Neonatal dairy and beef calves are required to ingest adequate volumes of high-quality colostrum during their first hours of life to acquire transfer of passive immunity (TPI). As such, immunoglobulin G (IgG) has largely been the focus of colostrum research over recent decades. Yet, little is known about the additional bioactive compounds in colostrum that potentially influence newborn calf development and metabolism. The purpose of this narrative review is to synthesize research regarding the effects of colostrum management practices on TPI, as well as to address the potential role of additional colostral bioactive molecules, including oligosaccharides, fatty acids, insulin, and insulin-like growth factor-I, in promoting calf development and metabolism. Due to the importance of IgG in ensuring calf immunity and health, we review past research describing the process of colostrogenesis and dam factors influencing the concentrations of IgG in an effort to maximize TPI. We also address the transfer of additional bioactive compounds in colostrum and prepartum management and dam factors that influence their concentrations. Finally, we highlight key areas of future research for the scientific community to pursue to ultimately improve the health and welfare of neonatal dairy calves.

Artificial neural network (ANN) and random forest models for predicting rumen fill of cattle and sheep were developed. Data on rumen fill were collected from studies that reported body weights, measured rumen fill, and stated diets fed to animals. Animal and feed factors that affected rumen fill were identified from each study and used to create a dataset. These factors were used as input variables for predicting the weight of rumen fill. For ANN modelling, a three-layer Levenberg–Marquardt back-propagation neural network was adopted and achieved 96% accuracy in prediction of the weight of rumen fill. The precision of the ANN model’s prediction of rumen fill was higher for cattle (80%) than sheep (56%). On validation, the ANN model achieved 95% accuracy in prediction of the weight of rumen fill. A random forest model was trained using a binary tree-based machine-learning algorithm and achieved 87% accuracy in prediction of rumen fill. The random forest model achieved 16% (cattle) and 57% (sheep) accuracy in validation of the prediction of rumen fill. In conclusion, the ANN model gave better predictions of rumen fill compared with the random forest model and should be used in predicting rumen fill of cattle and sheep.

This study was conducted to investigate effects of saccharified corn straw (SCS) on broiler growth. A total of 250 one-day-old female Arbor Acres (AA) broilers were distributed into five groups. The broilers in groups 1–5 were fed with diets containing 0% (basal diet), 4%, 8%, 12% SCS, and 8% SCS (high oil), respectively. The experiment lasted 42 d including early and later stages. In the early stage, average daily gain (ADG) and feed conversion ratio (FCR) in groups 2 and 5 were almost the same as the control group; higher levels of SCS additions would decrease ADG and increase FCR (P < 0.05). In the later stage, ADG was higher, and FCR was lower in group 5 than that in other groups (P < 0.05); ADG in groups 3–4 was higher than that in groups 1 (P < 0.05) and 2. The different levels of SCS supplementation had different effects on nutrient metabolic rates and relative organ weight (P < 0.05), but they had insignificant effects on relative organ length. In the later stage, SCS supplementation could significantly increase serum total antioxidant capacity activity. It could be concluded that dietary 4% SCS in the early stage and 4%–12% SCS in the later stage had no negative effects on growth performance and nutrient metabolic rates for broilers.

The objective of this study was to evaluate the use of barley (BS) or corn (CS) silage when fed with dry-rolled barley grain (BG), corn grain (CG), or an equal blend (BCG) of BG and CG for backgrounding cattle. Ruminally cannulated heifers (n = 5) were assigned to an incomplete 6 × 6 Latin square design. Treatments contained either BS or CS in combination with BG, CG, or BCG. Samples were collected to determine dry matter intake, ruminal fermentation, total-tract nutrient digestibility, and nitrogen (N) balance. Interactions between cereal silage and cereal grain sources were detected for the molar proportions of propionate and butyrate where the magnitude of change with the type of cereal grain was increased in heifers fed CS relative to BS. Feeding CS increased estimated microbial N production (silage, P = 0.022) and fecal N excretion (silage, P = 0.042) over BS. Diets containing BG had greater dry matter, organic matter, starch, and gross energy digestibility values compared with CG, but values for BCG were not different (grain, P ≤ 0.043). Based on limited silage × grain interactions, use of CS in backgrounding diets may increase microbial N production relative to BS and dry-rolled CG may reduce apparent total-tract nutrient digestibility relative to dry-rolled BG.

Effect of xylanase (Xyl) and live yeast (LY) supplementation on gut microbiome composition, growth performance, and nutrient digestibility of weanling pigs was determined. A total of 180 weanling pigs were assigned to five treatments from weaning to market. Treatments were designated based on whether Xyl, LY, or their combination were fed in the first 2 wk postweaning or thereafter until finishing at day 141 postweaning. Treatments were (days 1–15; days 15–141): control–control, control–Xyl, Xyl–Xyl, LY–Xyl, Xyl + LY–Xyl. Xylanase was added at 16 000 BXU·kg⁻¹ and LY at 1 kg·t⁻¹. Pigs fed with LY and LY + Xyl from days 0–15 had greater body weight and average daily gain at day 15 compared with control (P < 0.05). Glucose transporter 2 mRNA was higher in LY and LY + Xyl groups on day 15 compared with control (P < 0.05). Xylanase supplementation from week 2 postweaning increased apparent total tract nutrient digestibility of gross energy, nitrogen, and phosphorus on day 43. Live yeast with or without Xyl improved growth performance in the first 2 wk after weaning; Xyl + LY–Xyl and control–Xyl groups had improved overall feed efficiency. In conclusion, LY and Xyl supplementation improved performance of weanling pigs in the first 2 wk after weaning with no effects on long-term growth performance.

A total of 16 sows (Landrace × Yorkshire) were used in a 33-d trial (7 d before expected parturition) to determine the effects of dietary-coated omega-3 fatty acid supplementation on reproduction performance, growth performance, nutrient digestibility, and blood profiles in lactating sows and suckling piglets. Pigs were randomly allotted into two treatments with eight replicates per treatment, and the parity was 4.9. The dietary treatments were as follows: CON, corn–soybean-meal-based diet [omega-6:omega-3 polyunsaturated fatty acids (PUFA) ratio of 17:1] and TRT, CON + 0.9% omega-3 PUFA (omega-6:omega-3 PUFA ratio of 5:1). The supplementation of coated omega-3 increased piglet’s body weight (BW) (day 7) and average daily gain (ADG) (days 0–7) (P < 0.05) from farrowing to weanling compared with control. No differences (P > 0.05) were observed on reproduction performance, nutrient digestibility, and blood profile in sows. In conclusion, our study demonstrated that the dietary supplementation of 0.9% omega-3 PUFA in corn–soybean-meal-based diet (omega-6:omega3 PUFA ratio of 5:1) improved BW and ADG of suckling piglets during the first week.

This study was designed to evaluate dry matter intake (DMI), ruminal fermentation, ruminal digesta outflow, omasal flow of N constituents, and ruminal and total-tract digestibility in response to increasing dietary lipid content derived from high-lipid by-product-based pellets for finishing beef cattle. Five ruminally cannulated heifers were used in a 5 × 5 Latin square design. Dietary treatments were iso-nitrogenous with increasing ether extract (EE) concentrations resulting in dietary concentrations of 3.5%, 4.2%, 4.7%, 5.1%, and 5.9% of dry matter. Periods were 28 d in duration with the first 19 d used for dietary adaptation and the last 9 d for sample and data collection. Dry matter intake, ruminal pH, omasal flow of N constituents, and short-chain fatty acid concentrations were not affected by increasing dietary EE content (P ≥ 0.10). Increasing dietary EE content increased outflow of EE from the rumen (P < 0.001). Apparent ruminal and total-tract digestibility of EE increased linearly (P ≤ 0.03) with increasing dietary EE levels. Results indicate that increasing dietary EE content from 3.5% up to 5.9% of DM by including high-lipid by-product-based pellets does not alter site of nutrient digestibility with no negative effects on nutrient intake, ruminal fermentation, or apparent ruminal, and total-tract digestibility.

Effect of calcium oxide (CaO) treatment of barley straw and salt on rumen fermentation, microbiota, digestibility, growth, and carcass quality of cattle was assessed. A replicated 4 × 4 Latin square metabolism experiment was conducted using eight heifers fed a wheat finishing diet with barley silage (B-SIL), barley straw (B-S), or 5.0% CaO-treated barley straw (CaOS) with or without NaCl (CaOS-NS). Growth over 115 d was assessed using 75 individually housed steers fed the above diets and an additional diet (I-CaOS), where CaO was added to straw just before feeding. There was no effect (P ≥ 0.08) of diet on rumen fermentation, digestibility, or carcass quality, although CaO decreased (P < 0.001) maximum pH and retained Na was decreased (P < 0.05) by CaOS-NS. Rumen bacterial abundance was altered (P ≤ 0.05) by diet. The average daily gain (ADG) of B-SIL and CaOS-NS steers was 14.1% greater (P ≤ 0.05) than BS and CaOS steers, whereas the gain:feed of CaOS-NS steers was 14.2% greater (P ≤ 0.05) than B-S and CaOS steers. Steers fed I-CaO had similar ADG and gain:feed to other treatments. CaO-treated straw without NaCl could replace barley silage in wheat diets, without compromising digestibility or growth in steers.

The objective was to evaluate the effects of feeding two different commercially available blends of essential oils to finishing steers to replace conventional feed additives in feedlot diets. Angus-based crossbred steers [N = 43; starting body weight (BW) = 466 ± 31 kg] were used in a randomized complete block design. Steers were randomly assigned to four different dietary treatments for the 100 d finishing period in which steers were fed high-moisture corn/alfalfa silage/soybean meal diets. Dietary treatments included a negative control (no additives; CON), a positive control (33 mg·kg⁻¹ monensin and 11 mg·kg⁻¹ tylosin added to the diet; M/T), and two different proprietary blends of essential oils [EO-1: 1 g·steer⁻¹·d⁻¹ Victus Liv (DSM Nutritional Products) and EO-2: 4 g·steer⁻¹·d⁻¹ Fortissa Fit 45 (Provimi Canada ULC)]. Growth performance, carcass characteristics, meat quality, sensory attributes (excluding juiciness), most fatty acid parameters, and shelf-life (color and lipid oxidative stability) were generally unaffected by the inclusion of two different commercially available essential oil blends when compared with both a negative control (CON) and a positive control (M/T). This indicates that commercially available essential oil blends may show promise as a replacement to conventional feed additives like antibiotics without causing negative effects to meat quality, storage stability, and eating experience.

Two experiments were conducted to determine the effects of a fibrolytic enzyme pretreatment on growth performance, apparent total tract digestibility, and ruminal pH throughout the grower and early finisher period (exp. 1), and to examine the impact of Saccharomyces cerevisiae supplementation on intake, performance, and indicators of gut health in the late finisher period (exp. 2). A total of 54 steers were randomly assigned to a subgroup determining experimental treatment groups. In exp. 1, steers were randomized to control (CON1; no enzyme) or enzyme [ENZ; 0.75 mL·kg⁻¹ dry matter (DM) of feed] dietary treatments. Digestibility was improved (P ≤ 0.05) in ENZ steers for DM, crude protein, net energy for gain, and sugars but did not affect (P ≥ 0.12) dry matter intake (DMI), average daily gain (ADG), or reticulo-ruminal pH. In exp. 2, the treatments were control (CON2; no yeast) or yeast (YST; 3.0 g·animal⁻¹ daily) supplemented diets. Rumen papillae were collected for mRNA expression of gut barrier function (OCLN, CLDN, ZO1, and ZO2) and immune response (TLR2, TLR4, and FCAR) genes and histological measurements. Yeast supplementation decreased (P < 0.001) DMI by 31%, reduced variation in DMI, and improved feed conversion ratios but did not impact rumen health mRNA expression or histology measures (P ≥ 0.07). Overall, enzyme supplementation improved the digestibility of some nutrients in the grower period, and yeast supplementation improved feed efficiency, without impacting growth performance or gut health.

A total of 144 mixed sex pigs [(Landrace × Yorkshire) × Duroc] with an initial average body weight (BW) of 52 kg were used in a 11 wk trial in a 2 × 2 factorial design with the following factors: group size (three pigs per pen vs. five pigs per pen) and 0% or 0.2% homeopathic product supplementation to evaluate growth performance, nutrient digestibility, meat quality, and stress-related hormones. The homeopathic product supplementation resulted in increased (P < 0.05) BW at week 11, average daily gain (ADG) during days 42–63 and 64–77. In addition, an increase (P < 0.05) in ADG and average daily feed intake during overall experiment period and an increase (P < 0.05) in apparent total tract digestibility of dry matter at day 77 were observed in pigs receiving homeopathic product. A trend in increase (P = 0.088) in serum cortisol concentration during day 42 and increase (P > 0.05) during day 77 was observed in pigs with group size of five pigs per pen, and this was reduced when homeopathic product was supplemented to the diet. In conclusion, the variation in number of animals per pen had no effects on performance and production traits, but the animals in bigger group size had higher serum cortisol concentrations which were reduced by the homeopathic product supplementation.

The use of supplements to feed grazing ruminants may improve the productivity and profitability of beef cattle productive systems. This study aimed to evaluate the effect of different supplementation amounts on the meat quality of Nellore steers finished on pasture. A total of 40 steers were maintained on Brachiaria brizantha ‘Marandu’ pasture and finished on different concentrate supplementation amounts: 0%, 0.3%, 0.6%, and 0.9% of body weight (BW). There was no effect (P > 0.10) of supplementation on 14:0, 14:1 n-5, 15:0, 15:1 n-6, 16:1 n-10, 16:1 n-9, 16:1 n-7, 18:1 c-9, 18:1 t-9, 18:2 n-6, conjugated linoleic acid, 20:4 n-6, 22:0 and 22:5 n-3. However, the 17:1 n-10 decreased linearly (P < 0.01), whereas 18:0 increased linearly (P < 0.01) when supplementation was added. There was a quadratic effect (P < 0.10) for 16:0 and 18:1 t-11, as well as for 18:3 n-6. The total concentration of n-3 was linearly reduced, whereas the n-6/n-3 ratio was linearly increased. The use of concentrate supplements for Nellore steers finished on pasture, at amounts up to 0.9% of BW, does not improve the unsaturated fatty acids content. In contrast, the supplementation increases the content of saturated fatty acids in meat of steers.

In the random regression model (RRM) for milk yield, by replacing empirical lactation curves with the five-order Legendre polynomial to fit fixed groups, the RRM can be transformed to a hierarchical model that consisted of a RRM in the first hierarchy with Legendre polynomials as individuals’ lactation curves resolved by restricted maximum likelihood (REML) software, and a multivariate animal model for phenotypic regression coefficients in the second hierarchy resolved by DMU software. Some empirical lactation functions can be embedded into the RRM at the first hierarchy to well fit phenotypic lactation curve of the average observations across all animals. The functional relationship between each parameter and time can be described by a Legendre polynomial or an empirical curve usually called submodel, and according to three commonly used criteria, the optimal submodels were picked from linear and nonlinear submodels except for polynomials. The so-called hierarchical estimation for the RRMs in dairy cattle indicated that more biologically meaningful models were available to fit the lactation curves; moreover, with the same number of parameters, the empirical lactation curves (MIL1, MIL5, and MK1 for 3, 4, and 5 parameters, respectively) performed higher goodness of fit than Legendre polynomial when modelling individuals’ phenotypic lactation curves.

This study investigated the effects of three pine-based biochar products on nutrient disappearance, total gas and methane (CH₄) production, rumen fermentation, microbial protein synthesis, and rumen microbiota in a rumen simulation technique (RUSITEC) fed a barley-silage-based total mixed ration (TMR). Treatments consisted of 10 g TMR supplemented with no biochar (control) and three different biochars (CP016, CP024, and CP028) included at 20 g·kg^?1 DM. Treatments were assigned to 16 fermenters (n = 4 per treatment) in two RUSITEC units in a randomized block design for a 17 d experimental period. Data were analyzed using MIXED procedure in SAS, with treatment and day of sampling as fixed effects and RUSITEC unit and fermenters as random effects. Biochar did not affect nutrient disappearance (P > 0.05), nor total gas or CH₄, irrespective of unit of expression. The volatile fatty acid, NH₃-N, total protozoa, and microbial protein synthesis were not affected by biochar inclusion (P > 0.05). Alpha and beta diversity and rumen microbiota families were not affected by biochar inclusion (P > 0.05). In conclusion, biochar did not reduce CH₄ emissions nor affect nutrient disappearance, rumen fermentation, microbial protein synthesis, or rumen microbiota in the RUSITEC.