Exposure to the mother activates the main olfactory bulb of lambs

The brain structures by which the lamb recognizes and bonds to its’ mother are unknown. The aim of this study was to compare the neuronal activation of the main olfactory bulb (MOB) of lambs exposed to their mothers, lactating ewes or no social stimuli. The testing pen consisted of two similar pens (3mx2m) separated by a metallic fence. At separation, suckling lambs of one month of age were isolated for 90 min in one area of the testing pen. Thereafter, either the mother (n=10; group MOT) or a lactating-ewe (n=9; group LE) were introduced to an adjacent pen for another 90 min. In the third group, lambs remained isolated (n=9, group ISO). Neuronal activation was investigated 90 min later according to the time required for maximum c-Fos expression in sheep. A lamb was considered to be in the contact zone of a ewe when it was less than 80 cm from it. The time spent by the lamb walking in the contact zone, the time sniffing the ewe, the number of vocalizations and contact attempts with the ewe were recorded during the first 20 min. Thereafter, the lambs were anaesthetized with an I.V. injection of sodium thiopental (12.5 mg/kg) followed by bleeding. The MOBs were dissected and fixed in paraformaldehyde and stored in sucrose solution. The MOBs were sectioned using a cryostat, and sections were used for c-Fos immunohistochemistry. The number of c-Fos-positive cells in the granular layer of the MOB (12 sections/animal) was measured using a light microscope, and the density of labelled cells was determined using the Mercator software. The lambs of the three groups differed in the time walking (3.1±17 s, 29.4±10.0s and 210.5±37.6s; for ISO, LE and MOT lambs, respectively, P<0.0001). MOT and LE lambs vocalized more than ISO lambs (17.3±4.7 and 7.4±4.5 vs 0.1±0.1;P=0.01 and P=0.02, respectively). MOT lambs attempted to reunite with their mother more than LE lambs did with the lactating ewe (21.7±5.8 vs 2.6±1.0;P=0.04), sniffed more often the mother (13.3±3.3 vs 4.0±1.1;P=0.01), and tended to do so during more time (27.1±11.1s vs 4.9±1.4s;P=0.059). C-Fos immunoreactivity differed according to the treatment (P=0.049): it was greater in MOT than ISO lambs (1.59±0.27X10-3mm3 vs 1.17±0.26X10-3mm3; P=0.014), while LE lambs had intermediate values that did not differ from any (1.38±0.28X10-3mm3). Recognition of the mother is accompanied with an increased activation of the MOB of lambs, suggesting that olfactory cues from the mother are important for the recognition process.Agencia Nacional de Investigación e Innovació

Comparison of two methods of progesterone application in a fixed time artificial insemination protocol in beef cows

Two experiments were conducted at two commercial farms to compare pregnancy rates of nulliparous (n = 178) and primiparous (n = 130; Farm 1), and multiparous (n = 161; Farm 2) Aberdeen Angus cows, when 200 mg s-c of injectable oil-based progesterone (MAD-4) or a 558 mg progesterone releasing intravaginal device (DIV) were used in a fixed time artificial insemination protocol based on estradiol benzoate (EB), prostaglandin (PG), equine chorionic gonadotropin (eCG) and gonadotropin-releasing hormone (GnRH). Primiparous and multiparous cows were weaned 30 d before treatment (60–90 d postpartum). The ovarian status was determined by rectal palpation and the animals classified as cycling or in superficial anoestrus or deep anoestrus. The P4 source affected (P&lt;0.0001) the pregnancy rate of primiparous and multiparous cows, but not that of nulliparous cows (Farm 1: Nulliparous: 51% and 42%; Primiparous: 42% and 10%, DIV and MAD-4, respectively, with a treatment x category interaction (P = 0.0056). Farm 2: DIV: 51% vs. MAD4: 9%, P=0.0001). Independently of the hormonal treatment, the ovarian status influenced pregnancy rates (P&lt;0.0001), cycling cows showed the highest value and cows in deep anoestrus the lowest. No significant treatment x ovarian status interaction was found. It is concluded that replacing the DIV by MAD-4 decreased pregnancy rate of primiparous and multiparous cows, but not that of nulliparous ones

LEPTIN DETERMINATION AND SERUM LEVELS IN ADULT ALPACAS WITH DIFFERENT BODY CONDITION

El presente estudio tuvo como objetivo determinar la presencia de la hormona leptina en alpacas adultas, cuantificar sus valores y relacionarlos con la condición corporal. Se utilizaron 36 alpacas hembras adultas, vacías y sin cría, las cuales fueron divididas en dos grupos, según su condición corporal (CC): G1: CC &lt;3.0 y G2: CC &gt;3.0, de acuerdo a una escala 1 - 5 (1: emaciada, 5: obesa). Se tomaron muestras de sangre por punción de la vena yugular y el suero resultante fue mantenido en congelación a –20 ºC hasta su análisis. La determinación de leptina fue realizada mediante la técnica de radioinmunoensayo (RIA). La media general de la concentración de leptina fue de 17.23 ± 0.81 ng/ml. Los valores encontrados para G1 fueron de 18.14 ± 1.12 ng/ml y para G2: 16.32 ± 1.15 ng/ml, sin diferencias estadísticas entre grupos. Los resultados obtenidos permiten evidenciar la presencia de leptina en alpacas.The aim of this study was to determine the presence of leptin in adults alpacas, in order to quantify leptin values for these animals, and to relate them with body condition. For this purpose, 36 non pregnant and non nursing female adult alpacas were used. They were divided in two groups according to body condition (BC): G1: BC &lt;3.0 and G2: BC&gt;3.0, using the 1 to 5 scale (1: emaciate, 5: obese). Blood samples by jugular venipunction to obtain serum were taken. Serum samples were maintained at -20 ºC until analysis. The leptin determination was carried out by the radioimmunoassay technique (RIA). The mean of leptin concentration was 17.23 ± 0.81 ng/ml. Values for G1 were 18.14 ± 1.12 ng/ ml and for G2. were 16.32 ± 1.15 ng/ml, without statistical differences between groups. The results showed that the leptin hormone is also present in alpacas

Festas no início ou final do inverno em ovelhas nulíparas: efeitos sobre o comportamento materno e de sua progênie

In nulliparous ewes grazing natural field that gave birth at the beginning or at the end of winter, the metabolic status was compared during advanced gestation, parturition and early postpartum, parturition behavior, lamb mortality, milk production and quality, weight (PV) of the lambs during the first 60 days, the presentation of jealousy of the lambs in their first autumn and the reproductive behavior of the mothers in the following service. 64 nulliparous Corriedale ewes were used; 39 calved at the beginning (Group J) and the remaining 25 at the end of the winter (Group S). Neither the mortality of lambs born by simple calving during the first 7 days of life, nor the behavior at calving, nor the milk production was different between groups. Metabolic status at delivery was better in Group J than in Group S (higher PV, body condition, plasma glucose, cholesterol, and total protein concentration, and lower urea; P &lt;0.05). However, this situation was reversed during the early postpartum period. Milk quality was better in Group J than in Group S (higher protein and fat content; P &lt;0.0001). The LW of lambs at birth (PNAC) was not different, but the global mean was higher in Group S than in Group J (Group S: 9.51 ± 0.21 kg vs Group J: 8.87 ± 0, 21 kg; P = 0.05). No consequences were observed on reproductive behavior in ewes at the second service. Nor was a greater proportion of lambs in heat observed in their first autumn. The results allow us to conclude that advancing the calving month to the beginning of winter increases the metabolic status of the ewe at calving without effects on PNAC, lamb mortality, or calving behavior.En ovejas nulíparas pastoreando campo natural que parieron al inicio o al final del invierno se comparó el estatus metabólico durante la gestación avanzada, parto y posparto temprano, el comportamiento al parto, la mortalidad de corderos, la producción y calidad de la leche, el peso (PV) de los corderos durante los primeros 60 días, la presentación de celos de las corderas en su primer otoño y el comportamiento reproductivo de las madres en el siguiente servicio. Se utilizaron 64 ovejas Corriedale nulíparas; 39 parieron a inicio (Grupo J) y las restantes 25 a final del invierno (Grupo S). Ni la mortalidad de corderos nacidos de parto simple durante los primeros 7 días de vida, ni el comportamiento al parto, ni la producción de leche fue diferente entre grupos. El estatus metabólico al parto fue mejor en el Grupo J que en el Grupo S (mayor PV, condición corporal, concentración plasmática de glucosa, colesterol, y proteína total, y menor de urea; P&lt;0,05). Sin embargo, esta situación se revirtió durante el pos parto temprano. La calidad de leche fue mejor en el Grupo J que en el S (mayor contenido de proteína y grasa; P&lt;0,0001). El PV de los corderos al nacer (PNAC) no fue diferente, pero la media global fue mayor en el Grupo S que en el J (Grupo S: 9,51 ± 0,21 kg vs Grupo J: 8,87 ± 0,21 kg; P = 0,05). No se observaron consecuencias en el comportamiento reproductivo en las ovejas al segundo servicio. Tampoco se observó mayor proporción de corderas en celo en su primer otoño. Los resultados permiten concluir que adelantar el mes de parto al inicio del invierno aumenta el estatus metabólico de la oveja al parto sin efectos sobre el PNAC, mortalidad de los corderos, o el comportamiento al parto.Em ovelhas nulíparas pastando em campo natural que pariram no início ou no final do inverno, o estado metabólico foi comparado durante a gestação avançada, parto e pós-parto inicial, comportamento de parto, mortalidade de cordeiros, produção e qualidade do leite, peso (PV) do cordeiros durante os primeiros 60 dias, a apresentação de ciúmes dos cordeiros no primeiro outono e o comportamento reprodutivo das mães no serviço seguinte. Foram utilizadas 64 ovelhas Corriedale nulíparas; 39 pariram no início (Grupo J) e os 25 restantes no final do inverno (Grupo S). Nem a mortalidade dos cordeiros nascidos de parto simples nos primeiros 7 dias de vida, nem o comportamento ao parto, nem a produção de leite foram diferentes entre os grupos. O estado metabólico no parto foi melhor no Grupo J do que no Grupo S (maior PV, condição corporal, concentração plasmática de glicose, colesterol e proteína total e menor ureia; P &lt;0,05). No entanto, essa situação foi revertida durante o período pós-parto inicial. A qualidade do leite foi melhor no Grupo J do que no Grupo S (maior teor de proteína e gordura; P &lt;0,0001). O PV dos cordeiros ao nascer (PNAC) não foi diferente, mas a média global foi maior no Grupo S do que no Grupo J (Grupo S: 9,51 ± 0,21 kg vs Grupo J: 8,87 ± 0,21 kg; P = 0,05). Não foram observadas consequências no comportamento reprodutivo das ovelhas do segundo serviço. Nem foi observada uma proporção maior de cordeiros em cio no primeiro outono. Os resultados permitem concluir que o avanço do mês de parto para o início do inverno aumenta o estado metabólico da ovelha ao parto, sem efeitos sobre o PNAC, mortalidade dos cordeiros ou comportamento de parto

Influence of nutrition on testicular growth in Corriedale rams during spring

International audienc

La duración del tratamiento con esponjas intravaginales impregnadas con medroxiprogesterona en la estación reproductiva influye la respuesta a la sincronización de celos en ovejas Corriedale y Merino : Sincronización de celos en ovinos

The aim of this work was to compare the effect of 12 or 14 days of treatment with intravaginal sponges (IVS) containing medroxyprogesterone on the reproductive performance of Corriedale and Australian Merino (AM) ewes during the breeding season. Corriedale (weight: 42.4 ± 4.2 kg; mean ± SD) and AM (weight: 38.6 ± 4.0 kg) multiparous ewes were used under randomized block experimental design. The IVS were removed at 12 days (Group IVS12d; n = 224; Corriedale: 110; AM: 114), or 14 days (Group IVS14d; n = 187; Corriedale: 100; AM: 87). The estrus was detected AM and PM during 5 days after IVS withdrawal, using 10% of vasectomized rams. The ewes were submitted to cervical insemination (AI) with fresh semen obtained from rams of their same breed, 12 and 24 h after estrus was detected. Pregnancy and number of fetuses were diagnosed with ultrasound 45 days after AI. The longer permanence of the IVS increased the percentage of estrus (IVS14d: 94.7% vs. IVS12d: 82.6%; P = 0.0003), decreased the interval IVS – estrus (IVS14d: 48.8 ± 1.3 h vs. IVS12d: 58.8 ± 1.3 h; P &lt; 0.0001), and increased the fertility (IVS14d: 72.7% vs. IVS12d: 60.7%, pregnant ewes/treated ewes; P=0.01), without affecting the conception rate (pregnant ewes/inseminated ewes) or the prolificacy (fetus/pregnant ewes). The fecundity was affected by the breed (Corriedale: 0.8 vs. AM: 0.6, fetus/treated ewes; P = 0.04). We concluded that 14 days of treatment with IVS during the breeding season increased and concentrated the estrus presentation without affecting conception rate. As a result, as we used AI associated with estrus detection, the fertility improved Corriedale ewes had greater fecundity than AM ewes, independently of the length of hormonal treatment.El objetivo del presente trabajo fue comparar el efecto de 12 o 14 días de tratamiento con esponjas intravaginales (EIV) impregnadas con medroxiprogesterona sobre el comportamiento reproductivo de ovejas Corriedale y Merino Australiano (MA) durante la estación reproductiva. Se utilizaron ovejas multíparas de la raza Corriedale (peso: 42,4 ± 4,2 kg; media ± DE) y MA (peso: 38,6 ± 4,0 kg) en un diseño experimental de bloques al azar. Las EIV fueron retiradas a los 12 días (Grupo EIV12Dd; n = 224; Corriedale: 110; MA: 114) o 14 días (Grupo EIV14d; n = 187; Corriedale: 100; MA: 87). Se detectó celo AM y PM durante 5 días después del retiro de las EIV, utilizando 10% de carneros vasectomizados. Las ovejas fueron inseminadas (IA) por vía cervical con semen fresco de carneros de su misma raza a las 12 y 24 h de ser identificadas en celo. Se diagnosticó la preñez y la carga fetal por ultrasonografía 45 días pos IA. La mayor permanencia de la EIV aumentó la presentación de celos (EIV14d: 94,7% vs. EIV12d: 82,6%; P = 0,0003), disminuyó el intervalo retiro de EIV – celo (EIV14d: 48,8 ± 1,3 h vs. EIV12d: 58,8 ± 1,3 h; P &lt; 0.0001) y aumentó la fertilidad (EIV14d: 72,7% vs. EIV12Dd: 60,7%, ovejas preñadas/ovejas tratadas; P=0,01), sin afectar la tasa de concepción (ovejas preñadas/ovejas inseminadas) o la prolificidad (fetos/ovejas preñadas). La fecundidad fue influida por la raza (Corriedale: 0,8 vs MA: 0,6, fetos/ovejas tratadas; P = 0,04). Se concluye que 14 días de tratamiento con EIV durante la estación reproductiva mejoró y concentró la presentación de celos, sin afectar la tasa de concepción. Como resultado, al utilizar IA asociada a detección de celos, aumentó la fertilidad. Las ovejas Corriedale presentaron mejor fecundidad que las ovejas MA, independientemente del largo del tratamiento hormonal

Supplementation with a mixture of whole rice bran and crude glycerin on metabolic responses and performance of primiparous beef cows

ABSTRACT - This study investigated the effect of a supplement containing whole rice bran and crude glycerin for 21 days before mating on metabolic, productive, and reproductive responses of 28 primiparous suckling beef cows. Cows were randomly assigned to a control group (CON, n = 14), grazing on grasslands, and a supplemented group (SUP, n = 14), grazing on grasslands and supplemented daily individually with 1 kg dry matter (DM) of whole rice bran + 550 mL crude glycerin (224 g kg−1 DM of methanol) per cow. After 33 days of natural mating, cows that had not expressed estrus were subjected to a fixed-time artificial insemination protocol. Ten days after the insemination program, bulls were reintroduced for 21 days. Supplementation increased milk yield (SUP: 5.7±0.2 vs. CON: 5.0±0.2 kg d−1), milk protein content (SUP: 3.1±0.2 vs. CON: 2.8±0.2%), and body weight of cow (SUP: 379±2 vs. CON: 373±2 kg) and calf (SUP: 150±2 vs. CON: 142±2 kg). Supplementation improved the energy balance, increased plasma concentrations of cholesterol (SUP: 223.2±6.4 vs. CON: 202.1±6.4 mg dL−1) and glucose (SUP: 72.0±1.2 vs. CON: 68.6±1.2 mg dL−1), and reduced non-esterified fatty acids (SUP: 0.45±0.02 vs. CON: 0.56±0.02 mmol L−1). The percentage of cows on superficial anestrous after supplementation was greater in SUP than in CON group (57 vs. 21%, respectively); however, no difference in final pregnancy rate was found (SUP: 79 vs. CON: 64%). There was no evidence that the ingestion of crude glycerin with high content of methanol induced clinical or hepatic disorders. Supplementation of whole rice bran and crude glycerin is not toxic, and can improve the energy balance, reflecting in increase in milk yield and calf growth, with a slight effect on the reproductive activity

Effects of rice bran and glycerin supplementation on metabolic and productive responses of beef cows

Fifty-seven primiparous Angus, Hereford, and crossbred cows were used to study the effect of strategic supplementation on metabolic, productive, and reproductive responses. The experiment had two periods including four phases: prepartum supplementation (phase I; 52 days), early postpartum (phase II; 43 days), pre-mating supplementation (phase III; 21 days), and the last phase including mating, gestation, and lactation until weaning (phase IV; 103 days). Phases I and II were considered as period 1, and phases III and IV were considered as period 2. During phase I (−52±2 days before calving to birth), half of the cows received a supplement (S-), and the rest only grazed native swards (C-). For phase III (59±2 days postpartum [DPP] until mating), cows from the previous treatments (C- or S-) were sorted in two levels of pre-mating supplementation, supplemented (-S) or not supplemented (-C), resulting in four treatment combinations (CC, CS, SC, and SS). The supplement was 1 kg dry matter/cow per day of whole rice bran and 550 mL/cow per day of crude glycerin. In period 1, cows receiving prepartum supplementation increased concentration of cholesterol, glucose, and albumin and decreased concentration of non-esterified fatty acids, betahydroxybutyrate, and urea. This improvement in energy balance was reflected in a higher body condition score at calving. Alternatively, in period 2, pre-mating supplementation only increased cholesterol concentration. None of the supplementation periods affected the weaning weight of calves. Prepartum, but not pre-mating, supplementation increased total pregnancy rate. A short prepartum supplementation improves pregnancy rate of primiparous cows managed under extensive production systems. However, there is no additional benefit of supplementation during the pre-mating perio

Out-of-season breeding and ewe-lamb bond from birth to weaning in Corriedale sheep

International audienceOut-of-season lambing is based in productive aims; however also modifies the basic physiology of the ewe. It might affect ewes and lambs' behaviours at birth, their bond, the process of lambs' independence from their mothers and their response to weaning. This study aimed to compare the ewe-lamb bond from birth to artificial weaning in out-of-season lambing (autumn) and spring lambing. A complementary aim was to determine if out of-season breeding affects ewes' udder size, milk yield and composition, body condition score (BCS) and body weight of the ewes and lambs. The study was performed with 26 multiparous single-lambing Corriedale ewes that lambed in spring (natural season: group SPR), and 26 ewes that lambed in autumn (out-of-season: group AUT) and their lambs. The ewe-lamb behaviours were recorded during a separation-reunion test performed 24-36 h after birth. Lambs' behaviours were recorded before and after weaning (at 80 days of age). Ewes' BCS and body weight were recorded at mating, lambing and weaning. Lambs' body weight was recorded at lambing, before and after weaning. Ewes' milk yield and composition were determined before weaning. During the separation reunion test, although AUT lambs vocalised more often than SPR lambs their mothers remained further away (P = 0.01). Before weaning, AUT ewe-lamb dyads were observed more often far from each other (P < 0.001); AUT lambs attempted to suckle more times (P < 0.001) and grazed less frequently than SPR lambs (P = 0.004). At weaning, AUT lambs walked more frequently, but were less often standing up than SPR lambs (P < 0.001 for both behaviours). While SPR lambs decreased their grazing frequency on the day of weaning, AUT lambs increased it, grazing more frequently than SPR lambs (P < 0.001). AUT ewes lambed with a greater BCS and body weight than SPR ewes (P = 0.01 and P = 0.031, respectively), but this was reverted at weaning (BCS: P < 0.001; body weight: P = 0.002). SPR ewes had a greater milk yield, with more fat, lactose and protein amount than AUT ewes (P < 0.001 for all variables). At weaning, SPR lambs were heavier than AUT lambs (P < 0.001). In conclusion, although AUT ewes were in better body condition after birth, the ewe-lamb bond of the AUT group was weaker. This was associated with a lower expression of maternal attention when AUT lambs requested maternal care. The better environmental conditions of SPR dyads during lactation might positively impact their social and nutritional behaviours. The difference between groups remained until weaning, so AUT and SPR lambs displayed different behavioural strategies to cope with artificial weaning