Global drivers such as the growing human population, evolving consumer preferences, globalization, and climate change have put pressure on the agri-food sector to produce more livestock products with less land, feed, and water. Taste, nutritional value, cost, convenience, source, animal welfare, and environmental sustainability of food are criteria upon which purchasing decisions are made. In response, an environmental footprint analysis composed of greenhouse gas emissions, nutrient and water use efficiency, water quality, carbon storage, and biodiversity has been completed for many commodities. However, as livestock production systems occur within complex agro-ecosystems, it is extremely challenging to formulate a single overall sustainability metric. There is no “silver bullet” to solve the environmental concerns of all livestock production systems as they operate under different constraints on different landscapes, with different water and nutrient cycles, and soil types. Furthermore, the lack of scientific evidence regarding the interactions between livestock production, human nutritional adequacy, and the health of our environment makes it difficult for consumers to interpret this information and make informed food choices. This review examines these complex interactions and trade-offs, as well as the potential impacts of changes in consumer dietary choice on environmental sustainability, nutritional adequacy, and land use.

Chicken Farmers of Canada has been progressively phasing out prophylactic use of antibiotics in broiler chicken production. Consequently, hatcheries, veterinarians, and nutritionists have been mandated to contend with less reliance on the use of preventive antibiotics. A topical concern is the increased risk of proliferation of enteric pathogens leading to poor performance, increased mortality, and compromised welfare. Moreover, the gut harbors several taxa such as Campylobacter and Salmonella capable of causing significant illnesses in humans via contaminated poultry products. This has created an opportunity for research and development of dietary strategies designed to modulate gastrointestinal environment for enhanced performance and food safety. Albeit with inconsistent responses, literature data suggest that dietary strategies such as feed enzymes, probiotics/prebiotics, and phytogenic feed additives can bolster gut health and function in broiler chickens. However, much of the efficacy data were generated at controlled research settings that vary significantly with the complex commercial broiler production operations due to variation in dietary, health, and environmental conditions. This review will summarize implications of mandated restrictions on the preventative use of antibiotics and emerging Canadian broiler production programs to meet processor specifications. Challenges and opportunities for integrating alternative dietary strategies in commercial broiler production settings will be highlighted.

To establish a baseline understanding of feeding practices on Canadian dairies, a survey was distributed online to dairy producers. Responses were split into three categories as follows: western provinces (WP; Alberta, British Columbia, Manitoba, and Saskatchewan; n = 84), Ontario freestall farms (n = 75), and Ontario tiestall (OT) farms (n = 71). Regional differences were observed for many feed ingredients; for example, corn and soybean meal were more commonly used in Ontario, whereas barley, wheat products, and grass hays were more commonly used in the WP (P ≤ 0.01), consistent with local production of those crops. Producers ranked the most important factors in balancing rations in the following order: production (lactating cattle or heifers) or health (dry cows), cost, simplicity, and nutrient management; however, nutrient management was more important in the west for all types of diets (P < 0.01). Most farms frequently tested for ration dry matter and nutrient composition, although OT farms tested less often than other groups (P = 0.09). Overall, feeds aligned with common crops grown within region. Canadian farmers have a stated interest for improving production and health and place less emphasis on other factors such as cost, simplicity, and nutrient management.

The objectives of this study were to determine the incidence proportion of lameness in feedlot cattle and the associated risk factors. Lameness was studied in two southern Alberta feedlots over a 2 yr period. The incidence proportion of lameness was 36.3% for all calves pulled for treatment. Risk factors associated (P < 0.0001) with increased lameness included body weight (BW), type of cattle, source, stocking density, percentage of forage in the diet, season, precipitation 1 d before diagnosis, and average temperature range 3 d prior to diagnosis. As BW (P < 0.001) increased, the odds of becoming lame also increased. Yearlings and Holsteins had greater (P < 0.001) incidence of lameness than respiratory disease. The odds of becoming lame decreased (P < 0.001) with increased pen density and percentage of forage in the diet. Lameness was greatest in spring (P < 0.001) with the odds of becoming lame being more likely (P < 0.001) with increased precipitation and temperature range (P < 0.001). Use of a multifactorial approach including animal, managerial, and environmental factors in a single analysis will improve our understanding of the risk of increased lameness and aid in development of strategies to reduce its incidence in feedlots.

The objective of this study was to investigate the underlying molecular mechanisms of mitochondrial Ca²⁺ homeostasis disequilibrium in mitochondrial apoptosis and its impact on yak meat tenderness. Results indicated that CaCl₂ treatment significantly promoted glycolysis by increasing lactic acid level and decreasing glycogen content, pH, and ATP production (P < 0.01 and P < 0.05). The activities of Na⁺-K⁺-ATPase pump and Ca²⁺-ATPase pump in the early aging stage were significantly influenced by CaCl₂ treatment. The activities of synchronous digital hierarchy and citrate synthase were also significantly improved by CaCl₂ treatment (P < 0.01 and P < 0.05). Mitochondrial reactive oxygen species (ROS) levels were significantly higher in the CaCl₂ group than in the control group (P < 0.01); at 24 h, the value in the Ca²⁺ group was 64.27% higher than that in the control group. Furthermore, CaCl₂ treatment significantly enhanced the mitochondrial apoptosis cascade reaction and meat tenderization by improving the myofibril fragmentation index and shear force (P < 0.01). These results demonstrated that the imbalance of mitochondrial Ca²⁺ homeostasis played a significant role in the mitochondrial apoptosis pathway by regulating energy metabolism factors, meat intracellular environment, mitochondrial functions, and ROS-mediated oxidative stress. These conditions further improved meat tenderization during postmortem aging.

The purpose of this study was to evaluate the effects of dietary supplementation of Quillaja saponin (QS) on growth performance, nutrient digestibility, fecal microbiota, and fecal gas emission in growing pigs. A total of 50 crossbred growing pigs [(Yorkshire × Landrace) × Duroc] with an initial body weight of 23.83 ± 1.95 kg were randomly assigned to one of two treatments for a 56 d trial with five replicate pens per treatment and five pigs (two barrows and three gilts) per pen. Dietary treatments including control diet and control diet supplemented with 200 mg·kg⁻¹ QS. The average daily gain was significantly increased during days 0–56, whereas the fecal ammonia emission on day 56 and fecal coliform bacteria counts on day 28 were significantly decreased in pigs fed with QS-containing diet. However, dietary supplementation of QS had no significant effects on apparent total tract digestibility. In conclusion, dietary supplementation of 200 mg·kg⁻¹ QS had beneficial effects on growth performance, fecal microbiota, and fecal gas emission in growing pigs. Considering the carry-over effects, the adaption period should be at least 28 d when supplementing 200 mg·kg⁻¹ QS to the diet of growing pigs for improving the growth performance.

LUMAN/CREB3 is a stress regulatory gene that affects the activity of the hypothalamic–pituitary–adrenal axis in mice and presents a promising avenue for exploring variable stress-responsiveness in pigs. Pigs with similar characteristics to LUMAN-deficient mice, including greater resilience to stress and receptivity to human handling, would be valuable in the pork industry from animal welfare and production efficiency perspectives. We previously identified eight genetic variations and five haplotypes throughout the LUMAN locus in Yorkshire pigs. In this study, we analysed associations between LUMAN variations with behavioural stress response during three tests (open field test, novel object test, and human approach test), physiological stress responsiveness (cortisol), and carcass/meat quality measurements from purebred Yorkshire pigs. Haplotypes A1 and A2 were associated with decreased activity levels in novel environments and greater plasma cortisol concentrations at slaughter. Haplotype A1 was associated with lower carcass scratch scores and meat with lower cooking losses and greater tenderness. Haplotypes B1 and B2 were associated with the opposite traits including increased activity levels in novel environments and characteristics for lower meat quality including greater cooking losses, lower marbling, and paler coloured meat. We conclude that DNA variations in the LUMAN locus could potentially be used as genetic markers for stress resistance and meat quality in pig breeding.

A total of 320 one-day-old Cobb 500 chicks with an initial weight of 48.3 ± 3.3 g·pen⁻¹ were assigned to four dietary treatments with eight replicates provided in three phases for 46 d. The treatments were fed as mash diets and included (1) negative control (NC) corn-soybean basal diet, (2) positive control (PC) basal diet with 30 ppm avilamycin, (3) basal diet supplemented with 1000 ppm red-osier dogwood extracts (RDE1), and (4) basal diet with 3000 ppm red-osier dogwood extracts (RDE2). Results showed reduced jejunal crypt depth in RDE1 and increased villus:crypt ratio in groups (either RDE1 or RDE2) (P < 0.05). Cationic amino acid (AA) transporter mRNA abundance was decreased (P < 0.05) in RDE1, RDE2, and PC treatments, but peptide and neutral AA transporter mRNA abundance were higher (P < 0.05) in RDE2 compared with NC. Apparent ileal digestibility of crude fat was increased in RDE2 and PC compared with NC, whereas AA digestibility was greater in RDE1, RDE2, and PC (P < 0.05). In conclusion, red-osier dogwood had no effect on growth performance, improved the intestinal health and function of broiler chickens, and had no detrimental effects on meat quality.

Two experiments were conducted to determine standardized ileal digestibility (SID) of amino acids (AA) and the concentration of metabolizable energy (ME) in non-heat-treated and heat-treated soybean expellers (L-0, L-12, and L-48). L-0 underwent short-term steam conditioning for 60 s, whereas L-12 and L-48 underwent short-term steam conditioning for 60 s and long-term steam conditioning for 12 or 48 min. All heat-treated soybean expellers were expander processed. In experiment 1, 10 ileal-cannulated barrows (54.22 ± 4.54 kg) were allotted to a replicated 5 × 4 Youden square design with eight replicate pigs per diet. Each source of soybean expellers was included in one diet, and a nitrogen-free diet was also used. Results indicated that the SID of AA in non-heat-treated soybean expellers was less (P < 0.01) than in heat-treated soybean expellers. In experiment 2, 40 barrows (17.52 ± 1.63 kg) housed in metabolism crates were allotted to a corn-based diet or four corn–soybean expellers diets. Feces and urine were collected with 5 d adaptation and 4 d collection periods. The ME in non-heat-treated soybean expellers was less (P < 0.01) compared with L-0, L-12, or L-48. In conclusion, the SID of AA and the ME in heat-treated soybean expellers were greater than in non-heat-treated soybean expellers.

This study is to evaluate the effects of mineral detoxified nano-sulfur dispersion (DSD) on growth performance, fecal score, fecal microbiota, gas emissions, blood profile, nutrient digestibility, and meat quality in finishing pigs. A total of 160 pigs with an initial body weight (BW) of 54.90 ± 5.10 kg were randomly assigned to two treatments including basal diet and basal diet with 10 ppm DSD. During the 10 wk trial, there were no differences in BW, average daily gain, average daily feed intake, and gain to feed ratio between the control and DSD groups. Also, the fecal score, fecal microbiota, gas emission were not affected by DSD diet. Dietary inclusion of DSD tended to increase water-holding capacity and decrease cooking loss and drip loss. At week 5, serum concentrations of glucose, calcium (Ca), total cholesterol, and high-density level cholesterol were increased, and triglyceride concentration was reduced in pigs fed with DSD than control diets. In summary, the inclusion of dietary DSD in the finishing pig diet has improved serum Ca, glucose concentrations, and lipid profiles as well as improves some meat quality traits.

The effect of trenbolone acetate + estradiol (TBA) implants, melengestrol acetate (MGA), and ractopamine hydrochloride + TBA (RAC + TBA) on growth performance and carcass characteristics in beef cattle (n = 680; 279 ± 10.1 kg) fed barley grain/corn silage was examined in a 4 yr study (four pens per treatment per year; 262 ± 8 d feeding period). In the first 2 yr, treatments were (1) control heifers (H-CON; no growth promoters), (2) TBA-implanted heifers (H-TBA), (3) MGA heifers (H-MGA), (4) control steers (S-CON; no growth promoters), and (5) TBA-implanted steers (S-TBA). A sixth treatment (6) RAC + TBA steers (RAC + TBA) was included in years 3 and 4. Overall dry matter intake (DMI) of heifers was increased (P < 0.001) by TBA but not MGA. Compared with H-CONs, H-TBA had greater average daily gain (ADG) (P < 0.001), gain to feed ratio (G/F) (P < 0.001), and carcass weight (P < 0.001), whereas S-TBA had increased ADG (P < 0.001), G/F (P< 0.001), and carcass weight (P < 0.001) compared with S-CON. Compared with H-CON, H-MGA had increased (P < 0.01) ADG, G/F, and carcass weight. The RAC + TBA had increased (P < 0.01) ADG and carcass weight (3.2%) but not G/F or DMI compared with S-TBA. This 4 yr study showed a consistent positive impact of growth-enhancing technologies on the performance of Canadian feedlot cattle.

The effect of dietary bark charcoal containing vinegar liquid (BCV) on the growth performance, carcass and visceral organs, intestinal histology, fecal ammonia nitrogen, and nutrient digestibility were investigated in a total of 350 one-day-old unsexed Ross 308 broilers raised under a high environmental temperature (heat stress) from 0 to 42 d of age. They were divided into 0% (control group), 1%, 2%, 3%, and 4% dietary BCV groups. Compared with the control group, the body weight gain (BWG) of the 1% dietary BCV group at 21–42 d of age and the feed efficiency of the 2% dietary BCV group at 0–42 d of age increased (P < 0.05). The carcasses of the 1% and 3% dietary BCV groups significantly decreased (P < 0.05). The digestibility of dry matter and gross energy of the 4% dietary BCV group improved at 21 d (P < 0.05). The duodenum of the 3% and 4% dietary BCV groups was significantly heavier than those in the control groups (P < 0.05). This result suggests that BCV can shorten the time to shipping date for broilers to before 42 d of age and can contribute to the development of poultry production in tropical regions.

This study was implemented to assess the effect of Pinus koraiensis extract (PKE) compared with zinc oxide on growth performance, nutrient digestibility, blood profile, fecal bacterial count, and fecal gas emission of post-weaned pigs. This 6 wk experiment was divided into phase 1 (days 1–7), phase 2 (days 8–21), and phase 3 (days 22–42). A total of 150 crossbred weaning pigs (body weight; 10.14 ± 0.78 kg) were randomly sorted in five treatment diets (six replications per treatment; five pigs per pen) presented as CON, basal diet; ZnO, CON + 0.30% zinc oxide; PKE1, CON + 0.05% PKE; PKE2, CON + 0.10% PKE; and PKE3, CON + 0.15% PKE. Pinus koraiensis extract supplementation linearly reduced gain to feed ratio in all phases except phase 3. It also linearly increased average daily gain in the overall experiment compared with the CON group. The increasing level of PKE supplementation brought linear improvement in aspartate aminotransferase of blood profile. Escherichia coli bacterial count and NH₃ gas emission were decreased linearly by PKE supplementation in comparison to the CON diet. Though PKE supplementation did not show similar influence as ZnO, it showed beneficial results in weaning pigs’ growth, nutrient digestibility, fecal bacterial count, and reduction of fecal gas emission.

A total of 160 growing pigs (24.69 ± 1.89 kg) were randomly assigned to one of four treatments in a 2 × 2 factorial design with two different levels of nutrient density diet with or without 0.3% probiotic (Lactobacillus plantarum). Each treatment had eight replicates with five pigs (three gilts and two barrows) per pen. At the end of the trial, pigs fed 0.3% probiotic supplement had significantly increased body weight, whereas the average daily gain and gain to feed ratio was significantly increased in both probiotic and high-nutrient density (HD) diet. The nutrient digestibility of dry matter was significantly increased in pigs fed HD diet, whereas nitrogen and gross energy digestibility and blood characters immunoglobulin and lymphocyte counts were significantly increased in both HD and probiotic groups. Inclusion of HD diet with 0.3% probiotic significantly decreased NH₃ and H₂S gas emission. Moreover, nitrogen and energy showed a significant interaction between probiotic and density diet. In summary, dietary probiotics with HD diet increased the growth performance, nutrient digestibility, blood profile, and reduced gas emission. We suggest that 0.3% probiotic with HD diet could serve as an alternative feed additive to enhance the growth performance of growing pigs.

This study aimed to investigate the effects of homo/heterofermentative lactic acid bacteria (LAB) on the quality of corn silage and its rumen digestibility. Maize (Zea mays strain Xingsiyu No. 10), at the early dough stage, was harvested, chopped, ensiled in vacuum bags, and divided into four groups: (1) control (without added bacteria); (2) with the homofermentative LAB Lactobacillus plantarum and Pediococcus pentosaceus (1:1 mixture, 1 × 10⁵ cfu·g⁻¹); (3) with the heterofermentative LAB Lactobacillus buchneri (1 × 10⁵ cfu·g⁻¹); and (4) with the homo/heterofermentative LAB L. plantarum, P. pentosaceus, and L. buchneri (1:1:1 mixture). At 2, 8, 15, 45, and 60 d of ensiling, nutritional quality, fermentation characteristics, and microbial content were assessed. After 60 d, aerobic stability and rumen digestibility tests were performed. The addition of homo- and (or) hetero-fermentative LAB significantly improved the nutritional quality, fermentation characteristics, and microbial content. Addition of the heterofermenter L. buchneri, with or without the homofermenters L. plantarum and P. pentosaceus, improved aerobic stability. The different LAB inoculants increased the degradation rates of dry matter, acid detergent fiber, and neutral detergent fiber of the corn silage by sheep ruminants. Analysis indicated that L. buchneri yielded the best corn silage.

There is a paucity of information on the reproductive biology of guinea hens. A study was conducted to document postembryonic developmental changes in the ovarian histology and associated progesterone and 17β-oestradiol profiles until 32 wk of age (WOA). Highly significant increases (P < 0.001) were noticed in oocyte and follicular diameters beyond 16 WOA. Other ovarian follicular morphometric traits showed inconsistent increases until 16 WOA. The first phase of yolk deposition occurred between hatching and 20 WOA, the second phase between 20 and 26 WOA, and the third and final phase between 27 and 28 WOA. Peripheral 17β-oestradiol concentrations increased from 20 WOA until it peaked at 28 WOA, whereas peripheral progesterone concentrations fluctuated considerably during sexual development. Both oestradiol and progesterone concentrations were negatively and moderately correlated (P < 0.01) with oocyte nuclei diameter, granulosa and theca layer heights. However, oestradiol concentrations were positively and strongly correlated (P < 0.001) with oocyte and follicular diameters, and moderately with progesterone concentrations. Three phases of yolk depositions were found in the guinea hen, with the final phase terminating at 28 WOA, at a much smaller oocyte diameter than in the domestic chicken. Oestradiol might play a role in yolk deposition in this species.

Burlap has been proposed as an enrichment option for the conventional farrowing crate environment. Our objectives were to determine if burlap sheets hung in farrowing crates were used by sows and piglets and had any effect on farrowing and litter performance. Before sow entry, a sterilized burlap sheet (165 cm × 60 cm) was attached to every second farrowing crate so that it hung to the floor with easy animal access. Its length was measured immediately after farrowing and weaning. Routine sow and litter information from farrowing to weaning (day 18) were recorded. Complete data were analyzed for mixed-parity sows and litters with burlap (BURL; n = 277) and without burlap (CTRL; n = 277). Sows and their litters manipulated the burlap sheet to varying degrees. The BURL sows had a lower percentage of stillbirths (6.5% vs. 8.3%, BURL vs. CTRL, SE 0.4; P = 0.004), although there was only a trend towards more born alive (13.00 vs. 12.54, SE 0.25; P = 0.113). More piglets were fostered off BURL sows (8.4 vs. 7.1, SE 0.5; P = 0.049). No significant differences were apparent for other sow and litter measurements. Burlap sheets as a farrowing crate enrichment have potential to improve sow and litter performance.

Broilers were allocated to eight treatments consisting of two energy levels: normal (NE) and high (HE), and four folic acid (FA) levels (2.2, 5, 10, and 15 ppm). On day 42, two male and two female chickens were euthanized per pen, and white striping (WS) evaluation was performed on the pectoralis major. Birds fed HE diets had reduced (P < 0.05) feed intake and feed conversion rate than those on NE diets. With increasing FA levels, there was reduced (P < 0.05) WS score and increased (P < 0.05) normal breast fillet percentage in female chickens but not in the males. WS scores were higher (P < 0.01) in male chickens than in the females.

A total of 360 one-day-old broiler chicks were randomly assigned to four treatments with five replicate cages and 18 birds per cage for a 35 d trial to investigate the effects of supplementing Achyranthes japonica Nakai (AJN) root extract in low crude protein (CP) diet on growth performance and carcass traits. Experimental diets were divided as standard CP content diet, low CP content (LCP) diet, and LCP diet supplemented with 0.025% or 0.050% AJN root extract. Dietary CP reduction impaired growth performance and carcass traits, whereas supplementing AJN root extract improved growth performance and carcass traits.

A candidate-gene high-density single-nucleotide polymorphism (SNP) scanning approach was used to investigate the swine LUMAN/CREB3 locus for polymorphisms in 232 Ontario Yorkshire and 29 Chinese Meishan pigs. Inter- and intra-breed differences in genetic diversity were characterized. In the Yorkshire breed, eight variations (three coding and five non-coding) were identified. Two linkage disequilibrium (LD) blocks (550 bp and ∼4 kb in length) featuring two and three haplotypes, respectively, were reconstructed. In the Meishan breed, six variations (two coding and four non-coding) and one LD block (∼3 kb in length) with three haplotypes were detected. This investigation may provide insight into variable stress responsiveness among pigs.

Eggshell and bone quality were investigated at 72 wk of age (WOA) using Lohmann Brown and Dekalb White hens raised with a rearing spacing allowance (SA) of 247 and 299 cm²·bird⁻¹ from days 0 to 16 before being transferred to a common SA (755 cm²·bird⁻¹) for lay cycle. Eggshell thickness, breaking strength, along with tibia and femur weight, breaking strength, length, and ash were measured at 72 WOA. Strain and SA did not interact on any above parameter (P > 0.05). Hens reared in high SA during the pullet phase had heavier tibia and more femur ash, indicating rearing environment during the pullet phase influences the bone quality of hens in the late laying stage (P < 0.05).