Health value and keeping quality of chevon from goats fed finisher diets containing hemp (Cannabis sativa L.) seed cake.

Wether goats (n = 7) were fed finishing diets containing either 0, 25, 50, 75 or 100 g/kg DM of hempseed cake (HSC) substituting soybean meal to evaluate chevon fatty acid, volatile and oxidative profiles. Feeding HSC diets linearly decreased (P < 0.05) chevon c9-16:1, 16:0, total saturated FA (SFA) and protein oxidation but linearly increased (P < 0.05) t9-18:1, t11-18:1, conjugated linoleic acids, n-3 polyunsaturated FA (PUFA), individual long-chain n-6 PUFA and antioxidant activity. On day 1 and 7 of retail display, diets containing 75 and 100 g/kg DM HSC had greater (P < 0.05) TBARS than the other diet × day interactions. Addition of HSC to the diet increased (P < 0.05) and preserved (P < 0.05) chevon contents of hexanal and methyl caprate throughout the retail display period. Overall, feeding HSC up to 100 g/kg DM enhances chevon profiles of healthful PUFA, desirable flavor volatiles and protein shelf-stability.

Non-invasive assessment of culture media from goat cloned embryos associated with subjective morphology by gas chromatography - mass spectroscopy-based metabolomic analysis.

Pre-implantation embryo metabolism demonstrates distinctive characteristics associated with the development potential of embryos. We aim to determine if metabolic differences correlate with embryo morphology. In this study, gas chromatography - mass spectroscopy (GC-MS)-based metabolomics was used to assess the culture media of goat cloned embryos collected from high-quality (HQ) and low-quality (LQ) groups based on morphology. Expression levels of amino acid transport genes were further examined by quantitative real-time PCR. Results showed that the HQ group presented higher percentages of blastocysts compared with the LQ counterparts (P < 0.05). Metabolic differences were also present between HQ and LQ groups. The culture media of the HQ group showed lower levels of valin, lysine, glutamine, mannose and acetol, and higher levels of glucose, phytosphingosine and phosphate than those of the LQ group. Additionally, expression levels of amino acid transport genes SLC1A5 and SLC3A2 were significantly lower in the HQ group than the LQ group (P < 0.05, respectively). To our knowledge, this is the first report which uses GC-MS to detect metabolic differences in goat cloned embryo culture media. The biochemical profiles may help to select the most in vitro viable embryos.

Pharmacokinetics, milk penetration and PK/PD analysis by Monte Carlo simulation of marbofloxacin, after intravenous and intramuscular administration to lactating goats.

The main objectives of this study were (i) to evaluate the serum pharmacokinetic behaviour and milk penetration of marbofloxacin (MFX; 5 mg/kg), after intravenous (IV) and intramuscular (IM) administration in lactating goats and simulate a multidose regimen on steady-state conditions, (ii) to determine the minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) of coagulase negative staphylococci (CNS) isolated from caprine mastitis in Córdoba, Argentina and (iii) to make a PK/PD analysis by Monte Carlo simulation from steady-state pharmacokinetic parameters of MFX by IV and IM routes to evaluate the efficacy and risk of the emergence of resistance. The study was carried out with six healthy, female, adult Anglo Nubian lactating goats. Marbofloxacin was administered at 5 mg/kg bw by IV and IM route. Serum and milk concentrations of MFX were determined with HPLC/uv. From 106 regional strains of CNS isolated from caprine mastitis in herds from Córdoba, Argentina, MICs and MPCs were determined. MIC90 and MPC90 were 0.4 and 6.4 µg/ml, respectively. MIC and MPC-based PK/PD analysis by Monte Carlo simulation indicates that IV and IM administration of MFX in lactating goats may not be adequate to recommend it as an empirical therapy against CNS, because the most exigent endpoints were not reached. Moreover, this dose regimen could increase the probability of selecting mutants and resulting in emergence of resistance. Based on the results of Monte Carlo simulation, the optimal dose of MFX to achieve an adequate antimicrobial efficacy should be 10 mg/kg, but it is important take into account that fluoroquinolones are substrates of efflux pumps, and this fact may determine that assumption of linear pharmacokinetics at high doses of MFX may be incorrect.

Estimation of tulathromycin depletion in plasma and milk after subcutaneous injection in lactating goats using a nonlinear mixed-effects pharmacokinetic modeling approach.

BACKGROUND: Extra-label use of tulathromycin in lactating goats is common and may cause violative residues in milk. The objective of this study was to develop a nonlinear mixed-effects pharmacokinetic (NLME-PK) model to estimate tulathromycin depletion in plasma and milk of lactating goats. Eight lactating goats received two subcutaneous injections of 2.5 mg/kg tulathromycin 7 days apart; blood and milk samples were analyzed for concentrations of tulathromycin and the common fragment of tulathromycin (i.e., the marker residue CP-60,300), respectively, using liquid chromatography mass spectrometry. Based on these new data and related literature data, a NLME-PK compartmental model with first-order absorption and elimination was used to model plasma concentrations and cumulative excreted amount in milk. Monte Carlo simulations with 100 replicates were performed to predict the time when the upper limit of the 95% confidence interval of milk concentrations was below the tolerance. RESULTS: All animals were healthy throughout the study with normal appetite and milk production levels, and with mild-moderate injection-site reactions that diminished by the end of the study. The measured data showed that milk concentrations of the marker residue of tulathromycin were below the limit of detection (LOD = 1.8 ng/ml) 39 days after the second injection. A 2-compartment model with milk as an excretory compartment best described tulathromycin plasma and CP-60,300 milk pharmacokinetic data. The model-predicted data correlated with the measured data very well. The NLME-PK model estimated that tulathromycin plasma concentrations were below LOD (1.2 ng/ml) 43 days after a single injection, and 62 days after the second injection with a 95% confidence. These estimated times are much longer than the current meat withdrawal time recommendation of 18 days for tulathromycin in non-lactating cattle. CONCLUSIONS: The results suggest that twice subcutaneous injections of 2.5 mg/kg tulathromycin are a clinically safe extra-label alternative approach for treating pulmonary infections in lactating goats, but a prolonged withdrawal time of at least 39 days after the second injection should be considered to prevent violative residues in milk and any dairy goat being used for meat should have an extended meat withdrawal time.

Application of overall dynamic body acceleration as a proxy for estimating the energy expenditure of grazing farm animals: relationship with heart rate.

Estimating the energy expenditure of farm animals at pasture is important for efficient animal management. In recent years, an alternative technique for estimating energy expenditure by measuring body acceleration has been widely performed in wildlife and human studies, but the availability of the technique in farm animals has not yet been examined. In the present study, we tested the potential use of an acceleration index, overall dynamic body acceleration (ODBA), as a new proxy for estimating the energy expenditure of grazing farm animals (cattle, goats and sheep) at pasture with the simultaneous evaluation of a conventional proxy, heart rate. Body accelerations in three axes and heart rate for cows (n = 8, two breeds), goats (n = 6) and sheep (n = 5) were recorded, and the effect of ODBA calculated from the body accelerations on heart rate was analyzed. In addition, the effects of the two other activity indices, the number of steps and vectorial dynamic body acceleration (VeDBA), on heart rate were also investigated. The results of the comparison among three activity indices indicated that ODBA was the best predictor for heart rate. Although the relationship between ODBA and heart rate was different between the groups of species and breeds and between individuals (P<0.01), the difference could be explained by different body weights; a common equation could be established by correcting the body weights (M: kg): heart rate (beats/min) = 147.263∙M-0.141 + 889.640∙M-0.179∙ODBA (g). Combining this equation with the previously reported energy expenditure per heartbeat, we estimated the energy expenditure of the tested animals, and the results indicated that ODBA is a good proxy for estimating the energy expenditure of grazing farm animals across species and breeds. The utility and simplicity of the procedure with acceleration loggers could make the accelerometry technique a worthwhile option in field research and commercial farm use.

Closantel plasma and milk disposition in dairy goats: assessment of drug residues in cheese and ricotta.

Closantel (CLS) is currently used in programs for the strategic control of gastrointestinal nematodes. CLS is extralabel used in different dairy goat production systems. From available data in dairy cows, it can be concluded that residues of CLS persist in milk. The current work evaluated the concentration profiles of CLS in plasma and milk from lactating orally treated dairy goats to assess the residues pattern in dairy products such as cheese and ricotta. Six (6) female Saanen dairy goats were treated orally with CLS administered at 10 mg/kg. Blood and milk samples were collected between 0 and 36 days post-treatment. The whole milk production was collected at 1, 4, 7, and 10 days post-treatment to produce soft cheese and ricotta. CLS concentrations in plasma, milk, cheese, whey, and ricotta were determined by HPLC. The concentrations of CLS measured in plasma were higher than those measured in milk at all sampling times. However, the calculated withdrawal time for CLS in milk was between 39 and 43 days postadministration to dairy goats. CLS residual concentrations in cheese (between 0.93 and 1.8 µg/g) were higher than those measured in the milk used for its production. CLS concentrations in ricotta were sixfold higher than those in the milk and 20-fold higher than those in the whey used for its production. The persistent and high residual concentrations of CLS in the milk and in the cheese and ricotta should be seriously considered before issuing any recommendation on the extralabel use of CLS in dairy goat farms.

Assessment of goat activin receptor type IIB knockdown by short hairpin RNAs in vitro.

BACKGROUND: Targeted knockdown of ACVR2B, a receptor for TGF beta superfamily, has been seen as a potential candidate to enhance the muscle mass through RNAi approach. METHODS: We have evaluated the potential short hairpin RNAs targeting goat ACVR2B in human HEK293T cells and goat myoblasts cells by transient transfection and measured their knockdown efficiency and possible undesired interferon response by quantitative real-time PCR. RESULTS: We observed a significant silencing (64-81%) of ACVR2B in 293T cells with all seven shRNAs (sh1 to sh7) constructs and 16-46% silencing with maximum of 46% by sh6 (p = 0.0318) against endogenous ACVR2B whereas up to 66% (p = 0.0002) silencing by sh6 against exogenously expressed ACVR2B in goat myoblasts cells. Transient knockdown of ACVR2B in goat myoblasts cells by shRNAs did not show significant correlation with the expression of MyoD (r = 0.547; p = 0.102), myogenin (r = 0.517; p = 0.126) and Myf5 (r = 0.262; p = 0.465). As reported earlier, transfection of plasmid DNA induced potent interferon response in 293T and goat myoblasts cells. CONCLUSIONS: The present study demonstrates the targeted knockdown of ACVR2B by shRNAs in HEK293T and goat myoblasts cells in vitro. The transient knockdown of ACVR2B by shRNAs in goat myoblasts did not alter the myogenic gene expression program. However, shRNAs showing significant knockdown efficiency in our study may further be tested for long term and stable knockdown to assess their potential to use for enhancing muscle mass in vivo. As reported earlier, expression of shRNAs through plasmid expression vectors induces potent interferon response raising the concern of safety of its application in vivo.

The effects of insulin and follicle-simulating hormone (FSH) during in vitro development of ovarian goat preantral follicles and the relative mRNA expression for insulin and FSH receptors and cytochrome P450 aromatase in cultured follicles.

The actions of different concentrations of insulin alone or in combination with follicle-stimulating hormone (FSH) were evaluated by in vitro follicular development and mRNA expression of cytochrome P450 aromatase (CYP19A1) and as receptors for insulin (INSR) and FSH (FSHR) from isolated, cultured goat preantral follicles. Goat preantral follicles were microdissected and cultured for 18 days in the absence or presence of insulin (5 and 10 ng/ml or 10 µg/ml) alone or in combination with FSH. After 18 days, the addition of the maximum concentration of insulin to the culture medium reduced follicular survival and antrum formation rates significantly compared to the other treatments. However, when FSH was added to the culture medium, no differences between these two parameters were observed. Preantral and antral follicles from the fresh control as well as from all cultured follicles still presented a normal ultrastructural pattern. In medium supplemented with FSH, only insulin at 10 ng/ml presented oocytes with higher rates of meiosis resumption compared to control, as well as oocytes in metaphase II. Treatment with insulin (10 ng/ml) plus FSH resulted in significantly increased levels of INSR and CYP19A1 mRNA compared to that with other treatments. In conclusion, 10 ng/ml insulin associated with FSH was more efficient in promoting resumption of oocyte meiosis, maintaining survival, stimulating follicular development, and increasing expression of the INSR and CYP19A1 genes in goat preantral follicles.

Assessment of trace elements in animal tissues from Turkey.

In this study, trace element contents of animal tissues were determined by atomic absorption spectrometry after microwave digestion method. The accuracy of the method was confirmed by analysis of standard reference material (NIST SRM 1577b Bovine Liver). Trace element contents in animal tissue samples were found in the range of 98.3-18.2 µg/g (Fe), 2.89-0.26 µg/g (Mn), 23.9-4.54 µg/g (Zn), 0.08-0.01 µg/g (Pb), 32.9-1.66 µg/g (Cu), and 0.32-0.01 µg/g (Cd). The results were compared with literature values. The results obtained for toxic and trace elements in analyzed animal tissue samples were acceptable to human consumption at nutritional and toxic levels.

High rates of mammary tissue protein turnover in lactating goats are energetically costly.

The high energetic demands and metabolism of amino acids (AA) within the lactating mammary gland have been ascribed to the requirements for milk component synthesis and tissue maintenance. Our objective in this work was to assess rates of protein synthesis from several AA so that the energetic costs of tissue maintenance could be better reflected. Lactating goats (n = 4) were given staggered infusions of 5 labeled forms of phenylalanine (Phe) initiated at 30, 12, 9, 6, and 3 h before goats were killed. [5-(13)CH(3)] Methionine (Met), [1-(13)C] leucine, and [1-(13)C] valine were also infused for 30 h, during which time, the glands were milked hourly and arteriovenous flux measurements were performed the last 6 h. A dynamic, compartmental model capable of simulating fluxes of AA through extracellular and intracellular free, slow and fast turnover tissue-bound, and milk protein pools was developed and fitted to the observed data. The udder removed 81% of the Phe present in plasma using 31% for milk protein synthesis and releasing 66% back into plasma. Transamination accounted for 40% of Phe flux in the mammary and transmethylation accounted for a portion of mammary Met flux. Mammary tissue protein synthesis was >300% the value of milk protein synthesis with fractional protein synthesis rates >130%/d. Assuming 4 mol of ATP/mol of peptide bond formed, we estimate that approximately 50% of ATP generated by the lactating mammary glands is used for synthesis of tissue (nonmilk) protein.

Technical Note: Effects of tethering on herbage selection, intake and digestibility, grazing behavior, and energy expenditure by Boer x Spanish goats grazing high-quality herbage.

Twenty-four yearling Boer x Spanish goats were used in a crossover experiment to determine the effects of tethering on herbage selection, intake and digestibility, grazing behavior, and energy expenditure (EE) with high-quality herbage. Four 0.72-ha paddocks of wheat (Triticum aestivum) and berseem clover (Trifolium alexandrium) were grazed in the spring. Each paddock hosted 6 animals, 3 with free movement and 3 attached to a 3-m tether that was moved daily and provided access to an area of 28.3 m(2). One animal of each treatment and paddock was used to determine herbage selection, fecal output, or grazing behavior and EE. Herbage DM mass in tethered areas before grazing averaged 2,649 and 2,981 kg/ha in periods 1 and 2, respectively. The CP concentration in ingesta was greater (P < 0.05; 23.1 and 20.3 +/- 0.82%) for free vs. tethered animals, although in vitro true DM digestion (75.7 and 76.5 +/- 1.20%, respectively) did not differ (P > 0.05) between treatments. Intake of ME based on in vitro true DM digestion and fecal output was greater (P < 0.05) for free vs. tethered animals (12.7 and 10.4 +/- 0.89 MJ/d). No treatment effects were observed (P > 0.05) for time spent ruminating or grazing (405 and 366 +/- 42.5 min/d, respectively), although mean EE was greater (P < 0.05) for free vs. tethered animals (633 and 512 +/- 27.4 kJ/kg of BW(0.75) for free and tethered, respectively), with differences (P < 0.05) between treatments at each hour of the day. Tethering animals may be acceptable to model those with free movement for some measures such as ingesta composition but appears inappropriate for others, such as energy metabolism.

[The correlation analysis of blood protein polymorphism with economic traits in Liaoning new-breeding cashmere goat].

Polymorphism of six blood protein loci from Liaoning new-breeding cashmere goat was studied by using vertical discontinuous polyacrylamide gel electrophoresis(PAGE)and the relationship between blood protein loci to economic traits was analyzed. Economic traits were analyzed by PROC GLM of SAS. And the data were multiple compared. The results showed that EsBB was the favourable genotypes to body weight, and TfBB and Amy1-2 were the favourable genotypes to cashmere yield. They may be regarded as gene marker for marker assisted selection.

Isolation and characterization of goat ovarian aromatase cDNA: assessment of the activity using an intact cell system and placental expression.

Goat ovarian follicles produce estrone and estradiol from androgens. The synthesis of C18 estrogens from C19 androgens requires cytochrome P450 aromatase, but little information about this key enzyme is available in the goat. We report here for the first time the cDNA sequence of the goat ovarian aromatase, the activity of the enzyme in a cell system, and its expression in the term goat placenta. A cDNA library from goat ovarian poly(A)+ RNA was constructed. Human aromatase cDNA was selected as probe to screen the library; several clones were isolated, but none was complete. The longest clone was 3.1 kb long, but it lacked the sequence coding for a few amino acids in the NH(2)-terminal. To obtain the missing sequence, we performed reverse amplification of the cDNA end (RACE). Sequence analysis indicated that goat aromatase possessed a very long 3'-untranslated region ( approximately 1790 bp), and a polyadenylation signal (AATAAA) located at position 3320 downstream from the ATG start codon. The coding region of goat cDNA was inserted in an expression vector and transfected into HEK-293 cells that were cultured in presence of [14C]-androstenedione, steroids extracted and further separated by TLC. The transfected cells efficiently transformed [14C]-androstenedione into estrone. This activity was inhibited by 4-hydroxyandrostenedione. We also investigated the presence of mRNA for P450 aromatase in the goat placenta, using reverse transcription-polymerase chain reaction (RT-PCR) and primers derived from the cDNA ovarian sequence and confirmed the expression of the mRNA in term placenta.

Eprinomectin in goat: assessment of subcutaneous administration.

Eprinomectin is only available as a topically applied anthelmintic for dairy cattle. To determine whether eprinomectin can be administered in the goat as an injectable formulation, it was subcutaneously delivered to six goats and measured in the plasma at different times after administration. The area under the concentration-time curve (AUC) reported after subcutaneous administration of 0.2 mg kg(-1) eprinomectin (68.5+/-23.2 ng day(-1) ml(-1)) was similar to the AUC previously reported for goats after a pour-on administration of 0.5 mg kg(-1) eprinomectin. Thus, our results clearly show that subcutaneous administration is 2.5 times more effective than pour-on administration, in terms of amount of drug present in the organism. This work should encourage the development of a subcutaneous formulation of eprinomectin and should contribute to defining optimal therapeutic conditions for goat anthelmintic treatment.

Assessment of molasses-urea blocks for goat and sheep production in the Sultanate of Oman: intake and growth studies.

The goal of this study was to develop a molasses-urea block (MUB) for purposes of supplementing trace minerals to domestic ruminant livestock in Oman. To accomplish this, the utility of molasses and date syrup as fermentable energy sources, of straw, date flakes and wheat bran as fibre sources, and of cement and lime as binders were evaluated. The proportion of cement needed for adequate hardening of the block was also studied. Molasses- and date syrup-based blocks hardened equally well. However, the higher cost of date syrup precluded its use. Wheat straw yielded a low-density block that hardened slowly. Date fibre retained moisture and hardened extremely slowly. Wheat bran-based blocks hardened quickly and yielded dense blocks. Hence, wheat bran was judged to be the superior source of fibre. Lime did not effectively bind the blocks. A cement content of 15% allowed hardening of the blocks within 2-3 weeks. A level of 10% cement in the block reduced the hardening rate by about 50%. Sheep and goats consumed both the straw- and wheat bran-based blocks but at different rates. Consumption of the straw-based block by sheep ranged from 50 to 179 g/head per day, whereas the denser wheat bran-based block was consumed at a rate of 8-20 g/head per day. Consumption of the straw-based block by goats was low (8 g/head per day) compared to that of wheat bran-based blocks (16-24 g/head per day). On the basis of the intake of the bran-based block by sheep, a block was designed that would provide approximately 50% of an animal's trace mineral requirements per day. This block consisted of 45% molasses, 10% urea, 5% trace minerals, 2.5% NaCl, 22.5% wheat bran and 15% cement. Sheep consuming this block gained more weight than sheep fed a conventional mineral block or sheep receiving no mineral supplementation. MUBs are inexpensive (9.5 US cents/kg). We conclude that MUBs have utility for providing trace elements in ruminant diets.

Energy expenditure by dry and lactating Alpine does estimated by entry rate of carbon dioxide.

Four dry and four lactating (wk 6 of lactation) Alpine does [50.5 +/- 2.2 and 45.9 +/- 2.2 kg of initial body weight (BW), respectively] that consumed a 67% alfalfa diet for ad libitum intake were used 1) to compare estimates of CO2 entry rate (via continuous infusion of NaH13CO3 into the peritoneum) based on continuous saliva collection with simpler, more reliable, and less laborious sampling of urine, serum, or breath; 2) to determine effects of lactation state on CO2 entry rate and total heat production, and 3) to compare three published equations used to predict total heat production (megajoules per kilogram of BW0.75) from CO2 entry rate (liters of CO2 per kilogram of BW0.75) based on saliva samples. The entry rate of CO2 calculated from 13CO2 concentration in saliva was less variable than that determined from urine, serum, or breath samples (SE = 2.0, 4.7, 4.2, and 5.6 L/kg of BW0.75 per d, respectively); therefore, saliva samples were used to estimate total heat production. The entry rate of CO2 was 34% greater for lactating does than for dry does. Total heat production calculated from each equation was linearly related to metabolizable energy intake. Estimated heat production during feed deprivation was 0.196, 0.431, and 0.311 MJ/kg of BW0.75 per d, and estimated metabolizable energy used for maintenance was 475, 755, and 818 kJ/kg of BW0.75 per d for the three published equations. In conclusion, saliva appeared to be more suitable to estimate CO2 entry rate than did urine, serum, or breath; CO2 entry rate was appreciably greater for lactating does than for dry does; and published equations to predict total heat production from CO2 entry rate warrant careful consideration.