated EBVs across all animals in the pedigree was (0.07; 0.0 to 0.72). More research on evaluation models and the genetics underlying sow stress and behaviour is warranted to improve the reliabilities of modeling and to identify robust genetic markers for animal breeding for the implementation.