Translational Animal Science最新文献

This study assessed the growth, carcass traits, and rumen morphology of feedlot cattle fed reduced levels of organic trace minerals (OTM) in proteinate forms and Se-yeast, replacing inorganic trace minerals (ITM) sources in combination with exogenous amylase. One hundred and twenty commercial yearling Nellore bulls with an initial body weight (BW) of 349.20 ± 22.90 kg were allocated to 24 pens. The study employed a completely randomized block design with a 2 × 2 factorial treatment arrangement. Factors included ITM or OTM sources/level with or without exogenous amylase (Amaize, Alltech, Maringá, PR, Brazil [0.5 g/kg of dry matter]). The ITM supplement contained Co, Cu, Fe, Mn, and Zn in sulfate form, with Se provided as sodium selenite. The OTM supplement provided Co, Cu, Fe, Mn, and Zn in proteinate form at 50% of the levels supplied by the ITM supplement, while Se, as Se-yeast, was included at the same level as in the ITM supplement. Both supplements also contained Cr as Cr-yeast and I as sodium iodide. Cattle were fed the same diets, except for the inclusion of trace minerals and exogenous amylase. There was no interaction (P ≥ 0.12) between trace mineral and exogenous amylase for any variable evaluated. Cattle fed OTM tended to have higher average daily gain (ADG; P = 0.07) and gain-to-feed (G: F) ratio (P = 0.06) compared to cattle fed ITM. Cattle fed exogenous amylase had greater dry matter intake (DMI), whether measured in kg/d (P = 0.03) or as a percentage of BW (P = 0.02), with no (P ≥0.10) effect on ADG and G: F ratio compared to cattle not fed exogenous amylase. There was no main effect of trace mineral or exogenous amylase inclusion (P ≥ 0.15) on any of the carcass traits evaluated, except for final Biceps femoris fat thickness (P = 0.05), which were higher in cattle fed OTM. Rumenitis score and rumen morphology were also not different (P ≥0.14). Overall, feeding reduced OTM levels did not exert adverse effects on growth, carcass traits, or rumen morphology in feedlot Nellore cattle, while modestly enhancing ADG, G: F ratio, and Biceps femoris fat thickness compared to ITM sources. The exogenous amylase inclusion increased DMI without differences in ADG, G: F ratio, carcass characteristics, or rumen morphology.

Feeding cattle a total mixed ration (TMR) instead of offering dietary ingredients separately (instead of individually) is generally recommended. Feeding TMR enhances production by reducing feed sorting, decreasing manual labor, and preventing digestive diseases. However, producing TMR requires a specialized mixer that can be expensive and necessitates trained personnel and regular maintenance. Furthermore, some roughages need prior processing before adding to the mixer. Consequently, providing TMR is a methodology hard to adopt by small-sized farm operations. The goal of this study was to evaluate growth performance and carcass characteristics of feedlot cattle offered a TMR or non-mixed ration (NMR; hay and concentrate were provided separately). Angus-Simmental cattle (324.8 ± 29.6 kg) were fed using either a TMR strategy (TMRS; n = 29) or a non-mixed ration strategy (NMRS; concentrate and hay were fed separately; n = 30). Steers were housed individually and fed once a day using individual feed bunks. Irrespective of the treatment, feed offered was subjected to a slicked bunk management. For the NMRS treatment, each bunk was bisected by a wooden plunk bolted to it, for hay and concentrate to be offered in one half each. The ratio hay-to-concentrate (7-to-93) offered was the same between treatment groups. Steers were weighed every 28 d while feed offer and refusals were recorded daily. Post slaughter, yield grade, hot carcass weight, back fat, ribeye area, kidney-pelvic-heart fat, and quality grades (marbling, skeletal maturity, lean maturity) were recorded at the slaughterhouse. Data were analyzed considering the fixed effect of treatment. No differences (P ≥ 0.15) were observed for growth performance or carcass characteristics between treatments. These results likely stem from bunk management practices, allowing adjustments in the amount of feed offered based on the amount remaining in the bunk each day, thus maintaining similar feedstuff ratios across treatments. However, the feed management approaches used in this study might not align with animal group housing, conventionally used in feedlot operations, due to bunk competition and diet selection.

Recent legislative approval of industrial hemp (IH) cultivation has increased interest in the possibility of using IH and IH byproducts in livestock feed. Understanding the therapeutic effects of IH is critical for regulatory decisions and application to the cattle industry. The objective of this pilot study was to describe the effects of IH administration on stress and inflammatory biomarkers and activity in cattle experiencing repeated transportation. Twelve Holstein steers (430 kg, SEM = 3.4; 947 lb, SEM = 7.6) were assigned randomly to treatment sequences (n = 3 per sequence) in a 4 × 4 Latin Square design study (four periods and four treatment sequences). Treatments consisted of one of two drugs (IH or placebo; HEMP, PLBO) and one of two transportation events (transport or control; TRANS, CNTL) during each period so that every steer received all treatment combinations during the study. Industrial hemp was dosed at 5.5 mg/kg cannabidiolic acid (CBDA), with IH or placebo given once by oral bolus immediately prior to the transport or control event. Body weight, accelerometry, kinetic gait analysis, mechanical nociceptive threshold, infrared thermography, complete blood count (CBC), serum biochemistry, blood cortisol, prostaglandin E₂ metabolite (PGEM), and serum amyloid A (SAA) were assessed using multiple linear regression. Summary statistics for plasma cannabinoid concentration were generated. There was a drug by transport by time interaction for change in PGEM from baseline (P = 0.03): steers in the HEMP-CNTL group had negative change at 48 h, whereas PLBO-CNTL steers had positive change at 48 h. Both TRANS and CNTL steers had increased lying times in the period immediately after transport. Steers in the TRANS group had greater body weight loss (P <0.0001), neutrophils (P < 0.0001), monocytes (P = 0.04), blood glucose (P < 0.0001), and total protein (P <0.0001) compared to CNTL steers immediately following transport. Cortisol area under the curve values were greater for TRANS versus CNTL steers (P < 0.0001). Lymphocyte concentrations were decreased for TRANS steers compared to CNTL following transport (P < 0.0001). There was a transport by time interaction for SAA (P < 0.0001), with TRANS steers at 24 and 32 h having the greatest SAA concentrations. Further investigation is required to confirm if feeding IH reduces PGEM. Novel outcomes evaluated in this pilot study will assist in design of future transportation trials.

A total of 1005 sows and their litters were used to evaluate the effect of initial litter size relative to functional teat count on sow and litter performance. Sows were blocked by parity (1, 2 to 4, or 5+) and functional teat count (≤13, 14 to 15, or ≥16) categories and allotted to one of four treatments with 251 or 252 replications. Treatments consisted of 1 less pig than functional teats (-1), same number of pigs as functional teats (0), 1 more pig than functional teats (+1), or 2 more pigs than functional teats (+2). Pigs were individually weighed after cross-fostering and before weaning. Pigs born <0.9 kg were fostered onto sows not included in this study. Replacement pigs were not added to litters after a removal or mortality. Sow body weight (BW), caliper score, and backfat depth were collected at farrowing house entry and weaning (d 22). Parity category, treatment, and their interaction were fixed effects in the model along with teat category. As litter size relative to functional teat count increased, sows lost more BW and caliper units, but culling rate due to non-conception decreased (linear, P ≤ 0.038). Litter size and weight increased (linear, P < 0.001) as initial litter size relative to functional teat count increased at d 2 and weaning. Litter average daily gain (ADG) exhibited a quadratic relationship (P = 0.045) where -1 and +2 sows had numerically greater litter ADG compared to 0 and +1 sows. Mean pig weaning BW (linear, P < 0.001) and pig ADG decreased (quadratic, P = 0.042) and removals and mortality (d 2 to weaning) increased (linear, P < 0.001) as initial litter size relative to functional teat count increased. Pigs weaned per sow per year (PSY) increased (linear, P < 0.001) as initial litter size relative to functional teat count increased. Wean-to-estrus interval (WEI) exhibited a quadratic relationship (P = 0.049) where 0 sows had longer WEI compared to +2 sows with -1 and +1 sows intermediate. Subsequent farrowing rate did not differ; however, subsequent liveborn increased (linear, P = 0.017) and total born tended to increase (linear, P = 0.061) as previous litter size relative to functional teat count increased. In conclusion, sows with 1 less pig than functional teats after cross-fostering had the lowest piglet mortality and sow BW loss and greatest piglet weaning BW. However, sows with 2 more pigs than functional teats after cross-fostering had the greatest number of pigs weaned per litter, litter WW, and PSY.

This study evaluated how varying crude protein levels in rations that incorporated canola meal or wheat-based dried distillers' grains with solubles as alternative protein sources affected growth performance, carcass traits, and liver mineral status in feedlot bison heifers. Ninety-six crossbred bison heifers (initial body weight; 215.5 ± 22.2 kg) were stratified by weight and randomly assigned to one of three dietary treatments: (i) a conventional control diet (CON), (ii) CON with canola meal (CM), or (iii) CON with wheat-based dried distillers' grains with solubles (WDDGS). Diets were fed over a 302-d period, consisting of a 122-d backgrounding phase and a 180-d finishing phase. During the backgrounding phase, CM and WDDGS diets were formulated to 14.0% crude protein (CP) compared with 10.0% in the CON diet. In the finishing phase, CM and WDDGS diets were formulated to 14.0% CP compared to 12.5% in the CON diet. The dry matter intake (DMI) was lower (P = 0.04) in heifers fed CM and WDDGS (5.9 kg/d) compared to CON (6.2 kg/d) during backgrounding. However, average daily gain and gain-to-feed ratio did not differ among treatments in any phase (backgrounding, finishing, or overall; P ≥ 0.27). Final body weight, hot carcass weight, dressing percentage, ribeye area, backfat thickness, marbling occurrence, and liver abscess incidence were not affected by dietary treatment (P ≥ 0.20). Hepatic copper (P = 0.02) and zinc (P = 0.03) concentrations were greater in heifers fed by-product diets compared to CON. A pronounced seasonal pattern in DMI was observed with a peak occurring in summer and a nadir in the winter. These results indicate that bison heifers can achieve similar growth performance and carcass characteristics when fed diets formulated to 10.0% CP during backgrounding and 12.5% CP during finishing, and that increasing dietary CP to 14.0% through the inclusion of CM or WDDGS did not enhance productivity. These results indicate that CM or WDDGS can be fed as protein sources without compromising the performance of bison heifers.

An experiment was conducted to compare the effects of feeding a proprietary blend of probiotics (Bacillus licheniformis and Bacillus subtilis) mixed with a blend of monoterpene and phenylpropene essential oils (EO), known as Palisade (Sulutions, Frankfort, KS) against monensin sodium, and their combination, on intake and growth performance responses of growing beef steers. Two hundred and forty Charolais × Angus crossbred steers (initial BW 340 ± 26.7 kg, ∼ 6 ± 1 month of age) were used. All steers received a basal corn-silage-based diet, with the inclusion of different feed additives: A) Palisade at 0.02% of the diet DM (PAL), B) Monensin sodium at 28 g/Ton (MON), and C) the combination of PAL and MON (PAL + MON). Steers were housed in 30 pens with 10 pens/treatment, and 8 steers/pen. Steers were fed for 83 days, and BW was measured every 28 days, and digestibility was determined from three fecal samplings using insoluble Ash as an internal marker. On d 83, steers fed MON were 8.9 and 11.8 kg heavier than steers fed the PAL or PAL + MON diets, respectively (P = 0.01), with no difference between the last two. As a result, average daily gain (ADG) was greater for MON-fed steers, compared with steers fed with PAL or PAL + MON (P = 0.01), without differences between the last two. Steers fed with the PAL + MON consumed less feed (P = 0.01) than those fed either PAL or MON, with no difference between the last two. The cumulative gain to feed ratio (GF) was greater for MON-fed steers, compared with steers fed with PAL or PAL + MON (P <0.01), with no difference between the last two (P >0.10). Similarly, apparent Net energy of gain was greater for MON-fed steers than for PAL-fed steers (P = 0.01), while PAL + MON steers were intermediate and did not differ with the other two groups. Around the days of nutrient digestibility determination, steers fed the PAL + MON diet consumed less (P <0.01) dry matter than steers receiving the PAL and MON diets, with no difference between the last two. No differences were observed in apparent total tract nutrient digestibility of nutrients (P >0.44), nor in the gross energy determined with a bomb calorimeter from feed and feces (P >0.76). Hence, the GE intake was reduced (P <0.01) for the PAL + MON-fed steers compared with steers fed with PAL or MON diets, with no difference between the last two. Steers fed with monensin alone had greater intake, body weight gain and feed efficiency than those fed PAL or PAL + MON.

The aim of this experiment was to investigate the differences between intact (ram) and castrated (wether) lambs by evaluating animal growth pre- and post-weaning, feed efficiency, carcass characteristics, and carcass cutability. A total of 144 lambs were used for this feeding experiment (ram; n = 72 and wether; n = 72) and 70 lambs (ram; n = 35 and wether; n = 35) were slaughtered at the end of an 8-wk finishing period. Treatment (ram or wether) was randomly assigned shortly after birth. During the finishing period, lambs were weighed every 14 d. Lambs were slaughtered over five harvest dates based on live weight targets, evaluated for carcass characteristics 24-h postmortem, and fabricated into subprimal cuts 48-h postmortem, with weights collected from each subprimal. Results for the finishing period were analyzed using PROC MIXED in SAS with a fixed effect of sex with random effects of group (location and lambing season) and block. Carcass and economic value data were analyzed using PROC GLIMMIX in SAS with a fixed effect of sex and random effects of pen, block, and season. In terms of animal growth, there was a sex × time interaction (P < 0.01) for lamb body weight (BW), resulting in rams having heavier BW throughout the 8-wk finishing period. In addition, ram lambs also had a greater gain to feed (G:F) ratio (P < 0.01) and average daily gain (ADG) (P < 0.01). Furthermore, there was a sex × time interaction for dry matter intake (DMI) (P = 0.04) as ram lambs consumed more feed when compared with wether lambs. In the abattoir, ram lambs retained heavier carcasses (P < 0.01), with larger ribeyes (P < 0.01) and were trimmer (backfat thickness; P < 0.01 and bodywall thickness; P = 0.02), with overall lamb quality being equivalent between treatments as indicated by similar overall quality grades (P = 0.99) and degree of fat flank streakings (P = 0.53). Moreover, ram lambs were higher yielding for several meat cuts including neck, shoulder, foreshank, breast, trotters, and leg (P < 0.05) when compared with wether lambs. Within the context of this experiment, ram lambs exhibited greater weight gain, feed efficiency, carcass yield, and cutability. With uncertainties remaining as to the consumer acceptability of meat produced from ram lambs, coupled with increased DMI required by growing ram lambs; further investigation is needed to support the production of ram lambs for meat production.

This study evaluated effects of a nutrient-enriched late gestation diet (LGPHASE) on reproductive performance and blood-based biomarkers in sows and their progeny through weaning. Seventy sows (parity 0-5) at 70 ± 2 d gestation were assigned to a control (CON; n = 35; 11% CP, 0.52% SID lysine, industry-standard organic trace minerals, and vitamins) or a LGPHASE diet (n = 35; 16% CP, 0.87% SID lysine, 2 × CON industry-standard organic trace minerals and vitamins except selenium, plus 500 mg/kg vitamin C) fed from days 70 to 110 of gestation. All sows received a common lactation diet. Blood was collected from sows at day 70 ± 2, day 110 ± 2, and weaning (lactation day 19 ± 3) for blood counts and serum analysis. Piglet Hb was measured at birth (CON: n = 479; LGPHASE: n = 495) and at weaning (CON: n = 395; LGPHASE: n = 431), and serum was collected from 2 piglets per litter (n = 70 per treatment) at 40-48 h post farrow and weaning. Sow and piglet serum was analyzed for copper, iron, zinc, ferritin, and 25(OH)D₃. Farrowing duration was shorter in LGPHASE than CON sows (290.4 vs. 359.9 min; P = 0.028). Litter size and birth weight were similar between treatments, however, a reduced stillbirth rate tended to occur in LGPHASE sows (3.4% vs. 6.8%; P = 0.099). LGPHASE sows tended to wean more (13.4 vs. 12.3; P = 0.062) and lighter pigs (5.70 vs. 6.16 kg; P = 0.087) with increased piglet survivability (90.5% vs. 84.8%; P = 0.019). LGPHASE sows tended to have higher Hb at day 110 (11.2 vs. 10.7 g/dL; P = 0.091) and had higher Hb at weaning (10.7 vs. 9.9 g/dL; P = 0.004) than CON sows. At day 110, LGPHASE sows had greater serum 25(OH)D₃ (54.8 vs. 35.5 ng/mL; P = 0.002), and tended to have greater serum ferritin at weaning than CON sows (38.5 vs. 28.3 ng/mL; P = 0.074). At day 2, LGPHASE piglets had greater serum ferritin (25.1 vs. 19.1 ng/mL; P = 0.079). At weaning, serum copper was greater in LGPHASE piglets (2.26 vs. 2.17 µg/mL; P = 0.022) and serum 25(OH)D₃ tended to be greater in the LGPHASE piglets than CON piglets (7.5 vs. 6.9 ng/mL; P = 0.080). In the subsequent cycle, LGPHASE sows had more total born (19.24 vs. 16.84; P = 0.041) and live born pigs (17.70 vs. 15.00; P = 0.015), reflecting increases of 2.74 total born (P = 0.024) and 2.50 live born pigs (P = 0.031) from the prior cycle. Late-gestation nutrient needs exceed typical feeding levels; phase feeding improved micronutrient status, farrowing duration, piglet survival, and subsequent litter size.

[This corrects the article DOI: 10.1093/tas/txae055.].

Two experiments were conducted to determine the effect of increasing retention time in the conditioner prior to pelleting on digestibility of energy, protein, and amino acids (AA) in diets for growing pigs. Four dietary treatments were used in both experiments and consisted of a mash diet, and 3 pelleted diets that were conditioned for 30, 60, or 180 s. In Exp. 1, 12 ileal canulated barrows with an initial average body weight of 44.9 ± 2.70 kg were allotted to a triplicated 4 × 4 Latin square with 4 dietary treatments and 4 experimental periods in each square for a total of 12 replicate pigs per treatment. Each period consisted of 5 days of adaptation and 2 days of collection of ileal digesta. In Exp. 2, 12 barrows (initial average body weight: 34.1 ± 1.03 kg) were allotted to a triplicated 4 × 3 incomplete Latin square design with 4 dietary treatments and 3 experimental periods. Each period consisted of 5 d of adaptation and 5 d of collection of feces and urine. Pigs were individually housed in metabolism crates and feces, and urine were collected. Results of Exp. 1 indicated an overall treatment effect (P < 0.05) on standardized ileal digestibility (SID) of crude protein and all AA except Lys, Met, and Trp. The SID of crude protein, Arg, Leu, Thr, Ala, Ser, and Tyr was greater (P < 0.05) in all pelleted diets compared with the mash diet. The SID of His, Ile, Phe, Val, Asp, and Glu was less (P < 0.05) in the mash diet compared with the pelleted diets conditioned for 60 s or 180 s. The SID of Cys was less (P < 0.05) in the mash diet compared with the pelleted diet conditioned for 180 s. Increasing the retention time in the conditioner from 30 to 180 s increased (linear; P < 0.05) the SID of CP and most AA. Results of Exp. 2 demonstrated that pelleted diets had greater (P < 0.05) apparent total tract digestibility (ATTD) of gross energy compared with the mash diet, but no treatment effects were observed for ATTD of dry matter or on digestible energy, metabolizable energy or the metabolizability of digestible energy. These results indicate that increasing conditioning time up to 180 s improved AA digestibility for most AA and pelleting also increased ATTD of gross energy.