The combination of melatonin implants and prostaglandin F2 alpha improves lamb production in a late-autumn mating season

To determine the effect of the combination of melatonin implants and prostaglandin (PG) F2 alpha on reproductive performance in the late breeding season (Dec at the northern hemisphere), 500 Lacaune ewes were divided into four groups. On day 0 (7 Nov), 150 ewes were treated with a melatonin (M) implant. From that group, 64 ewes (M + 1PGF group) were injected with 10-mg prostaglandin (PG) F2 alpha 34 d after melatonin implantation (11 Dec). The remaining 86 ewes (M group) were treated with melatonin, only. Another group of 75 ewes (2PGF group) was treated with double injection of PGF2 alpha (9 days between the first and second application) (2 and 11 Dec), and 75 non-treated ewes (C group) were the control group. The remaining 200 ewes of the flock were not considered in the study. Rams (n = 23) were introduced on 11 Dec. The percentage of prolificacy, lambing and fecundity rates were calculated. Lambing rate did not differ among groups (M: 79%; M + 1PGF: 78%; 2PGF: 69%; C: 71%). The M + 1PGF group had a higher % of prolificacy than the 2PGF group (P < 0.10) and the C group (P = 0.06) (M: 1.65 +/- 0.07; M + 1PGF: 1.74 +/- 0.09; 2PGF: 1.54 +/- 0.08; C: 1.54 +/- 0.07 lambs/lambing) (P < 0.05), and a higher fecundity than the 2PGF group (P < 0.05) and the C group (P < 0.10) (M: 1.30 +/- 0.09; M + 1PGF: 1.36 +/- 0.11; 2PGF: 1.07 +/- 0.10; C: 1.08 +/- 0.09 lambs/ewe). Ewes implanted with melatonin had significantly higher prolificacy (1.69 +/- 0.06 lambs/lambing) (P < 0.05) and fecundity (1.33 +/- 0.07 lambs/ewe) (P = 0.01) than did ewes that did not receive melatonin (1.54 +/- 0.04 and 1.08 +/- 0.04, resp.). In conclusion, melatonin implants increased the number of lambs born per ewe in a late-autumn mating season, and the effect was greatest if it was given in combination with PGF2 alpha administration at ram introduction

EFFECTS OF LEVELS OF INSOLUBLE AND SOLUBLE FIBRE IN DIETS FOR GROWING RABBITS ON FAECAL DIGESTIBILITY, NITROGEN RECYCLING AND IN VITRO FERMENTATION

[EN] The effect of neutral detergent fibre (NDF) and neutral detergent soluble fibre (NDSF) on in vivo faecal digestibility and caecal fermentation pattern was studied in growing rabbits, in four diets formulated according to two levels of NDF, 370 (LI) and 450 (HI) g/kg, and two levels of NDSF, 150 (LS) and 180 (HS) g/kg in substitution of starch, in a 2x2 factorial structure. Twenty four New Zealand White rabbits weaned at 28 d (630 ± 80.2 g weight) were allocated to digestibility cages from 42 to 49 d of age to determine apparent faecal digestibility of each diet (n=6). Urine was collected for determination of purine derivatives (PD). Once the digestibility trial finished, rabbits were fitted with PVC neck collars for 24 h total caecotrophe collection. After one day of recovery, animals were slaughtered and caecal contents were used as inocula for 18 h in vitro gas production and caecal degradation (ivDMcD) study, using an HCl-pepsin and pancreatin pre-digested substrate. Diet digestibility was also determined by the in vitro three-step enzymatic procedure. There were no effects of the NDF x NDSF interaction for any digestibility parameter (P>0.10). Both dry matter and organic matter digestibility (DMD and OMD) decreased from 0.518 to 0.442 and from 0.526 to 0.447, respectively, with the inclusion of NDF (P0.10). In contrast, NDF digestibility (NDFD) and ivDMcD did not respond to NDF (P>0.10) but increased from 0.156 to 0.200 and 0.141 to 0.210 with a ratio of NDSF (P<0.01). Weight of caecal contents increased with both NDF (P<0.001) and NDSF (P<0.01). However, total production of caecotrophes increased from 20.1 to 25.5 g DM/d with NDF (P<0.05), but was not affected by NDSF. The crude protein (CP) proportion in caecotrophes decreased with NDF (P<0.001) and increased with NDSF (P<0.01), and total CP recycled as caecotrophes tended (P=0.093) to be higher in HS diets, being unaffected by the dietary level of NDF. Diets rich in NDSF rendered higher gas volumes (P<0.001) than those with LS from 2 to 18 h incubation, whereas inclusion of high proportions of NDF reduced gas volume (P<0.01). Results indicate that NDF reduces faecal digestibility, whereas NDSF promotes better conditions for caecal fermentation.This work was financed through the Project AGL2006-07596, from the Ministry of Education and Science (Spanish Government). Ms. Norelys Rodríguez-Romero’s stage at in the University of Zaragoza was financed though a Doctoral fellowship from the Universidad Nacional Experimental del Táchira (Venezuela)Rodríguez-Romero, N.; Abecia, L.; Fondevila, M.; Balcells, J. (2011). EFFECTS OF LEVELS OF INSOLUBLE AND SOLUBLE FIBRE IN DIETS FOR GROWING RABBITS ON FAECAL DIGESTIBILITY, NITROGEN RECYCLING AND IN VITRO FERMENTATION. World Rabbit Science. 19(2):85-94. https://doi.org/10.4995/wrs.2011.828SWORD859419

Manipulating rumen microbiome and fermentation through interventions during early life: a review:Rumen manipulation in early life

The nutritional manipulations of the rumen microbiome to enhance productivity and health are rather limited by the resilience of the ecosystem once established in the mature rumen. Based on recent studies, it has been suggested that the microbial colonisation that occurs soon after birth opens a possibility of manipulation with potential to produce lasting effects into adult life. This paper presents the state-of-the-art in relation to early-life nutritional interventions by addressing three areas: the development of the rumen as an organ in regards to the nutrition of the new-born, the main factors that determine the microbial population that first colonizes and establishes in the rumen, and the key immunity players that contribute to shaping the commensal microbiota in the early stage of life to understand host-microbiome specificity. The development of the rumen epithelium and muscularization are differently affected by the nature of the diet and special care should be taken with regards to transition from liquid (milk) to solid feed. The rumen is quickly colonized by all type of microorganisms straight after birth and the colonization pattern may be influenced by several factors such as presence/absence of adult animals, the first solid diet provided, and the inclusion of compounds that prevent/facilitate the establishment of some microorganisms or the direct inoculation of specific strains. The results presented show how early-life events may be related to the microbial community structure and/or the rumen activity in the animals post-weaning. This would create differences in adaptive capacity due to different early life experiences and leads to the idea of microbial programming. However, many elements need to be further studied such as: the most sensitive window of time for interventions, the best means to test long term effectiveness, the role of key microbial groups and host-immune regulations

Auditory, Olfactory and Tactile Contact is not an Obstacle for Studies Involving Hormonal Interrelationships

Thirty-two ewes were used to determine whether individual housing, allowing contact with neighbours, induces a stress response. Ewes were housed in individual pens designed to allow the ewes to see, hear, smell and touch adjacent animals, and were distributed into four groups (n=8/group): ewes with subcutaneous implants containing melatonin and oestradiol (M+E), melatonin (M), oestradiol (E) and non-implanted control ewes (C). Heart rate, stress indicators (plasma cortisol, glucose, lactate and creatine kinase (CK) concentrations) and luteinizing hormone (LH) concentrations were measured hourly and compared with the resting values (before and after pen housing). Heart rate increased significantly during the introduction into the pen (P&lt;0.001) in all groups, in comparison with the resting values. No significant differences between groups were observed for cortisol concentrations, with the exception of the M group, which showed the highest response (P&lt;0.001) when ewes were introduced into the pens. Lactate, CK and glucose changes in comparison with the resting values were similar between groups. LH concentrations during pen housing decreased significantly in all groups in comparison with resting values. In conclusion, individual confinement of sheep allowing visual, auditory, olfactory and tactile contact with their neighbouring animals was not an obstacle for investigating particular hormonal interrelationships with multiple sampling procedures. However further investigations are required to determine if this conclusion applies to other hormone systems in sheep

Performance of Slow-Growing Chickens Fed with Tenebrio molitor Larval Meal as a Full Replacement for Soybean Meal

Insect larval meal is an increasingly common protein source in poultry systems. In this study, the effect of replacing soybean meal with Tenebrio molitor larval meal on the performance of slow-growing chickens was assessed. A total of 128 one-day-old chickens (Colorield) were randomly divided into a control group (C) (n = 64), fed with soybean meal, and an experimental group (TM) (n = 64), fed with T. molitor larvae meal. The chicks were slaughtered after 95 days. Three different isoenergetic and isoproteic diets (F1, F2 and F3) were used for each group. The F1 diet resulted in higher body weight gain and higher feed and water intakes in group C, but a lower feed conversion ratio. Contrarily, diets F2 and F3 did not produce differences in the studied parameters between the two groups, except for body weight gain in the case of diet F2, which was highest in group C. Therefore, weight gain and feed and water intakes were significantly higher in group C, but there were no differences in feed conversion ratio or live weight. In conclusion, the total replacement of soybean meal with T. molitor larvae meal resulted in a reduction in feed intake and a consequent reduction in weight. During this period, partial rather than total substitution may be recommended. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

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

GPS, LiDAR and VNIR data to monitor the spatial behavior of grazing sheep

Traditional knowledge about the behavior of grazing livestock is about to disappear. Shepherds well know that sheep behavior follows non-random patterns. As a novel alternative to seeking behavioral patterns, this study quantified the grazing activities of two sheep flocks of Churra breed (both in the same area but separated by 10 years) based on Global Position System (GPS) monitoring and remote monitoring sensing techniques. In the first monitoring period (2009-10), geolocations were recorded every 5 min (4, 240 records), while in the second one (2018-20), records were taken every 30 min (7, 636 records). The data were clustered based on the day/night and the activity (resting, moving, or grazing). An airborne LiDAR dataset was used to study the slope, aspect, and vegetation height. Four visible-infrared orthophotographs were mosaicked and classified to obtain the land use/land cover (LU/LC) map. Then, GPS locations were overlain on the terrain features, and a Chi-square test evaluated the relationships between locations and terrain features. Three spatial statistics (directional distribution, Kernel density, and Hot Spot analysis) were also calculated. Results in both monitoring periods suggested that the spatial distribution of free-grazing ewes was non-random. The flocks showed strong preferences for grazing areas with gentle north-facing slopes, where the herbaceous layer formed by pasture predominates. The geostatistical analyses of the sheep locations corroborated those preferences. Geotechnologies have emerged as a potent tool to demonstrate the influence of environmental and terrain attributes on the non-random spatial behavior of grazing sheep. © 2022 Malque Publishing. All rights reserved