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This study, conducted at São Paulo University feedlot, Dracena, Brazil, was designed to evaluate the effect of adding either high-moisture corn, calcium salts of fatty acids (CSFA), or organic Zn+Cr on feedlot performance and carcass traits of Nellore cattle fed for 112 days. One-hundred fifty 18-mo-old Nellore bulls (404±24kg) were used and initially ranked, according to sires’ information, into groups of high and low EPD. Secondly, cattle were blocked by weight and randomly allocated to 30 pens (n = 5/pen), which were randomly assigned to the following 2x2 + 1 arrangement of treatments: Finely-ground corn, High-moisture corn, Finely-ground + CSFA, High-moisture corn + CSFA, and High-moisture corn + CSFA + Zn (90 ppm) and Cr (0.45 ppm). All diets contained 25 ppm of monensin. On day 0, one animal per pen was randomly selected to be slaughtered for baseline purposes. The replacement of finely-ground by high-moisture corn increased (P < 0.05) final BW (585 vs. 573 kg), ADG, HCW (321 kg vs. 315 kg) and decreased (P < 0.01) DMI (9.7 vs. 10.1 kg). Likewise, the addition of CSFA increased final BW, ADG (1.62 vs. 1.50 kg), and HCW (321 vs. 314 kg). The addition of Cr+Zn led to increased (P = 0.02) dressing percentage. No treatment effect was observed on final marbling (P > 0.55). It was observed interactions between treatments and EPD for G:F (P = 0.02) and final 12thrib-fat thickness (P = 0.03), where cattle from low-EPD groups needed high-moisture corn, CSFA and organic Zn+Cr to improve G:F and increase fat deposition; however, animals from high-EPD groups required only high-moisture corn. The adding of either high-moisture corn, CSFA, or organic Zn+Cr improved feedlot performance of Nellore cattle, and its effects seemed to be more effective in animals from low-EPD groups.

Made available in DSpace on 2022-04-29T08:32:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-08-02 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Feedlot cattle are usually adapted to high-concentrate diets containing sodium monensin (MON) in more than 14 days. However, for finishing diets with lower energy content, the use of MON during adaptation may hold dry matter intake (DMI), and virginiamycin (VM) may be an alternative. This study was designed to determine the potential of shortening the adaptation of Nellore cattle to high-concentrate diets using only VM as a sole feed additive relative to feedlot performance, feeding behavior, and ruminal and cecum morphometrics. The experiment was designed as a completely randomized block replicated six times (four animals/pen) in which 120 Nellore bulls (390.4 ± 19.0 kg) were fed in 30 pens for 111 days according to the following treatments: (1) MON and adaptation for 14 days (MON14), (2) MON + VM and adaptation for 14 days (MONVM14), (3) VM and adaptation for 14 days (VM14), (4) VM and adaptation for 9 days (VM9), and (5) VM and adaptation for 6 days (VM6). At the end of the adaptation, 30 animals (n = 1 per pen) were randomly slaughtered for rumen and cecum evaluations. The remaining 90 bulls were harvested at the end of the study. No effects of treatments were observed (P < 0.10) for final body weight, average daily gain (ADG), and hot carcass weight (HCW). Cattle fed VM14 presented a greater (P ≤ 0.03) DMI, expressed as percent of body weight (BW), than animals fed either MON14 or MONVM14; however, cattle fed either MON14 or MONVM14 improved (P ≤ 0.02) the gain-to-feed ratio (G/F) by 10.4 or 8.1%, respectively, when compared to bulls fed VM14. Bulls fed VM14 had smaller (P < 0.05) papillae area (0.34 vs. 0.42 cm2) and rumen absorptive surface area (28.9 vs. 33.8 cm2) than those fed MON14. The shortening of the adaptation period linearly decreased the 12th rib fat (P = 0.02) and biceps femoris fat daily gain (P = 0.02) of Nellore bulls fed only VM, which linearly decreased the final biceps femoris fat thickness (P < 0.01). Feedlot cattle fed VM as a sole feed additive should not be adapted to high-concentrate diets in less than 14 days. Regardless of either adaptation length or feed additive, feedlot cattle need at least 14 days to adapt to finishing diets. Department of Breeding and Animal Nutrition School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) Department of Animal Production College of Agricultural and Technological Sciences São Paulo State University (UNESP) Department of Breeding and Animal Nutrition School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) Department of Animal Production College of Agricultural and Technological Sciences São Paulo State University (UNESP)

Made available in DSpace on 2022-05-01T07:58:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) This survey aimed to provide a current outlook of nutritional recommendations and management practices adopted by feedlot nutritionists in Brazil. The survey questionnaire consisted of 96 questions that included general information on nutritionists, animals, ingredients utilized in finishing diets, management and formulation practices, feeding management, and challenges associated with applying nutritional recommendations in practice. Thirty-six nutritionists, responsible for 4,671,062 animals in Brazil, responded our questionnaire. An increase in the percentage of nutritionists (38.9%) recommending 66% or more grain inclusion in the diets was observed. Fine grinding remained the preferred grain processing method by nutritionists (44.4%); however, more than 50% of nutritionists recommended highmoisture harvest and storage as the secondary grain processing method of choice. The average level of concentrate in the diets was 83.3%, which is higher compared with past surveys. The preferred fiber analysis method by 80.6% respondents was physically effective neutral detergent fiber (peNDF), and corn silage remained the main roughage source in finishing diets (69.4%). Improvements in diet mixing and distribution were also noted. While 79.0% of nutritionists’ clients use a truck-mounted mixer and 69.5% of them also use programmed delivery per pen, 44.4% of the nutritionists reported that their clients use clean-bunk management. Respiratory diseases and acidosis (reported by 71.4 and 27.6% of the respondents, respectively) are among the main health problems. The present survey provides an overview of nutritional practices currently adopted by feedlot nutritionists, who played an important role on the improvement of feeding management in Brazil over the last 10 years. Universidade Estadual Paulista Faculdade de Medicina Veterinária e Zootecnia Universidade Estadual Paulista Faculdade de Ciências Agrárias e Tecnológicas Universidade Estadual Paulista Faculdade de Medicina Veterinária e Zootecnia Universidade Estadual Paulista Faculdade de Ciências Agrárias e Tecnológicas

This study, conducted at São Paulo State University feedlot, Dracena campus, Brazil, had the objective to evaluate the effect of ranking Nellore bulls according to residual feed intake (RFI) on feedlot performance and rumen morphometric variables. Twenty-seven 18-mo-old Nellore bulls (425.5 ± 20.1 kg) were randomly allocated in 27 pens (one animal per pen) and fed for 107 days. The multiple step-up diets program consisted of ad libitum feeding of diets with the concentrate level increasing from 70% to 86% concentrate. At harvest, rumen epithelium samples were collected from cranial for rumen morphometric measurements. The RFI was calculated by the difference between the predicted DMI values [DMI = (0.0544*BW0.75) + (2.9659*ADG)] and observed DMI. Then, Nellore bulls were distributed into RFI groups: High (0.5 SD above the mean; n = 8), Medium (±0.5 SD of the mean; n=9) and Low (0.5 SD below the mean; n = 10). Low-RFI Nellore bulls improved (P = 0.04) G:F when compared to High- and Medium-RFI animals (0.142 vs. 0.125 and 0.130; respectively); however, no significant RFI grouping effect was observed for ADG (P = 0.54), final BW (P = 0.54), HCW (P = 0.27), dressing percentage (P = 0.24), final LM area (P = 0.87), final 12th rib fat (P = 0.82), final P8 fat thickness (P = 0.67) and final marbling (P = 0.82). Regarding rumen morphometrics, High-RFI Nellore bulls had larger (P = 0.09) rumen absorptive surface area than Low- and Medium-RFI animals (43.31 vs. 32.95 and 31.27; respectively), which was associated to the greater (P = 0.01) DMI presented by High-RFI animals (10.2 vs. 9.1 and 9.0 for Medium- and Low-RFI Nellore bulls; respectively). Nevertheless, no significant RFI grouping effect was observed for number of papillae (P = 0.28) or mean papillae area (P = 0.61). Thus, Low-RFI Nellore bulls improved feed efficiency without promoting any positive effects on carcass traits and rumen morphometrics.

Made available in DSpace on 2020-12-12T02:47:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-31 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Beef cattle are key contributors to meat production and represent critical drivers of the global agricultural economy. In Brazil, beef cattle are reared in tropical pastures and finished in feedlot systems. The introduction of cattle into a feedlot includes a period where they adapt to high-concentrate diets. This adaptation period is critical to the success of incoming cattle, as they must adjust to both a new diet and environment. Incoming animals are typically reared on a variety of diets, ranging from poor quality grasses to grazing systems supplemented with concentrate feedstuffs. These disparate pre-adaptation diets present a challenge, and here, we sought to understand this process by evaluating the adaptation of Nellore calves raised on either grazing on poor quality grasses (restriction diet) or grazing systems supplemented with concentrate (concentrate diet). Given that nutrient provisioning from the diet is the sole responsibility of the ruminal microbial community, we measured the impact of this dietary shift on feeding behavior, ruminal fermentation pattern, ruminal bacterial community composition (BCC), and total tract digestibility. Six cannulated Nellore bulls were randomly assigned to two 3 × 3 Latin squares, and received a control, restriction, or concentrate diet. All cohorts were then fed the same adaptation diet to mimic a standard feedlot. Ruminal BCC was determined using Illumina-based 16S rRNA amplicon community sequencing. We found that concentrate-fed cattle had greater dry matter intake (P < 0.01) than restricted animals. Likewise, cattle fed concentrate had greater (P = 0.02) propionate concentration during the adaptation phase than control animals and a lower Shannon’s diversity (P = 0.02), relative to the restricted animals. We also found that these animals had lower (P = 0.04) relative abundances of Fibrobacter succinogenes when compared to control animals during the pre-adaptation phase and lower abundances of bacteria within the Succinivibrio during the finishing phase, when compared to the control animals (P = 0.05). Finally, we found that animals previously exposed to concentrate were able to better adapt to high-concentrate diets when compared to restricted animals. Our study presents the first investigation of the impact of pre-adaptation diet on ruminal BCC and metabolism of bulls during the adaptation period. We suggest that these results may be useful for planning adaptation protocols of bulls entering the feedlot system and thereby improve animal production. School of Veterinary Medicine and Animal Science São Paulo State University (UNESP College of Technology and Agricultural Sciences São Paulo State University (UNESP Department of Bacteriology University of Wisconsin–Madison School of Veterinary Medicine and Animal Science University of São Paulo Purina Animal Nutrition LLC School of Veterinary Medicine and Animal Science São Paulo State University (UNESP College of Technology and Agricultural Sciences São Paulo State University (UNESP FAPESP: 2014/26210-4 FAPESP: 2015/00106-9

Made available in DSpace on 2020-12-12T02:36:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-01 Context: The use of two feed additives, to maximise rumen fermentation, in finishing diets offered to feedlot cattle may positively impact performance. Aims: This study, conducted at the São Paulo State University feedlot, Botucatu campus, Brazil, was designed to evaluate the effects of the combined use of monensin (MON; 30 mg/kg of dry matter; (DM)) and virginiamycin (VM; 25 mg/kg of DM) in high-concentrate diets during the adaptation and finishing periods on feedlot performance, carcass traits, feeding behaviour, blood gas profile, rumen morphometrics and apparent total tract digestibility of nutrients of Nellore cattle. Methods: The experiment was designed as a completely randomised block, replicated six times (3 bulls/pen), in which 72 20 months of age yearling Nellore bulls (388.0 ± 31.1 kg) were fed in 24 pens for 90 days according to the treatments: (1) MON during the entire feeding period (T1), (2) MON + VM during adaptation and only VM during the finishing period (T2), (3) MON + VM during the entire feeding period (T3), and (4) VM during the adaptation and MON + VM during the finishing period (T4). The adaptation program consisted of ad libitum feeding of three diets over the adaptation period of 19 days with concentrate level increasing from 69% to 84% of diet DM. Key results: Overall, bulls fed on T2 had a greater DM intake (P < 0.01), final bodyweight (P = 0.04), average daily gain (P = 0.03), hot carcass weight (P < 0.01), final Longissimus muscle area (P = 0.05), Longissimus muscle area daily gain (P = 0.01), improved carcass G:F (P < 0.01) and increased dressing percentage (P < 0.01). Similarly, bulls fed on T2 were faster to consume 1 kg of either DM (P < 0.01) or neutral detergent fibre (P < 0.01) after 60 days on feed. Furthermore, bulls fed on T2 presented a greater (P = 0.05) cell proliferation index in the rumen papillae. Conclusions: According to the results, Nellore yearling bulls should be fed high-concentrate diets containing MON and VM during adaptation, and only VM during the finishing period to improve overall feedlot performance. Implications: The use of both MON and VM proved to be helpful only during the adaptation period. São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) College of Technology and Agricultural Sciences São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) College of Technology and Agricultural Sciences

This study, conducted at São Paulo State University feedlot, Dracena, Brazil, was designed to evaluate the effects of increasing diet energy content and withdrawing monensin (MON) by the end of the finishing period, while combined with virginiamycin (VM), on rumen fermentation patterns and DMI of Nellore cattle. The experiment was designed as a 5 x 5 Latin square, in which five 32-mo-old Nellore steers (531 ± 22 kg) cannulated in the rumen were utilized. Each period lasted 28-d, which was divided into phases as follows: 14-d adaptation (66% to 78% concentrate), 7-d finishing 1 (84% concentrate) and 7-d finishing 2 (88% concentrate). The treatments were: MON throughout phases, VM throughout phases, MON+VM throughout phases, MON+VM during adaptation and only VM during finishing 1 and 2, and MON+VM during adaptation and finishing 1 and only VM during finishing 2. Monensin and VM were added into diets at 30 and 25 ppm, respectively (DM basis). Rumen fermentation pattern was assessed by measuring ruminal pH and by collecting samples for SCFA determination on the last day of each phase. No treatment effect was observed (P > 0.05) for any of the SCFA variables measured, except for acetate:propionate, where cattle fed MON+VM throughout phases had greater ratio than those fed MON throughout phases on finishing 1 (P = 0.02; Table 1). Cattle consuming only VM in the study presented greater DMI throughout phases (P < 0.01), which did not negatively impact rumen pH (Table 2). Feeding MON+VM and withdrawing MON on finishing 2 did not affect SCFA concentrations, but decreased DMI, when compared to cattle fed VM either throughout phases or just during finishing, without affecting rumen pH. Thus, increasing diet energy content and withdrawing MON by the end of finishing period negatively impacted DMI without altering ruminal fermentation pattern.

Made available in DSpace on 2019-10-06T17:05:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-05-01 The objectives of this study were: 1) To identify which specific week or weeks at the beginning of feeding period was most closely correlated with intake of net energy for gain (NEg) and dry matter (DM) for the full feedlot period of 140–180 d, and 2) to determine how various performance measurements were correlated with intake during this selected time frame. The database was compiled from one commercial feedlot, contained 2,495 pens of steers and 1,637 pens of heifers representing a total of 485,458 animals. Diets had similar composition across a 6 years period. Responses in intake of DM and NEg for the full finishing period were tested separately by including gender, initial body weight (BW) and days on feed as covariates in PROC NLIN of SAS. The PROC CORR was used to determine the correlation between intakes of DM and NEg early in the feedlot period with intake of DM and NEg for the entire finishing period. Intake periods of interest included individual weeks or the combination of weeks 5–12. Among the individual weeks, intakes of DM and NEg during week 7 were correlated most closely with intakes of DM and NEg across the entire finishing period for steers (r = 0.72) and heifers (r = 0.66). Based on mean DM intake during week 7, pens were grouped into quartiles: Top, High, Lower and Lowest. Pens of steers and heifers within the Top ¼ group during week 7 had greater (P < 0.05) final BW and average daily gain (ADG) across the full feeding period than pens of steers and heifers in other quartiles. However, G:F for steers within the Top ¼ group was lower than for pens in the Lower ¼ and Lowest ¼ groups. Pens of cattle within the Lowest ¼ group had more sick head days (P < 0.05) and greater death loss (P < 0.05) than pens of cattle of the Top ¼ group. Pens of cattle within the Top ¼ group had greater (P < 0.05) week-to-week DM intake fluctuation expressed in kg for both steers and heifers. Mean DM intake during week 7 can be utilized as an index to detect pens with the greatest potential of ADG and should help to identify pens with health or management anomalies so that proper corrective actions might be taken. São Paulo State University (UNESP) College of Agricultural and Technological Sciences Purina Animal Nutrition LLC, Arden Hills São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science Area Extension Livestock Specialist Oklahoma State University São Paulo State University (UNESP) College of Agricultural and Technological Sciences São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science

The objective of this study was to evaluate the effect of adding monensin into high-concentrate diets based on either finely-ground or high-moisture corn during the transition from adaptation to finishing diets on ruminal pH of cannulated Angus and Nellore steers. Four 30-mo-old Nellore and four 30-mo-old Angus steers were divided (± 550 kg) into two 4 x 4 Latin squares, where each square was composed by animals from same breed, and randomly submitted to a 2 x 2 factorial arrangement of treatments as follows: T1) Finely-ground corn + monensin; T2) Finely-ground corn; T3) High moisture corn + monensin; T4) High-moisture corn. Periods were divided as follows: 14 days of adaptation diets and 18 days of finishing diet (80% concentrate). The study lasted 149 days, including three 7-d washout intervals. The rumen pH was assessed continuously via data loggers on days 4, 8, 12, 16, 20, 24 and 28. Interactions between breed and days were observed for DMI (P = 0.02) and pH duration below 5.6 (P = 0.01), where Angus steers had greater DMI and spent a longer time below 5.6 than Nellore animals on days 12, 16, 20, 24 and 28. The addition of monensin decreased (P = 0.01) DMI on days 16, 20, 24 and 28. Regarding pH duration and area below 5.6, an interaction between breed and corn was observed (P = 0.001), in which Angus steers fed finely-ground corn spent a longer time (416 min/day) and had a larger area (224.6 min x pH units/day) below 5.6 than animals from other treatments. For mean pH, steers consuming high-moisture corn had higher pH (6.45 vs. 6.29); and an interaction was observed (P = 0.03) between breed and monensin, where monensin addition decreased pH for Angus (5.96 vs. 6.18), but not for Nellore steers (6.68 vs. 6.63). The feeding of monensin and finely-ground corn did not positively impact rumen pH of Angus steers.

Made available in DSpace on 2020-12-12T02:36:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-04-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The study was designed to evaluate the effects of either nutritional restriction or intake of concentrate feedstuffs before beginning the adaptation period on days to adapt, feedlot performance, feeding behavior, carcass characteristics, rumen and cecum morphometric of Nellore cattle. The experiment was designed as a completely randomized block, replicated 8 times (4 animals/pen), in which 96 Nellore bulls with an initial body weight (BW) of 365.52 ± 39.19 kg were fed in 24 pens according to the treatments, as follows: Restriction (Tifton hay fed at 1.4% of BW + mineral supplement); Control (Tifton hay fed ad libitum + mineral supplement) and Concentrate (Tifton hay fed ad libitum + 0.5% of BW of a mix of concentrate feedstuffs and mineral supplement). This study lasted 144-d, divided into 2 periods, as follows: 32-d of preadaptation, in which cattle were submitted to the treatments previously described, and 112-d of finishing period, where all cattle were fed the same diets. At the end of preadaptation period, one animal per pen was slaughtered (n = 24) for carcass, cecum and rumen evaluations, and the remaining 72 animals were harvested after 112-d of finishing period. No significant (P > 0.10) treatment effect was observed for days to adapt to the high-concentrate diet, which was 14 days (SEM: 0.63). Cattle submitted to restriction had greater (P < 0.10) ADG in kg (Restriction: 1.29; Control: 1.06; Concentrate: 1.18; SEM: 0.04), DMI in kg (Restriction: 9.19; Control: 8.56; Concentrate: 8.86; SEM: 0.28), G:F ratio (Restriction: 0.140; Control: 0.124; Concentrate: 0.133; SEM: 0.004), number of papillae (Restriction: 72.76; Control: 63.28; Concentrate: 62.99; SEM: 3.41) and absorptive surface area in cm2 of rumen wall (Restriction: 26.89; Control: 22.29; Concentrate: 22.30; SEM: 1.36) compared with cattle in the control group at the end of the study. Cattle submitted to either restriction or concentrate supplementation had greater (P < 0.10) final HCW in kg (Restriction: 285.35; Control: 274.10; Concentrate: 287.30; SEM: 4.51), final 12th rib fat in mm (Restriction: 4.57; Control: 3.93; Concentrate: 4.50; SEM: 0.21) and final Biceps femoris fat thickness in mm (Restriction: 6.14; Control: 5.23; Concentrate: 5.91; SEM: 0.23) compared with cattle in the control group at the end of the study. Thus, either restriction or concentrate supplementation before beginning the adaptation period to high-concentrate diets did not impact adaptation length, and both may be used as nutritional strategies to improve performance and carcass characteristics of feedlot Nellore cattle. São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) College of Technology and Agricultural Sciences São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) College of Technology and Agricultural Sciences FAPESP: 2014/26210-4 FAPESP: 2015/00106-9

This study, conducted at São Paulo University feedlot, Dracena, Brazil, was designed to evaluate the effects of feeding virginiamycin (VM), as sole feed additive, to shorten the adaptation period to high-concentrate diets on feedlot performance of Nellore cattle. The experiment was designed as a completely randomized block, replicated 6 times (4 animals/pen), in which 120 18-mo-old yearling Nellore bulls (394.5 ± 19.0 kg) were fed in 30 pens for 112-d according to the treatments: sodium monensin (MON) and 14-d adaptation period, MON plus VM and 14-d adaptation, VM and 14-d adaptation; VM and 9-d adaptation, and VM and 6-d adaptation. MON and VM were added into diets at 30 and 25 ppm, respectively (DM basis). Three adaptation diets were fed over periods of 14-d, 9-d or 6-d with concentrate level increasing from 69% to 84% (DM basis). Contrasts were used to assess linear and quadratic effects of adaptation length in cattle fed only VM, and differences between cattle fed VM and adapted for 14-d and those fed MON or MON+VM. No treatment effect was observed (P>0.10) for final BW, ADG, and HCW. As the adaptation period lasted longer, DMI in kg (MON: 9.74, MON+VM: 9.70, VM 6-d: 9.92, VM 9-d: 10.43, VM 14-d: 10.03) was affected (P=0.02) quadratically, and final back fat thickness in mm increased linearly (MON: 5.61, MON+VM: 6.26, VM 6-d: 4.87, VM 9-d: 5.60, VM 14-d: 5.99), in cattle fed only VM. Cattle fed MON or MON+VM had improved G:F when compared those fed VM and adapted for 14-d (MON: 0.149, MON+VM: 0.146, VM 6-d: 0.138, VM 9-d: 0.135, VM 14-d: 0.135). However, cattle fed MON+VM had a decreased dressing percentage when compared to cattle fed VM and adapted for 14-d (53.7% vs. 55.0%). Thus, adaptation period should not be shortened when VM is fed as sole feed additive.