RESUMEN

The objective was to determine effects of old and new rubber matting in a slatted, indoor cattle feeding facility on cattle growth performance, locomotion, and carcass characteristics. In experiment 1, fall-born Angus × Simmental steers (N = 207; body weight = 222 ± 38 kg) were blocked by weight and assigned to 32 pens. Pens were randomly assigned to 1 of 4 treatments: no matting/concrete (CONC1), 12-yr-old Animat Pebble matting (OLD1), new Animat Maxgrip matting (MG), and new Animat Pebble matting (PEB1). Steers were fed a common diet for 209 d with a minimum stocking density of 3.40 m2 per animal. Final body weight (BW) and average daily gain (ADG) were affected (P = 0.02 and P < 0.01, respectively) by treatment with steers on PEB1 finishing heaviest with the greatest growth, MG and CONC1 intermediate, and OLD1 finishing at the lightest final BW with the least growth. Flooring treatment did not affect overall dry matter intake (DMI; P = 0.16) or gain to feed ratio (G:F; P = 0.94). Flooring treatment did not affect (P ≥ 0.19) any carcass traits. Locomotion scores (LS) were affected (P < 0.01) by flooring treatment with CONC1 having the worst mobility while OLD1, MG, and PEB1 were similar (P ≥ 0.24). Locomotion score had a day effect (P < 0.01) where cattle gait and mobility worsened as days on feed increased. In experiment 2, fall-born Angus × Simmental steers (N = 189; BW = 352 ± 43 kg) were blocked by weight and assigned to 21 pens. Pens were randomly assigned to 1 of 3 treatments: no matting/concrete (CONC2), 15-yr-old Animat Pebble matting (OLD2), and new Animat Pebble matting (PEB2). Steers were fed a common diet for 152 d with a stocking density of 2.65 m2 per steer. After 152 d on feed, flooring treatment did not affect (P ≥ 0.30) BW, ADG, or DMI nor did treatment affect (P ≥ 0.17) carcass traits. However, steers housed on OLD2 or PEB2 had improved locomotion scores (P = 0.02) compared with steers housed on CONC2. Locomotion score had a day effect (P < 0.01) as cattle gait and mobility worsened with greater number of days on feed, regardless of treatment. Overall, results suggest that new rubber matting increased ADG and HCW during a 209-d trial when cattle were stocked at 3.4 m2 in small pens and that rubber matting regardless of age improved cattle locomotion scores in slatted indoor feeding facilities.

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Many feedlots in the Midwest have constructed slatted indoor cattle feeding facilities to improve winter pen conditions and decrease land requirements. Finishing cattle in indoor feeding facilities can increase cattle growth and carcass value, but greater prevalence of cattle lameness is a concern. Rubber matting is commonly used in these facilities, but it is a consumable product with a variable lifespan. This study evaluated the effects of old and new rubber matting in a slatted, indoor cattle feeding facility on cattle growth performance, locomotion, and carcass characteristics in two experiments. In experiment 1, steers in pens with new Animat Pebble matting had increased growth compared with steers in pens with no matting and 12-yr-old Animal Pebble matting. Furthermore, steers in pens with no matting had the poorest locomotion scores. In experiment 2, flooring treatments did not affect cattle growth or carcass traits, but steers in pens with old or new rubber matting had more desirable locomotion scores than cattle in pens with no matting. Therefore, new rubber matting can improve cattle growth in small pens with slatted floors when cattle were stocked at 3.4 m2 per steer (experiment 1) and that rubber matting regardless of age improved cattle locomotion.

Asunto(s)

Alimentación Animal , Goma , Alimentación Animal/análisis , Animales , Composición Corporal , Bovinos , Dieta/veterinaria , Locomoción , Goma/farmacología , Aumento de Peso

RESUMEN

The objectives were to analyze the effects of housing cow-calf pairs in drylots (DL) or pasture (PAST) on cow performance and reproduction as well as calf performance and behavior through feedlot receiving. Simmental × Angus (2 yr; 108/yr; 81 ± 15.3 d postpartum) spring-calving cows were stratified by age, body weight (BW), body condition score (BCS), and calf sex and allotted to six groups per year. Groups were randomly assigned to one of two treatments: DL or PAST. Cows in DL were limit-fed at maintenance and calves had ad libitum access to the cow diet in an adjacent pen. Pairs on PAST were rotationally grazed and calves received creep ad libitum 3 wk prior to weaning. On day 110, calves were fence-line weaned and behavior was observed on days 111 and 112. On day 116, calves were transported 272 km to a feedlot for a 42-d receiving period. Behavior was evaluated again on days 117 and 118. Data were analyzed using the MIXED procedure of SAS except reproductive data which was analyzed using the GLIMMIX procedure. Cows on DL had greater (P ≤ 0.01) BW and BCS at weaning. There were no differences (P ≥ 0.42) detected in reproductive data. Cows on DL had greater (P = 0.02) milk production. Calves on DL had greater BW (P ≤ 0.01) on day 55 and at weaning and greater preweaning average daily gain (ADG). There were treatment × time effects (P = 0.01) for lying and eating on days 111 and 112. More DL calves were eating in the morning and lying in the evening. More (P < 0.01) PAST calves were walking on day 111. Pasture calves vocalized more (P ≤ 0.01) on day 112. On day 117, more (P ≤ 0.05) pasture calves were lying and eating, and DL vocalized more. On day 118, treatment × time and treatment effects were detected (P ≤ 0.02) for lying and walking. More PAST calves were lying and more DL calves were walking. Drylot calves had greater (P ≤ 0.02) BW at the beginning and end of the receiving phase. Pasture calves had greater (P < 0.01) ADG and tended (P = 0.10) to have greater gain efficiency during feedlot receiving phase. In conclusion, housing cow-calf pairs in drylots improved BW, BCS, and milk production of cows but did not affect reproductive performance. Drylot calves had increased BW and ADG during the preweaning phase. Calf behavior at weaning and receiving was influenced by preweaning housing. Pasture calves had improved receiving phase ADG and feed efficiency but were still lighter than drylot calves after 42-d receiving phase.

Asunto(s)

Alimentación Animal , Vivienda para Animales , Animales , Bovinos , Dieta/veterinaria , Femenino , Reproducción , Destete

RESUMEN

This study evaluated the effects of offering growing bulls a diet with 40% modified wet distillers grains plus solubles (MWDGS; dry matter [DM] basis) on growth, composition, hoof scores, and reproductive performance. Simmental × Angus bulls (n = 28) were stratified by body weight (BW; 316 ±â€…29 kg), sire, and day 0 semen production (Y/N) and assigned into one of six pens. Pens were randomly assigned to one of two dietary treatments (n = 3 pens/treatment): 1) offered free-choice access to a corn-based diet with no MWDGS (CON) or 2) offered free-choice access to a diet with 40% MWDGS (DST; DM basis). Bulls were offered treatments for 140 d and, then, switched to a free-choice, common, low-energy diet for an additional 70 d. Bull BW, body condition score (BCS), hip height (HH), ultrasound (rump fat depth [RF], 12th rib fat thickness [BF], marbling score [MS], and longissimus muscle depth [MD]), hoof evaluations, breeding soundness examination (BSE), and semen evaluations were performed on days 0, 28, 56, 84, 112, 140, 175, and 210. There was a tendency (P < 0.09) for a treatment × time effect for BW. Bulls fed DST tended (P ≤ 0.10) to be heavier on days 28 and 56 than CON bulls. A treatment × time effect was detected (P < 0.01) for RF. Bulls fed DST had greater (P = 0.02) RF on day 84 than CON bulls. Treatment × time and treatment effects were detected (P ≤ 0.05) for BF, in which DST bulls had greater (P ≤ 0.05) BF on days 84, 112, and 175 and tended (P ≤ 0.10) to be greater on days 56 and 210 than CON bulls. A treatment × time effect was detected (P < 0.02) for percentage of major sperm defects. Bulls fed DST had a greater (P < 0.01) percentage of major sperm defects on day 140 than control bulls. There was a tendency (P = 0.09) for a treatment × time effect for percentage of sperm with proximal droplets. Bulls fed DST had a greater (P = 0.01) percentage of sperm with proximal droplets on day 140 than CON bulls. In conclusion, offering growing bulls a diet with 40% MWDGS (DM basis) resulted in heavier BW at days 28 and 56, increased RF at day 84, and increased BF and increases in both major sperm defects and sperm with proximal droplets at day 140. However, after 70 d on the common low-energy diet, there were no carryover effects for any growth, composition, hoof, or reproductive measures except for a tendency for BF.

RESUMEN

This study evaluated how corn supplementation and age of female affected body weight (BW), body condition score (BCS), artificial insemination (AI) pregnancy rate, and blood metabolites (nonesterified fatty acid [NEFA], ß-hydroxybutyrate [BHBA], and blood urea nitrogen [BUN]) when grazing lush spring pasture. Angus and Angus × Simmental beef females (n = 361) were blocked by location, stratified by BW and BCS, and then were assigned to groups (n = 8 groups/treatment combination; 9-14 females/group). The study utilized a stratified, randomized complete block design with a 2 × 2 factorial arrangement of treatments. The four treatment combinations were: yearling heifers receiving no supplement (CON-H); yearling heifers receiving supplement of dry-rolled corn (SUPP-H; 1.81 kg as-fed/heifer/d) for 42 d; 2-yr-old lactating cow-calf pairs receiving no supplement (CON-C); and 2-yr-old lactating cow-calf pairs receiving supplement of dry-rolled corn (SUPP-C; 1.81 kg as-fed/cow/d) for 42 d. Supplementation began at AI (end of April) when cows began grazing tall fescue (Festuca arundinacea schreb)-red clover (Trifolium pratense) pastures. Pasture forage was collected weekly for analysis. Throughout the study, forage crude protein decreased (P < 0.01) over time, but acid detergent fiber (ADF), neutral detergent fiber, dry matter, forage height, and forage mass all increased (P < 0.01) over time. Females receiving SUPP tended (P = 0.10) to have greater BW and greater BW change over the supplementation period. Supplementation × age effects for BCS were detected (P = 0.04); SUPP-H had greater BCS than all other treatment combinations at d 42. Cow BHBA was greater (P < 0.01) compared with heifers. Female NEFA increased (P < 0.01) from d 12 to 42. Control females had greater (P = 0.02) serum NEFA concentrations compared with SUPP females. Control females had greater (P = 0.03) BUN concentrations compared with SUPP females. Cow BUN was greater (P < 0.01) than heifer BUN. Supplementation effects were not detected (P ≥ 0.25) for AI or overall pregnancy rate. In conclusion, there were no supplementation × age interactions excluding d 42 BCS. Supplementation regardless of female age tended to improve d 42 BW and BW change. Cow BHBA and BUN was greater compared with the heifers, whereas the supplemented females had decreased NEFA and BUN. Cows tended to have greater AI pregnancy rates than heifers, but supplementation did not affect AI or overall pregnancy rates.

RESUMEN

Adipogenic/lipogenic transcriptional networks regulating intramuscular fat deposition (IMF) in response to weaning age and dietary starch level were studied. The longissimus muscle (LM) of beef steers on an early weaning (141 days age) plus high-starch diet (EWS) or a normal weaning (NW, 222 days age) plus starch creep-feed diet (CFS) was biopsied at 0 (EW), 25, 50, 96 (NW), 167, and 222 (pre-slaughter) days. Expression patterns of 35 target genes were studied. From NW through slaughter, all steers received the same high-starch diet. In EWS steers the expression of PPARG, other adipogenic (CEBPA, ZFP423) and lipogenic (THRSP, SREBF1, INSIG1) activators, and several enzymes (FASN, SCD, ELOVL6, PCK1, DGAT2) that participate in the process of IMF increased gradually to a peak between 96 and 167 days on treatment. Steers in NW did not achieve similar expression levels even by 222 days on treatment, suggesting a blunted response even when fed a high-starch diet after weaning. High-starch feeding at an early age (EWS) triggers precocious and sustained adipogenesis, resulting in greater marbling.

RESUMEN

Among 36 differentially-expressed genes during growth in longissimus muscle (LM) of Angus steers, Yin Yang 1 (YY1) had the most relationships with other genes including some associated with adipocyte differentiation. The objective of this study was to examine the effect of nutritional management on mRNA expression of YY1 along with its targets genes PPARG, GTF2B, KAT2B, IGFBP5 and STAT5B. Longissimus from Angus and Angus × Simmental steers (7 total/treatment) on early weaning plus high-starch (EWS), normal weaning plus starch creep feeding (NWS), or normal weaning without starch creep feeding (NWN) was biopsied at 0, 96, and 240 days on treatments. Results suggest that YY1 does not exert control of adipogenesis in LM, and its expression is not sensitive to weaning age. Among the YY1-related genes, EWS led to greater IGFBP5 during growing and finishing phases. Pro-adipogenic transcriptional regulation was detected in EWS due to greater PPARG and VDR at 96 and 240 d vs. 0 d. GTF2B and KAT2B expression was lower in response to NWS and EWS than NWN, and was most pronounced at 240 d. The increase in PPARG and GTF2B expression between 96 and 240 d underscored the existence of a molecular programming mechanism that was sensitive to age and dietary starch. Such response partly explains the greater carcass fat deposition observed in response to NWS.