Lamb Serum Research Articles

Serum thyroid hormones and performance of offspring in ewes receiving propylthiouracil with or without melatonin

Two experiments were conducted during mid-gestation to examine effects in ewes of propylthiouracil (PTU) treatment alone or with melatonin on serum thyroid hormones, postpartum reproduction, and lamb performance. In the first experiment, beginning on day 0 (first day of treatment when all animals were 72.2 ± 0.9 days of gestation), ewes received daily treatments (gavage) consisting of either 0 mg ( n = 6) or 40 mg ( n = 6) PTU/kg body weight/day for 15 days. After 15 days, the 40 mg dosage was decreased to 20 mg/kg body weight for an additional 20 days (35 days of PTU). Serum thyroxine (T4) did not differ ( P > 0.10) between groups through day 4; but on day 5, control females had a serum value of 67 ng/ml compared with 46 (±5) ng/ml for PTU-treated ewes ( P = 0.02). On the last day that 40 mg of PTU was administered, serum T4 averaged 67 and 7 (±5) ng/ml ( P < 0.001) in the two respective groups. Serum T4 remained low and was 80 and 1 ng/ml ( P < 0.001) in control and treated ewes on day 34. Serum T4 rose gradually after PTU but remained different from that observed in control ewes through day 48. Lambs from control and treated ewes had similar ( P = 0.46) T4 values at birth but lambs from PTU-treated ewes had lower ( P = 0.03) birth weights than did those from control ewes. Serum progesterone (P4) after parturition indicated a lack of cyclicity in all ewes. In the second experiment, beginning on day 0 (76.8 ± 4.7 days of gestation), ewes received PTU as in Experiment 1. In addition, after 15 days of PTU, melatonin was given (i.m. injections at 5 mg/day) for 30 days. Propylthiouracil decreased ( P ≤ 0.05) serum T4 on days 25 through 41 of the treatment period. Serum T3 was lower ( P < 0.05) in PTU-treated ewes from day 8 through the end of PTU administration. Postpartum P4 was below 1 ng/ml on all days indicating acyclicity. Lamb body weight and serum IGF-I were similar ( P > 0.60) for lambs born to control and treated ewes. Female offspring of PTU + melatonin-treated dams reached puberty, became anestrus, and returned to cyclicity at similar ( P > 0.10) times to contemporary ewe lambs. Results indicate that 40/20 mg PTU alone or with melatonin does not induce cyclicity after lambing in spring lambing ewes and has little effect on offspring performance.

Lamb serum vitamin E and immunoglobulin G concentrations in response to various maternal mineral and iodine supplementation regimens

AbstractThe objective of the first of three studies (experiment 1) was to evaluate the effects of supplementing the pregnant ewe diet with high levels of minerals for the final 4 weeks of gestation on lamb serum vitamin E and immunoglobulin G (IgG) concentration at 24 h post partum. Sixty ewes were allocated to one of two treatments (no. =30) and offered a basal diet fortified with 52 g of supplementary minerals/vitamins containing Ca, Mg, Na, P, Co, I, Mn, Se, Zn and vitamin E (M1) for the final 4 weeks of pregnancy or no mineral/vitamin supplement was added (C1). Immediately after birth, lambs were allocated to one of four treatments in a 2×2 factorial design with the factors being ewe treatment (± minerals) and colostrum origin (± minerals). Irrespective of the colostrum origin, the progeny of the mineral supplemented ewes had lower serum vitamin E and IgG concentrations and IgG absorption efficiency at 24 h post partum (P&lt;0·001). In a second study (experiment 2), 44 ewes were allocated to one of four treatments (no. =11) in week 13 of pregnancy and offered a basal diet in addition to one of the following mineral/vitamin fortifications: 0 g (C2), 52 g of a mineral supplement as in experiment 1 (M2), a supplement as in M1 but with iodine excluded (-I), iodine only offered at a rate (40 mg per ewe per day) equivalent to 52 g of minerals (IO). When iodine was offered either M2 (P&lt;0·01) or (IO) (P&lt;0·001) it resulted in the progeny having a reduced serum vitamin E concentration at 24 h post partum. The -I progeny had higher serum vitamin E concentrations at 24 h post partum than the progeny of treatments C2, M2 (P&lt;0·01) and IO (P&lt;0·001). In a third study (experiment 3) the effect of incremental levels of iodine supplementation on lamb serum vitamin E concentration was studied. Forty-eight ewes were allocated to one of four treatments (no. =12) and offered the following levels of supplementary dietary iodine: 0 mg (C3), 8·9 mg (LI), 17·7 mg (MI) or 26·6 mg (HI) for the final 6 weeks of pregnancy. There was a linear (P&lt;0·001) reduction in lamb serum vitamin E concentration as maternal iodine supplementation increased. We conclude that when ewes are offered high levels of iodine during the final 6 weeks of gestation their progeny are pre-programmed in utero to have a reduced ability to absorb colostral vitamin E. These findings support our earlier studies and provide further evidence of the need to reduce the current toxicity values for iodine. for the ewe in late pregnancy.

The effects of mineral supplementation to ewes in late pregnancy on colostrum yield and immunoglobulin G absorption in their lambs

One hundred and eight ewes were allocated to nine treatments ( n = 12) to determine the effects of various mineral/vitamin supplements during the final 6 weeks of pregnancy on colostrum production and quality, lamb serum immunoglobulin G (IgG) concentration and IgG absorption efficiency. Ewes were offered grass silage ad libitum supplemented with 400 g/ewe/day of concentrate from days 98 to 133 of gestation and thereafter with 600 g/ewe/day until parturition. Ewes received one of the following supplements: C, no supplement; M, mineral/vitamin supplement (Ca, P, Mg, Na, Zn, Se, I, Mn, Co and vitamin E (Vit. E)); Zn, mineral/vitamin supplement excluding zinc; P, excluding phosphorous; Se, excluding selenium; I, excluding iodine; Mg, excluding magnesium, Mn, excluding manganese; Co, excluding cobalt. The ewes were milked at 1, 10 and 18 h post partum and the colostrum was fed back to the lambs. The progeny of ewes receiving supplementary iodine (M, Zn, P, Se, Mg, Mn, Mg and Co) had lower serum IgG concentrations and IgG absorption efficiencies at 24 h than the progeny of ewes not receiving iodine supplementation (C and I; P < 0.001). We conclude that high level dietary inclusion of iodine results in a reduced lamb serum IgG concentration and efficiency of colostral IgG absorption.

The effect of varying levels of mineral and iodine supplementation to ewes during late pregnancy on serum immunoglobulin G concentrations in their progeny

AbstractThree experiments were carried out to evaluate the effects of varying levels of mineral and iodine supplements when offered to ewes in late pregnancy on lamb serum immunoglobulin G (IgG) concentrations. In experiment 1, 44 individually housed ewes were allocated to one of four treatments (no. = 11) and offered a basal diet of grass silage ad libitum which was supplemented with 500 g/day of a concentrate (190 g/kg of crude protein (CP)), in addition to mineral/vitamin fortification at the rate of 0 g (C), 17.3 g (LM), 34.6 g (MM) or 52.0 g (HM) per day for the final 7 weeks of pregnancy. The mineral/vitamin supplement contained Ca, P, Na, Mg, Mn, Se, I, Co, Mn and vitamin E. The ewes were milked at 1 h, 10 h and 18 h postpartumand measured quantities of colostrum, proportional to lamb birth weight, were fed back to the lambs via a stomach tube. Treatment had no effect on total colostrum yield or total IgG yield to 18 h postpartum(P&gt; 0.05). There was a linear decrease in serum IgG concentration and IgG absorption efficiency as mineral supplementation increased (P&lt; 0.001). In experiment 2, which was carried out in conjunction with experiment 1, 44 ewes were allocated to four treatments (no. = 11) and offered the same basal silage/concentrate diet as in experiment 1, in addition to receiving one of the following supplements : (C) control, as in experiment 1; (HM), as in experiment 1; (−I), ewes offered the same mineral/vitamin supplement as HM but with iodine excluded; (I0), ewes offered a daily mineral supplement of iodine only at a level of 40 mg per ewe, equivalent to the iodine inclusion in the 52 g of minerals offered in HM. The iodine-supplemented progeny (HM and IO) had lower (P&lt; 0.001) serum IgG concentrations and higher soil scores (P&lt; 0.05) than the C and −I progeny. In experiment 3, the effects of varying levels of iodine supplementation when offered to ewes during the final 6 weeks of pregnancy on lamb serum IgG values were examined. Forty-eight individually housed ewes were allocated to one of four treatments (no. = 12) and offered grass silage ad libitum, which was supplemented initially with 500 g of a concentrate (140 g/kg of CP) from days 99 to 130 of gestation and then replaced with 700 g/day of a concentrate (180 g/kg of CP) from day 131 of gestation until lambing. In addition, the diet of each ewe was supplemented on a daily basis with iodine at the rate of 0 mg (C), 8.9 mg (LI), 17.7 mg (MI) or 26.6 mg (HI). There was a negative linear reduction in serum IgG concentration and IgG absorption efficiency as maternal dietary iodine supplementation increased (P&lt; 0.001). We conclude that supplementation of the ewe's diet in late pregnancy with 17.3 g of a mineral supplement as formulated in the current experiment lowers the lamb's ability to absorb colostral IgG, and offering only the iodine component of this mineral supplement, at a level which approximates to about one third of currently quoted toxicity levels, will result in reduced serum IgG concentration in the lamb. These findings suggest the need to re-examine current toxicity values for iodine.

The effect of timing of mineral supplementation of the ewe diet in late pregnancy on immunoglobulin G absorption by the lamb

AbstractTwo experiments were carried out to examine the effects of the timing and duration of mineral supplementation of the ewe's diet in the final 6 weeks of gestation on immunoglobulin G (IgG) absorption by their progeny. In experiment 1, 60 single-bearing ewes were allocated to one of four dietary treatments (no. = 15) and offered a basal diet of grass silage ad libitum, containing 50 g/kg molassed sugar-beet pulp, which was supplemented with concentrates for the final 7 weeks of pregnancy and were additionally provided with a daily mineral/vitamin supplement for the final 6 weeks (W-6), 4 weeks (W-4), 2 weeks (W-2) or no mineral/vitamin supplement, (control; W-0). The supplement contained Ca, P, Na, Mg, Mn, Zn, Se, Co, I and vitamin E and was offered at the daily rate of 48 g per ewe. The ewes were milked at 1, 10 and 18 h postpartumand measured quantities of colostrum, proportional to birth weight were fed back to the progeny via a stomach tube. At each milking, colostrum yield was recorded and colostrum samples taken to determine the concentration and yield of IgG. Treatment had no effect (P&gt; 0.05) on the yields of colostrum or IgG to 18 h postpartum. The efficiency of IgG absorption was lower (P&lt; 0.001) in the progeny of ewes who received supplementary minerals (W-6, 0.069, W-4, 0.078, W-2, 0.072, W-0, 0.261; s.e. 0.0244.P&lt; 0.001) regardless of the duration of the mineral/vitamin supplementation period and this resulted in a reduced concentration of IgG in the lamb's serum. In experiment 2, 40 twin-bearing ewes were allocated to one of four dietary treatments (no. = 10) and offered a basal diet of grass silage ad libitum which was supplemented initially with 500 g of a concentrate containing 140 g crude protein (CP) per kg from day 98 to 133 of gestation and then replaced with 700 g/day of a concentrate containing 180 g/kg CP from day 134 of gestation until lambing, in addition to one of the following mineral/vitamin supplementation treatments : no supplementary minerals, W0 (control); 48 g of supplement per ewe per day in weeks 6 and 5 pre- partum (W6–5), or weeks 4 and 3 pre-partum (W4–3), or for the final 2 weeks pre-partum (W2–1). The ewes were milked and the lambs fed as in experiment 1. Again, treatment had no effect (P&gt; 0.05) on the yields of colostrum or IgG to 18 h postpartum. When ewes were offered the mineral/vitamin supplement in the final 2 weeks of gestation their progeny had a lower (P&lt; 0.01) serum IgG concentration (4.6 g/l) than in the control treatment (14.0 g/l) or when the supplement was offered either in weeks 3 and 4 (11.3 g/l) or weeks 5 and 6 pre-partum (14.3 g/l). IgG absorption efficiency followed the same pattern as lamb serum IgG concentration. We conclude that supplementation of the ewe's diet at the level used in these studies for the final 2 weeks of pregnancy results in the production of offspring with a reduced ability to absorb colostral IgG. Furthermore, in order for this impairment of the IgG absorptive ability of the lamb to manifest itself the supplementation must occur for the final 2 weeks of gestation and supplementation for a 2-weekly period earlier in gestation will not elicit the same effect.

The effects of offering mineral blocks to ewes pre-mating and in late pregnancy on block intake, pregnant ewe performance and immunoglobulin status of the progeny

AbstractTwo experiments were carried out to quantify the intake of mineral blocks by ewes in group- and individually fed situations, and to examine the effects of mineral block intake on food and water intake, colostrum production and lambs' immunoglobulin G (IgG) absorption when ewes are individually housed and offered maize or grass silage with a concentrate supplement. In experiment 1, mineral blocks were offered to 359 ewes either when grazing at mating time (no. = 200) or, when indoors in the last 4 or 7 weeks of pregnancy, the latter as either twin-bearing ewes that were group-fed (no. = 18) or individually fed (no. = 27) or single-bearing ewes that were group-fed (no. = 114). Block intake was measured on a weekly basis. In experiment 2,a2X2 X 2 factorial design was used to compare the effects of forage (grass or maize silage), restricted mineral block access and added minerals/vitamins in the concentrate on food and water intakes, colostrum production and immunoglobulin absorption by the lamb using 64 twin- bearing ewes that were individually housed. Grass silage and maize silage were offered ad libitum, concentrates were offered at a flat rate of 400 g per head per day. Mineral blocks were offered to ewes for 3 h/day. Following lambing, the ewes were hand milked at 1,10 and 18 h post partum. Colostrum samples were assayed for immunoglobulin G (IgG) content. Lambs were blood sampled at 24 h old to determine serum IgG value. In experiment 1, mean daily mineral block intake per ewe was lowest at mating time (19 g) and highest when ewes were individually housed (194 g). In experiment 2, intakes of dry matter(DM) and energy were higher (F &lt; 0.05) in the maize silage treatments. Similarly, when ewes had access to mineral blocks they had higher (P &lt; 0.05) intakes of DM, energy and protein in addition to having a higher water intake (2.24 v. 0.771 per ewe per day; s.e. 0.139; P &lt; 0.01). The mean total colostrum yield to 18 h post lambing at 1734 ±98.0 ml was unaffected by any of the treatments. When ewes had access to mineral blocks their lambs had lower (6.8 v. 18.8; s.e. 1.48; P &lt; 0.01) serum IgG values and the efficiency of IgG absorption from the colostrum into the blood stream was reduced (0.097 v. 0.247; s.e. 0.0214; P &lt; 0.01). In conclusion, the data show that there is wide variation in mineral block intake in different situations and that intake of some minerals can exceed toxic values. Additionally, when individually fed pregnant ewes have access to blocks for just 3 h/day, there is a significant increase in water intake and a dramatic reduction in lamb serum IgG concentration and in the efficiency of absorption of colostral IgG into the blood. We suggest that while mineral blocks can confer advantages in specific situations, there is the need to revisit their formulation and to further research the mode of action responsible for the compromised IgG absorption.

Macroelements concentration in the osseous tissue of caudal vertebrae in domestic sheep lambs and of mandibular bone in roe deer bucks coming from the northern and the southern region of Western Pomerania in Poland

Abstract. The aim of the studies was to compare Na, K, Ca, Png and Mg concentrations in the blood serum of lambs coming from the northern and the southern region of Western Pomerania, as well as to compare the concentration of these elements in the osseous tissue of caudal vertebrae in sheep lambs and of mandible in roe deer bucks populating the areas of the same agrocenoses – cultivated fields and meadows. The studies were carried out in the same year on the blood serum and the osseous tissue of the 4th and 5th caudal vertebrae of 99-days-old Polish Merino lambs (± 2 days) of both sex and on the mandibular osseous tissue of 62 roe deer bucks (Capreolus capreolus) of an "ecological field population". Fifty lambs, with the average body weight of 7.26 kg ± 1.49, came from a fold in the coastal zone of the Western Pomeranian Province (53°59' N; 15°18' E), and 49 lambs, with the average body weight of 7.64 kg ± 1.87, from an area far removed by approximately 130 km to the south (53°25' N; 14°81' E). The feeding of lamb dams was standardized. In the blood serum of lambs from the north, higher concentrations of K (P ≤ 0.05) and Ca, Png and Mg (P ≤ 0.01) were recorded, as well as a lower concentration of Na (P ≤ 0.05). The osseous tissue of caudal vertebrae of these lambs contained significantly less Na, Ca, Png and Mg (P ≤ 0.01) and more K (P ≤ 0.01) compared to the lambs from the south. The age of bucks was not a source of variation for the content of examined macroelements in the osseous tissue of their mandibles. Higher concentration of Ca (P ≤ 0.01) was recorded in the mandibular osseous tissue of bucks aged 1–2 and 3–5 years compared to similar ones from the southern part. The concentration of Mg in the osseous tissue of bucks aged 3–5 and 6–9 years was significantly lower compared to individuals from the south. The results of the own studies showed significant differences in the abundance of the blood serum and the osseous tissue of young lambs in examined macroelements according to the area of Western Pomerania region. One may not exclude that the source of that variation is geological substrate of agrocenoses, being a food base of domestic ruminants. Higher concentration of calcium in the mandibular osseous tissue of bucks from the north compared to animals from the south confirms the fact of significant effect of the natural intensive light with limited abundance of substrate in that element on its concentration in organism. On the other hand, its lower concentration in the osseous tissue of lambs from that area points to the necessity of supplementing their dams in that element during pregnancy. These results prove simultaneously the food selectivity of roe deer and their ability to unconstrained supplementation of possible deficiencies, which may serve as a recommendation for ecological agriculture.

The effects of mineral-block components when offered to ewes in late pregnancy on colostrum yield and immunoglobulin G absorption in their lambs

AbstractNinety twin-bearing ewes were given food individually and allocated to five (no. = 18) treatments in order to determine the effects of supplementing their diet in late pregnancy with mineral-block components on colostrum production, lamb serum immunoglobulin G (IgG) concentration and colostral IgG absorption. Ewes were offered grass silage ad libitum, supplemented with 400 to 500 g per ewe per day of concentrates from day 99 of gestation, in addition to receiving one of the following supplements: C, (control) no supplement; B, mineral block; ML, liquid molasses; MN, granular minerals; ML + MN, liquid molasses and granular minerals. The experiment commenced on day 99 of gestation. Ewes were milked at lh, 10 h and 18 h post lambing and all lambs were fed measured quantities of colostrum, proportionate to birth weight, via stomach tube. Treatment had no effect (P &gt; 0-05) on colostrum yield at lh, 10 h or 18 h post partum or on total colostrum yield to 18 h post partum. Ewes offered molasses (ML) or molasses plus minerals (ML + MN) had a lower colostral IgG concentration at lh post lambing than the control ewes (C) (P &lt; 0-05). Ewes offered molasses (ML) also had a lower colostral IgG concentration than the control (C) at 10 h post partum (P &lt; 0-05). Treatment had no effect on total IgG yield to 18 h post partum. When ewes were supplemented with minerals in any combination, with or without molasses (B, MN, ML + MN) it resulted in lambs having an impaired ability to absorb colostral IgG. Lambs from treatments B, MN and ML + MN had significantly poorer efficiency of colostral IgG absorption than lambs born to control ewes (C) or molasses (ML) supplemented ewes (P &lt; 0-001). This in turn resulted in the progeny of mineral supplemented ewes (B, MN or ML + MN) having lower serum IgG concentration at 24 h post partum than either the control (C) or the molasses treatments (ML) (P &lt; 0-001). When ewes were supplemented with molasses only (ML) lamb serum IgG content at 24 h was lower than in lambs born to control (C) ewes (P &lt; 0-05) but this was as a result of a lower intake of colostral IgG (P &lt; 0-05) and not a result of reduced IgG absorption efficiency. In conclusion, the data show that when ewe mineral intake is high in late pregnancy, as was the case in the current experiment, lamb serum IgG concentration and colostral IgG absorption efficiency are reduced. Further work is required to determine which component of the mineral formulation is responsible for this reduced IgG absorption efficiency and the mechanism through which this impaired efficiency operates.

Lethal effects of freezing Echinococcus multilocularis eggs at ultralow temperatures.

Methods for killing Echinococcus multilocularis eggs within stool or intestinal samples, without damaging the diagnostic value of the sample, would significantly reduce the risk of animal health providers acquiring alveolar hydatid disease. The first objective of this study was to determine whether E. multilocularis eggs located in fox intestines can survive storage at -70 C for at least 4 days. Results showed that none of 72,000 E. multilocularis eggs remained infectious to defined strains of mice under these conditions, yet, similar eggs recovered from nonfrozen carcasses stored at 4 C for the same time period were viable. The structural identities of adult worms and eggs were not significantly altered by the freezing and thawing processes. These results indicate that ultracold temperatures can be used to kill or inactivate E. multilocularis eggs, making them safe to handle when diagnosing this parasite in definitive hosts. The second objective of this study was to determine whether E. multilocularis eggs could survive freezing to -70 C if commonly used cryopreservation protocols were used. The use of the cryoprotectant solution, 5% dimethyl sulfoxide-35% saline-60% lamb serum, with a -1 C/min freezing rate was unable to prevent the eggs from being killed by freezing to -70 C. Rapid cooling by plunge freezing into liquid nitrogen was also lethal to E. multilocularis eggs. Only a few of the many potential cryopreservation protocols were tested in this study, so it is not yet possible to completely rule out the possibility of preserving these eggs at ultralow temperatures, but it does indicate that temperatures below -70 C are lethal to eggs even under favorable storage conditions.

Red cell agglutination: the first description by Creite (1869) and further observations made by Landois (1875) and Landsteiner (1901).

Red cell agglutination: the first description by Creite (1869) and further observations made by Landois (1875) and Landsteiner (1901).

Inhibition of nitric oxide enhances ovine lentivirus replication in monocyte-derived macrophages

Ovine lentivirus (OvLV) also known as maedi-visna virus, infects and replicates primarily in macrophages. This investigation examined the role of nitric oxide in the replication of OvLV in cultured macrophages. Peripheral blood mononuclear cells were collected from OvLV-free sheep and cultured in Teflon coated flasks at a high concentration of lamb serum. The cells were subsequently infected with OvLV strain 85/34. OvLV replication was assessed under different experimental treatments by comparison of reverse transcriptase (RT) activity in culture supernatant. Cultures that were treated with exogenous nitric oxide via S-nitroso-acetylpenicillamine did not have altered levels of RT activity compared to cultures treated with the inactive control compound, acetylpenicillamine. However, blockage of nitric oxide production by treatment with aminoguanidine, a competitive inhibitor of inducible nitric oxide synthase (iNOS), led to a significant rise in RT activity. This rise in RT activity was partially reversed in aminoguanidine treated cultures by l-arginine, the normal substrate for iNOS. Finally, the number of viral antigen producing cells was also quantified after aminoguanidine treatment and found to be significantly higher than untreated cultures. Collectively, these results indicate that nitric oxide is a negative regulator of OvLV replication in macrophages.

Genetic and environmental factors of macroelements concentration in blood serum and osseous tissue of lambs in north-west Poland

Abstract. The aim of the study was to determine the concentration of Na, K, Ca, Pig and Mg in blood serum and osseous tissue of the lambs of various breeds at age of 14 days. The studies were carried out on 221 lambs in various sheepfolds in Northwest Poland. The material for the studies comprised the blood serum and osseous tissue ash of the 4th and 5th caudal vertebrae. The values of macroelement concentrations in osseous tissue were expressed in mmol/l in 1g of dry matter. The highest (P ≤ 0.01 and P ≤ 0.05) Na concentration was found in the serum of Ile de France lambs (152.31 mmol/l ± 7.50), of K and Pig in the Kent lambs (5.52 mmol/l ± 0.48; 3.37mmol/l ± 0.51), and Ca and Mg — in the Polish Merino lambs (2.42 mmol/l ± 0.27; 1.25 mmol/l ± 0.09). The Ca/P ratio was similar (0.70 ± 0.09), whereas the Ca/Mg ratio was the highest for the Polish Merino lambs (2.35 ± 0.27). Osseous tissue Na concentration was similar (2.25mmol/l ± 0.43). The highest osseous tissue concentration of K was found in the lambs: Kent and Polish Merino (1.29 mmol/l ± 0.23) and Ile de France (1.36 mmol/l ± 0.27). The lowest Ca was recorded in the lambs Kent and Merino (9.50 mmol/l±1.72), the highest – in Blackheaded (19.74 mmol/l ±2.02). The lowest Pig concentration was found in the osseous tissue of the Polish Merino (9.70 mmol/l ±1.76). The concentration of magnesium ranged between 0.83 mmol/l ± 0.11 in the serum of Kent lambs and 1.02 mmol/l ± 0.15 in the serum of the Leine lambs. The lowest Ca/P ratio was observed in the osseous tissue of the Kent lambs (0.50 ± 0.10), whereas the highest was found in the Ile de France lambs (1.17 ± 0.17). A wide range (P ≤ 0.01) of the Ca/Mg ratio were recorded, from 11.40 ±1.72 in Kent to 20.37 ± 2.09 in Blackheaded. Basing on the concentrations of Na, K, Ca, Pig and Mg in the blood serum of 14-day-old lambs, no conclusions should be drawn as to the content of the elements in the osseous tissue.

The requirements of calcium by Awassi ewes at early lactation

The proper development and growth of the fetus and newborn lambs requires an adequate transport of nutrients across the placenta during late gestation and the mammary gland during early lactation. The effect of calcium (Ca) supplementation as calcium carbonate (CC) and injection of Vitamin AD 3E (75 000 IU) on Awassi ewe productivity at early lactation and the growth of newborn lamb was studied. Forty Awassi ewes, 3.5±1 years old, weighing 61±6.4 kg BW at parturition were selected and assigned randomly to four treatment groups based on ration supplementation and vitamin injection: group 1 received 1.4% CC in the ration; group 2 received 2.4% CC in the ration; group 3 received 1.4% CC in the ration plus two intramuscular doses of Vitamin AD 3E; group 4 received 2.4% CC in the ration plus two intramuscular doses of Vitamin AD 3E. Vitamin injections in groups 3 and 4 were given 15 and 30 days postpartum. The experiment started in January and ended in March. Blood and milk samples were collected from dams and lambs every 20 days and the animals were weighed every 15 days. Milk and blood samples were prepared and analyzed for Ca concentrations by atomic absorption spectrophotometry (AAS). Ca concentrations in blood serum of ewes and newborn lambs for group 4, at 60 days postpartum were higher (8.9 and 9.6 mg/dl; P<0.10) compared to other groups. A significant ( P<0.05) increase in lambs average body weight gain (g per day) was detected during the last 15 days before weaning in groups 2 and 4 (268.3 and 269.7 g per day, respectively) compared to groups 1 and 3 (230.1 and 21 6.4 g per day, respectively). Moreover, a significant ( P<0.05) increase in milk ash percentage was observed 60 days postpartum in groups 2 and 4 (1.23 and 1.1%, respectively) compared to groups 1 and 3 (1.02 and 0.96%, respectively). No significant differences were detected on milk yield and body weight between the four ewe groups as a result of treatments. Results indicated that feeding 2.4% CC with or without Vitamin AD 3E to Awassi ewes at parturition improved their blood serum Ca and the average body weight gain of their lambs.

Leptin concentrations in periparturient ewes and their subsequent offspring.

Leptin is an adipocyte-derived hormone that suppresses feed intake and increases energy expenditure. Leptin is also involved in regulating body temperature. Thus, the presence of leptin in milk, which can be absorbed through the gut of neonates immediately after birth, may aid in the survival of neonates born in cold weather. Our objectives were to determine the temporal relationship between concentrations of leptin in postpartum ewe blood serum and ewe milk serum, and to determine whether ewe blood and milk serum leptin concentrations were correlated with concentrations of leptin in lamb blood serum in their off-spring. Approximately 1 wk before the expected date of lambing, blood samples, weights, and body condition scores (BCS; 0 to 5 scale) were collected from 27 mixed-parity ewes. Following parturition, ewe blood and milk samples were collected within 2 h of parturition (d 0), 12 h (d 0.5) and 24 h (d 1) after parturition, again on d 5, and weekly thereafter until d 47. Lambs were blood-sampled and weighed within 2 h of parturition (d 0), bled daily until d 5, and bled and weighed weekly thereafter to d 47. Prior to lambing, ewe blood serum leptin was positively correlated with congruent BCS (r2 = 0, 10, P = 0.06), but not weight (P = 0.14). Following parturition, ewe blood serum leptin was positively correlated with BCS, weight, and milk serum leptin (r2 = 0.14, P < 0.0001, r2 = 0.12, P < 0.0001, and r2 = 0.028, P = 0.04). Leptin in milk serum was correlated with ewe weight (r2=0.05, P = 0.007) but not ewe BCS (P = 0.7); however, concentrations of leptin in both ewe blood and milk serum varied with day of lactation (P = 0.0001), being maximal within 24 h of parturition and declining to nadir concentrations by d 5. Leptin in lamb serum was correlated with milk serum leptin, (r2 = -0.05; P = 0.001), but not ewe blood serum leptin (P = 0.5). Concentrations of leptin in lamb serum increased from birth to d 5 and declined thereafter to nadir concentrations by d 19. Elevated concentrations of leptin in milk during the early stages of lactation may provide a mechanism for thermoregulation, satiation, and homeostatic endocrine control in the neonate.

Serum antibody response and Cryptosporidium parvum oocyst antigens recognized by sera from naturally infected sheep

The response of specific serum immunoglobulins (IgG, IgM and IgA) and the major antigens of Cryptosporidium parvum recognized by these isotypes were investigated by using enzyme-linked immunosorbent assay and immunoblot techniques in lambs and ewes naturally infected throughout an outbreak of cryptosporidiosis. Serum samples were collected from 20 lambs the first day they showed diarrhoea (D1), and Days 11 and 22, in addition to single serum samples from 17 of their dams. Serum anti- C. parvum IgG, IgM and/or IgA antibodies were detected in lambs as early as Day 1. Levels of IgM antibodies remained steady from D1 to D11 and increased at D22, whereas the IgG response decreased from D1 to D11 and subsequently increased. In contrast, IgA antibodies rapidly fell from D1 and all lambs were seronegative at D11 and D22. The highest levels of specific antibodies were detected in sera from ewes. In fact, all ewes were seropositives for IgM and IgA isotypes and most (16/17) showed positive levels of IgG. Four protein fractions (37–39, 42–48, 51–57 and 60–69 kDa) were the most frequently recognized by IgG and IgM from lamb sera. A low molecular weight fraction (12–14 kDa) reacting with IgG and IgA in most lamb sera was scarcely recognized by IgM and three broad bands were frequently recognized by IgA antibodies (23–25, 51–57 and 90–95 kDa). The recognition pattern of 23–25 kDa peptides by IgA from lamb sera clearly increased with the age. Peptides of 42–48, 51–57, 60–69 and 71–78 kDa were most frequently recognized by IgG and IgM from ewe sera. In relation to IgA antibodies from ewe sera, a frequent immunoreactivity was found with proteins in the intervals between 12 and 22 kDa as well as between 32 and 34 kDa and practically all sera reacted with fractions from 42 to 95 kDa.

Mycoplasma conjunctivae infection is self-maintained in the Swiss domestic sheep population

Bacteriological and serological investigations were performed to assess whether the domestic sheep population is a reservoir of Mycoplasma conjunctivae in Switzerland. Among a sample of 69 sheep showing clinical signs of infectious keratoconjunctivitis (IKC) in three Swiss cantons, M. conjunctivae was identified 53 times (76.8%). A commercially prepared indirect ELISA was used to detect M. conjunctivae antibodies in 674 sera of adult sheep. We analysed a stratified random sample of 123 sheep herds from 25 out of the 26 Swiss cantons. At least one positive animal was detected in 89.4% of the herds. In positive herds ( n=110), 57.1% of the individual animals tested positive. To assess the importance of sheep’s age in the spread of M. conjunctivae, 209 sera of adult sheep and 93 lamb sera among eight sheep herds were analysed using the indirect ELISA. Seroprevalence in 2–6-month-old lambs was 50.5%, indicating that the IKC agent is spread in sheep flocks during raising. Lambs experimentally infected with M. conjunctivae carried the agent for 8 and 23 weeks, respectively, depending on the strain used for challenge. We conclude that the M. conjunctivae-infection is endemic and self-maintained in the domestic sheep population in Switzerland.

Specific immunoglobulins in serum of newborn lambs fed with a single dose of colostrum containing anti-peroxidase IgG

The apparent efficiency of absorption and the decrease of specific colostral IgG after its passage into the blood stream were determined in newborn lambs fed with a single dose of colostrum containing anti-peroxidase IgG at 30 minutes, 12 hours and 24 hours after birth. When colostrum was given at 30 minutes after birth, a value of 16¶9 ° 4¶0 per cent of anti-peroxidase IgG ingested appeared in lamb circulation. This percentage was reduced to 9¶8 ° 0¶8 per cent when the feeding was done at 12 hours after birth and no specific IgG was detected in lambs fed at 24 hours after birth. The concentration of anti-peroxidase IgG in lambs’ serum declined quickly within 96 hours of age to about 48 per cent of the initial value, and afterwards the level decreased slowly reaching a value of 10 per cent at 32 days of age. This behaviour probably reflects the protein distribution and use of absorbed anti- peroxidase IgG.

Transferrin Polymorphism versus Growth Rate in Lambs, Polish Long-wool Sheep – II. Analysis of relation between transferrin polymorphism of lamb blood serum versus growth rate of lambs up to age of 5 months

Abstract. The flock comprised 3419 lambs, either sex, from the four subsequent lambings ofthe Polish long-wool sheep and the subject ofthe study was to attempt to verify a hypothesis ofthe polygenic inheritance ofthe growth rate of lambs in the six periods of living, (0–28, 0–100, 0–152, 28–100, 28–152 and 100–152 days respectively) and to find possible relations between the transferrin polymorphism and lamb growth rate. The relations found between the transferrin polymorphism and lamb growth rate and the preliminary evaluation leading to the identification of alleles of large effectiveness show possibilities to use the transferrin polymorphism as a genetic marker of the traits concerned for the breeding – selecting scheme.

Effect of active immunization against luteinizing hormone on carcass and meat quality of Romanov lambs

Romanov male ( n=37) and female ( n=6) lambs 50 d old were used to investigate the possibility of improving carcass and meat quality at slaughter with a non-surgical method of castration. Seven groups were compared: intact untreated control (C1); surgically castrated (SC); immunized with 0.25 (T 0.25), 0.50 (T 0.50) or 1.00 (T 1.00) mg porcine LH (injected at 50±7 d of age and three more times 10 d apart); control, injected only with adjuvant (C2) and females (F). Blood samples were collected at d 50 and thereafter at 3 wk intervals until slaughter to determine testosterone and LH concentrations, and presence of antibodies. Scrotal circumference and body weight were determined every 3 wk. The lambs were slaughtered at 43±2 kg live weight and detailed carcass evaluations were performed. Testicular weight, width and length were recorded and diameter of the seminiferous tubules was measured. Immunization with the higher levels of LH (T 0.5 and T 1.0) reduced growth rate and feed efficiency to levels similar to those of F and SC. Dressing percentages of C1 and T 0.25, T 0.50 and T 1.0 were similar and 3.6–4.0% lower than in SC lambs mainly as a result of lower carcass fat. Both SC and immunization reduced carcass shoulder proportion. Whereas, SC increased the loin-proportion, immunization treatments increased the leg proportion. The 12th rib measurements of all immunized lambs showed an increase in lean (45.7–53.3% vs 40.9%) and bone (19.8–23.1% vs 16.4%) content and a decrease in fat content (24.4–33.6% vs 41.5%) compared with SC lambs ( P>0.05). Dissection of half of each carcass showed similar results. Marked decrease ( P<0.01) in backfat was observed in all immunized lambs compared with SC, F, C1 and C2 lambs. Testes weights decreased 15–29% in immunized lambs as compared with C2 and 5–20% as compared with C1 lambs ( P>0.05). Testes circumferences and widths showed dose-dependent decreases. No significant differences among treatments in seminiferous tubule circumference was observed. Free LH was not detectable in serum of immunized lambs but elevated levels of LH antibodies were present at the termination of the study. Significant correlation coefficients were calculated between testosterone concentration and various carcass traits. It is concluded that immunizing against LH could improve the proportions of the most valuable cuts without increased deposition of adipose tissues associated with castration.

An evaluation of the efficacy of injectable microencapsulated Vitamin B12 in increasing and maintaining the serum and liver Vitamin B12 concentrations of lambs

Aim. To develop a long-acting vitamin B, injection to prevent Co deficiency in sheep. Methods. Formulations of microencapsulated Vitamin B12 in lactide-glycolide polymers were injected intramuscularly or subcutaneously into the anterior neck region of groups of 10 lambs and their efficacy determined from changes in serum and liver Vitamin B12 concentrations. Results. The 955 lactide glycolide and the 100 lactide formulations containing more than 12.5% Vitamin B12 w/w significantly increased and maintained serum Vitamin B12 concentrations for at least 210 days as well as liver Vitamin B12 concentrations in treated lambs when compared with untreated controls. Conclusions. Injections of microencapsulated Vitamin B12 in lactide-glycolide copolymers are able to increase and maintain the Vitamin B12 status of lambs for at least 210 days. Clinical significance. Another option for the prevention of Co deficiency in sheep is now available using a long acting injectable Vitamin B12.