METHANOGENESIS IN RABBIT CAECUM AS AFFECTED BY THE FERMENTATION PATTERN: IN VITRO AND IN VIVO MEASUREMENTS

[EN] Methane formation and caecal fermentation patterns were studied in vivo and in vitro in 16 white New Zealand rabbits (70-80 d and 2.27 ± 0.064 kg) allocated to four diets formulated to have a similar neutral detergent fibre (33.8±0.53%) and protein (17.7±0.33%) content, with two different fibre sources (alfalfa hay, AH or sugar beet pulp, SP) and starch (wheat or maize). Animals received the diet for 16 to 20 days before methane production was measured in vivo in a respiratory chamber. Animals were subsequently slaughtered at approximately 9:00 and caecal contents were sampled and used as inoculum for in vitro incubations to determine gas and methane production. Volatile fatty acid (VFA) and purine base (PB) concentrations were determined from both caecal content and incubation medium after 6 h. Total VFA concentration in caecal content decreased (P<0.05) in rabbits fed AH-maize diet compared with rabbits fed AH-wheat and SP-maize diets (37.7 vs. 59.6 mM), with those fed SP-wheat showing an intermediate value (53.0 mM). Fermentation pattern was affected when maize was the source of starch compared to wheat, with lower acetate (0.72 vs. 0.79; P<0.01) and higher butyrate (0.19 vs. 0.14; P<0.001) molar proportions. Fermentation in vivo vs. in vitro showed some differences (molar proportions of acetate, 0.76 vs. 0.73, P<0.001, and propionate, 0.069 vs. 0.091, P<0.001, in vivo and in vitro, respectively), probably due to differences in pH (6.0 vs. 6.7 in vivo and in vitro; P<0.001). Only 2 out of 16 rabbits produced a substantial volume of methane in vivo (on average, 12.6 ml/BW0.75/d or 0.56 mmol/BW0.75/d), showing a high inter-individual variability that hindered comparison of treatment differences. In contrast, methane was detected in vitro in all cases and volumes were more homogenous, a higher formation (P<0.05) being observed with maize compared to wheat. A similar effect was shown in total gas production. The low methane production and H2 recovery suggest the importance of H2 disposal mechanisms other than methanogenesis, such as reductive acetogenesis. PB concentration in caecal content and the incubation medium, as an index of microbial concentration, was highest when SP was added with maize (P<0.05).For the realisation of this work, A. Belenguer and L. Abecia received grants from the Spanish Ministry of Education and Science and the Basque Government, respectively. This work was financed by the Diputación General de Aragón through project DGA PM095/2006.Belenguer, A.; Fondevila, M.; Balcells, J.; Abecia, L.; Lachica, M.; Carro, M. (2011). METHANOGENESIS IN RABBIT CAECUM AS AFFECTED BY THE FERMENTATION PATTERN: IN VITRO AND IN VIVO MEASUREMENTS. World Rabbit Science. 19(2):75-83. doi:10.4995/wrs.2011.826SWORD758319

Efficiency of Artificial Insemination at Natural Estrus in Organic Churra Ewes

Hormonal treatments used in the artificial insemination (AI) of sheep can cause several physiological problems that can affect negatively fertility and animal health; however, AI protocols based on the detection of natural estrus offer a more sustainable option and can achieve high fertility. In this study, an AI protocol at natural estrus in organic Churra sheep was performed. In the first phase (AI protocol development), 125 ewes were exocervically inseminated, and their fertility was assessed based on the following factors: number of AI, physiological state, body condition, estrus detection–AI interval, and vaginal fluids in cervix. That protocol was repeated for six consecutive years. In all individuals, fertilities based on the timing of insemination after estrus detection were very high. Lactating ewes produced better results than did dry ewes, which was probably because of the better feeding of the former. In addition, double insemination increased the fertility of ewes whose estrus was detected within 16 h of onset. Body condition and amount of vaginal fluid were correlated with fertility. Exocervical inseminations at natural estrus can produce acceptable fertility and prolificity in Churra ewes

The continuous presence of ewes in estrus in spring influences testicular volume, testicular echogenicity and testosterone concentration, but not LH pulsatility in rams

The continuous presence of active male small ruminants prevents seasonal anestrus in females, but evidence of the same mechanism operating from the females to the males is scarce. This study assessed the effects of the continuous presence of ewes in estrus in spring on ram sexual activity, testicular size and echogenicity, and LH and testosterone concentrations. On 1 March, 20 rams were assigned to two groups (n = 10 each): isolated (ISO) from other sheep, or stimulated (STI) by 12 ewes, which were separated from the rams by an openwork metal barrier, allowing contact between sexes. Each week, four ewes were induced into estrus by intravaginal sponges. Live weight, scrotal circumference, testicular width (TW) and length (TL) were recorded at the beginning and at the end of the experiment, and testicular volume (TV) was calculated; at the same time, testicular ultrasonography and color Doppler scanning were performed. Blood samples (March to May) were collected once per week for testosterone determinations, and at the end of the experiment, blood samples were collected for 6 h at 20-min intervals for LH analysis. Rams were exposed to four estrous ewes in a serving-capacity test. Scrotal circumference, TW and TL were higher in the STI than in the ISO rams (P < 0.05) in May, and TV was higher (P < 0.05) in the STI (391 ± 17 cm3) than in the ISO rams (354 ± 24 cm3). In ISO rams, the number of white pixels was higher (P < 0.01) in May (348 ± 74) than in March (94 ± 21) and differed significantly (P < 0.01) from that of the STI rams in May (160 ± 33). In ISO rams, the number of grey pixels was higher (P < 0.05) in May (107 ± 3) than it was in March (99 ± 1). Stimulated and ISO rams did not differ significantly in mean LH plasma concentrations (0.8 ± 0.5 v. 0.9 ± 0.4 ng/ml), LH pulses (2.1 ± 0.5 v. 2.2 ± 0.2) and amplitude (2.0 ± 0.4 v. 3.2 ± 0.7 ng/ml, respectively). Stimulated rams had significantly higher testosterone concentrations than ISO rams from April to the end of the experiment. Stimulated rams performed more (P < 0.05) mountings with intromission (3.0 ± 0.4) than did ISO rams (1.5 ± 0.5). In conclusion, after 3 months in the continuous presence of ewes in estrus in spring, rams had higher TV and some testicular echogenic parameters were modified than isolated rams. Although exposed rams also had higher levels of testosterone after 2 months in the presence of estrous ewes, their LH pulsatility at the end of the study was not modified

Polymorphisms of the melatonin receptor 1A (MTNR1A) gene influence the age at first mating in autumn-born ram-lambs and sexual activity of adult rams in spring

The aim of this study was to determine whether polymorphisms of the melatonin receptor 1A (MTNR1A) gene influence the age at first mating in autumn-born ram-lambs and influence the out-of-season sexual activity of adult rams. In experiment 1, 24 Rasa Aragonesa ram-lambs born in September were genotyped for their RsaI and MnlI allelic variants of the MTNR1A gene, and the date of their first mounting with ejaculation after a period of semen collection training was documented. In experiment 2, the reproductive behavior, testicle size, and plasma testosterone concentrations of 18 adult rams (6 rams for each RsaI genotype) were recorded at the beginning (March) and end (May) of the seasonal anestrus. The number of days of training to achieve the first mating with ejaculation in T/T (C/C: 85.17 ± 12.08 C/T: 86.60 ± 18.87; T/T; 26.50 ± 24.50 d; P < 0.05), and G/G ram-lambs (G/G: 51.57 ± 14.99; A/G: 95.58 ± 10.95 d; P < 0.05) was significantly fewer than it was in the other genotypes. Likewise, for the RsaI genotype, 55% of the vulva-sniffing (P < 0.001), 48% of the approaches (P < 0.01), 48% of the mountings (P < 0.05) and 49% total activities (P < 0.001) were performed by T/T rams in March, and 50% of the sexual events in May (P < 0.001). For the Mnll variant, G/G rams performed a significantly (P < 0.001) larger proportion of the vulva-sniffing (41%), approaches (46%) and total activities (40%) in March, and 52% of the vulva-sniffing (P < 0.001), 43%, of the approaches (P < 0.001), 46% of the mountings (P < 0.05), and 47% of the total activities (P < 0.001) in May. Scrotal circumference, testicular volume, and plasma testosterone concentrations did not differ significantly among genotypes. Results confirmed that the polymorphisms of the MTNR1A gene sequence can influence reproductive performance in young and adult rams. Autumn-born ram-lambs that carried the T/T or G/G genotype had an advanced ability to reproduce, and T/T or G/G adult rams exhibited the most intense reproductive behavior. Genotyping might be a useful procedure for identifying the correct and rational use of rams in modern sheep farming

Revisiting cattle temperament in beef cow-calf systems: Insights from farmers’ perceptions about an autochthonous breed

Understanding temperament is an important part of cattle production since undesirable temperament may cause serious problems associated with aggression, maternal care, and human safety. However, little is known about how farmers define or assess temperament, especially in autochthonous cattle breeds. The aim of this study was to explore perceptions of farmers about the temperament of the Pyrenean cattle breed with special attention to beef cow-calf systems in Spain. The methodology used to obtain the information was focus group discussions (FGD). Farmers defined temperament as a behavioural response to challenging situations imposed by human handling. Specific terms used were related to active or passive reactions to fear (e.g., “strong”, “aggressive”, “nervous”, “fearful”). The speed of response to stimuli was also important. Female temperament was thought to become more docile with age while bull temperament was more variable. Maternal aggressiveness was highlighted as a potential human safety problem, but also desirable in an extensively bred animal who may need to defend calves against predators. Anatomical characteristics were seen as unreliable predictors of temperament, while behavioural indicators were more widely used, such as “alertness”, which was a general trait of the breed, and “gaze”, which, when associated with an alert expression, suggests a potential threat. Sensory acuity, such as sight and smell, were thought to be related with temperament in some FGDs but there was no overall agreement as to whether different behavioural responses were due to differences in sensory acuity. The results from the study could be useful during training programs or in the development of new genetic selection schemes and evaluation protocols involving cattle temperament

Maximising embryo production in endangered sheep breeds: in vitro procedures that complement in vivo techniques

This study investigated the use of previously superovulated ovaries as a source of oocytes, assessing the competence of them for in vitro embryo production. Two superovulatory treatments were performed: equine Chorionic Gonadotrophin (eCG) plus porcine Follicle-Stimulating Hormone (pFSH) in a single dose or the conventional protocol of six decreasing doses of pFSH. Thirty donor ewes of the endangered Ojalada breed were given either the simplified (group S; n=15) or the decreasing-dose (group D; n=15) treatments three times at intervals of ≥50 days. Ovaries were recovered on day 7 after the oestrus following the third treatment, just after embryo flushing, and the oocytes were collected to assess in vitro maturation, fertilisation and development to the blastocyst stage. The two superovulatory treatments did not differ in the mean number of oocytes selected for maturation (7.1±1.2 and 8.5±1.5 per ewe in the D and S groups, respectively). The oocytes recovered from ewes in Group D (87.5%) had a significantly (p<0.05) higher maturation rate than did those recovered from ewes in group S (75%), but no differences were found in fertilisation rate (94% and 94.6% in the D and S groups, respectively); both groups did not differ in their blastocyst rates and the total number of cells in in vitro-produced blastocysts. In the two experimental groups, 1.7 (D) and 1.8 (S) in vitro-produced blastocysts were generated per ewe, which indicate that it is feasible to combine in vivo and in vitro techniques to maximise embryo production in endangered sheep breeds.EEA ChubutFil: Forcada, Fernando. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Buffoni, Andres. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Abecia, José Alfonso. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Asenjo, B. Universidad de Valladolid. Escuela Universitaria de Ingenierías Agrarias de Soria; EspañaFil: Palacin, José Ignacio. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Vázquez, M.I. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Rodriguez Castillo, José del Carmen. Benemérita Universidad Autónoma de Puebla. Facultad de Medicina Veterinaria y Zootecnia; MéxicoFil: Sanchez Prieto, L. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Casao, A. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; Españ

Peripheral blood mononuclear cells (PBMC) microbiome is not affected by colon microbiota in healthy goats

This work was supported by grants from the Spanish Ministry of Science and Innovation (MCI) co-financed with FEDER funds [AGL2017-86757 to LA, AGL2017-86938-R to DRY]. Other contributions were SAF2015-65327-R to JA and SAF2015-73549-JIN to HR. LA is a Ramón y Cajal fellow [RYC-2013-13666] from the Spanish Ministry of Science and Innovation. APC is a recipient of a fellowship from the University of the Basque Country. We thank the MCI for the Severo Ochoa Excellence accreditation (SEV-2016-0644) and the Basque Department of Industry, Tourism and Trade (Etortek and Elkartek programs