Associations between locomotion score and kinematic measures in dairy cows with varying hoof lesion types.

During this study we explored the gait attributes commonly used in subjective locomotion scoring systems and use new technology to evaluate these gait attributes objectively on 60 Holstein lactating dairy cattle. Kinematic gait analysis more commonly used in sports and equine science was adapted for use on dairy cattle to assess stride characteristics, joint flexion, and spine posture in dairy cows with different lameness status. Cows that were lame had shorter stride length and had negative tracking distance compared with nonlame cattle. Lame cattle did not show any difference in spine posture when walking. Gait alterations were more evident in cows with sole ulcers, which showed considerable shortening of stride and had more negative tracking compared with cows with no hoof lesions. Cows with sole ulcers also showed significant shortening of the spine when walking than cows with no hoof lesions.

Effect of supplementing sows' feed with alpha-tocopherol acetate and vitamin C on transfer of alpha-tocopherol to piglet tissues, colostrum, and milk: aspects of immune status of piglets.

The aim of this study was to investigate the effects of dietary supplementation of sows with alpha-tocopherol acetate (ATA) and vitamin C on deposition of alpha-tocopherol (AT) in piglet lymphoid organs, such as bone marrow, thymus, and spleen at birth and at weaning, as well as on indicators of immune response in piglets. Sows were given the following treatment diets: control, vitamin C 10 g/day, ATA 500 mg/kg feed, and combined vitamins (ATA 500+Vit-C 10). Supplementation with vitamins started at the beginning of pregnancy and lasted until weaning at 21+/-3 days of age. AT was determined in colostrum, milk, piglet plasma (cord blood) and tissues at birth and on day 21. Immunoglobulins were measured in piglet plasma, milk, and colostrum. Lymphocyte proliferation in response to PHA and ConA was determined in sow and piglet blood. ATA supplementation resulted in a significant increase (P<0.001) in the AT content of colostrum, milk, piglet plasma, liver, thymus, bone marrow, and spleen at weaning. The AT content of colostrum and milk significantly (P<0.001) influenced the AT content of piglet plasma and tissues at weaning (day 21). Total Ig and IgG concentrations in piglet plasma were significantly increased in piglets given the combined vitamin treatment. No effect of AT supplementation was observed on IgG and IgA in colostrum and milk. In sows, vitamin C given alone significantly increased lymphocyte response to ConA and PHA; whereas, in piglets, there was no significant effect of treatments on lymphocyte response to PHA and ConA.

Usefulness of near-infrared reflectance (NIR) spectroscopy and chemometrics to discriminate fishmeal batches made with different fish species.

Near-infrared reflectance (NIR) spectroscopy combined with chemometrics was used to identify and authenticate fishmeal batches made with different fish species. Samples from a commercial fishmeal factory (n = 60) were scanned in the NIR region (1100-2500 nm) in a monochromator instrument in reflectance. Principal component analysis (PCA), dummy partial least-squares regression (DPLS), and linear discriminant analysis (LDA) based on PCA scores were used to identify the origin of fishmeal produced using different fish species. Cross-validation was used as validation method when classification models were developed. DPLS correctly classified 80 and 82% of the fishmeal samples. LDA calibration models correctly classified >80% of fishmeal samples according to fish species The results demonstrated the usefulness of NIR spectra combined with chemometrics as an objective and rapid method for the authentication and identification of fish species used to manufacture the fishmeal.

The effect of dietary polyunsaturated fatty acids (PUFA) on infection with the nematodes Ostertagia ostertagi and Cooperia oncophora in calves.

Diet-induced changes in the polyunsaturated fatty acid (PUFA) content of immune cells influences the immune phenotype that develops following infection. The aim of this study was to examine the effect of manipulating dietary PUFA supply on tissue fatty acids composition and immunity to a mixed infection with an abomasal and an intestinal nematode parasite in calves. Calves (n=24) were allocated into two treatment groups and fed 25 g/day of either fish oil (n-3 group) or a binary mixture of palm/rapeseed oil (normal group) as a supplement in milk replacer. Within each treatment group eight calves were infected with 2000 L3 Ostertagia ostertagi and Cooperia oncophora, three times per week for 8 weeks, the remaining calves were pair-fed uninfected controls. Faecal egg counts (FEC) were carried out twice weekly. At slaughter, the whole gut was removed intact for worm counts and tissue samples were taken for fatty acid analysis. Samples of abomasum, duodenum and mid-gut were also collected for immunohistological analysis. FEC were not significantly influenced by oil supplement but tended to remain higher in the palm/rapeseed oil-fed group (normal infected). The number of intestinal immature worms was significantly (p<0.05) higher in the n-3 group. Mucosal mast cell (MMC) and eosinophil numbers were significantly increased (p<0.05) by infection and were significantly lower (p<0.05) in the intestinal tissue of the fish oil supplemented and infected group (n-3 infected group). These results suggest that feeding an n-3 PUFA-rich supplement (fish oil) can influence cellular mediators of immunity to nematode infection. This is the first report of the establishment of patency and the subsequent development of immunity to a mixed infection with O. ostertagi and C. oncophora in calves undergoing early rumen development. The trend in the FEC, MMC and eosinophil numbers in the n-3 group suggests that decreasing the dietary n-6/n-3 PUFA ratio may be a worthwhile immunonutritional strategy for potentiating the immune response to nematode parasite infection in the calf.

Mechanisms linking under-nutrition and ovarian function in beef heifers.

Prolonged reduction in energy intake in beef heifers has been reported to suppress ovulation but the mechanisms involved are poorly understood. The objective of this study was to examine whether changes in the pattern of LH secretion following each of three different tests predicted the functional state of the hypothalamo-pituitary-ovarian (H-P-O) axis. Test 1 examined the ratio of LH secretion during the 1h before and 2h after naloxone (NAL) administration. The other two tests assessed the LH surge following an exogenous oestradiol positive feedback signal (Test 2) or exogenous progesterone priming (Test 3). In phases 1 and 3, each of 8 weeks duration, the heifers were fed 100% of their maintenance energy requirements. In phase 2, of 9 weeks duration, they were fed 50% of their maintenance energy requirements. Oestrus was induced in all heifers by PG administration at the start of the experiment. Heifers were administered a naloxone challenge of 50, 100, 200 or 400mg naloxone hydrochloride i.v. (one dose per heifer) during the mid-luteal period of phase 1 and all four naloxone treated heifers received 400mg naloxone hydrochloride at the end of phases 2 and 3. Doses of 10, 20 or 40 mg oestradiol benzoate (EB) i.m. were each administered to two of the remaining heifers during the mid-luteal period of phase 1. One heifer on each dose of oestradiol benzoate in phase 1 had the same dose administered at the end of phases 2 and 3. The progesterone challenge was administered to three heifers by insertion of a PRID for 12 days starting in the middle of phase 2. In Test 1, the ratio of LH secretion before and after naloxone administration in phase 1 was 1:1 (50mg), 1:4 (100mg), 1:4 (200mg) and 1:9 (400mg) (50mg versus 100mg and 100mg versus 200mg doses, P<0.05); 50mg versus 400mg doses, P<0.001). In phase 2, this ratio was 1:1 and there was no response to 400mg dose of naloxone in any of the four heifers. In phase 3, the ratio depended on the ovarian activity in the heifer and ranged from 1:1 to 1:4 (P<0.05). In Test 3, a positive oestradiol feedback signal was detected in cyclic heifers in phases 1-3 but not in the acyclic heifer in phase 2. Heifers challenge with exogenous progesterone did not have oestradiol or LH values above threshold levels. We conclude that all three tests successfully predicted the functional state of the hypothalamo-pituitary-ovarian axis. In nutritionally undernourished beef heifers onset of ovarian acyclicity is either preceded or accompanied by the loss of a positive feedback signal (Test 2) and progesterone priming ability (Test 3), and that a plasma LH ratio of > or =1:2 following naloxone challenge (Test 1) is a sign of recovery of the functional state of the hypothalamo-pituitary-ovarian axis.

Protein utilization during energy undernutrition in sheep sustained by intragastric infusion. Effect of body fatness on the protein metabolism of energy-restricted sheep.

The effect of body fat content on the protein metabolism of energy-restricted sheep has been studied in two experiments. In the first experiment, six Suffolk-cross wether sheep, three weighing about 39 kg and three of about 61 kg, were given progressively increasing amounts of casein-N from 0 to 3000 mg N/kg metabolic body weight (W0.75) daily with constant energy, 91 kJ/kg W0.75 daily, from a high-propionic acid mixture of volatile fatty acids (VFA). In the second experiment, two lean and two fat sheep of similar body weights were given progressively increasing amounts of casein with the same VFA mixture. All the animals attained a positive N balance when they were in negative energy balance. N balance was not affected by body fatness of the magnitude studied, although lean animals utilized increasing levels of standard VFA (acetate-propionate-butyrate 65:25:10, molar proportions) infusion for N accretion more efficiently than fat animals. Endogenous energy was utilized for protein accretion with an efficiency of 0.56. Supply of glucogenic VFA equivalent to 28 mmol glucose/kg W0.75 reduced fasting N excretion by 39%. Fasting heat production decreased from 335 to 300 kJ/kg W0.75 with the infusion of casein and glucogenic VFA. It is argued that fasting induces additional heat losses due to raised protein metabolism and is unsuited as a baseline for dietary assessment.

Protein utilization during energy undernutrition in sheep sustained by intragastric infusion: effects of protein infusion level, with or without sub-maintenance amounts of energy from volatile fatty acids, on energy and protein metabolism.

Utilization of endogenous and exogenous energy for protein accretion during energy undernutrition has been studied. Nine lambs nourished by intragastric infusion were given either progressively increasing or decreasing amounts of casein-N up to 2550 mg/kg metabolic weight (W0.75), with or without 250 kJ/kg W0.75 of volatile fatty acids daily. Energy balance (respiration calorimetry) and N balance were measured. While all experimental animals were in negative energy balance, N balance increased curve-linearly with the increase in casein-N infusion and attained positive N balance. Endogenous energy (presumably body fat) was found to meet the energy needs for protein accretion during energy undernutrition. It is concluded that body fat can be effectively utilized to support lean-tissue growth during energy undernutrition, so that the classical nutritional concept of dietary energy:protein ratio is only meaningful when both endogenous and exogenous energy are considered.

Effect of different dietary supplemental fats and oils on the tissue fatty acid composition and growth of female broilers.

1. A study was undertaken to examine the effect of supplementation of diets with fats of different chain length and degree of unsaturation on the performance, carcase characteristics and tissue fatty acid composition of broilers. 2. Three hundred and sixty 19-day-old female broilers were fed on diets containing supplemental fat/oil (50 g/kg) in the form of beef tallow (BT) (diet T-T), soyabean oil (SBO) (diet S-S), rapeseed oil (RSO) (diet R-R), marine oil (MO) (diet M-M) or binary mixtures (0.5:0.5 w/w) of these lipids (diets T-S, T-R, T-M, S-R, S-M, and R-M) to 54 d of age. Food intake, live weight, plucked weight and the lipid concentration and fatty acid composition of abdominal fat pad, liver and breast muscle were measured. 3. Food intake, plucked weight and live weight were greatest for diet T-T and lowest for diet R-R. Food conversion ratio was poorest for birds fed on diets containing BT. Lipid concentration in abdominal fat pad was significantly higher in birds fed on diets containing SBO. Liver lipid concentration was significantly reduced by diets containing RSO. 4. Abdominal fat pad fatty acid profile was most readily altered by dietary fatty acids. There was a strong correlation between dietary fatty acid composition and tissue fatty acid composition for all fatty acids except C14:0, C20:0, C20: 2n-6 and C20: 4n-6. The tissue P/S ratio ranged from 0.40 for diet T-T to 1.40 for diet S-S. The n-6/n-3 ratio was significantly increased by the inclusion of SBO and decreased by the inclusion of MO. 5. Liver fatty acid profile was least modified by dietary fatty acids. There was an inverse relationship between liver and dietary C20:4n-6 concentration. Tissue C18:2n-6 and C20:4n-6 were highly correlated, suggesting significant interconversion by delta-6 desaturase in this tissue. The n-6/n-3 ratio was significantly increased by inclusion of SBO and significantly decreased by the inclusion of MO. 6. In breast muscle MO-based diets increased the proportion of n-3 PUFA at the expense of n-6 PUFA. The tissue concentrations of C18:1n-9, C18:2n-6, C20:1n-9, C20:5n-3, C22:5n-3 and C22:6n-3 were strongly correlated with dietary fatty acid composition. Muscle and diet P/S and n-6/n-3 ratios were highly correlated.

Effects of subcutaneous implantation of trenbolone acetate and oestradiol-17 beta on plasma lipid concentrations in sheep.

Twenty eight Greyface x Suffolk wethers were allocated to four treatment groups designated TG0, TG1, TG2 and TG3 and were implanted with either 0, 1, 2, or 3 pellets of Revalor containing 17.5 mg trenbolone acetate and 2.5 mg oestradiol-17 beta per pellet. Blood samples were taken at regular intervals and were analysed for plasma cholesterol, triglyceride, non-esterified fatty acids and phospholipid. Plasma cholesterol concentrations appeared to exhibit a biphasic response to implantation. The magnitude of the response was directly related to the dose level of the implant. In comparison with group TG0, significant decreases in the cholesterol levels in all implanted animals were demonstrated one week after implantation. Between weeks 3 and 5 the cholesterol concentrations in groups TG2 and TG3 showed a considerable increase. At week 5 the concentration in group TG3 was 18% higher than group TG0. These changes coincided (1) with the initial rapid release and then the gradual decrease after week 2 in the concentration of trenbolone acetate in plasma and (2) with the more gradual release of oestradiol-17 beta which reached a maximum level in groups TG2 and TG3 between weeks 5 and 6. There were significant differences between groups TG1, TG2 and TG3 at weeks 1, 3 and 5. Plasma triglyceride concentrations in all implanted groups fell markedly by week 5 and remained well below control values until slaughter. The concentration of plasma non-esterified fatty acids decreased by approximately 50% in all four treatment groups. The differences between control and treatment groups were not significant.

Short chain acyl-CoA synthetases in ovine rumen epithelium.

The activation of and interactions between physiological concentration of acetate, propionate, and butyrate are reported. A partially purified shortchain acyl-CoA synthetase has been prepared from ovine rumen epithelium and its kinetic properties characterised. These properties suggest the activation of volatile fatty acids by two short-chain acyl-CoA synthetases. One is capable of activating acetateactivating acetate, propionate and butyrate and the other will only accept butyrate as a substrate.

Utilization of methylmalonate for the synthesis of branched-chain fatty acids by preparations of chicken liver and sheep adipose tissue.

1. The utilization of methyl[2-14C]malonyl-CoA for fatty acid synthesis was investigated using synthetase preparations from chicken liver and sheep adipose tissue. 2. The rate of fatty acid synthesis from acetyl-CoA and malonyl-CoA was greatly diminished in the presence of methylmalonyl-CoA. 3. In the absence of malonyl-CoA, methylmalonyl-CoA was utilized for fatty acid synthesis only very slowly by the synthetase from sheep adipose tissue and not at all by that from chicken liver. 4. Despite the inhibitory effect of methylmalonyl-CoA on fatty acid synthesis from malonyl-CoA, it was utilized by the synthetase preparations from both species to produce a complex mixture of methyl-branched fatty acids.

Effect of vitamin B12 status on the occurrence of branched-chain and odd-numbered fatty acids in the liver lipids of the baboon.

Branched chain fatty acids of the anteiso series and others with methyl substitution nearer to the carboxyl group were found, together with odd numbered, straight chain fatty acids, in very small proportions in baboon liver lipids. The proportions were increased in vitamin B12-depleted animals, especially after administration of a B12 analogue.

Synthesis of deoxyribonucleic acid in BHK-21-C13 cells.

Newly synthesized (3)H-labelled DNA was extracted from baby hamster kidney cells (BHK-21/C13 cells) and was shown to possess single-stranded properties when examined by column chromatography on benzoylated naphthoylated DEAE-cellulose, hydroxyapatite and methylated albumin on kieselguhr, and by its affinity for nitrocellulose filters. Some of the newly synthesized DNA was shown to be of lower molecular weight than the bulk of the DNA when examined by alkaline sucrose-density-gradient centrifugation. The properties observed were not affected by treatment of the DNA with ribonuclease, Pronase or amylase. The effect of the size of the DNA on its observed properties was examined and is discussed. It is concluded that DNA synthesis in BHK-21/C13 cells proceeds according to the discontinuous-mechanism model in at least one of the strands.