Effect of dietary protein: lipid ratio on growth and body composition in bullfrog (Lithobates catesbeianus)

A feeding trial was performed to assess dietary protein:lipid ratios for the grow-out phase of the bullfrog (Lithobates catesbeianus). Nine balanced isoenergetic diets were formulated, combining three different protein levels (300, 400, and 500 g kg−1) with three different lipid levels (50, 100, and 200 g kg−1), designated as P300/50L, P300/100L, P300/200L, P400/50L, P400/100L, P400/200L, P500/50L, P500/100L, and P500/200L. Additionally, a commercial fish feed, commonly used in Mexico to feed bullfrogs, was also tested during the experiment. Growth performance, animal performance parameters, carcass composition, and fatty acid profiles in muscle and liver were evaluated. The feeding trial results showed that all the experimental diets enhanced growth, feed conversion ratio, and frog-leg weight compared with the commercial diet. Bullfrogs had higher growth with 400 and 500 g kg−1 of dietary protein regardless of dietary lipid content. It was also notable that with the P500/200L diet, frogs doubled the weight of those fed the commercial diet. DHA, EPA, and total omega-3 fatty acids were double in muscle and two to eight times higher in the liver compared with the commercial diet. In all cases, the final proximal composition of carcass reflected the diet composition. It is suggested that a diet containing 400 g kg−1 of protein and 50 g kg−1 lipids (protein/lipid ratio: 7.4; gross energy: 18.2 MJ kg−1) is adequate for bullfrog performance during the grow-out phase to achieve market size in a shorter period, thus, reducing farming risks and production costs.

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.

Effects of weather and other factors on milk production in the Churra dairy sheep breed

The objective of this study was to investigate the influence of meteorological and other factors on the quality and quantity of milk of the Spanish Churra sheep breed, based on an analysis of 359,808 milk controls from 9,904 ewes on 15 farms in 8 years. Daily milk yield (DMY), fat, protein, and lactose (%), and somatic cell count (SCC) data were obtained from monthly alternating milk controls. Mean, maximum, and minimum temperatures (T) (°C), mean relative humidity (RH) (%), wind speed (WS, m/s), mean solar radiation (SR, MJ/m2), and total rainfall (RF, mm) on the day before each milk control day were documented. Year, farm, number of lambing and stage of lactation, and all of the meteorological factors had asignificant (P < 0.0001) effect on DMY and milk quality. DMY and SCC differed among seasons (P < 0.001), and maximum DMY and minimum SCC occurred in spring, and minimum DMY and maximum SCC occurred in autumn. Fat, protein, and lactose content differed significantly (P < 0.001) among seasons, and fat and protein contents were highest in autumn. DMYwas highest in the second lambing of the ewe and steadily declined in subsequent lambings. SCC increased significantly from the first to the 10th lambing of the ewe. DMY, SCC, and fat content differed significantly (P < 0.001) among years. In conclusion, meteorological conditions had a significant effect on milk quality and production in Churra sheep conditions in a season-dependent manner such that factors such as temperature had the opposite effect on milk production in hot and cold seasons.(AU)

Effects of weather and other factors on milk production in the Churra dairy sheep breed

The objective of this study was to investigate the influence of meteorological and other factors on the quality and quantity of milk of the Spanish Churra sheep breed, based on an analysis of 359,808 milk controls from 9,904 ewes on 15 farms in 8 years. Daily milk yield (DMY), fat, protein, and lactose (%), and somatic cell count (SCC) data were obtained from monthly alternating milk controls. Mean, maximum, and minimum temperatures (T) (°C), mean relative humidity (RH) (%), wind speed (WS, m/s), mean solar radiation (SR, MJ/m2), and total rainfall (RF, mm) on the day before each milk control day were documented. Year, farm, number of lambing and stage of lactation, and all of the meteorological factors had asignificant (P < 0.0001) effect on DMY and milk quality. DMY and SCC differed among seasons (P < 0.001), and maximum DMY and minimum SCC occurred in spring, and minimum DMY and maximum SCC occurred in autumn. Fat, protein, and lactose content differed significantly (P < 0.001) among seasons, and fat and protein contents were highest in autumn. DMYwas highest in the second lambing of the ewe and steadily declined in subsequent lambings. SCC increased significantly from the first to the 10th lambing of the ewe. DMY, SCC, and fat content differed significantly (P < 0.001) among years. In conclusion, meteorological conditions had a significant effect on milk quality and production in Churra sheep conditions in a season-dependent manner such that factors such as temperature had the opposite effect on milk production in hot and cold seasons.(AU)

Effects of weather and other factors on milk production in the Churra dairy sheep breed

The objective of this study was to investigate the influence of meteorological and other factors on the quality and quantity of milk of the Spanish Churra sheep breed, based on an analysis of 359,808 milk controls from 9,904 ewes on 15 farms in 8 years. Daily milk yield (DMY), fat, protein, and lactose (%), and somatic cell count (SCC) data were obtained from monthly alternating milk controls. Mean, maximum, and minimum temperatures (T) (°C), mean relative humidity (RH) (%), wind speed (WS, m/s), mean solar radiation (SR, MJ/m2), and total rainfall (RF, mm) on the day before each milk control day were documented. Year, farm, number of lambing and stage of lactation, and all of the meteorological factors had asignificant (P < 0.0001) effect on DMY and milk quality. DMY and SCC differed among seasons (P < 0.001), and maximum DMY and minimum SCC occurred in spring, and minimum DMY and maximum SCC occurred in autumn. Fat, protein, and lactose content differed significantly (P < 0.001) among seasons, and fat and protein contents were highest in autumn. DMYwas highest in the second lambing of the ewe and steadily declined in subsequent lambings. SCC increased significantly from the first to the 10th lambing of the ewe. DMY, SCC, and fat content differed significantly (P < 0.001) among years. In conclusion, meteorological conditions had a significant effect on milk quality and production in Churra sheep conditions in a season-dependent manner such that factors such as temperature had the opposite effect on milk production in hot and cold seasons.

High levels of docosahexaenoic acid are present in eight New World silversides (Pisces: Atherinopsidae)

Docosahexaenoic acid (DHA) is the most critical and least available omega-3 fatty acid in the Western human diet. Currently, the source of omega-3 long chain polyunsaturated fatty acids (LC-PUFA) is mainly dependent on wild fisheries, making this resource unsustainable in the foreseeable future. In recent years, a high rate of biosynthesis and accumulation of DHA has been discovered in a freshwater species (Chirostoma estor) belonging to the Atherinopsidae family. Interest in evaluating fatty acid composition in other members of the family has emerged, so this study compiles original data of flesh composition of eight atherinopsid species from freshwater and brackish environments, either wild or cultured. High levels of DHA (16 to 31%) were found in all analyzed members of the family, except in C. grandocule, independently of their habitat or origin. The analyzed species of the Jordani group (C. estor, C. promelas and C. humboldtianum) showed high DHA and low EPA levels (<0.5%) as previously reported for cultured C. estor. The low trophic niche of these atherinopsids and their fatty acid accumulation capabilities are factors that make these species noteworthy candidates for sustainable aquaculture.(AU)

O ácido docosahexaenóico (DHA) é o ácido graxo ômega-3 mais importante e menos disponível na dieta humana ocidental. Atualmente, a fonte de ácidos graxos poliinsaturados de cadeia longa ômega-3 (LC-PUFA) depende principalmente da pesca extrativista, tornando esse recurso insustentável em um futuro próximo. Nos últimos anos, uma alta taxa de biossíntese e acúmulo de DHA foi descoberta em uma espécie de água doce (Chirostoma estor) pertencente à família Atherinopsidae. Deste modo, surgiu o interesse em avaliar a composição de ácidos graxos em outros membros da família. Portanto, este estudo compila dados originais da composição de carne de oito espécies de aterinopsídeos de ambientes de água doce e salobra, selvagens ou cultivadas. Altos níveis de DHA (16 a 31%) foram encontrados em todos os membros da família analisados, exceto em C. grandocule, independentemente de seu habitat ou origem. As espécies analisadas do grupo Jordani (C. estor, C. promelas e C. humboldtianum) apresentaram altos níveis de DHA e EPA baixos (<0,5%), como relatado anteriormente para C. estor cultivado. O baixo nicho trófico desses aterinopsídeos e sua capacidade de acumulação de ácidos graxos são fatores que tornam essas espécies notáveis candidatas à aquicultura sustentável.(AU)

High levels of docosahexaenoic acid are present in eight New World silversides (Pisces: Atherinopsidae)

ABSTRACT Docosahexaenoic acid (DHA) is the most critical and least available omega-3 fatty acid in the Western human diet. Currently, the source of omega-3 long chain polyunsaturated fatty acids (LC-PUFA) is mainly dependent on wild fisheries, making this resource unsustainable in the foreseeable future. In recent years, a high rate of biosynthesis and accumulation of DHA has been discovered in a freshwater species (Chirostoma estor) belonging to the Atherinopsidae family. Interest in evaluating fatty acid composition in other members of the family has emerged, so this study compiles original data of flesh composition of eight atherinopsid species from freshwater and brackish environments, either wild or cultured. High levels of DHA (16 to 31%) were found in all analyzed members of the family, except in C. grandocule, independently of their habitat or origin. The analyzed species of the Jordani group (C. estor, C. promelas and C. humboldtianum) showed high DHA and low EPA levels ( 0.5%) as previously reported for cultured C. estor. The low trophic niche of these atherinopsids and their fatty acid accumulation capabilities are factors that make these species noteworthy candidates for sustainable aquaculture.

RESUMO O ácido docosahexaenóico (DHA) é o ácido graxo ômega-3 mais importante e menos disponível na dieta humana ocidental. Atualmente, a fonte de ácidos graxos poliinsaturados de cadeia longa ômega-3 (LC-PUFA) depende principalmente da pesca extrativista, tornando esse recurso insustentável em um futuro próximo. Nos últimos anos, uma alta taxa de biossíntese e acúmulo de DHA foi descoberta em uma espécie de água doce (Chirostoma estor) pertencente à família Atherinopsidae. Deste modo, surgiu o interesse em avaliar a composição de ácidos graxos em outros membros da família. Portanto, este estudo compila dados originais da composição de carne de oito espécies de aterinopsídeos de ambientes de água doce e salobra, selvagens ou cultivadas. Altos níveis de DHA (16 a 31%) foram encontrados em todos os membros da família analisados, exceto em C. grandocule, independentemente de seu habitat ou origem. As espécies analisadas do grupo Jordani (C. estor, C. promelas e C. humboldtianum) apresentaram altos níveis de DHA e EPA baixos ( 0,5%), como relatado anteriormente para C. estor cultivado. O baixo nicho trófico desses aterinopsídeos e sua capacidade de acumulação de ácidos graxos são fatores que tornam essas espécies notáveis candidatas à aquicultura sustentável.

The effects of weather on milk production in dairy sheep vary by month of lambing and lactation phase

A total number of 609 bulk-tank milk controls on a dairy sheep farm in Spain were used to determine how weather affects milk production in sheep, related to lambing period and lactation phase. Data from individuals were assigned to one of five lactation periods based on the timing of lambing: FEB (n=124); APR (n=141); JUL (n=114); SEP (n=102), and NOV (n=128). Milk yield per ewe per day was calculated as total milk volume/number of ewes milked. Lactation was divided into three phases: Early-lactation (from lambing to month 2), Mid-lactation (from month 3 to 7), and Late-lactation (month 8). Milk yield per ewe was higher (P<0.01) in SEP than in FEB, APR, or NOV; production peaked in JUL and was lowest in FEB. In lactations initiated in JUL and SEP, milk yield per ewe per day was higher (P<0.05) in early lactation than it was in the other lambing periods; however, in APR and SEP, per ewe production was highest (P<0.01) in mid-lactation. Milk yield in each of the five lambing periods was significantly (P=0.001) associated with several meteorological variables, and the strongest (R2 =0.732) was with solar radiation and minimum temperature in the APR lactation period. In all lactation periods, the relationship between milk yield and weather differed among the three phases of lactation. In conclusion, the effects of meteorological conditions on milk yield in sheep cannot be understood without assessing production among milking periods in the same year and the phases of lactation, especially if milking periods are long.(AU)

The effects of weather on milk production in dairy sheep vary by month of lambing and lactation phase

A total number of 609 bulk-tank milk controls on a dairy sheep farm in Spain were used to determine how weather affects milk production in sheep, related to lambing period and lactation phase. Data from individuals were assigned to one of five lactation periods based on the timing of lambing: FEB (n=124); APR (n=141); JUL (n=114); SEP (n=102), and NOV (n=128). Milk yield per ewe per day was calculated as total milk volume/number of ewes milked. Lactation was divided into three phases: Early-lactation (from lambing to month 2), Mid-lactation (from month 3 to 7), and Late-lactation (month 8). Milk yield per ewe was higher (P<0.01) in SEP than in FEB, APR, or NOV; production peaked in JUL and was lowest in FEB. In lactations initiated in JUL and SEP, milk yield per ewe per day was higher (P<0.05) in early lactation than it was in the other lambing periods; however, in APR and SEP, per ewe production was highest (P<0.01) in mid-lactation. Milk yield in each of the five lambing periods was significantly (P=0.001) associated with several meteorological variables, and the strongest (R2 =0.732) was with solar radiation and minimum temperature in the APR lactation period. In all lactation periods, the relationship between milk yield and weather differed among the three phases of lactation. In conclusion, the effects of meteorological conditions on milk yield in sheep cannot be understood without assessing production among milking periods in the same year and the phases of lactation, especially if milking periods are long.

Climate zone influences the effect of temperature on the day of artificial insemination on fertility in two Iberian sheep breeds

The aim of this study was to determine the effect of temperature on the day of artificial insemination (AI) on fertility, and to study how climate zone of the farm may modify this effect, in two breeds of sheep that are reared on the Iberian Peninsula on four farms located within one of three climate zones, based on the Köppen Climate Classification. A total number of 1,931 AI were studied from Spanish farms of the Rasa Aragonesa (RA) (July) and Churra (CH) (June) breeds. Farms were categorized as Köppen BSk (Farm BSkRA; n=229), and Köppen Cfb (Cfb-RA; n=372), Köppen Csb (Csb-CH; n=908), and Köppen Cfb (Cfb-CH; n=422). Mean, maximum, and minimum temperatures (°C) were recorded, and thermal amplitude (maximum-minimum temperatures) calculated. Each set of temperature data was distributed between percentile-groups (≤50% and >50%), below or above the median. Temperatures at AI were higher (P50 percentile groups indicated that inseminations performed when temperatures were within the >50 percentile had a higher proportion (P1 for one or more of the meteorological variables under study; meanwhile, in the other two climates, OR were <1 (P>0.05). In conclusion, the effects of temperature on fertility after AI differed depending on the climate zone in which the flocks were reared. The results have implications for the scheduling of insemination dates to achieve the maximal performances.(AU)

Climate zone influences the effect of temperature on the day of artificial insemination on fertility in two Iberian sheep breeds

The aim of this study was to determine the effect of temperature on the day of artificial insemination (AI) on fertility, and to study how climate zone of the farm may modify this effect, in two breeds of sheep that are reared on the Iberian Peninsula on four farms located within one of three climate zones, based on the Köppen Climate Classification. A total number of 1,931 AI were studied from Spanish farms of the Rasa Aragonesa (RA) (July) and Churra (CH) (June) breeds. Farms were categorized as Köppen BSk (Farm BSkRA; n=229), and Köppen Cfb (Cfb-RA; n=372), Köppen Csb (Csb-CH; n=908), and Köppen Cfb (Cfb-CH; n=422). Mean, maximum, and minimum temperatures (°C) were recorded, and thermal amplitude (maximum-minimum temperatures) calculated. Each set of temperature data was distributed between percentile-groups (≤50% and >50%), below or above the median. Temperatures at AI were higher (P50 percentile groups indicated that inseminations performed when temperatures were within the >50 percentile had a higher proportion (P1 for one or more of the meteorological variables under study; meanwhile, in the other two climates, OR were 0.05). In conclusion, the effects of temperature on fertility after AI differed depending on the climate zone in which the flocks were reared. The results have implications for the scheduling of insemination dates to achieve the maximal performances.