Implementing Dairy Goat Nutrition Programs on Farms for Improved Sustainability

Since the mid-1990’s, the number of commercial dairy goat farms have been on the rise in Vermont and in surrounding states. Many produce their own farmstead cheese but the bulk of the milk produced in Vermont is sold to one, large artisan cheese company. In 2003, at a meeting of farmers who shipped their milk, they all indicated that finding help balancing rations for their goats was a big problem. Most feed companies did not know what advice to give or ignored their inquiries for grain and forage analysis; presumably because the farmers did not buy the volume of grain that dairy cow farms purchased. Only one farmer was using a milk production recording system whose information would greatly assist a feed nutritionist in balancing a diet. Farmers were not used to measuring or keeping track of the dry matter intake, body weights and body scores of their goats. Thus, both parties needed to implement appropriate information and a method for collecting data for ration balancing that optimized production and profitability. If this could be accomplished, the final goal would be to change the behavior of dairy goat farmers and feed company nutritionists to work together.

In this project over 3 years, a total of 13 dairy goat farms were enlisted to work on developing balanced feed rations, in terms of protein and energy, to improve or optimize the diets for the best milk production and feed cost. While there was an online goat nutrient calculator program, there were no well-tested ration balancing software programs to work with that had up-to-date research information. To form the basis for ration formulation, this project provided the following measurements on-farm: monthly individual goat milk production, milk components, milk urea nitrogen (MUN), quarterly goat body weights and condition scores, and feed intake. The PI became the liaison between the farmers and the feed companies and paid for forage analysis when the feed companies did not provide that service. Preliminary farm data was collected in the first part of year one when the project’s ruminant nutritionist, originally written into the project, was no longer available.

In year two of data collection, 8 farms worked with a skilled ruminant nutritionist from one feed company and custom feed rations were formulated and applied to the farms based on milk production, dry matter intake, goat weight and condition and feed analysis. By the end of the study, many farmers have continued working with a feed nutritionist and one still pays for a milk recording service. During the period of the study, resources to aid in calculating appropriate rations were looked at including the Langston University’s [E Kika de la Garza Institute for Goat Research] Goat Nutrient Calculator (LUGNC), http://www.luresext.edu/goats/research/nutr_calc.htm, and the Small Ruminant Nutrition System (SRNS) which launched its preliminary goat module in 2008 (and is based on the Cornell Net Carbohydrate and Protein System –CNCPS- mathematical modeling programs) http://nutritionmodels.tamu.edu/srns.htm. In addition to this, at the project’s close, guidelines for suggested levels of CP, undegradable protein, starch and sugar, ADF, NDF, Fat, Ca, Ph, Mg, Se, Vitamin E were developed and applied using more of a NSC (Nonstructural carbohydrate) approach to nutrient balancing.

• Complete Final Report LNE04-200 as pdf

Introduction:

Demand for dairy goat products in Vermont continues to outstrip the state milk supply as noted by Vermont farmstead cheese makers and the largest Vermont artisan goat cheese company which purchases from 20 goat dairies. One barrier to profitable milk production is high feed costs, accounting for 55-65% of total production costs. The goat’s physiology differs from cows in that the dairy goats’ dry matter intake (DMI) is much higher per pound of body weight than that of dairy cows (5.5% vs. 3.5% DMI/BW). To accomplish this high intake level to meet their higher energy needs per pound of body weight, goats are able to select the most nutritious parts of plants and harvested feed and concentrates offered to them. This means they are able to function on a higher concentrate to forage ratio than cows, thus making their diet more expensive. Their higher intake also means a higher rate of passage and potential lowered digestibility that comes with faster passage rates. Most feed manufacturers serving goat dairies have been unable to formulate appropriate rations for dairy goat farms because of a lack of readily available goat nutrient software programs. The goat’s physiological and intake behavior differences run counter to the standard practical assumptions and mathematical modeling on which dairy cow ration programs are based. Goats are still ruminants, however, and some proven feeding strategies that feed companies use for cows will work with goats. These feed companies were, for the most part, unmotivated to invest time and resources into serving goat dairies because the volume of concentrate purchased was low as compared to cow dairies. Nutrient requirements for goats were published by the US National Research Council (NRC) in 1982 and were only recently updated recently, in 2008, and await incorporation into a useful software nutrient balancing software package (UC Davis is developing such a software program and it is slated for release February 2009; CAPRICORN WIN08) http://animalscience.ucdavis.edu/extension/software/capricorn). A couple other software or online nutrient calculator programs mentioned above) became available during the study and were evaluated.

Farmers making cheese or shipping fluid milk are rewarded financially by milk protein content, and often feed high nitrogen(N) rations in hopes that they will maximize their milk protein. Feeding improperly balanced N causes wasted N in the form of high milk and blood urea N (MUN/BUN), and ultimately high N urine which contributes to high levels of ammonia volatilization into the environment. At the same time, over feeding N also decreases milk production as more energy is needed to remove excess N which robs energy from the goat to produce milk. While an MUN range of 12-19 mg/dl is purportedly the ideal range for protein digestion, the relationship between MUN and protein intake is much weaker than in cows and sheep. We still wanted to see if MUN values were a useful assessment tool for goats’ diets on Vermont farms.

In this study, we not only wanted to change the behavior of farmers and feed company representatives, we hoped to see correlations between grain fed, grain cost, protein fed, MUN, body weight, body scores and milk yield, fate yield and protein yield. It would also be useful to measure actual milk production over a long period of time as milk production measurement was rare on commercial dairy goat farms in Vermont and in the region. In the final year of the study, the distribution of farms included 6 grazing/browsing herds during the growing season and their milk production curves are a unique data set to share.