Electronic bolus design impacts on administration.

Electronic identification of animals has become increasingly important worldwide to improve and ensure traceability. In warm and hot climates, such as Brazil, boluses can have advantages over ear tags as the internal devices reduce the risks of ear tag losses, tissue damage, and lesions on the ear. Electronic boluses, however, are often perceived as having negative characteristics, including reported difficulties of administration in small ruminants. This paper describes the factors associated with bolus design that affect the swallowing of a bolus in sheep. Other factors that might influence bolus swallowing time have also been considered. In addition, the effect of bolus design on its performance was evaluated. A total of 56 Suffolk ewes were used to assess the ease of administration and retention of 3 types of electronic ruminal boluses (mini, 11.5 × 58.0 mm and 21.7 g; small, 14.8 × 48.5 mm and 29.5 g; standard, 19.3 × 69.8 mm and 74.4 g) during a whole productive year, including pregnancy and lamb suckling. Ewe age (5.6 ± 2.3 yr) and weight (85.07 ± 8.2 kg BW) were recorded, as well as time for bolus swallowing. The deglutition of the bolus and any resulting blockages in the esophagus were monitored by visual observations. Retention and readability of the boluses were regularly monitored for d 1, wk 1, mo 1, and every mo until 1 yr. Time for bolus swallowing differed substantially with bolus type and was greater (P < 0.05) for the standard bolus (32.8 ± 6.9 s) when compared to small and mini boluses, which did not differ (8.5 ± 2.0 vs. 9.2 ± 2.7 s; P > 0.05). The bolus o.d. and length were positively correlated with swallowing time (P < 0.01). The ewe weight was negatively correlated with swallowing time (P < 0.05). At 6 mo all electronic boluses showed 100% retention rate, and at 12 mo, bolus retention was 100%, 94.5%, and 100% for mini, small, and standard boluses, respectively (P > 0.05). At 12 mo, all boluses showed 100% readability, except for small boluses, which had a readability of 94.5%. In conclusion, bolus design affected swallowing time and bolus readability. A reduction in boluses length and o.d. needs to be carried out to provide ease of administration and for boluses to be used as an effective means of electronic identification. Therefore, this study shows that adequately designed boluses are safe and suitable for identifying adult sheep and can therefore be used in hot climates.

Consumo alimentar residual e sua relação com medidas de desempenho e eficiência e características in vivo da carcaça de cordeiros / The residual feed intake and its relationship with performance and efficiency measures and in vivo carcass characteristics of lambs

Avaliou-se o consumo alimentar residual (CAR) e a conversão alimentar (CA) de 20 cordeiros, com o objetivo de estimar as correlações entre essas variáveis com medidas de desempenho e com características in vivo da carcaça. Os animais tiveram o consumo de MS (CMS) mensurado por 65 dias e foram pesados a cada 13 dias para obtenção do ganho médio diário (GMD). Foram considerados o peso vivo inicial (PVI), o peso vivo final (PVF), o peso metabólico (PM), o GMD, a taxa de crescimento relativo (TCR), a taxa de Kleiber (TK), a CA, o CMS e o CMS em percentual do PV (CMSPV). As avaliações de carcaça foram realizadas por ultrassom. O CAR se mostrou correlacionado com o CMS (+0,81), o CMSPV (+0,90) e a CA (+0,63). Correlações significativas foram encontradas entre CA e GMD; CA e TCR; CA e TK; e CA e PVI (-0,63, -0,74, -0,75 e +0,51, respectivamente). O CAR e a CA não se mostraram correlacionados com características de carcaça, e, da mesma forma, não houve diferença entre as classes de CAR para essas variáveis. Confirmou-se o potencial do CAR como medida de eficiência alimentar para cordeiros em confinamento, sem existência de relações com o ganho de peso e o tamanho corporal e sem alterações na composição da carcaça.

The residual feed intake (RFI) and the feed conversion ratio (FCR) of 20 lambs was evaluated in order to estimate the correlations between these traits and performance measures and with in vivo carcass characteristics. The animals had their dry matter intake (DMI) measured over 65 days and they were weighed every 13 days to determine the average daily weight gain (ADG). Initial body weight (IBW), final body weight (FBW), metabolic weight (MW), ADG, relative growth rate (RGR), Kleiber ratio (KR), FCR, DMI and DMI in BW percentual (BWDMI) were considered. The carcass evaluation was performed by ultrasound. The RFI was correlated with the DMI (+0.81), BWDMI (+0.90) and with FCR (+0.63). Significant correlations were found between FCR and ADG; FCR and RGR; and FCR and KR; and FCR and IBW (-0.63, -0.74, -0.75 and +0.51 respectively). The RFI and the FCR were not correlated with carcass traits and similarly there was no difference between the RFI-classes for these variables. It was proved the RFI has potential as a measure of feed efficiency for housed lambs, without the existence of relations with weight gain and body size of animals and without changes in carcass composition.

Adição de plasma seminal ao sêmen descongelado e taxa de prenhez de ovelhas inseminadas em tempo fixo / Addition of seminal plasma to frozen-thawed semen and pregnancy rate of fixed time inseminated ewes

Avaliou-se o efeito da adição de plasma seminal ovino ao sêmen descongelado sobre a taxa de prenhez de ovelhas em rebanho comercial. Cento e setenta e quatro ovelhas cruza Texel foram distribuídas em quatro tratamentos: T1) inseminação artificial cervical (IAC) com sêmen descongelado (SD) diluído em solução tampão fosfato salino (PBS); T2) IAC com SD e adição de plasma seminal ovino; T3) grupo-controle I: IAC com sêmen fresco diluído em PBS; T4) grupo-controle II: inseminação artificial por laparoscopia com SD diluído em PBS. Para indução de cio, utilizaram-se esponjas impregnadas com acetato de medroxiprogesterona (MAP) por 12 dias, com aplicação intramuscular de 400 UI de eCG (Novormon®) e de 37,5µg de cloprostenol sódico (Sincrocio®), no dia da retirada das esponjas. O aparecimento de cio foi monitorado com rufiões vasectomizados a partir da retirada das esponjas até a inseminação artificial em tempo fixo - 54 a 60 horas. A taxa de prenhez do tratamento com adição de plasma seminal ao sêmen descongelado (7,0%) não diferiu (P>0,05) do tratamento sem adição de plasma (4,3%), entretanto foi menor (P<0,05) se comparada à taxa de prenhez dos grupos-controle I inseminação via cervical superficial com sêmen fresco diluído (50,0%) e II inseminação via laparoscopia com sêmen descongelado (39,4%). A inseminação artificial por via cervical superficial com adição de plasma seminal ao sêmen descongelado não elevou o percentual de prenhez em valores que justifiquem a indicação desta biotecnologia em rebanhos comerciais de ovinos.

The effect of seminal plasma addition to thawed-frozen ram semen on the pregnancy rate of commercial herd ewes was evaluated. One hundred and seventy-four crossbred Texel sheep were allocated to four treatments: T1) cervical artificial insemination (CAI) using frozen-thawed semen (FTS) diluted in phosphate buffered saline solution (PBS); T2) CAI using FTS diluted in ovine seminal plasma; T3) control group I: CAI using fresh semen diluted in PBS; T4) control group II: laparoscopic insemination using FTS diluted in PBS. Estrus induction was performed with medroxiprogesterone acetate (MAP) impregnated sponges for 12 days, followed by intramuscular injection of 400 IU of eCG (Novormon®) and 37.5µg of sodium cloprostenol (Sincrocio®) on the day of sponge removal. Estrus was monitorated with vasectomized rams, beginning at the time of the sponge removal until the fixed time artificial insemination - 54 to 60 hours. The pregnancy rate of FTS diluted in seminal plasma treatment (7.0%) did not differ (P>0.05) for the treatment without addition of seminal plasma (4.3%), however it was lower (P<0.05) when compared to the pregnancy rate of the cervical inseminated control I group with PBS diluted fresh semen (50.0%) and laparoscopic inseminated control group II with PBS diluted FTS (39.4%). The cervical artificial insemination with the addition of seminal plasma to frozen-thawed semen did not increase the pregnancy rate at acceptable values to make this biotechnology useful on commercial herds.