Effects of restricted vs. step up dietary adaptation for 6 or 9 days on feedlot performance, feeding behaviour, ruminal and blood variables of Nellore cattle

In the present study, the effects of restricted intake of the final finishing diet as a means of dietary adaptation compared with diets increasing in concentrate content (step-up) over periods of 14 and 21 days on growth performance, carcass characteristics, feeding behaviour and rumen morphometrics of Nellore cattle were evaluated. One hundred and twenty 20 months old Nellore bulls (initial BW = 372.2 kg, s.d. = 21.5 kg) were randomly allocated in 24 pens (n = 5 per pen) and fed for 84 days. The study had a completely randomised design with a 2 × 2 factorial arrangement: adaptation using both 14-day and 21-day step-up and restriction protocols. Each treatment was replicated 6 times. One bull per pen was slaughtered (n = 24) at the end of adaptation period to evaluate rumen morphometrics. The remaining bulls (n = 96) were slaughtered at the end of experimental period. Interactions were observed (P < 0.05) for growth performance, feeding behaviour and rumen morphometrics variables. Overall, no protocol or adaptation length main effect (P > 0.05) was observed for any of the growth rate and carcass traits evaluated, except for hot carcass weight (P = 0.03) and dressing percentage (P = 0.04), where bulls adapted for 14 days had heavier carcasses and increased dressing percentage when compared with cattle adapted for 21 days. Cattle adapted for 21 days had a larger (P = 0.005) rumen wall absorptive surface area at the end of adaptation period than those adapted for 14 days; however, no differences were detected at the end of finishing period. Thus, Nellore yearling bulls could be adapted for 14 days regardless of the protocol.

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Impacts of adding functional oils or sodium monensin in high-concentrate diets on performance, feeding behaviour and rumen morphometrics of finishing Nellore cattle

The Journal of Agricultural Science ◽

10.1017/s002185962000026x ◽

2020 ◽

Vol 158 (1-2) ◽

pp. 136-142

Author(s):

A. C. B. Melo ◽

M. C. S. Pereira ◽

A. L. N. Rigueiro ◽

D. D. Estevam ◽

A. F. Toledo ◽

...

Keyword(s):

Feeding Behaviour ◽

Dry Matter ◽

Feed Additives ◽

Dry Matter Intake ◽

Feed Ratio ◽

State University ◽

Feedlot Performance ◽

Nellore Cattle ◽

Functional Oils ◽

Daily Gain

AbstractThis study, conducted at the São Paulo State University feedlot, Dracena campus, Brazil, was designed as a completely randomized block with 2 × 2 factorial arrangement of treatments to evaluate the effects of adding functional oils (FO) or sodium monensin (MON) on feedlot performance, carcass traits, feeding behaviour and rumen morphometrics of Nellore cattle. Ninety-six 20-mo-old Nellore bulls (365.52 ± 39.19 kg) were randomly allocated to 24 pens (n = 4/pen), which were assigned to the treatments: (1) Control (no feed additives); (2) FO (500 ppm); (3) MON (27 ppm); and (4) MON + FO (27 + 500 ppm, respectively). Each treatment was replicated 6 times, and cattle were fed for 105 days. From 0 to 28 days on feed, cattle fed FO had lower dry matter intake (DMI) variation, sorted for medium particles and presented smaller papillae width. The feeding of FO did not negatively impact feedlot performance overall. When MON was added to the diet, cattle had lower DMI overall and 12th rib fat daily gain, and improved gain to feed ratio. The addition of MON to diets improved feedlot performance but reduced the rate of carcass fat deposition. The few effects observed when FO was added to diets were not sufficient to impact feedlot performance.

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Effects of restricted versus conventional dietary adaptation on feedlot performance, carcass characteristics, site and extent of digestion, digesta kinetics, and ruminal metabolism

Journal of Animal Science ◽

10.2527/2002.80102726x ◽

2002 ◽

Vol 80 (10) ◽

pp. 2726 ◽

Cited By ~ 10

Author(s):

W. T. Choat ◽

C. R. Krehbiel ◽

M. S. Brown ◽

G. C. Duff ◽

D. A. Walker ◽

...

Keyword(s):

Carcass Characteristics ◽

Feedlot Performance ◽

Dietary Adaptation

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Feedlot performance, feeding behavior and rumen morphometrics of Nellore cattle submitted to different feeding frequencies

Scientia Agricola ◽

10.1590/1678-992x-2016-0335 ◽

2018 ◽

Vol 75 (2) ◽

pp. 121-128 ◽

Cited By ~ 3

Author(s):

Juliana da Silva ◽

Tássia Veluma Barbosa Carrara ◽

Murillo Ceola Stefano Pereira ◽

Cassiele Aparecida de Oliveira ◽

Ivan Carlos Batista Júnior ◽

...

Keyword(s):

Feeding Behavior ◽

Feedlot Performance ◽

Nellore Cattle

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Different combinations of sodium monensin and virginiamycin during feedlot finishing of Nellore cattle

Animal Production Science ◽

10.1071/an18657 ◽

2020 ◽

Vol 60 (8) ◽

pp. 1061

Author(s):

A. L. N. Rigueiro ◽

M. C. S. Pereira ◽

M. M. Squizatti ◽

M. M. Ferreira ◽

S. C. Dondé ◽

...

Keyword(s):

Average Daily Gain ◽

Feed Additives ◽

Proliferation Index ◽

Adaptation Period ◽

Longissimus Muscle ◽

Feeding Period ◽

Feedlot Performance ◽

Muscle Area ◽

Nellore Cattle ◽

Daily Gain

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.

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