Relationship between condition score, physical measurements and body fat percentage in mares

Applications of ultrasound in analysis, processing and quality control of food: A review

Dietary requirements and functions of α-linolenic acid in animals

To investigate the genetic factors that affect fatty acid composition of beef, we compared the full-length bovine stearoyl-CoA desaturase (SCD) cDNA from 20 Japanese Black steers. Two types of the SCD gene with single nucleotide polymorphisms (SNPs) were observed in the ORF of SCD cDNA, in which an amino acid replacement from valine (type V) to alanine (type A) was predicted. We developed a method for genotyping these two SCD genes based on PCR-RFLP. We have classified 1003 Japanese Black carcasses into three genotypes, VV, VA, and AA, and compared fatty acid composition among them. The SCD type A gene contributed to higher MUFA percentage and lower melting point in intramuscular fat. The SCD genotype was not the only genetic factor contributing to fatty acid composition of Japanese Black steers, but the SCD genotype was considered one of the causes of genetic variation in fatty acid composition of Japanese Black steers. Transcription factors such as sterol regulatory element binding protein-1c (SREBP-1c) may account for the remaining part of the genetic variation in fatty acid composition.

Genotype of stearoyl-CoA desaturase is associated with fatty acid composition in Japanese Black cattle

Recent studies associate obesity and in- sulin resistance in horses with development of abnor- mal reproductive function and debilitating laminitis. The factors contributing to insulin resistance in obese horses are unknown. However, human studies provide evidence that elevated inflammatory cytokines such as tumor necrosis factor α (TNFα), IL1, and IL6 play direct roles in development of obesity-associated insulin resis- tance. Thus, inflammation may be a key link between obesity and insulin resistance in horses. The aim of the current investigation was to examine possible relation- ships between obesity, inflammatory cytokines, and in- sulin sensitivity (IS) in the horse. Age was recorded and BCS and percent body fat (% FAT) were determined as measures of obesity in 60 mares. In addition, blood mRNA expression of IL1, IL6, and TNFα and circulat- ing concentrations of TNFα protein (TNFp) were deter- mined in each mare. Finally, fasted concentrations of insulin were determined, and IS was determined using the hyperinsulinemic, euglycemic clamp. Significant correlations between several variables provided evi- dence for the design of 4 population regression models to estimate relationships between measures of obesity, inflammatory factors, and IS in the sample population. The results of these analyses revealed that IS decreased as BCS and % FAT increased (P < 0.001) in the sample population. Additionally, increased IL1 (P < 0.05) and TNFp (P < 0.01) were associated with decreased IS. However, increased TNFα (P < 0.001) was associated with decreased IS only in mares 20 yr of age and older. Increased BCS and % FAT were associated with in- creased expression of TNFα (P = 0.053) and IL1 (P < 0.05), and increased TNFp (P < 0.05). Surprisingly, increased BCS and % FAT were associated with de- creased IL6 expression (P = 0.05) in mares <20 yr of age. Finally, evaluation of the influence of obesity and inflammatory cytokines on IS within the same model suggested that BCS and % FAT (P < 0.001) with TNFα (mRNA (P = 0.07) and protein (P < 0.05)) are inversely associated with IS independently of one another. Com- bined, these results provide the first evidence associat- ing obesity with increased inflammatory factors in the horse. Furthermore, the results suggest that an interre- lationship exists among obesity, inflammatory cytok- ines, and IS in the horse and emphasize the need for further studies to elucidate the nature of these rela- tionships.

https://www.paardenwelzijnscheck.nl/app/webroot/files/ckeditor_files/files/Voeding%20en%20Water/Vick%20et%20al.%20(2007)%20Relationships%20among%20inflammatory%20cytokines%2C%20obesity%2C%20and%20insulin%20sensitivity%20in%20the%20horse.pdf

Relationships among inflammatory cytokines, obesity, and insulin sensitivity in the horse.

Estimating Fatness in Horses and Ponies

SUMMARY— Bovine intramuscular lipids extracted from the semitendinosus, triceps brachii and longissimus dorsi muscles were fractionated into phospholipids and neutral fats by silicic acid column chromatography. In spite of the wide range in total fat content at each location, phospholipids were present in all three muscles at a level of approximately 500 mg per 100 g of muscle tissue. This result, coupled with the lower total fat content of the semitendinosus as compared to the other two muscles, indicated a significantly higher percentage of phospholipid material in the total fat from the semitendinosus as compared to the triceps brachii or longissimus dorsi.



The fatty acids were identified in both lipid fractions using retention time data obtained on both a polar and a non-polar column. The identity of the unsaturated fatty acids was confirmed when their peaks did not appear on the chromatographs obtained from brominated samples. There was significantly more C14:0 in the longissimus dorsi neutral fat fractions than in the semitendinosus neutral fat fractions. In the phospholipids, there was significantly more C16:0 and significantly less C18:0 in the longissimus dorsi as compared to either the semitendinosus or triceps brachii. Although the two lipid fractions of the longissimus dorsi contained slightly higher percentages of total saturated fatty acids than the corresponding fractions in the other two muscles, the effects were not significant.

Composition of Bovine Muscle Lipids at Various Carcass Locations

Development and Application of Ultrasonic Methods for Measuring Fat Thickness and Rib-Eye Area in Cattle and Hogs

Thirty-nine Holstein steer calves were assigned to one of five treatments at birth and individually fed for 200 d with milk replacer reconstituted to equal the fat and protein concentration of beef cow milk. Treatment levels were the quantities of reconstituted milk fed per day based on lactation curves, which were based on peak milk levels (PML) of 2.72, 5.44, 8.16, 10.88, and 13.6 kg/d, respectively. In addition to reconstituted milk, chopped alfalfa hay was offered ad libitum to allow for maximal voluntary forage consumption. All calves were fed a high-energy diet postweaning until they reached a similar degree of fatness in the 12th rib (4 to 5% chemical fat) as determined by ultrasound. There were differences (P < 0.05) among groups in weaning weight, preweaning ADG, age, and weight at slaughter. During the preweaning phase, there was a linear relationship (P < 0.01) for daily milk and forage DE intake; however, DE intake per unit of BW did not differ across treatments (P = 0.06). Increasing PML resulted in a linear (P < 0.01) decrease in alfalfa hay intake in the preweaning phase, and G:F increased quadratically (P < 0.01). During the postweaning phase, preweaning milk intake had no meaningful effect on postweaning ADG, but overall ADG had a linear relationship (P < 0.01) with preweaning milk level. There was no effect of PML on the 12th-rib lipid percent, marbling score, or quality grade, but protein and fat concentration in the carcass and empty BW increased linearly (P < 0.01) with PML. The group fed at 2.72 kg/ d PML was 58 kg lighter (P = 0.03) and required 34 d more (P < 0.01) to reach the predetermined degree of fatness at slaughter than the group fed at 13.6 kg/d PML, suggesting that increased milk production by the dam can decrease the number of days to the slaughter weight at which a similar rib lipid concentration is reached.

The effect of milk intake on forage intake and growth of nursing calves

The objectives of this study were to describe a system to assess KPH fat by using real-time ultrasound (RTU) and to develop equations to predict total physical separable internal fat (IFAT) based on ultrasound measurements. Data for this study were obtained from 24 Angus steers fed either hay- or corn-based diets during the backgrounding phase. Steers were serially slaughtered in 3 groups: at weaning (baseline), then at 4 and 8 mo after weaning. A fourth group was composed of 4 steers from the hay-fed group that were slaughtered at approximately 10 mo after weaning. The RTU measurements were collected every 2 mo, with a preslaughter scan approximately 7 d before the slaughter time. The RTU measurements consisted of 12th- to 13th-rib backfat thickness, 12th to 13th ribeye area, percentage of intramuscular fat, and kidney fat depth, which was measured in a cross-sectional image collected between the first lumbar vertebra and the 13th rib. For kidney fat, the ultrasound probe was placed on the flank region approximately 15 cm from the midline of the animal. Images were stored in the ultrasound console, and measurements were taken between the ventral part of the iliocostalis muscle and the end of the KPH fat at the chute side. The relationship between carcass and ultrasound measurements in the depths of kidney fat (cKFd and uKFd, respectively) had an r(2) of 0.93, with a root mean square error (RMSE) of 1.14 cm. An allometric regression between carcass KPH weight (cKPHwt) and cKFd was identified, and the untransformed regression had an r(2) of 0.96. The linear regression between total IFAT and cKPHwt had an r(2) of 0.97, with an RMSE of 2.67 kg. Therefore, a system was developed to predict IFAT from uKFd measurements by combining these equations. Additionally, a single linear regression between IFAT and uKFd measurements was developed (r(2) = 0.89, RMSE = 5.32 kg). Even though the system of equations had a lower RMSE of prediction and greater r(2) compared with the single linear regression (4.80 vs. 5.10 kg and 0.91 vs. 0.89, respectively), there was no difference between these methods in predicting IFAT (P = 0.4936) by using a pairwise mean square error of prediction analysis. Our results indicated that uKFd measurements can accurately and precisely predict the cKFd of steers consuming either high concentrate or forage rations. The results also showed that cKFd is highly correlated with cKPHwt, which can be used to estimate total IFAT. More research is needed to further evaluate this technique with different feeding strategies, breeds, and sexes.

J. R. Stouffer

Papers

Estimating Fatness in Horses and Ponies

Composition of Bovine Muscle Lipids at Various Carcass Locations

Development and Application of Ultrasonic Methods for Measuring Fat Thickness and Rib-Eye Area in Cattle and Hogs

The effect of milk intake on forage intake and growth of nursing calves

Technical note: A novel technique to assess internal body fat of cattle by using real-time ultrasound.