Revista Colombiana de Ciencias Pecuarias 2021-10-23T13:55:20-05:00 Editor-in-chief: Jorge Agudelo, PhD Open Journal Systems <ul> <li class="show"><strong>ISSN Impreso: </strong>0120-0690</li> <li class="show"><strong>ISSN electrónico: </strong>2256-2958</li> <li class="show"><strong>Periodicidad:</strong> Trimestral</li> <li class="show"><strong>Creative Commons:</strong> <a href="" target="_blank" rel="noopener">by-nc-sa</a></li> </ul> Influence of the storage period on the nutritional and microbiological value of sun-dried brewer’s grains 2021-10-23T12:40:23-05:00 Andressa Faccenda Maximiliane A Zambom André S Avila Deise D Castagnara Ricardo Dri Maria L Fischer Rodrigo C R Tinini Jéssica G Dessbesell Ana-Ruth E Almeida Kleves V Almeida <p><strong>Background:</strong> Brewer's grains, a by-product of the brewery industry, can be included in the diet of ruminants. However, its high humidity makes it difficult to store and preserve. <strong>Objective:</strong> To evaluate the efficiency of sun dehydration of wet brewer’s grains (WBG) and the effect of storage period on its nutritional and microbiological quality. <strong>Methods:</strong> A completely randomized experimental design was used to evaluate WBG dehydration efficiency, with treatments corresponding to 0, 1, 2, 4, 6, 8, 10, 12, 14 and 16 hours of sun exposure. A second experiment was carried out using also a completely randomized design to evaluated the effect of storage with the following treatments: 0, 10, 20, 30, 60, 90, 120, 150 and 180 days of storage of the dry by-product. <strong>Results:</strong> Dry matter (DM) content linearly increased with dehydration period. The chemical composition of the dried brewer's grains had no effect as a function of storage period. Indigestible protein (C fraction) increased linearly but did not compromise the cumulative gas production and the <em>in vitro</em> digestibility of DM and protein. Storage time had no effect on fungus population. The maximum aflatoxin value was 45.5 μg/kg, and remained within acceptable limits for bovine feed. <strong>Conclusion:</strong> Dehydration of WBG in the sun is efficient to guarantee conservation and makes it possible to store the by-product. The storage of the dry by-product for 180 days does not compromise its nutritional or microbiological quality.</p> 2020-10-15T00:00:00-05:00 Copyright (c) 2020 Revista Colombiana de Ciencias Pecuarias Feeding behavior of lambs fed diets containing old man saltbush hay 2021-10-23T12:58:00-05:00 Greicy-Mitzi Bezerra-Moreno Hirasilva Borba Gherman G Leal-de-Araújo Luis-Gabriel Alves-Cirne Oscar Boaventura-Neto Salete Alves-de-Moraes Gleidson-Giordano Pinto-de-Carvalho Dorgival M de Lima-Júnior Douglas dos-Santos-Pina <p><strong>Background:</strong> We hypothesized that a diet with old man saltbush hay used as an alternative source of nutrients could partially replace the concentrate in the feeding of feedlot lambs. <strong>Objective:</strong> This study evaluated the behavior and performance of lambs fed diets containing increasing levels of old man saltbush hay plus concentrate. <strong>Methods:</strong> Twenty-four castrated Santa Inês lambs at approximately eight months of age (22 ± 1.97 kg) were confined in a randomized complete design and fed diets containing 30, 40, 50, and 60% (dry matter: DM) of old man saltbush hay. <strong>Results:</strong> The intake of DM and neutral detergent fiber was not affected (p&gt;0.05) by the level of old man saltbush hay. Intake of mineral salt decreased (p&lt;0.01) as the proportion of old man saltbush in the diet increased. Weight gain (kg) and feed efficiency worsened (p&lt;0.05) with 40% inclusion of old man salt bush hay. The time spent on feeding and chewing increased (p&lt;0.05), while idle time was reduced (p&lt;0.01) with dietary inclusion of old man saltbush. Feed efficiency decreased (p&lt;0.05) with the inclusion of old man saltbush. <strong>Conclusion:</strong> Dietary inclusion of old man saltbush affects the feeding behavior and performance of lambs in feedlot.</p> 2020-11-30T00:00:00-05:00 Copyright (c) 2020 Revista Colombiana de Ciencias Pecuarias Population genetic structure of two herds of Aberdeen Angus cattle breed in Colombia 2021-10-23T13:06:50-05:00 Alejandra M Moreno-Sierra Mario F Cerón-Muñoz Iván D Soto-Calderón <p><strong>Background:</strong> Two biotypes of Aberdeen Angus cattle breed, known as <em>Old Type</em> and <em>New Type</em>, that differ in their origin and beef production are formally recognized. In Colombia, this breed has been commercialized for approximately 80 years. Studies on the origin, kinship and levels of genetic diversity of this breed in Colombian herds are scarce, yet important for planning crossing and management strategies. <strong>Objective:</strong> To measure the genetic diversity and structure of two Colombian herds of <em>Old Type</em> and <em>New Type</em> biotypes of Aberdeen Angus from Huila and Cundinamarca provinces and assess mitochondrial introgression with other breeds. <strong>Methods:</strong> A set of ten microsatellites and sequences of the Mitochondrial Control Region were characterized. Estimators of genetic diversity and population differentiation along with tests of population assignment were applied. <strong>Results:</strong> Nuclear loci were highly polymorphic as shown by the Polymorphic Information Content (0.599) and the Probability of Identity (1.896 10<sup>-08</sup>). Both populations were highly diverse and clearly differentiated into two groups corresponding to the <em>Old Type</em> and <em>New Type</em> phenotypes. In contrast, mitochondrial data failed to distinguish these two groups and showed extensive admixture. <strong>Conclusions:</strong> This study optimized a set of ten highly polymorphic nuclear markers that may be used for parentage and population genetic studies of Aberdeen Angus. Genetic differentiation in these loci agreed with phenotypic differences of the <em>Old</em> and <em>New Types</em>. However, mitochondrial data indicated ancestry of multiple European breeds in the origin of Colombian Aberdeen Angus.</p> 2020-11-06T00:00:00-05:00 Copyright (c) 2020 Revista Colombiana de Ciencias Pecuarias Influence of blood metabolites and body condition score at parturition on fertility and milk yield in Holstein cows 2021-10-23T13:30:47-05:00 Edir Torres José E García Francisco G Véliz Carlos Leyva Ulises Macías-Cruz Juan D Hernández-Bustamante Miguel Mellado <p><strong>Background:</strong> Variables associated with body tissue mobilization place dairy cows at greater risk of reproductive failure. <strong>Objective:</strong> To investigate the association between blood metabolites and body condition score (BCS) at the beginning of lactation and the reproductive efficiency and milk yield of Holstein cows in a hot environment. <strong>Methods:</strong> In total, 165 Holstein cows were selected for the study from which blood samples were taken to determine the concentration of various blood metabolites and their association with the reproductive efficiency and milk yield. <strong>Results:</strong> Cows with serum β-hydroxybutyrate (BHBA) ≤0.8 mmol/L one week postpartum were 3.3 times more likely to become pregnant at first service, and 2.2 times more likely to become pregnant before 80 d postpartum than cows with higher serum BHBA levels. The odds (OR 2.7; 95% CI 1.3–5.4; p&lt;0.01) of a cow getting pregnant at first service were higher in cows with serum creatinine levels higher than 2.0 mg/dL one week postpartum than cows with lower blood levels of this metabolite. The BCS at 30 and 60 d postpartum that predicted pregnancy at first service and pregnancy to all services was 3.0. Blood urea nitrogen &gt;15 mg/dL, creatinine &lt;1.8 mg/dL, total protein ≤5.0 mg/dL one week postpartum, and &gt;0.40 units of BCS loss during the first 30 d postpartum were critical threshold that predicted the likelihood of 305-d milk yield higher than 10,500 kg. <strong>Conclusions:</strong> Serum BHBA and creatinine one wk after calving as well as BCS 30 and 60 d post-calving provided reasonably accurate cut-off screening values to discriminate cows with better reproductive performance and higher 305-d milk yield.</p> 2020-11-30T00:00:00-05:00 Copyright (c) 2020 Revista Colombiana de Ciencias Pecuarias Preservation of sugarcane silage with urea and calcium oxide: performance and metabolic efficiency of dairy cows 2021-10-23T13:43:46-05:00 Susi C S G Martins Gleidson G P Carvalho Aureliano J V Pires Laudí C Leite Daiane Lago-Novais Ronaldo L Oliveira Luis G A Cirne Bruna M A Carvalho <p><strong>Background:</strong> Inclusion of urea and calcium oxide (CaO) during sugarcane ensilage has been hypothesized to improve dairy cow performance. <strong>Objective:</strong> To evaluate the use of urea and calcium oxide as additives to preserve sugarcane silage quality and determine whether they improve dairy cow performance and metabolic efficiency. <strong>Methods:</strong> Four diets were used: sugarcane silage without additive (SS), sugarcane silage with 10 g/kg urea (SU), sugarcane silage with 5 g/kg urea + 5 g/kg CaO (SUC), and sugarcane silage with 10 g/kg CaO (SC). Eight crossbred cows at approximately 100 days of lactation were distributed in two 4x4 Latin squares, and their diets were formulated to reach an average milk production of 15 kg/day. <strong>Results:</strong> Dry matter, non-fibrous carbohydrates, organic matter, total carbohydrates, and total digestible nutrient intake were the highest (p&lt;0.05) for the cows fed SC. Urinary excretion of nitrogen was higher (p&lt;0.05) for cows fed diets based on SUC than those fed diets with SC. Milk urea nitrogen content was the highest (p&lt;0.05) in animals fed SU diets. Nitrogen balance was positive in all treatments; however, the microbial protein synthesis was low for all diets. <strong>Conclusions:</strong> The diet with SU showed the highest nitrogen loss through the milk. Among the evaluated silages, those with SC and SUC are recommended to promote a high intake of nutritional components.</p> 2021-06-21T00:00:00-05:00 Copyright (c) 2021 Revista Colombiana de Ciencias Pecuarias Subject index for Volume 34, 2021 2021-10-23T13:53:38-05:00 RCCP rccp 2021-10-06T00:00:00-05:00 Copyright (c) 2021 Revista Colombiana de Ciencias Pecuarias Peer-Reviewer index for Volume 34, 2021 2021-10-23T13:49:37-05:00 RCCP rccp 2021-10-06T00:00:00-05:00 Copyright (c) 2021 Revista Colombiana de Ciencias Pecuarias Effects of supplemental xylanase on in vitro disappearance of dry matter in feed ingredients for swine 2021-10-23T13:48:23-05:00 Hyunwoong Jo Jung Yeol Sung Beob Gyun Kim <p><strong>Background:</strong> Alternative feed ingredients are widely used in swine diets to lower feed costs, but these ingredients contain a large quantity of non-starch polysaccharides. Supplemental xylanase is known to break down non-starch polysaccharides. However, the effects of exogenous xylanase from <em>Bacillus subtilis</em> on various feed ingredients have rarely been compared. <strong>Objective:</strong> To evaluate the effects of supplemental xylanase on <em>in vitro</em> disappearance of dry matter (DM) in various feed ingredients for pigs. <strong>Methods:</strong> Nine feed ingredients were used to measure <em>in vitro</em> ileal disappearance and in vitro total tract disappearance of DM. Each ground ingredient was supplemented with either supplemental xylanase (9,000 U/g) or cornstarch at 1.0%. <strong>Results:</strong> Supplemental xylanase increased <em>in vitro</em> ileal disappearance of DM in wheat, barley, wheat flour, and wheat bran (p&lt;0.05). The <em>in vitro</em> total tract disappearance of DM for barley and wheat bran increased with xylanase addition (p&lt;0.05). <strong>Conclusion:</strong> Exogenous xylanase could increase in vitro ileal DM disappearance in barley, wheat, wheat flour, and wheat bran, but did not affect <em>in vitro</em> total tract DM disappearance in wheat and wheat flour.</p> 2021-02-19T00:00:00-05:00 Copyright (c) 2021 Revista Colombiana de Ciencias Pecuarias Índice temático Volumen 34, 2021 2021-10-23T13:55:20-05:00 RCCP rccp 2021-10-06T00:00:00-05:00 Copyright (c) 2021 Revista Colombiana de Ciencias Pecuarias Author index for Volume 34, 2021. 2021-10-23T13:50:54-05:00 RCCP rccp 2021-10-06T00:00:00-05:00 Copyright (c) 2021 Revista Colombiana de Ciencias Pecuarias Mastitis, somatic cell count, and its impact on dairy-product quality… An omission in Colombia?: A review 2021-10-23T12:03:52-05:00 David S Riveros-Galán Mónica Obando-Chaves <p>Mastitis is the most common disease in dairy herds and the main cause of economic losses in milk production worldwide. This inflammatory reaction of the mammary gland affects the quantity, composition and quality of milk produced and its suitability for the dairy industry. Despite of its importance, Colombia has no regulations on somatic cell count (SCC); that is, no official upper limits have been established for the dairy industry. The current quality-based payment system for raw milk does not encourage local producers to reduce the level of somatic cells. Consequently, Colombia is at a disadvantage compared to countries that include this parameter in their payment schemes and subscribe to international free trade agreements, affecting the competitiveness of the Colombian dairy sector. This article reviews the types of somatic cells, the microbiology of mastitis, its etiology and diagnosis, the changes that generate the composition of milk, and the impact of high SCCs on the quality of dairy products, such as yogurt, cheese, and milk powder. The final section offers a reflection on the problem of high SCCs in Colombia and the lack of regulations in this regard.</p> 2020-12-14T00:00:00-05:00 Copyright (c) 2020 Revista Colombiana de Ciencias Pecuarias