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Estimation of Nitrogen Use Efficiency for Ryegrass-Fed Dairy Cows: Model Development Using Diet- and Animal-Based Proxy Measures. DAIRY 2021. [DOI: 10.3390/dairy2030035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This study aimed to identify suitable predictors of nitrogen (N) use efficiency (NUE; milk N/N intake) for cows that differed in breeds and were fed with ryegrass pasture, using existing data from the scientific literature. Data from 16 studies were used to develop models based on the relationships between NUE and dietary and animal-based factors. Data from a further 10 studies were used for model validation. Milk urea N (MUN) and dietary water-soluble carbohydrate-to-crudeprotein ratio (WSC/CP) were the best and most practical animal- and diet-based proxies to predict NUE. The results indicate that it might be necessary to adopt separate models for different breeds when using WSC/CP to predict NUE but not when using MUN.
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Gómez-Miranda A, Estrada-Flores JG, Morales-Almaraz E, López-González F, Flores-Calvete G, Arriaga-Jordán CM. Barley or black oat silages in feeding strategies for small-scale dairy systems in the highlands of Mexico. CANADIAN JOURNAL OF ANIMAL SCIENCE 2020. [DOI: 10.1139/cjas-2018-0237] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High costs from external inputs in small-scale dairy systems (SSDS) and possible effects of climate change, require forage alternatives as silage for the dry season, from small-grain cereals that have short cropping cycles, winter hardiness, and good nutritional quality. The objective was to assess the provision of 10 kg dry matter (DM) cow−1 d−1 of barley (BLY) or black oat (BKO) silages in three treatments: T1 = 100% BLY; T2 = 50% BLY + 50% BKO; T3 = 100% BKO for milking cows. All treatments also received 4.6 kg DM cow−1 d−1 of concentrates and access to pasture. Nine Holstein cows in groups of three were randomly assigned to a 3 × 3 Latin square design repeated three times, with 14 d experimental periods. Measurements of animal variables and sampling for chemical analyses of feeds were done during the last 4 d of each period. Feeding costs were by partial budgets. There were no differences (P > 0.05) for milk yield, milk fat and protein content, milk urea nitrogen, body condition score, or live weight. The cost of BLY silage was 8% less than BKO silage. T1 had the higher margin over cost of feeds followed by T2. Both silages alone or in combination are viable options for SSDS, as there were no differences in performance, or in feeding costs or margins.
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Affiliation(s)
- Aída Gómez-Miranda
- Instituto de Ciencias Agropecuarias y Rurales (ICAR), Universidad Autónoma del Estado de México, Campus UAEM El Cerrillo, El Cerrillo Piedras Blancas, 50090 Toluca, Estado de México, México
| | - Julieta Gertrudis Estrada-Flores
- Instituto de Ciencias Agropecuarias y Rurales (ICAR), Universidad Autónoma del Estado de México, Campus UAEM El Cerrillo, El Cerrillo Piedras Blancas, 50090 Toluca, Estado de México, México
| | - Ernesto Morales-Almaraz
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Campus UAEM El Cerrillo, El Cerrillo Piedras Blancas, 50090 Toluca, Estado de México, México
| | - Felipe López-González
- Instituto de Ciencias Agropecuarias y Rurales (ICAR), Universidad Autónoma del Estado de México, Campus UAEM El Cerrillo, El Cerrillo Piedras Blancas, 50090 Toluca, Estado de México, México
| | - Gonzalo Flores-Calvete
- Centro de Investigaciones Agrarias de Mabegondo (CIAM), Betanzos a Mesón do Vento, 15318 Mabegondo-Abegondo, La Coruña, Galicia, Spain
| | - Carlos Manuel Arriaga-Jordán
- Instituto de Ciencias Agropecuarias y Rurales (ICAR), Universidad Autónoma del Estado de México, Campus UAEM El Cerrillo, El Cerrillo Piedras Blancas, 50090 Toluca, Estado de México, México
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Beltrán IE, Al-Marashdeh O, Burgos AR, Gregorini P, Balocchi OA, Wittwer F, Pulido RG. The Order of Grass and Maize Silage Supplementation Modifies Milk Yield, Grazing Behavior and Nitrogen Partitioning of Lactating Dairy Cows. Animals (Basel) 2019; 9:ani9060373. [PMID: 31248163 PMCID: PMC6617380 DOI: 10.3390/ani9060373] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/17/2019] [Accepted: 06/16/2019] [Indexed: 11/16/2022] Open
Abstract
The aim of this study was to evaluate the effects of the order of grass silage (GS) and maize silage (MS) supplementation on milk yield, grazing behavior and nitrogen (N) partitioning of lactating dairy cows during autumn. Thirty-six Holstein-Friesian dairy cows were randomly assigned to one of three treatments, and cows remained on these treatments for a 62 days period: (1) MIX; cows supplemented with 3 kg of dry matter (DM) of silage containing 1.5 kg DM of MS and 1.5 kg DM of GS in both the morning and afternoon; (2) GS-MS; cows supplemented with 3 kg DM of GS in the morning and 3 kg DM of MS in the afternoon; (3) MS-GS; cows supplemented with 3 kg DM of MS in the morning and 3 kg DM of GS in the afternoon. All cows received a pasture allowance of 17 kg DM/cow/d and 3 kg DM of concentrate. Grazing time and pasture intake were unaffected by treatment; however, milk production was greater for MS-GS, while milk protein was greater for GS-MS. Urinary N excretion was greater for MS-GS than MIX. In conclusion, MS-GS resulted in high milk yield but also high urinary N excretion, while MIX resulted in low urinary N excretion but also decreased milk yield.
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Affiliation(s)
- Ignacio E Beltrán
- Graduate School, Faculty of Veterinary Sciences, Universidad Austral de Chile, P.O. Box 567, Valdivia, Chile.
- Instituto de Investigaciones Agropecuarias, INIA Remehue, Ruta 5 Norte, km 8, Osorno 5290000, Chile.
| | - Omar Al-Marashdeh
- Department of Agricultural Sciences, Lincoln University, P.O. Box 7647, Lincoln, New Zealand.
| | - Ana R Burgos
- Graduate School, Faculty of Veterinary Sciences, Universidad Austral de Chile, P.O. Box 567, Valdivia, Chile.
| | - Pablo Gregorini
- Department of Agricultural Sciences, Lincoln University, P.O. Box 7647, Lincoln, New Zealand.
| | - Oscar A Balocchi
- Animal Production Institute, Faculty of Agricultural Sciences, Universidad Austral de Chile, P.O. Box 567, Valdivia, Chile.
| | - Fernando Wittwer
- Veterinary Clinical Sciences Institute, Faculty of Veterinary Sciences, Universidad Austral de Chile, P.O. Box 567, Valdivia, Chile.
| | - Rubén G Pulido
- Animal Science Institute, Faculty of Veterinary Sciences, Universidad Austral de Chile, P.O. Box 567, Valdivia, Chile.
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