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The higher availability of zinc (Zn) from organic than inorganic sources is already established, but more assertive and cost-friendly protocols on the total replacement of inorganic with organic Zn sources for laying hens still need to be developed. Because some discrepancy in the effects of this replacement in laying hen diets is noticeable in the literature, the objective of this meta-analysis was to properly quantify the effect size of total replacing inorganic Zn with organic Zn in the diet of laying hens on their laying performance, egg quality, and Zn excretion. A total of 2340 results were retrieved from Pubmed, Scielo, Scopus, WOS, and Science Direct databases. Of these, 18 primary studies met all the eligibility criteria and were included in this meta-analysis. Overall, the replacement of inorganic Zn with organic Zn, regardless of other factors, improved (p < 0.01) egg production by 1.46%, eggshell thickness by 0.01 mm, and eggshell resistance by 0.11 kgf/cm2. Positive results of the same nutritional strategy on egg weight and Zn excretion were only observed at specific conditions, especially when organic Zn was supplemented alone in the feed, not combined with other organic minerals. Therefore, there is evidence in the literature that the total replacement of inorganic Zn with organic Zn improves egg production, eggshell thickness, and eggshell resistance. Factors such as hen age and genetics, organic Zn source, concentration of Zn in the feed, and the strategy of its supplementation have to be more carefully considered in protocols designed to address egg weight and Zn excretion by the hen.

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OBJECTIVE: A trial was conducted to investigate the effects of supplemental levels of Mn provided by organic and inorganic trace mineral supplements on growth, tissue mineralization, mineral balance, and antioxidant status of growing broiler chicks. METHODS: A total of 500 male chicks (8-d-old) were used in 10-day feeding trial, with 10 treatments and 10 replicates of 5 chicks per treatment. A 2×5 factorial design was used where supplemental Mn levels (0, 25, 50, 75, and 100 mg Mn/kg diet) were provided as MnSO4∙H2O or MnPro. When Mn was supplied as MnPro, supplements of zinc, copper, iron, and selenium were supplied as organic minerals, whereas in MnSO4∙H2O supplemented diets, inorganic salts were used as sources of other trace minerals. Performance data were fitted to a linearbroken line regression model to estimate the optimal supplemental Mn levels. RESULTS: Manganese supplementation improved body weight, average daily gain (ADG) and feed conversion ratio (FCR) compared with chicks fed diets not supplemented with Mn. Manganese in liver, breast muscle, and tibia were greatest at 50, 75, and 100 mg supplemental Mn/kg diet, respectively. Higher activities of glutathione peroxidase and superoxide dismutase (total-SOD) were found in both liver and breast muscle of chicks fed diets supplemented with inorganic minerals. In chicks fed MnSO4∙H2O, ADG, FCR, Mn balance, and concentration in liver were optimized at 59.8, 74.3, 20.6, and 43.1 mg supplemental Mn/kg diet, respectively. In MnPro fed chicks, ADG, FCR, Mn balance, and concentration in liver and breast were optimized at 20.6, 38.0, 16.6, 33.5, and 62.3 mg supplemental Mn/kg, respectively. CONCLUSION: Lower levels of organic Mn were required by growing chicks for performance optimization compared to inorganic Mn. Based on the FCR, the ideal supplemental levels of organic and inorganic Mn in chick feeds were 38.0 and 74.3 mg Mn/kg diet, respectively.

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Two trials were conducted to determine the non-phytate phosphorus (nPP) requirement for broiler under heat stress. In both trials, birds were distributed in a completely randomized 4 × 2 factorial design with four nPP concentrations: 0.25, 0.35, 0.45, and 0.55%, and two Ca supply techniques: Ca fixed at 0.899% (CaF) or varying along with nPP aiming a 2:1 Ca to nPP ratio (CaV). Both trials had eight pens/treatment, with nine and five birds/pen for exp. 1 and exp. 2, respectively. nPP concentration had no effect on feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), nor fat deposition ratio (FDR). nPP levels showed a linear effect on protein deposition ratio (PDR) only for CaF diets. The nPP levels had a significant effect, regardless the technique adopted, on tibia phosphorus (TibP), which varied quadratically, on tibia calcium (TibCa) that increased quadratically and linearly, respectively, on CaF and CaV diets, and on tibia ash (TibAsh) that showed a quadratic effect for both. No effect was observed on Ca to P ratio in the tibia (TibCa:TibP). The nPP levels showed a linear increase effect over phosphorus intake (PI), phosphorus excreted (PE), and phosphorus retained (PR), and a linear decrease effect on phosphorus retention coefficient (PRC). Therefore, the nPP requirement for broilers from 8 to 21 days of age that provided better performance and bone variables were 0.250 and 0.484%, respectively, for CaF diets and 0.250 and 0.511%, respectively, for CaV diets.

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Background: The post-partum period in dairy cows is accompanied by a low glucose metabolism in adipose tissue and skeletal muscle tissue, being glucose conducted to the milk production. In humans, low glucose metabolism is associated with metabolic syndromes, the high glucose levels reduce tubular reabsorption of Magnesium (Mg) and Calcium (Ca), leading to hypomagnesemia and hypocalcemia. These minerals are important to the dairy cow, as their decrease leads to diseases. The aim of this study was to evaluate the relationship between glucose metabolism rate with the urinary excretion of Ca and Mg in multiparous dairy cows during the post-partum period.Materials, Methods & Results: Twenty dairy cows were used from a commercial farm southern Brazil, in the semi-extensive system. Glucose tolerance tests were performed (TTG) on day 9 relative to calving. The cows were categorized into three groups according to the glucose metabolism rate (area under the glucose curve, glucose half-life and glucose consumption rate): High Glucose Metabolization (GA); Intermediate Glucose Metabolizing (GI); and Low Glucose Metabolization (GL). Blood and urine samples were collected on days 0, + 3, + 6, + 9, +16 and +23 in relation to calving for to determine the levels of Ca, Mg, insulin (Ins), non-esterified fatty acids (NEFA) and Glu. In urine was evaluated the excretion of Ca and Mg. The cows were milked twice a day (at 3:00 a.m. and 3:00 p.m.) and the milk yield (kg/cow) was recorded daily and averages were generated every five days from day 15 to day 60 postpartum. The statistical analyses were performed with the MIXED procedure to assess the main effect of group, time (in days) and their interaction by using version 9.2 SAS software.[...]

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Background: The post-partum period in dairy cows is accompanied by a low glucose metabolism in adipose tissue and skeletal muscle tissue, being glucose conducted to the milk production. In humans, low glucose metabolism is associated with metabolic syndromes, the high glucose levels reduce tubular reabsorption of Magnesium (Mg) and Calcium (Ca), leading to hypomagnesemia and hypocalcemia. These minerals are important to the dairy cow, as their decrease leads to diseases. The aim of this study was to evaluate the relationship between glucose metabolism rate with the urinary excretion of Ca and Mg in multiparous dairy cows during the post-partum period.Materials, Methods & Results: Twenty dairy cows were used from a commercial farm southern Brazil, in the semi-extensive system. Glucose tolerance tests were performed (TTG) on day 9 relative to calving. The cows were categorized into three groups according to the glucose metabolism rate (area under the glucose curve, glucose half-life and glucose consumption rate): High Glucose Metabolization (GA); Intermediate Glucose Metabolizing (GI); and Low Glucose Metabolization (GL). Blood and urine samples were collected on days 0, + 3, + 6, + 9, +16 and +23 in relation to calving for to determine the levels of Ca, Mg, insulin (Ins), non-esterified fatty acids (NEFA) and Glu. In urine was evaluated the excretion of Ca and Mg. The cows were milked twice a day (at 3:00 a.m. and 3:00 p.m.) and the milk yield (kg/cow) was recorded daily and averages were generated every five days from day 15 to day 60 postpartum. The statistical analyses were performed with the MIXED procedure to assess the main effect of group, time (in days) and their interaction by using version 9.2 SAS software.[...](AU)

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A total of 50 barrows were used to evaluate qualitative feed restriction on digestibility of dietary components, weight of organs of digestive tract, and composition and production of feces. Five experimental diets, with increasing levels of qualitative feed restriction of 0, 5, 10, 15, and 20 percent were used. There was linear reduction (P<0.001) of all digestibility coefficients on the levels of qualitative feed restriction, except for acid detergent fiber, which presented a quadratic response (P<0.05). Contents of total solids (P<0.01), volatile solids (P<0.05), and total minerals (P<0.001) in the feces augmented with increasing levels of qualitative feed restriction, whereas the levels of K (P<0.05), Cu (P<0.01), N, P, Na, Ca, Mg, Fe, and Zn (P<0.001) presented a quadratic response. Daily feces excretion; and contents of total solids, volatile solids, total minerals, and levels of N, P, K, Mn, and Cu (P<0.001) and Ca, Na, Mg, and Fe (P<0.05) presented a clear increase in function of the qualitative feed restriction level. Qualitative feed restriction can be an alternative for the disposal of agribusiness waste, providing good crop-fertilizing by the use of swine feces.

Foram utilizados 50 suínos machos castrados para avaliar o efeito da restrição alimentar qualitativa sobre a digestibilidade dos componentes dietéticos, os órgãos do trato digestório, a composição e a produção fecal. Foram utilizadas cinco dietas experimentais, com níveis de restrição qualitativa de 0, 5, 10, 15 e 20 por cento. Houve redução linear (P<0,001) para todos os coeficientes de digestibilidade, com exceção da fibra em detergente ácido, que apresentou resposta quadrática (P<0,05). Os teores de sólidos totais (P<0,01) e voláteis (P<0,05), e minerais totais (P<0,001) nas fezes aumentaram com os níveis de restrição alimentar, enquanto os níveis de K (P<0,05), Cu (P<0,01) e de N, P, Na, Ca, Mg, Fe e Zn (P<0,001), apresentaram resposta quadrática. A excreção diária de fezes, sólidos totais e voláteis, minerais totais, N, P, K, Mn e Cu (P<0,001), Ca, Na, Mg e Fe (P<0,05) apresentaram aumento em função do nível da restrição alimentar qualitativa. A restrição qualitativa pode ser alternativa para destinação de resíduos da agroindústria, conferindo boas propriedades às fezes suínas, no que diz respeito à utilização para adubação de culturas.

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A total of 50 barrows were used to evaluate qualitative feed restriction on digestibility of dietary components, weight of organs of digestive tract, and composition and production of feces. Five experimental diets, with increasing levels of qualitative feed restriction of 0, 5, 10, 15, and 20 percent were used. There was linear reduction (P<0.001) of all digestibility coefficients on the levels of qualitative feed restriction, except for acid detergent fiber, which presented a quadratic response (P<0.05). Contents of total solids (P<0.01), volatile solids (P<0.05), and total minerals (P<0.001) in the feces augmented with increasing levels of qualitative feed restriction, whereas the levels of K (P<0.05), Cu (P<0.01), N, P, Na, Ca, Mg, Fe, and Zn (P<0.001) presented a quadratic response. Daily feces excretion; and contents of total solids, volatile solids, total minerals, and levels of N, P, K, Mn, and Cu (P<0.001) and Ca, Na, Mg, and Fe (P<0.05) presented a clear increase in function of the qualitative feed restriction level. Qualitative feed restriction can be an alternative for the disposal of agribusiness waste, providing good crop-fertilizing by the use of swine feces.(AU)

Foram utilizados 50 suínos machos castrados para avaliar o efeito da restrição alimentar qualitativa sobre a digestibilidade dos componentes dietéticos, os órgãos do trato digestório, a composição e a produção fecal. Foram utilizadas cinco dietas experimentais, com níveis de restrição qualitativa de 0, 5, 10, 15 e 20 por cento. Houve redução linear (P<0,001) para todos os coeficientes de digestibilidade, com exceção da fibra em detergente ácido, que apresentou resposta quadrática (P<0,05). Os teores de sólidos totais (P<0,01) e voláteis (P<0,05), e minerais totais (P<0,001) nas fezes aumentaram com os níveis de restrição alimentar, enquanto os níveis de K (P<0,05), Cu (P<0,01) e de N, P, Na, Ca, Mg, Fe e Zn (P<0,001), apresentaram resposta quadrática. A excreção diária de fezes, sólidos totais e voláteis, minerais totais, N, P, K, Mn e Cu (P<0,001), Ca, Na, Mg e Fe (P<0,05) apresentaram aumento em função do nível da restrição alimentar qualitativa. A restrição qualitativa pode ser alternativa para destinação de resíduos da agroindústria, conferindo boas propriedades às fezes suínas, no que diz respeito à utilização para adubação de culturas.(AU)

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Nitrógeno (N) y fósforo (P) son elementos implicados en la contaminación ambiental. Con el objetivo de evaluar el balance de N y P se utilizaron 18 vacas bajo pastoreo en pasto kikuyo (Pennisetum clandestinum) en el Centro Agropecuario Marengo en Mosquera (Cundinamarca, Colombia). Los tratamientos consistieron en tres niveles (0, 0.7 y 1.4% del peso vivo) de oferta de ensilaje (MS) de avena (Avena sativa). Esta oferta diaria fue complementada con pasto kikuyo en pastoreo hasta alcanzar una oferta total del 4%. La relación kikuyo:ensilaje fue de 4:0, 3.3:0.7 y 2.6:1.4 para los tratamientos 1, 2 y 3, respectivamente. El ensilaje se suministró diariamente (AM y PM) en el potrero. Las vacas recibieron un alimento balanceado comercial a razón de 1kg por cada 4.2 kg de leche producida, y se mantuvo constante durante el periodo experimental que duró 14 días, con siete días de adaptación y siete de mediciones. La producción de leche (AM, PM) fue medida de manera individual; mientras que la producción de orina y heces fue medida los días 0, 7, y 14, para cuantificar N y P. El volumen de orina se estimó usando creatinina y el consumo usando cromo (cantidad de heces) y fibra en detergente acido indigerible (digestibilidad). El consumo de N (667.8 g/día) y la excreción en orina (240.6 g/d) fueron significativamente mayores (p<0.05) para el tratamiento 1 que para los tratamientos 2 (560.7 y 199.7 g/d) y 3 (594.8 y 200.8 g/d); sin embargo, no se encontraron diferencias estadísticas significativas (p>0.05) en la eficiencia de utilización de N (15.6; 16.6 y 15.1%, respectivamente). El consumo de P (98.2, 85.9, y 93.4 g/d), la excreción en orina (0.43, 0.39, y 0.48, g/d) y en heces (91.9, 100.7, y 108.6 g/d) no fueron estadísticamente diferentes entre tratamientos (p>0.05); sin embargo, el balance de P fue significativamente mayor (p<0.05) para el tratamiento 1 (5.9 g/d) que para los tratamientos 2 (-15.1g/d) y 3 (-15.6 g/d).

Nitrogen (N) and Phosphorus (P) have been implicated in environmental pollution. To evaluate N a P balance, eighteen lactating multiparous Holstein cows grazing kikuyu in the Livestock Center Marengo in Mosquera (Cundinamarca, Colombia). The treatments consisting three allowances of oat silage 0, 0.7 and 1.4 kg/100 kg of body weight. This daily allowance was completed with kikuyu on grazing to obtain a total dry matter allowance of 4kg/100 kg of body weight. The kikuyu and silage ratio was 4:0; 3.3:0.7 and 2.6:1.4 for treatments 1, 2 and 3, respectively. Cows received a commercial balanced feed 1kg for each 4.2kg of milk, and it was maintained during all the experimental period. This period lasted 14 days and consisted of 7 adaptation days and 7 experimental days. Individual milk production was measured (AM PM) and samples of urine and feces were taken on days 0, 7 and 14 to determine N and P. Urine volume was estimated using creatinine and dry matter intake using chromium (feces volume) and Indigestible Acid Detergent Fiber (Digestibility). N intake (667.8 g/d) and urine N excretion (240.6 g/d) was greater for cows on treatment 1 than for treatment 2 (560.7 and 199.7 g/d respectively) and for treatment 3 (594.8 and 200.8 g/d) respectively. However no differences were found on the efficiency of N utilization that was 15.6; 16.6 and 15.1 % for treatments 1, 2, and 3, respectively. Daily P intakes (98.2; 85.9 and 93.4 g/d), P excretion in urine (0.43; 0.42; and 0.35 g/d) and P excretion in feces (91.8; 100.7 and 108.6) were not different between treatments, however phosphorus balance was positive and greater for cows on treatment 1 (5.9 g/d) than cows in treatments 2 and 3 (-15.5, and -15.6 g/d, respectively).

Azoto (N) e fósforo (F) são elementos envolvidos na poluição ambiental. Com o objetivo de avaliar o balanço de N e P foram usadas 18 vacas em pastagem de capim kikuyu grass (Pennisetum clandestinum) no Centro Agropecuario Marengo em Mosquera (Cundinamarca, Colombia). Os tratamentos consistiram de três níveis (0, 0.7 e 1.4% do peso corporal) lance silagem (MS) de aveia (Avena sativa). Essa oferta por dia foi complementado com pastagem Kikuyu em um lance de chegar a 4% do total da ração. A relação Kikuyu erva:silagem foi de 4:0, 3.3:0.7 e 2.6:1.4 para os tratamentos 1, 2 e 3, respectivamente. A silagem foi fornecida diariamente (AM e PM), no paddock. As vacas foram agraciados com uma alimentação equilibrada a uma taxa de 1 kg para cada 4.2 kg de leite produzido, e permaneceu constante durante o período experimental, que durou 14 dias, com sete dias de adaptação e sete dias de medidas. A produção de leite (AM, PM) foi medido numa base individual; enquanto a produção de urina e fezes foi mensurado dias 0, 7, e 14, para quantificar N e P. O volume de urina é considerada utilização e consumo de creatina usando cromo (quantidade de fezes) e fibra em detergente ácido indigestível (digestibilidade). O consumo de N (667.8 g/dia) e excretada na urina (240.6 g/d) foram significativamente maiores (p<0.05) para o tratamento 1 em comparação com os tratamentos 2 (560.7 e 199.7 g/d) e 3 (594.8 e 200.8 g/d); No entanto, não houve diferenças estatisticamente significativas (p>0.05) na eficiência de utilização de N (15.6, 16.6 e 15.1%, respectivamente). O consumo de P (98.2, 85.9 e 93.4 g/d), excreção de urina (0.43, 0.39 e 0.48 g/d) e nas fezes (91.9, 100.7 e 108.6 g/d) não foram estatisticamente diferentes entre os tratamentos (p>0.05); No entanto, o balanço de P foi significativamente maior (p<0.05) para o tratamento 1 (5.9 g/d) do que para os tratamentos 2 (-15.1 g/d) e 3 (-15.6 g/d).

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