scholarly journals Performance and feed intake of beef heifers on rotational grazing of natural grassland receiving protein and energy supplement in cool season

2018 ◽  
Vol 48 (4) ◽  
Author(s):  
Bruno Castro Kuinchtner ◽  
Fernando Luiz Ferreira de Quadros ◽  
Felipe Jochims ◽  
Pedro Trindade Casanova ◽  
Gabriela Machado Dutra ◽  
...  
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
Protein Supplementation ◽  
Management Tool ◽  
Free Access ◽  
Beef Heifers ◽  
Leaf Elongation ◽  
Cool Season ◽  
Rotational Grazing ◽  
Natural Grasslands

ABSTRACT: The aim of this study was to evaluate the performance and feed intake of grazing beef heifers on two grazing intervals determined by thermal sum related to leaf elongation duration during cool season on natural grasslands. A complete randomized block design experiment with two treatments and three replications was conducted from May to September 2011 in the central part of the state of Rio Grande do Sul, Brazil. The treatments were two thermal sums calculated at 375 and 750 degrees-days (DD) to determine the intervals between grazing periods in a rotational grazing system. Thirty six beef heifers with average age of 18 months old and (initial body weight = 220±14kg) were used, all heifers received ground corn supplement at a rate of 5g kg-1 of body weight per day, at 2p.m., throughout the experiment and had free access to mineral and protein supplementation (450g kg-1 of CP). Similar average daily gain (ADG), beef production gain (BPG) and feed intake (FI), were obtained in both treatments. Leaf elongation duration is an alternative grazing management tool for improved animal production and to increase animal stocking rate.

Effect of post-weaning residual feed intake classification on grazed grass intake and performance in pregnant beef heifers

2015 ◽  
Vol 95 (3) ◽  
pp. 369-381 ◽  
Author(s):  
G. Manafiazar ◽  
J. A. Basarab ◽  
V. S. Baron ◽  
L. McKeown ◽  
R. R. Doce ◽  
...  
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
Average Daily Gain ◽  
Residual Feed Intake ◽  
Backfat Thickness ◽  
Automated System ◽  
Adaptation Period ◽  
Beef Heifers ◽  
Fat Thickness ◽  
And Performance

Manafiazar, G., Basarab, J. A., Baron, V. S., McKeown, L., Doce, R. R., Swift, M., Undi, M., Wittenberg, K. and Ominski, K. 2015. Effect of post-weaning residual feed intake classification on grazed grass intake and performance in pregnant beef heifers. Can. J. Anim. Sci. 95: 369–381. There is limited knowledge of how cattle tested for feed efficiency under drylot conditions perform when they graze on summer pasture. Residual feed intake adjusted for end of test backfat thickness (RFIfat) was determined on 171 beef crossbred heifers under drylot conditions over 2 yr using an automated system. Upon completion of the test, the 10 lowest and 10 highest RFIfat (–0.54±0.17 vs. 0.58±0.15 kg DM d−1) heifers in 2012, and the 14 lowest and 14 highest RFIfat (−0.47±0.16 vs. 0.53±0.19 kg DM d−1) heifers in 2013 were selected and placed on meadow bromegrass pasture to investigate the effect of RFIfat ranking on their grass intake and performance on the pasture. The pasture adaptation period (8 d in 2012 and 19 d in 2013) was followed by a pasture feed intake experiment during which heifers were dosed twice daily (0815 and 1415) with 500 g of C32-labeled feed pellet for 13 d (day 0 to 12) and fecal sampled twice daily (0815 and 1415) from day 8 to 12. Forage DM intake on pasture for each heifer was determined using the double alkane (C31/C32) methodology. High and low RFIfat heifers were similar in body weight (BW), backfat and rump fat thickness, and average daily gain (ADG) during the grazing trial period, except backfat thickness at the end of test period. However, low RFIfat heifers consumed 5.3% less forage when expressed as kg DM d−1 (8.20±0.08 vs. 8.66±0.09, P<0.001) and 5.1% less when expressed as a percentage of body weight (1.86±0.02 vs. 1.96±0.02% of BW, P<0.001) compared with high RFIfat heifers. RFIfat measured under drylot conditions in growing heifers was positively correlated to grazed RFIfat determined in pregnant heifers (rp=0.30, P=0.04). These results suggest that beef heifers classified as low RFIfat during the post-weaning drylot period had lower dry matter intake as heifers in their first pregnancy grazing tame pasture, with no negative impact on their body weight, back-fat thickness, and ADG compared with their high RFIfat herdmates.

Influence of amount and frequency of protein supplementation to ruminants consuming low-quality cool-season forages: Efficiency of nitrogen utilization in lambs and performance of gestating beef cows

2021 ◽  
Author(s):  
Bruno I Cappellozza ◽  
David W Bohnert ◽  
Maria M Reis ◽  
Megan L Van Emon ◽  
Christopher S Schauer ◽  
...  
Keyword(s):  
Body Condition Score ◽  
Beef Cows ◽  
Protein Supplementation ◽  
Neutral Detergent Fiber ◽  
Late Gestation ◽  
Free Access ◽  
Labor Costs ◽  
Cool Season ◽  
And Performance ◽  
N Use

Abstract We evaluated the influence of amount and crude protein (CP) supplementation frequency (SF) on nitrogen (N) use by wethers and performance of late-gestation beef cows. In Exp. 1, 7 Western whiteface wethers (31.8 ± 1.4 kg) were used in an incomplete 7 × 4 Latin square to evaluate intake and N use. Wethers received 1 of 7 treatments in a 2 × 3 factorial design containing 2 levels of supplemental soybean meal offered at a rate of 100 (F) or 50 (H; 50% of F) % of the estimated CP requirement daily (D), once every 5 (5D) or once every 10 d (10D), plus a non-supplemented control (CON). Low -quality cool-season forage [4.9 % CP; dry matter (DM) basis] was provided daily for ad libitum intake. Experimental periods lasted 30 d. In Exp. 2, 84 Angus × Hereford cows (560 ± 35 kg) were stratified by age, body condition score (BCS), and expected calving date, and allocated to 1 of 21 feedlot pens (3 pens/treatment). Pens were randomly assigned to receive the same treatments as in Exp. 1 and cows had free access to low-quality cool-season forage (2.9% CP; DM basis). Cow body weight (BW) and BCS were measured every 14 d until calving and within 24 h after calving. In Exp. 1, supplementation did not alter total DM and organic matter (OM) intake (P ≥ 0.26), but both parameters linearly decreased as SF decreased (P = 0.02). Supplementation increased DM, OM, and neutral detergent fiber (NDF) digestibility (P ≤ 0.02). Additionally, F feeding linearly increased DM, OM, and NDF digestibility as SF decreased (P ≤ 0.04). Digestibility of N, N balance, and digested N retained were greater with supplementation (P &lt; 0.01) and N digestibility linearly increased as SF decreased (P = 0.01). Mean PUN concentration was greater (P &lt; 0.01) for supplemented vs. non-supplemented wethers, but also greater (P = 0.03) for F vs. H. In Exp. 2, pre-calving BCS change was greater (P = 0.03) for supplemented cows. A linear effect of SF × supplementation rate for pre-calving BCS change was noted (P = 0.05), as F supplemented cows lost more BCS compared with H as SF decreased. When considering supplementation intervals greater than 5 d, reducing the quantity of supplement provided, compared with daily supplementation, may be a feasible management strategy to maintain acceptable nutrient use and animal performance while reducing supplement and labor costs.

Natural Grassland Response to Herbicides and Application Timing for Selective Control of Tall Fescue, an Invasive Cool-Season Grass

2010 ◽  
Vol 3 (3) ◽  
pp. 219-228 ◽  
Author(s):  
Marvin E. Ruffner ◽  
Thomas G. Barnes
Keyword(s):  
Tall Fescue ◽  
Canopy Cover ◽  
Plant Invasions ◽  
Management Tool ◽  
Cool Season ◽  
Native Grass ◽  
Application Timing ◽  
Nontarget Effects ◽  
Natural Grasslands ◽  
Herbicide Treatments

AbstractNatural grasslands are one of the most threatened ecosystems in North America. Conservation efforts are often hampered by exotic plant invasions in existing remnant natural grasslands. Tall fescue [Schedonorus phoenix(Scop.) Holub.] is an introduced cool-season (C3) forage/turf grass which readily invades natural grasslands in Kentucky and neighboring states. Our study objectives were to (1) compare the efficacy and application timing effect of clethodim to that of imazapic to selectively remove tall fescue from natural grasslands and (2) evaluate the response of the nontarget grassland plant community (i.e., native grass and forb canopy cover) following herbicide treatments. Clethodim and imazapic treatments consisted of early (April 4, 2001) and late (April 20, 2001) applications, and these were applied at 0.23 and 0.21 kg ai ha−1, respectively. Both herbicides reduced tall fescue cover (P ≤ 0.05); herbicide application timing had no effect on herbicide efficacy to control tall fescue. Native grass cover was higher (P ≤ 0.05) in all herbicide-treated plots compared to the untreated controls, except for the late clethodim-treated plots. All herbicide treatments increased forb abundance compared to controls. Spring applications of clethodim were equally effective to those of imazapic at controlling tall fescue in natural grasslands. Imazapic released native grasses better than clethodim, whereas clethodim was better at increasing forb abundance. Furthermore, early clethodim treatments had fewer nontarget effects on native C4grasses compared to late clethodim treatments. Overall, clethodim shows promise as a beneficial management tool for tall fescue control in C4-dominated natural grasslands.

Influence of amount and frequency of protein supplementation to steers consuming low-quality, cool-season forage: Intake, nutrient digestibility, and ruminal fermentation

2021 ◽  
Author(s):  
Bruno I Cappellozza ◽  
David W Bohnert ◽  
Maria M Reis ◽  
Kendall C Swanson ◽  
Stephanie J Falck ◽  
...  
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Latin Square ◽  
Nutrient Digestibility ◽  
Protein Supplementation ◽  
Neutral Detergent Fiber ◽  
Management Tool ◽  
Ruminal Fermentation ◽  
Cool Season ◽  
Linear Effect

Abstract This experiment evaluated the influence of protein supplementation frequency (SF) and amount offered on intake, nutrient digestibility, and ruminal fermentation by rumen-fistulated beef steers consuming low-quality [2.9% crude protein (CP); dry matter (DM) basis], cool-season forage. Seven Angus × Hereford steers (300 ± 27 kg) fitted with ruminal cannulas were randomly assigned to 1 of 7 treatments in an incomplete 7 × 4 Latin square. Treatments, in a 2 × 3 factorial design plus a non-supplemented control (CON), consisted of 2 levels of supplemental soybean meal, 100% (F) or 50% (H) of the estimated rumen-degradable protein requirement, provided daily (D), once every 5 d (5D), or once every 10 d (10D). Experimental periods were 30 d and dry matter intake (DMI) was measured from d 19 to 28. On d 21 (all supplements provided) and 30 (only daily supplements provided; day immediately prior to supplementation for 5D and 10D treatments) ruminal fluid was collected for ruminal pH, ammonia-N (NH3), volatile fatty acids (VFA), and determination of ruminal fermentation variables. Forage and total DM, organic matter (OM), and nitrogen (N) intake increased with supplementation (P ≤ 0.04). However, a linear effect of SF × amount of supplement interaction was observed for forage and total DM, OM, and N intake (P ≤ 0.04), with each variable decreasing as SF decreased, but the decrease being greater with F vs. H. Apparent total tract DM, OM, and neutral detergent fiber (NDF) digestibility was not affected by supplementation or amount of supplement provided (P ≥ 0.10). In contrast, N digestibility increased with supplementation and for F vs. H (P &lt; 0.01). Digestibility of DM, OM, and N increased linearly as SF decreased (P ≤ 0.03). When all supplements were provided, ruminal NH3, total VFA, and molar proportions of all individual VFA increased with supplementation (P ≤ 0.04), whereas acetate:propionate ratio decreased (P &lt; 0.01). When only daily supplements were provided, none of the aforementioned fermentation parameters were affected (P ≥ 0.09). In summary, reducing the amount of supplemental CP provided to ruminants consuming low-quality forages, when supplementation intervals are greater than 5 d, can be a management tool to maintain acceptable levels of DMI, nutrient digestibility, and ruminal fermentation while reducing supplementation cost.

scholarly journals Effect of a Feed Additive based on Papaveracea Roots and Nanoclays on Broiler Performance

2021 ◽  
Author(s):  
J.G. Vicente-Martínez ◽  
J.M. Pinos-Rodriguez ◽  
J.C. García-López ◽  
V.R. León-Cabada ◽  
J.M. Martínez-Hernández ◽  
...  
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
Average Daily Gain ◽  
Feed Additive ◽  
Free Access ◽  
Feed Conversion ◽  
Growth Promoters ◽  
Final Body Weight ◽  
Broiler Performance ◽  
Daily Gain

Background: Due to the resistance that various pathogens have developed to the unplanned use of antibiotic growth promoters (AGPs) and the risk to consumers health that this implies, AGPs could be replaced by natural products such as plants, essential oils or extracts. The current study was aimed to investigate the effects of a feed additive based on papaveraceae roots and nanoclays (Sangromix 10x®) on broiler performance. Methods: One hundred and twenty Cobb broilers one d old, were randomly assigned to a diet without additive or with additive at 20 g/t during 49 d. Broilers had free access to concentrate and fresh water and were weighed daily. Feed intake and body weight was measured daily and where used to estimate average daily gain and feed conversion ratio. Result: Broilers that received Sangromix 10x®, had higher final body weight, total gain, average daily gain and better feed conversion value as compared with broilers with no additive. The additive did not affect feed intake. The inclusion of Sangromix 10x® increased final body weight and improved feed conversion value and it can be concluded that is an efficient alternative for broiler production. Nevertheless, further research is required to determine their effect on meat and carcass quality, internal organs and blood biochemistry.

scholarly journals Does Rotational Grazing Based on Leaf Expansion Duration Modify Grazing Behavior and Feed Intake of Beef Heifers on Natural Grassland?

2021 ◽  
Vol 13 (10) ◽  
pp. 85
Author(s):  
Bruno Castro Kuinchtner ◽  
Fernando Luiz Ferreira de Quadros ◽  
Fernanda Maurer Taschetto ◽  
Gabriela Machado Dutra ◽  
Liane Seibert ◽  
...  
Keyword(s):  
Feed Intake ◽  
Repeated Measures ◽  
Block Design ◽  
Leaf Expansion ◽  
Ingestive Behavior ◽  
Beef Heifers ◽  
Rotational Grazing ◽  
Grazing Behavior ◽  
Low Efficiency ◽  
Natural Grassland

Grasslands develop a multifunctional role to humanity, with unique fauna and flora, besides being the primary feed source for herbivores. However, grasslands are usually considered a low-efficiency production system, often converted into other land uses such as crops and forestation (e.g., south Brazil). This study aimed to evaluate the effect of two rest intervals between grazing occupations in rotational grazing on the grazing behavior and feed intake of beef heifers. Two grazing intervals, 375 and 750 DD (degree-days) were used; based on the cumulative thermal sum necessary for the leaf expansion of native grasses of two functional groups. The experiment was conducted as a completely randomized block design, with two treatments, three replications, and repeated measures over time. The grazing behavior was evaluated continuously for 18 hours (7 a.m. to 11h59 p.m.). Herbage intake was estimated using an external marker (Cr2O3) in four periods (one for each season). The green leaf mass was similar between treatments, with a mean of 40% of the pregrazing mass (kg DM ha-1). On average grazing, time was 50% of the period, and the bite rate was 38.7 bites min-1. The number of daily meals was 6.5, with an average of 84 minutes for each meal. The number of feeding times (feeding stations by minute) visited was 6.4. On average, there was a 2.23% difference in dry matter intake (% BW) among seasons. Neither ingestive behavior or forage consumption of heifers was affected by the treatments, both maintain similar chemical composition on natural grassland.

The effects of bull exposure and lasalocid on the development of replacement beef heifers

2000 ◽  
Vol 80 (4) ◽  
pp. 615-624 ◽  
Author(s):  
J. A. Small ◽  
R. P. Del Vecchio ◽  
W. P. McCaughey ◽  
D. R. Ward ◽  
W. P. Sutherland
Keyword(s):  
Body Weight ◽  
Response Rate ◽  
Body Weight Gain ◽  
Management Tool ◽  
Delayed Puberty ◽  
Beef Heifers ◽  
Plasma Progesterone ◽  
First Time ◽  
Sire Breed ◽  
Housing Facility

At weaning in the fall, crossbred heifers (n = 224), born in either the winter (January–February) or spring (March–April), were assigned on the basis of age, sire-breed and body weight to one of two similar winter housing facilities (with or without sterilized bulls), and to one of two forage-based (87%) diets (with or without lasalocid, 200 mg d−1) within each housing facility. Observations for estrus were made twice daily. Timed AI (66 h after PGF2α) was used to breed heifers for the first time at 14 mo of age. Plasma progesterone concentrations were used to confirm estrus/ovulation and to determine the PGF2α response rate. Bull exposure advanced puberty in winter-born heifers, but delayed puberty in spring-born heifers (P ≤ 0.029). Similarly, timed AI pregnancy for winter-born heifers was higher with than without bull exposure (58.9 vs. 32.5 ± 5.3%; P = 0.017) while the opposite occurred for the spring-born group (27.1 vs. 59.1 ± 4.7%; P < 0.001). Bull-exposed spring-born heifers were the oldest at calving, the latest to calve, and their calves had the slowest growth and lowest weaning weight means (P < 0.027). Lasalocid did not influence puberty (P ≥ 0.273), had a small effect on body weight gain (P ≥ 0.033) that did not limit attainment of optimal body weight or condition at AI, but enhanced response rate for spring-born heifers (P = 0.075) and conception rate for winter-born heifers (P = 0.047). The efficacy of bull exposure and lasalocid is dependent upon the proximity of heifers to the attainment of puberty when the treatments are introduced; further research is required to determine the most appropriate use of either management tool for developing beef replacement heifers. Key words: Puberty, heifer development, bull exposure, ionophore, estrus, conception

scholarly journals Heifers rearing on natural grassland under rotational grazing during warm season

2020 ◽  
Vol 50 (9) ◽  
Author(s):  
Luciana Marin ◽  
Fernando Luiz Ferreira de Quadros ◽  
Leandro Bittencourt de Oliveira ◽  
Émerson Mendes Soares ◽  
Pedro Trindade Casanova ◽  
...  
Keyword(s):  
Body Weight ◽  
Structural Characteristics ◽  
Average Daily Gain ◽  
Warm Season ◽  
Beef Heifers ◽  
Rotational Grazing ◽  
Nutritional Conditions ◽  
And Performance ◽  
Natural Grassland ◽  
Rest Intervals

ABSTRACT: This study aimed to evaluate the effect of two rest intervals between grazing on the structural characteristics of pasture and performance of beef heifers in Campos grassland under rotational grazing. The treatments were two intervals between 375 and 750 DD (degree-days) grazing, based on the cumulative thermal sum for leaf expansion of native grasses belonging to capture and conservation groups of resources dominant in a natural grassland. The experiment was conducted during 151 days from October 2015 to March 2016, and twenty-four Braford heifers tests mean age = 12 months; mean body weight = 220kg (± 27.8) were used. The pre-grazing total forage mass (FMt) was on average 3791 kgMSha-1 and did not differ between treatments and season, the same occurred with the non-tussock FM. The average stocking rate was 469 kg ha-1 in both treatments. The average daily gain varied only between seasons, 0.102 kg animal-1 day-1 during spring and 0.372 kg animal-1 day-1 during summer. During the 151 evaluation days, the gain per area was a 103 kgha-1. The use of rest intervals between grazing based on the leaf elongation of dominant grasses, when applied to the areas of Campos grasslands, provided nutritional conditions to reach the target body weight for breeding 24 months old beef heifers.

scholarly journals Identification of blood immune and metabolic indicators explaining the variability of growth of pigs under contrasted sanitary conditions

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
N. Le Floc’h ◽  
F. Gondret ◽  
R. Resmond
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
Goodness Of Fit ◽  
Growing Pigs ◽  
Metabolic Changes ◽  
Housing Conditions ◽  
Blood Profile ◽  
Blood Concentrations ◽  
Antioxidant Power ◽  
Sanitary Conditions

Abstract Background Health and growth of pigs are affected by the hygiene of housing. Lower growth performance observed in poor hygiene of housing conditions is explained by reduced feed intake and metabolic changes caused by the activation of body defences. In a previous experiment, we reported contrasted average values of body weight gain, concentrations of circulating metabolites, redox and immune indicators in blood of pigs housed in good or poor hygiene conditions during the growing period. This study addressed inter-individual variability in these responses to determine whether a particular blood profile explains average daily gain (ADG) of the pig. Results The data originated from 160 growing pigs, half of which subjected to a hygiene challenge for 6 weeks (W0 to W6) and the others housed in good hygiene conditions. Pigs originated from two lines divergently selected for residual feed intake (RFI). Individual body weights were recorded during this period, and relative ADG (rADGW0-W6) was calculated as the ADG corrected by the initial body weight measured at W0. Blood samples were taken before (W0) and 3 weeks (W3) after the beginning of the challenge. The analysed dataset consisted of 51 metabolites and indicators of immune and inflammatory responses measured on 136 pigs having no missing value for any variables, when calculated as the differences W3 minus W0 in circulating concentrations. An algorithm tested all possible linear regression models and then selected the best ones to explain rADGW0-W6. Six variables were identified across the best models and correlated with rADGW0-W6 with a goodness of fit (adjusted R2) of about 67%. They were changes in haptoglobin, global antioxidant capacity of plasma (Biological Antioxidant Power or BAP), free fatty acids, and 3 amino acids: leucine, tryptophan, and 1-methylhistidine. The effects of housing conditions and RFI lines were comprised in the variables of the selected models and none of these conditions improved accuracy of the predictive models, leading to genericity of the pinpointed metabolic changes in relation to variability of ADG. Conclusions This approach allows us to identify blood variables, whose changes in blood concentrations correlated to ADG under contrasted sanitary conditions.

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