Effects Of Body Condition Score Research Articles

Metabolic and endocrine profiles of primiparous beef cows grazing native grassland. 2. Effects of body condition score at calving, type of suckling restriction and flushing on plasmatic and productive parameters

The objective of the present experiment was to analyse the effect of body condition score (BCS) at calving, type of suckling restriction and flushing on metabolic and endocrine profiles, and productive and reproductive responses of primiparous beef cows grazing native grassland. Primiparous beef (n = 56) cows in anestrus classified by BCS at calving (low ≤3.5 and moderate ≥4; 1–8 visual scale) were assigned randomly to four treatments in a two by two factorial arrangement of type of suckling restriction and flushing. Type of suckling restriction started at 55 ± 10 days postpartum (DPP ± s.e.m.; Day 0 = initiation of the treatment) and consisted of applying nose plates to calves for 12 days (i.e. TS treatment) or 5 days of isolation of the cow–calf pair, followed by applying nose plates to calves for 7 days as calves were reunited with their mothers (i.e. IS treatment). Immediately after the suckling restriction treatments were finished, the breeding season started, and each cow received (flushing group) or not (control group) 2 kg/day (fresh basis) of whole-rice middling for 22 days. The BCS was superior in moderate-BCS cows through the experiment. The type of suckling restriction did not affect any plasma parameter, but insulin-like growth factor I (IGF-I) concentrations increased in all cows during suckling restriction. Cholesterol concentration was affected by flushing × day interaction (P < 0.05), while insulin and IGF-I concentrations were affected by the interaction among BCS at calving, flushing and days (P < 0.03). Flushing increased cholesterol concentration in both BCS groups at calving, while insulin and IGF-I concentrations increased during flushing only in moderate-BCS cows. Suckling restriction, flushing, and BCS at calving did not affect calf weight or milk production. Moderate BCS cows had a shorter postpartum anestrous interval (PPI) (98 vs 123 DPP; P < 0.01). Isolated type of suckling reduced postpartum anestrous interval when compared with TS treatment (97 vs 115 DPP, P < 0.05). Early pregnancy rate was greater in flushed than in control cows (0.8 vs 0.55, P < 0.01) and in moderate-BCS cows than in low-BCS cows (0.84 vs 0.46, P < 0.01). Total pregnancy rate was also greater in flushed and moderate cows and tended to be affected by the interaction between flushing and BCS at calving (P = 0.06; flushed cows: moderate = 1 vs low = 0.5, P < 0.08; and control cows: moderate = 0.8 vs low = 0.4, P < 0.09). These results confirmed the great value of suckling restriction and flushing during post-calving and relevance of BCS at calving as a link between energetic nutrition and metabolic and reproductive processes in primiparous beef cows grazing native grassland.

Blood leptin, insulin and glucose concentrations in hair sheep raised in a tropical climate

The aims of this study were to determine the effects of body condition score (BCS), breed and dietary supplementation on the concentrations of leptin, insulin and glucose found in the blood obtained from hair sheep during the breeding season. A further aim was to investigate the possible association of fertility and prolificacy with these blood metabolites, BCS and body weight (BW). All ewes were grazed in paddocks with ad libitum access to mineral salts and water. A total of 96 ewes were divided into two groups according to breed and treatment: Santa Ines (supplemented or unsupplemented) (24×24) and Morada Nova (supplemented or unsupplemented) (24×24). Blood samples, and BW and BCS information were collected during the breeding season. The statistical analyses were performed using the program PROC GLM from the SAS software. The leptin concentrations in hair sheep raised in a tropical climate were low. Little effect of breed, treatment or sample collection was found for blood insulin concentrations (p<0.05), although the values were higher in the supplemented groups from both breeds. Significant differences were observed in glucose concentrations between the breeds in the same sample collections, with the higher concentrations being found in the Santa Ines sheep (p<0.05). The BCS for ewes that were not pregnant showed the highest correlation with leptin, insulin and glucose concentrations (r=0.53, 0.52 and 0.43, respectively). In the Morada Nova supplemented sheep (prolificacy: 1.45), there were verified correlations between BCS and BW, BCS and insulin concentration, and also between insulin and leptin concentrations. The present study shows that the Morada Nova breed has a higher reproductive efficiency than the Santa Ines breed. In conclusion, leptin was present in low concentrations in hair sheep and did not influence the reproductive processes in these animals. The dietary supplementation positively affected blood leptin, insulin and glucose concentrations in these breeds of hair sheep, but there was no major effect on the reproductive processes.

Effects of body condition score at calving on indicators of fat and protein mobilization of periparturient Holstein-Friesian cows

The objective was to study the effects of body condition score (BCS) at calving on dairy performance, indicators of fat and protein mobilization, and metabolic and hormonal profiles during the periparturient period of Holstein-Friesian cows. Twenty-eight multiparous cows were classed according to their BCS (0 to 5 scale) before calving as low (BCS ≤2.5; n=9), medium (2.75≤BCS≤3.5; n=10), and high (BCS ≥3.75; n=9), corresponding to a mean of 2.33, 3.13, and 4.17 points of BCS, and preceding calving intervals of 362, 433, and 640d, respectively. Cows received the same diets based on preserved grass to allow ad libitum feed intake throughout the study, and lactation diet contained 30% of concentrate (dry-matter basis). Measurements and sampling were performed between wk −4 and 7 relative to calving. No significant effects were observed of BCS group on dry matter intake (kg/d), milk yield, BCS loss, plasma glucose, and insulin concentrations. The high-BCS group had the lowest postpartum energy balance and the greatest plasma concentrations of leptin prepartum, nonesterified fatty acids and β-hydroxybutyrate postpartum, insulin-like growth factor 1, and milk fat content. Milk fat yield was greater for the high- than the low-BCS group (1,681 vs. 1,417g/d). Low-BCS cows had the greatest concentration of medium-chain fatty acids (e.g., sum of 10:0 to 15:0, and 16:0), and the lowest concentration and secretion of preformed fatty acids (e.g., cis-9 18:1) in milk fat. Milk protein secretion was lowest in the low-BCS group, averaging 924, 1,051, and 1,009g/d for low-, medium-, and high-BCS groups, respectively. Plasma 3-methylhistidine was greater in wk 1 and 2 postpartum compared with other time points, indicating mobilization of muscle protein. Plasma creatinine tended to be lower and the 3-methylhistidine: creatinine ratio was greater in low- compared with medium- and high-BCS cows, suggesting less muscle mass but more intense mobilization of muscle protein in lean cows. High-BCS cows were metabolically challenged during early lactation due to intense mobilization of body fat. Conversely, limited availability of body fat in low-BCS cows was associated with increased plasma indicators of body protein mobilization during the first weeks of lactation, and lower milk protein secretion. These results should be confirmed using an experimental approach where calving BCS variation would be controlled by design.

The effects of body condition score and nutrition of triplet-bearing ewes in late pregnancy

At day 128 (P128) of pregnancy, triplet-bearing Romney ewes were allocated to either a ‘Control’ or ‘ad-libitum’ (‘Adlib’) nutritional regimen until P142. Both nutritional regimens included ewes of body condition score (BCS): 2.0, 2.5 and 3.0. During the nutritional period the post grazing masses were 807.9±58.5 and 1254±61.1kgDM/ha for the Control and Adlib regimens respectively. At P142 Control ewes had lighter (P<0.05) live weight and lower (P<0.05), condition score and backfat depths than Adlib ewes. Neither ewe nutritional regimen nor BCS affected (P>0.05) lamb live weight or indices of colostrum uptake. There was no effect (P>0.05) of ewe nutritional regimen on lamb survival. Lambs born to BCS2.5 ewes had lower survival (P<0.05) than BCS3.0 lambs and BCS3.0 lambs tended (P=0.09) to have greater survival than BCS2.0 lambs. BCS3.0 ewes weaned a greater total weight of lamb (P<0.05) than BCS2.5 ewes. There were no (P<0.05) interactions between ewe nutritional regimen and BCS for any of the lamb traits measured. In conclusion, the data indicates triplet-bearing ewes can be managed under controlled grazing conditions with post grazing masses of approximately 800kgDM/ha to day 142 of pregnancy without affecting lamb performance. The present study also suggests farmers should aim to have their triplet-bearing ewes at a body condition score of 3.0 prior to late pregnancy to achieve higher levels of performance.

Short communication: Large-scale study on effects of metritis on reproduction in Danish Holstein cows

A total of 398,237 lactations of Danish Holstein dairy cows were studied with the main objective to investigate the effects of metritis on 2 fertility variables: interval from calving to first insemination (CFI) and nonreturn rate at 56d after first insemination (NR56), adjusting for milk production and body condition score as confounders. Metritis was defined as a score of at least 5 (indicating purulent vaginal discharge with abnormal smell) on the Danish uterine score scale (from 0 to 9, used to evaluate vaginal discharge in the first 19d postpartum on all fresh cows in herds participating in a national herd health program). Cows with metritis in early lactation presented a significant delay in first insemination (hazard ratio of 0.80) and a significantly reduced probability of success at first insemination. The effect of metritis was also present after adjusting for possible effects of body condition score, milk production in the first month of lactation, parity, herd, and year-season. Only a small part of the observed effect of metritis could be explained by variation in body condition score at calving and milk production in the first month after calving. The results from this large-scale study underscore the deleterious effects of metritis on the fertility variables CFI and NR56.

Effect of concentrate supplementation during early lactation on plasma IGF-I concentrations and reproductive performance of dairy cows

An experiment was conducted to assess the effects of body condition score (BCS) at calving and level of feed supplementation during early lactation on the Insulin-like growth Factor-I (IGF-I) and reproductive performance in 72 Holstein cows in a pasture-based system following seasonally-synchronized calving. At the start of the seasonal breeding, plasma IGF-I concentrations in cows that had recommenced ovarian activity with detected oestrus were compared with those in anoestrus. The cows (n = 72) were managed over a period of five months to calve in a BCS of 4, 5 or 6 - using a scale from 1 (thin) to 8 (obese). The cows were maintained on pastures and supplemented during early lactation with either 1 or 6 kg grain per day. The BCS at calving did not affect plasma IGF-I concentrations. The plasma IGF-I concentration at week 10 was elevated at the higher level of grain supplementation (87.8 vs. 72.1 ng/mL). Higher conception rate following the first insemination of cows calving with a BCS of 6 (71% vs. 46% and 37% for a BCS of 4 and 5, respectively) was associated with more cows in that group conceiving during the first three weeks of the artificial insemination (AI) programme (75% vs. 46% and 46% for a BCS of 4 and 5, respectively). At weeks 0 and 10, cows that commenced ovarian activity by the start of the intensive AI programme, recorded higher plasma IGF-I concentrations than anoestrous cows. These findings indicate that diet can affect the plasma IGF-I levels, which in turn may be involved in affecting the resumption of cyclic ovarian activity and conception in dairy cows.Keywords: BCS, conception, dairy cows, IGF-I, postpartum period

English

&nbsp; The aim of this study was to determine the effects of body condition score to metabolic acclimation in heat stressed Holstein cows.&nbsp;Body&nbsp;condition&nbsp;of cows&nbsp;had no&nbsp;effect&nbsp;on&nbsp;any&nbsp;of the&nbsp;tested parameters&nbsp;during the&nbsp;thermal&nbsp;neutral&nbsp;period,&nbsp;exceptfor&nbsp;the percentage of&nbsp;protein&nbsp;in milk.&nbsp;Heat&nbsp;stress&nbsp;has&nbsp;been&nbsp;demonstrated&nbsp;to have animpact on&nbsp;all&nbsp;the selected parameters,&nbsp;and&nbsp;has been&nbsp;found to be the cause ofdecreased milk production and quality, increased rectal temperature and respiration rate, decreased glucose,&nbsp;non esterified fatty acids&nbsp;(NEFA) and cholesterol concentration, increased urea and bilirubin concentration, and loss of subcutaneous fat.&nbsp;Obese cows&nbsp;(BCS&gt;4)&nbsp;had&nbsp;less&nbsp;ability of&nbsp;acclimation&nbsp;to&nbsp;heat&nbsp;stress as compared to normal and thin cows (significantly&nbsp;lower&nbsp;production&nbsp;and&nbsp;milk quality, and&nbsp;significantly&nbsp;higher&nbsp;rectal temperature and&nbsp;respiration&nbsp;level&nbsp;in relation to&nbsp;theother&nbsp;groups of cows).&nbsp;Obese&nbsp;cows&nbsp;showed&nbsp;a significantly higher&nbsp;concentration ofNEFA&nbsp;and&nbsp;significantly&nbsp;lower&nbsp;glucose&nbsp;during exposure to&nbsp;heat&nbsp;stress.&nbsp;The steady increase in&nbsp;NEFA&nbsp;concentrations&nbsp;and decrease&nbsp;of backfat thickness&nbsp;suggested thatfat&nbsp;was&nbsp;used&nbsp;for energy&nbsp;purposes,&nbsp;which&nbsp;significantly increased the&nbsp;heat&nbsp;balanceand&nbsp;led&nbsp;to&nbsp;poor&nbsp;acclimation&nbsp;to&nbsp;heat&nbsp;stress&nbsp;in obese&nbsp;cows.&nbsp;Cows with high body condition&nbsp;were&nbsp;at higher risk of developing liver&nbsp;failure and&nbsp;lipidosis (reduced cholesterol and elevated bilirubin concentration)&nbsp;during heat stress,&nbsp;which&nbsp;could be linked with&nbsp;increased&nbsp;concentrations of&nbsp;fatty&nbsp;acids&nbsp;in the&nbsp;blood.&nbsp;This was found with an&nbsp;increased&nbsp;concentration of&nbsp;urea&nbsp;during exposure to&nbsp;heat&nbsp;stress,&nbsp;with&nbsp;significantlyhigher&nbsp;concentration&nbsp;in&nbsp;obese&nbsp;cows. Using&nbsp;the&nbsp;fat&nbsp;for energy&nbsp;purposes&nbsp;depends onthe&nbsp;sensitivity&nbsp;to&nbsp;insulin,&nbsp;which&nbsp;increases&nbsp;during&nbsp;heat&nbsp;stress.&nbsp;Obese&nbsp;cows&nbsp;arenaturally&nbsp;less&nbsp;sensitive&nbsp;to&nbsp;insulin&nbsp;and&nbsp;more prone to&nbsp;lipolysis. However,&nbsp;these signsshould&nbsp;be the&nbsp;focus of&nbsp;future research. &nbsp; Key words:&nbsp;Body condition score,&nbsp;heat&nbsp;stress, metabolic status, cow.

The effect of body condition score at calving and supplementation with Saccharomyces cerevisiae on milk production, metabolic status, and rumen fermentation of dairy cows in early lactation

The objective of this study was to examine the effects of live yeast (LY) supplementation and body condition score (BCS, 1–5 scale) at calving on milk production, metabolic status, and rumen physiology of postpartum (PP) dairy cows. Forty Holstein-Friesian dairy cows were randomly allocated to a 2 × 2 factorial design and blocked by yield, parity, BCS, and predicted calving date. Treatments were body condition at calving (low for BCS ≤3.5 or high for BCS ≥3.75; n=20) and supplementation with LY (2.5 and 10g of LY/d per cow for pre- and postcalving, respectively; control, no LY supplementation; n=20). The supplement contained 109 cfu of Saccharomyces cerevisiae/g (Yea-Sacc1026 TS, Alltech Inc., Nashville, TN). Daily milk yield, dry matter intake, milk composition, BCS, body weight, and backfat thickness were recorded. Blood samples were harvested for metabolite analysis on d 1, 5, 15, 25, and 35 PP. Liver samples were harvested by biopsy for triacylglycerol (TAG) and glycogen analysis on d 7 precalving, and on d 7 and 21 PP. Rumen fluid was sampled by rumenocentesis for all cows on d 7 and 21 PP. Supplementation with LY had no effect on milk yield, dry matter intake, rumen fluid pH, or blood metabolites concentration of dairy cows with high or low BCS at calving. Feeding LY increased rumen acetate proportion and protozoal population, tended to increase liver glycogen, and decreased rumen ammonia nitrogen during early lactation. Over-conditioned cows at calving had greater body reserve mobilization and milk production and lower feed intake, whereas cows with a moderate BCS at calving had greater feed intake, lower concentrations of nonesterified fatty acids and β-hydroxybutyrate, lower liver TAG and TAG:glycogen ratio, and faster recovery from body condition loss. Additionally, the data suggest that concentrations of liver enzymes in blood might be used as an indicator for liver TAG:glycogen ratio. Results indicate that in the case of this experiment, where the control treatment was associated with an acceptable rumen pH, feeding yeast did not significantly improve indicators of energy status in dairy cows.

Effect of body condition score of does and use of bucks subjected to added artificial light on estrus response of Alpine goats

The effects of body condition score of does and exposure to sexually active bucks after exposure to long-day artificial photoperiod were examined in mature anovulatory French Alpine goat in Northern Mexico. In June, goats in good (2.3 +/- 0.2, scale 1 to 4; n = 10) or poor (1.6 +/- 0.3; n = 10) body condition were exposed during 15 day to sexually active bucks, which had been exposed to long photoperiod (16:8-h light-dark cycle, starting in December). A third group of goats in good body condition was exposed to bucks kept under the natural photoperiod of this region (26 degrees N). All goats in good body condition exposed to bucks treated with prolonged photoperiod exhibited estrus behavior, whereas only 50% of the does in poor body condition showed estrous behavior during the 15-day buck exposure. None of the does in good body condition showed estrus when exposed to bucks under natural photoperiod. These results revealed that a good body condition is required for maximum estrus response in anestrous Alpine goats and that exposure of bucks to long photoperiod in winter is essential for an adequate stimulus to reestablish estrus cycles in anovulatory Alpine does in Northern Mexico.

Effect of body condition and suckling restriction with and without presence of the calf on cow and calf performance

Nutrition and suckling are largely recognised as the most important factors affecting the postpartum period and consequently the reproductive efficiency of beef cattle. The aim of this study was to evaluate the effects of body condition score (BCS) and suckling restriction with and without the presence of the calf on milk production, reproductive efficiency and calf performance. Sixty-three crossbred (Angus × Hereford) multiparous cows were managed to maintain different BCS at calving and thereafter (low vs moderate; L, n = 31 and M, n = 32). Within each group of BCS (L and M) at week 9 postpartum (66 ± 0.88 days postpartum) cows were assigned to three suckling treatments (ST): (i) suckling ad libitum (S, n = 20); (ii) calves fitted with nose plates during 14 days remaining with their dams (NP, n = 22); and (iii) calves were completely removed from their dams for 14 days, and thereafter returned (CR, n = 21). Milk production was assessed by milking procedure at Day 65 (the day before onset of ST) and every 20–22 days until the end of the experiment. Cows were bled via jugular venipuncture every 28 days from Day –98 (Day 0 = calving) until Day 66. From Day 66 cows were bled every 7 days until the end of the mating period (Day 128). Concentrations of progesterone, non-esterified fatty acids and β-hydroxybutyrate acid and insulin were measured. Presence of corpus luteum (CL) was recorded and maximum follicle diameter was measured in all cows from the onset of the ST (Day 66) and during the following 4 weeks (until Day 94) in a weekly frequency. At Day 94, more cows (P &lt; 0.001) in NP and in CR had CL compared with S cows (68, 57 and 21% for NP, CR and S, respectively). At that time, more cows in M-BCS presented CL than cows in L-BCS (77 vs 25; P &lt; 0.0001). Within M-BCS, there were no differences in milk production between ST groups, while L-BCS cows with NP or CR produced less milk than S cows. Calf liveweight at weaning was 159.3 ± 3.1, 150.1 ± 2.9 and 147.0 ± 3.1 kg for S, NP and CR, respectively (P &lt; 0.001). Suckling restriction with and without the presence of the calf had similar effects on reproductive performance, milk production and calf growth, while BCS interacted with ST to influence milk production. These results indicate that temporary suckling restriction could be an excellent management tool to increase reproductive performance of cows in moderate condition.

Body Condition Change Ante‐ and Postpartum, Health and Reproductive Performance in German Holstein Cows

The effects of body condition score (BCS) change and status ante- and postpartum (pp) on health and reproductive performance in 234 German Holstein cows from eight dairy farms were evaluated. BCS was determined from 6 weeks antepartum until 20 weeks pp in 2-week intervals. Three and 5 weeks pp progesterone concentrations in blood serum were determined to detect the presence of luteal tissue as an indicator of cyclicity. The incidence of various diseases, percent cycling cows, reproductive measures and culling rate were assessed. Data were subjected to logistic regression to account for possible herd and lactation number effects. Cows with a low BCS status (<3.0) at calving and during early lactation (4-10 weeks pp) were at a higher risk of suffering from lameness (OR 2.9-9.4), not being cycling at 3 and/or 5 weeks pp (OR 2.24-3.99) and being culled (OR 2.56-2.79) than cows in better body condition (> or =3.0) In addition, cows with a low BCS status at parturition were at a higher risk of developing endometritis (OR 2.95) and becoming pregnant later than 105 days pp (OR 5.92) than cows with a BCS > or = 3.0. At 10 weeks pp, the risk of dystocia (OR 4.10) or retained placenta (OR 2.78) at the preceding calving and not being pregnant at 200 days pp (OR 2.42) was higher in cows with a BCS < 3.0 than with a BCS > or = 3.0. Cows with no BCS loss antepartum were more likely to have an interval from calving to first artificial insemination of <80 days and <105 days open, to be cycling at 3 and 5 weeks pp and to be pregnant at 200 days pp than cows with a BCS loss of >0.25 (OR 2.44-6.67). Furthermore, cows with no BCS loss from calving to 4 weeks pp had a lower risk of suffering from displaced abomasum than cows with a slight or a severe BCS loss (OR 0.09-0.07 respectively). In conclusion, our results suggest that body condition loss during the antepartal period affected BCS status at parturition and to a certain extent during lactation which was linked to a higher incidence of reproductive disorders and lameness, a higher culling rate and lower reproductive performance.

145 FACTORS AFFECTING PREGNANCY RATE FOLLOWING TIMED EMBRYO TRANSFER PROGRAM IN CATTLE UNDER FIELD CONDITIONS

Hormonal estrus synchronization followed by heat detection of recipient animals is a widely used technique in embryo transfer (ET) programs around the world. However, the successful outcomes of ET rely heavily on appropriate heat detection of recipient animals. Additionally, limited availability of personnel and time to detect heat makes ET impractical at times. Therefore, pregnancy rates (PR) following a timed embryo transfer (TET) program were evaluated taking into account different variables of recipient cows, donor embryos, and season of transfer under field conditions in Argentina. Recipient cows were synchronized utilizing a progesterone (P4) intravaginal device (DIB, Syntex, Argentina) for 7 days. On Day 0 (day of DIB insertion) 2 mg of estradiol benzoate (EB) i.m. was administered and immediately after DIB removal on Day 7, 500 μg of D(+) Cloprostenol i.m. (PG, Ciclase, Syntex), 400 IU of eCG i.m. (Novormon, Syntex) plus 1 mg of cypionate estradiol i.m. (ECP; König, Agentina) were administered to all recipient cows. Fresh (n = 1746) and frozen (n = 2047) beef bovine embryos were nonsurgically transferred into recipient cows on Day 9 after PG. The effects of body condition score (1–9, BCS I: ≤5, n = 804 and BCS II: ≥6, n = 2989), corpus luteum (CL) score (CL1: prominent papilla, n = 932, CL2: small papilla, n = 2028, and CL3: asymmetric, n = 833), location of embryo placement in uterine horn (upper, n = 3566, and lower, n = 227), and type of recipient such as heifer (n = 487), lactating (n = 1010), or dry cows (n = 2296) on PR were evaluated. Additionally, stage of embryo development (4–7), quality (1–3), and season of transfer (spring, summer, fall, and winter) were included in the analysis. Pregnancy rate was confirmed by rectal palpation 60 days after ET. Data were first screened by chi square and then analyzed by Proc Logistic of SAS (SAS Institute Inc., Cary, NC). Overall PR was 54.7%. body condition score, CL, type of recipients, stage of embryo development, and year were not significantly (P &gt; 0.05) associated with PR. As expected, cows that received direct fresh embryos had 1.49 times greater odds of conceiving (odds ratio, OR = 1.49, 95% CI: 1.22 to 1.82) than those receiving frozen embryos. Additionally, cows receiving embryos graded as quality 1 had greater probability to conceive (OR = 1.62, 95% CI: 1.34 to 1.95, or OR = 1.64, 95% CI: 1.25 to 2.21) compared to quality 2 or 3 respectively. Moreover, embryos placed into the upper portion of uterine horn were more likely (OR = 1.48) to conceive than those placed in the lower uterine portion. Regardless of embryos and recipient cow variables analyzed, there was a greater probability for cows to conceive during winter (OR = 1.41, 95% CI: 1.13 to 1.95) as compared with summer. In conclusion, synchronized recipient animals for a TET program resulted in acceptable PR for both fresh and frozen embryos. Results suggested that the quality and location of embryos (upper portion) in uterine horn were the most important variables associated with PR in recipient cows. Therefore, TET is a viable and practical option allowing a successful outcome for many beef operations where availability of personnel is limited.

Effects of Body Condition Score on Ovarian Activity of Bos indicus (ZEBU) Cows

Effects of Body Condition Score on Ovarian Activity of Bos indicus (ZEBU) Cows

Effects of body condition score at parturition and postpartum protein supplementation on estrous behavior and size of the dominant follicle in beef cows1,2

The objective of this study was to determine the effects of BCS at calving and the amount of postpartum protein supplementation on the dominant follicle (DF) and behavioral characteristics at the first postpartum estrus of mature beef cows. Multiparous Angus x Hereford cows (n = 45) were fed to calve in thin (T; < 5) or moderate (M; >or=5) BCS. Cows were stratified by BCS and calving date, and randomly assigned to receive lesser (L; 1.2 kg/d) or greater (G; 2.5 kg/d) amounts of a 42% CP supplement. All cows grazed the same native grass pasture and were fed in individual stalls for 49 +/- 2 d. Beginning 20 d after calving, blood samples were collected from each cow thrice weekly, and estrous behavior was monitored continuously with a radiotelemetry system. At 4 to 16 h after the onset of estrus, size of the DF was determined by ultrasonography. Body condition score of T cows was less (P < 0.01) at calving than M cows; L and G cows had similar BCS at calving and at the end of the feeding period. Body weight gains during treatment did not differ for L or G cows. Duration from calving to first estrus was greater (P < 0.01) for T than M cows. The incidence of a short luteal phase before first estrus was not influenced by BCS or protein supplement. Concentrations of IGF-I in plasma tended (P < 0.07) to be greater and size of the DF was greater (P < 0.01) for M than T cows. Size of the DF tended (P < 0.06) to be greater for G than L cows. Duration and number of mounts received at the first estrus were not influenced by BCS or supplement. Pregnancy rate of M cows during the breeding season was greater (P < 0.05) than T cows. Postpartum protein intake and BCS at calving influenced the size of the DF at the first postpartum estrus in mature suckled beef cows. Cows should be managed to calve in moderate BCS and maintain BW after parturition to decrease the interval to first estrus, increase follicular development, and maximize pregnancy rate.

Effects of body condition score at calving and feeding various types of concentrate supplements to grazing dairy cows on early lactation performance

The objective of the experiment reported here was to establish the effect of canola meal supplements of different protein degradability on the performance of grazing dairy cows with different body condition scores (BCS) in early lactation, and to compare this with feeding a cereal grain supplement instead. The experiment included a total of 72 cows in six treatments in a 2 * 3 factorial design, incorporating two BCS at calving (4.1 and 5.6 units on an 8-point scale), and three early lactation pelleted supplements. The three pelleted supplements were 100% wheat (wheat supplement), 50% wheat and 50% untreated mechanically extracted canola meal (a rumen degradable protein supplement), and 50% wheat and 50% canola meal that had been subjected to additional heat and pressure (a rumen undegradable protein supplement). It was hypothesised that fat cows would perform best with the treated canola meal supplement, which provided most rumen undegradable protein, whereas the type of protein would not be important for thin cows, and neither would the type of supplemental energy. Cows grazed pasture after calving at a daily pasture allowance of 35–40 kg DM/cow and were offered 6 kg concentrates each day. Cows were fed these diets for 92 days on average, from calving until three weeks into the mating period. Both canola meal-based supplements resulted in higher ( P < 0.05) daily milk production than the wheat supplement (33.3 and 34.0 v. 30.5 kg/cow) in both thin and fat cows. Body condition score at calving positively ( P < 0.05) affected average milk yield (31.6 v. 33.7 kg/cow), however, there was a time × BCS × supplement interaction whereby the fatter cows benefited from the use of either of the canola meal supplements for a longer period than did the thin cows. Average milk fat concentrations were greater ( P < 0.05) where the canola meal supplements were fed (39.3 and 39.6 v. 35.6 g/kg), and in fat cows relative to thin cows (40.0 v. 36.3 g/kg). Serum urea concentrations were significantly ( P < 0.05) lower in cows fed wheat than in those fed either of the canola meal supplements (3.1 v. 4.3 and 4.2 mmol/L). Serum β-hydroxybutyrate concentrations were lowest ( P < 0.05) where wheat pellets were fed, and highest ( P < 0.05) where treated canola meal pellets were fed, and plasma glucose concentrations were highest with wheat and lowest with the treated canola meal pellets. Thus, the hypothesis was not supported by the results of this experiment.

Plasma leptin concentration in dogs: Effects of body condition score, age, gender and breeds

Leptin is a cytokine produced by adipocytes, and plays a key role in the regulation of energy balance. In the present study, we measured plasma leptin concentrations of 166 normal and obese dogs visiting veterinary practices, and clarified the influence of age, gender and breed on plasma leptin levels in dogs. Leptin levels were higher in the dogs with higher body condition scores. There was no noticeable influence of age, gender and breed, but those in optimal puppies and obese Miniature Dachshund tended to be lower than those in corresponding groups. We conclude that plasma leptin is a reliable marker of adiposity in dogs regardless of age, gender and breed variations, and thereby useful as a blood biochemistry test for health examinations and treatment of obesity.

Effects of body condition score at parturition and postpartum supplemental fat on metabolite and hormone concentrations of beef cows and their suckling calves1

To determine the effects of BCS at parturition and postpartum lipid supplementation on blood metabolite and hormone concentrations, 3-yr-old Angus x Gelbvieh beef cows, which were nutritionally managed to achieve a BCS of 4 +/- 0.07 (479.3 +/- 36.3 kg of BW) or 6 +/- 0.07 (579.6 +/- 53.1 kg of BW) at parturition, were used in a 2-yr experiment (n = 36/yr). Beginning at 3 d postpartum, cows within each BCS were assigned randomly to be fed hay and a low-fat control supplement or lipid supplements with either cracked high-linoleate or high-oleate safflower seeds until d 61 of lactation. The diets were formulated to be isonitrogenous and isocaloric, and the safflower seed supplements were formulated to achieve 5% DMI as fat. On d 31 and 61 of lactation, blood samples were collected preprandially and then hourly postprandially (at 0, 1, 2, 3, and 4 h). Serum insulin (P = 0.27) and glucose (P = 0.64) were not affected by BCS at parturition. The mean concentrations of plasma NEFA (P = 0.08) and beta-hydroxybutyrate (P = 0.08) tended to be greater, and serum IGF-I was greater (P < 0.001) in BCS 6 than BCS 4 cows. Conversely, serum GH was greater (P = 0.003) for BCS 4 cows, indicating that regulation of IGF by GH may have been uncoupled in BCS 4 cows. The postpartum diet did not affect NEFA (P = 0.94), glucose (P = 0.15), IGF-I (P = 0.33), or GH (P = 0.62) concentrations. Oleate-supplemented cows had greater (P = 0.03) serum insulin concentrations, whereas control cows had greater (P = 0.01) plasma beta-hydroxybutyrate concentrations. Concentrations of NEFA (P = 0.05) and glucose (P < 0.001) were greater, and beta-hydroxybutyrate tended (P = 0.07), to be greater at d 3, whereas serum IGF-I was greater (P = 0.003) at d 6 of lactation. Similar concentrations of NEFA, glucose, GH, and IGF-I indicate that the nutritional status of beef cows during early lactation was not influenced by lipid supplementation. However, perturbations of the somatotropic axis in BCS 4 cows indicate that the influence of energy balance and BCS of the cow at parturition on postpartum performance should be considered when making managerial decisions.

Effects of body condition score at parturition and postpartum supplemental fat on adipose tissue lipogenic activity of lactating beef cows1

Three-year-old Angus x Gelbvieh beef cows nutritionally managed to achieve a BCS of 4 +/- 0.07 (479.3 +/- 36.3 kg of initial BW) or 6 +/- 0.07 (579.6 +/- 53.1 kg of initial BW) at parturition were used in a 2-yr experiment (n = 36/yr) to determine the effects of BCS at parturition and postpartum lipid supplementation on cow adipose tissue lipogenesis. Beginning 3 d postpartum, cows within each BCS were randomly assigned to be fed hay and a low-fat control supplement or supplements with either cracked high-linoleate safflower seeds or cracked high-oleate safflower seeds until d 60 of lactation. Diets were formulated to be isonitrogenous and isocaloric, and safflower seed diets provided 5% DMI as fat. Adipose tissue biopsies were collected near the tail-head region of cows on d 30 and 60 of lactation. Dietary treatment did not affect (P > or = 0.43) adipose tissue lipogenesis. Body condition score at parturition did not affect acetate incorporation into lipid (P = 0.53) or activity of acetyl CoA carboxylase (P = 0.77) or fatty acid synthase (P = 0.18). Lipoprotein lipase activity and palmitate incorporation into triacyl-glycerol tended to be greater (P = 0.06), and palmitate esterification into total acylglycerols was greater (P = 0.01) in cows with a BCS of 4 at parturition. Mean activity of acetyl-CoA carboxylase (P < 0.001), lipoprotein lipase (P = 0.01), and rate of palmitate incorporation into monoacylglycerol (P = 0.02), diacylglycerol (P = 0.001), triacylglycerol (P = 0.003), and total acylglycerols (P = 0.002) were greater at d 30 than d 60, suggesting a greater proclivity for fatty acid biosynthesis and esterification by adipose tissue at d 30 of lactation. Although dietary lipid supplementation did not affect adipose tissue lipogenesis, results suggest that cows with a BCS of 4 at parturition have a greater propensity to deliver exogenously derived fatty acids to the adipocyte surface and incorporate preformed fatty acids into acylglycerols as stored adipocyte lipid. Additionally, cows in early lactation seemed to be able to synthesize and incorporate more fatty acids into stored lipid than cows during peak lactation.

214 EFFECT OF TIMING OF PGF, eCG, AND ESTRADIOL BENZOATE IN RECIPIENTS SYNCHRONIZED WITH A PROGESTIN-BASED PROTOCOL FOR FIXED-TIME EMBRYO TRANSFER

An experiment was designed to evaluate alternative treatment protocols for fixed-time embryo transfer (FTET) in recipients in order to reduce cattle handling. Non-lactating, cycling Bos taurus � Bos indicus beef cows (n = 918), with a body condition score (BCS) of 2.5 to 3.5 out of 5, received a progesterone-releasing device (DIB; Syntex, Buenos Aires, Argentina) and 2 mg estradiol benzoate (EB; Syntex) IM on random days of the cycle (Day 0); DIB were removed on Day 8. Cows were placed randomly into 6 treatment groups in a 3 � 2 factorial design. The factors evaluated were time of administration of PGF and eCG [control treatment: PGF Day 5 and eCG Day 5 (Bo et al. 2002 Theriogenology 57, 53–72); PGF Days 0 and 8 and eCG Day 5; PGF Days 0 and 8 and eCG Day 8] and the time of administration of the second injection of EB (at DIB removal or 24 h later). Therefore, cows in the control treatment received 150 �g of d-Cloprostenol (PGF, Ciclase; Syntex) and 400 IU eCG (Novormon; Syntex) on Day 5, whereas cows in the other 2 treatments received 75 �g of PGF on Days 0 and 8 and 400 IU eCG on either Day 5 or Day 8. Each treatment group was further subdivided to receive 1 mg EB IM on either Day 8 (EB Day 8) or Day 9 (EB Day 9). All recipients, whether observed in estrus or not and with more than one CL with luteal area (total CL area minus cavity area) &amp;gt;76 mm2 on the day before embryo transfer, received frozen-thawed embryos (IETS Grade 1) on Day 16 (EB Day 8) or Day 17 (EB Day 9) by direct transfer. Pregnancy was determined by ultrasonography 30 days after FTET. Continuous data were analyzed by ANOVA and pregnancy rates were analyzed by logistic regression. No effects of body condition score or technician were detected (P &amp;gt; 0.1). Although there were no differences in conception rates between recipients treated with EB on Day 8 or Day 9 (168/321, 52.3% vs. 203/350, 58.0%, respectively; P &amp;gt; 0.1), treatment with EB on Day 8 resulted in fewer recipients selected/treated (321/460, 69.7% vs. 350/458, 76.4%; P &amp;lt; 0.05) and pregnant/treated (168/460, 36.5% vs. 203/458, 44.3%; P &amp;lt; 0.05) than 24 h later (EB Day 9), respectively. The mean interval from DIB removal to estrus was shorter (P &amp;lt; 0.05) for recipients in the EB Day 8 (28.1 � 7.2 h) than in the EB Day 9 (43.5 � 9.4 h) group, and the mean (� SEM) CL area was also less in the EB Day 8 group than in the EB Day 9 group (261.7 � 96.7 vs. 293.1 � 114. mm2; P &amp;lt; 0.05). The number of recipients selected/treated was higher in the group receiving PGF on Days 0 and 8 and eCG on Day 8 (243/305, 79.6%) than in the group receiving PGF on Days 0 and 8 and eCG on Day 5 (208/301, 69.1%) or the control group (220/312, 70.5%). Although the luteal area was greater (P &amp;lt; 0.05) in the PGF on Days 0 and 8 and eCG on Day 5 group (304.4 � 127.1 mm2) than in the groups receiving PGF and eCG on Day 5 (274.6 � 98.6 mm2) or PGF on Days 0 and 8 and eCG Day 8 (258.4 � 90.2 mm2), pregnancy rates did not differ between PGF and eCG treatment groups (P &amp;gt; 0.05). It was concluded that it may be possible to reduce animal handling by treating recipients with a half dose of PGF at the time of DIB insertion and removal, when eCG is also administered, without compromising pregnancy rates.

Effects of body condition score in cows peripartum on the onset of postpartum ovarian cyclicity and conception rates after ovulation synchronization/fixed-time artificial insemination.

The aim of this study was to examine whether the nutritional state of cows peripartum was associated with the recovery of ovarian function and conception rates after synchronization of ovulation and fixed-time artificial insemination (OVSYNCH/TAI). The effect of the interval in days from calving to the first ovulation on conception rates after OVSYNCH/TAI was also investigated. Conception rates of cows after OVSYNCH/TAI (n=39) were 43.6%. The conception rates of cows with a body condition score (BCS) of 2.75-3.25 at 30 d postpartum and on the day of OVSYNCH treatment were significantly higher than in cows with a BCS < or =2.5 (P<0.05). The percentage of cows establishing ovarian cyclicity before 55 d postpartum in cows with a BCS of 2.75-3.25 at 30 d postpartum and on the day of OVSYNCH treatment were significantly higher than in cows with a BCS < or =2.5 (P<0.05). The conception rates after OVSYNCH/TAI in cows which recovered ovarian cyclicity within 34 d postpartum were significantly higher than in cows with first ovulation > or =56 d (P<0.05). These results indicated that the nutritional state in cows peripartum influenced the conception rates after OVSYNCH/TAI and the postpartum ovarian cyclicity and also suggested that the conception rates after OVSYNCH/TAI decreased in cows with delayed recovery of ovarian cyclicity.